Maxim DS2156G T1/e1/j1 single-chip transceiver tdm/utopia ii interface Datasheet

DS2156
T1/E1/J1 Single-Chip Transceiver
TDM/UTOPIA II Interface
www.maxim-ic.com
GENERAL DESCRIPTION
FEATURES
The DS2156 is a software-selectable T1, E1, or J1
single-chip transceiver (SCT) for short-haul and
long-haul applications. The backplane is userconfigurable for a TDM or UTOPIA II bus interface.
The DS2156 is composed of a line interface unit
(LIU), framer, HDLC controllers, and a
UTOPIA/TDM backplane interface, and is controlled
by an 8-bit parallel port configured for Intel or
Motorola bus operations. The DS2156 is pin and
software compatible with the DS2155.
Complete T1/DS1/ISDN-PRI/J1 Transceiver
Functionality
Complete E1 (CEPT) PCM-30/ISDN-PRI
Transceiver Functionality
User-Selectable TDM or UTOPIA II Bus
Interface
Long-Haul and Short-Haul Line Interface for
Clock/Data Recovery and Waveshaping
CMI Coder/Decoder for Optical I/F
Crystal-Less Jitter Attenuator
Fully Independent Transmit and Receive
Functionality
Dual HDLC Controllers
Programmable BERT Generator and Detector
Internal Software-Selectable Receive and
Transmit-Side Termination Resistors for
75Ω/100Ω/120Ω T1 and E1 Interfaces
Dual Two-Frame Elastic-Store Slip Buffers that
Connect to Asynchronous Backplanes Up to
16.384MHz
16.384MHz, 8.192MHz, 4.096MHz, or
2.048MHz Clock Output Synthesized to
Recovered Network Clock
The LIU is composed of transmit and receive
interfaces and a jitter attenuator. The transmit
interface is responsible for generating the necessary
waveshapes for driving the network and providing
the correct source impedance depending on the type
of media used. T1 waveform generation includes
DSX-1 line buildouts as well as CSU line buildouts
of -7.5dB, -15dB, and -22.5dB. E1 waveform
generation includes G.703 waveshapes for both 75Ω
coax and 120Ω twisted cables. The receive interface
provides network termination and recovers clock and
data from the network.
APPLICATIONS
Features continued in Section 1.
Inverse Mux ATM (IMA)
T1/E1/J1 Line Cards
Switches and Routers
Add-Drop Multiplexers
ORDERING INFORMATION
UTOPIA
T1/E1/J1
NETWORK
DS2156
T1/E1/J1
TDM/UTOPIA
BACKPLANE
TDM
PART
TEMP RANGE
PIN-PACKAGE
DS2156L
DS2156L+
DS2156LN
DS2156LN+
DS2156G
DS2156G+
DS2156GN
DS2156GN+
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
100 LQFP
100 LQFP
100 LQFP
100 LQFP
100 CSBGA
100 CSBGA
100 CSBGA
100 CSBGA
+Denotes lead-free/RoHS-compliant package.
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata.
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DS2156
TABLE OF CONTENTS
1.
2.
MAIN FEATURES............................................................................................................ 9
DETAILED DESCRIPTION............................................................................................ 12
2.1
3.
BLOCK DIAGRAM........................................................................................................................ 14
PIN FUNCTION DESCRIPTION .................................................................................... 20
3.1
TDM BACKPLANE ...................................................................................................................... 20
3.1.1
3.1.2
3.2
UTOPIA BUS ............................................................................................................................ 26
3.2.1
3.2.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
4.
Transmit Side .......................................................................................................................................20
Receive Side ........................................................................................................................................23
Receive Side ........................................................................................................................................26
Transmit Side .......................................................................................................................................27
PARALLEL CONTROL PORT PINS ................................................................................................ 28
EXTENDED SYSTEM INFORMATION BUS ...................................................................................... 29
USER OUTPUT PORT PINS ......................................................................................................... 30
JTAG TEST ACCESS PORT PINS ................................................................................................ 31
LINE INTERFACE PINS ................................................................................................................ 32
SUPPLY PINS ............................................................................................................................. 33
L AND G PACKAGE PINOUT ........................................................................................................ 34
10MM CSBGA PIN CONFIGURATION .......................................................................................... 38
PARALLEL PORT ......................................................................................................... 39
4.1
4.2
5.
6.
REGISTER MAP .......................................................................................................................... 39
UTOPIA BUS REGISTERS .......................................................................................................... 45
SPECIAL PER-CHANNEL REGISTER OPERATION ................................................... 46
PROGRAMMING MODEL ............................................................................................. 48
6.1
POWER-UP SEQUENCE .............................................................................................................. 49
6.1.1
6.2
6.3
6.4
6.5
7.
8.
Master Mode Register..........................................................................................................................49
INTERRUPT HANDLING ............................................................................................................... 50
STATUS REGISTERS................................................................................................................... 50
INFORMATION REGISTERS .......................................................................................................... 51
INTERRUPT INFORMATION REGISTERS ........................................................................................ 51
CLOCK MAP.................................................................................................................. 52
T1 FRAMER/FORMATTER CONTROL AND STATUS REGISTERS ........................... 53
8.1
8.2
8.3
8.4
9.
T1 CONTROL REGISTERS........................................................................................................... 53
T1 TRANSMIT TRANSPARENCY ................................................................................................... 58
AIS-CI AND RAI-CI GENERATION AND DETECTION ..................................................................... 58
T1 RECEIVE-SIDE DIGITAL-MILLIWATT CODE GENERATION ......................................................... 59
E1 FRAMER/FORMATTER CONTROL AND STATUS REGISTERS........................... 62
9.1
9.2
9.3
10.
E1 CONTROL REGISTERS .......................................................................................................... 62
AUTOMATIC ALARM GENERATION ............................................................................................... 66
E1 INFORMATION REGISTERS .................................................................................................... 67
COMMON CONTROL AND STATUS REGISTERS ...................................................... 69
10.1
11.
12.
T1/E1 STATUS REGISTERS ........................................................................................................ 70
I/O PIN CONFIGURATION OPTIONS ........................................................................... 76
LOOPBACK CONFIGURATION.................................................................................... 78
12.1
13.
PER-CHANNEL LOOPBACK ......................................................................................................... 80
ERROR COUNT REGISTERS ....................................................................................... 82
13.1
13.1.1
13.1.2
13.2
LINE-CODE VIOLATION COUNT REGISTER (LCVCR) ................................................................... 83
T1 Operation ........................................................................................................................................83
E1 Operation ........................................................................................................................................83
PATH CODE VIOLATION COUNT REGISTER (PCVCR) .................................................................. 85
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DS2156
13.2.1
13.2.2
13.3
FRAMES OUT-OF-SYNC COUNT REGISTER (FOSCR).................................................................. 86
13.3.1
13.3.2
13.4
14.
15.
T1 Operation ........................................................................................................................................85
E1 Operation ........................................................................................................................................85
T1 Operation ........................................................................................................................................86
E1 Operation ........................................................................................................................................86
E-BIT COUNTER (EBCR) ........................................................................................................... 87
DS0 MONITORING FUNCTION..................................................................................... 88
SIGNALING OPERATION ............................................................................................. 90
15.1
RECEIVE SIGNALING .................................................................................................................. 90
15.1.1
15.1.2
15.2
TRANSMIT SIGNALING ................................................................................................................ 96
15.2.1
15.2.2
15.2.3
15.2.4
16.
Processor-Based Signaling..................................................................................................................90
Hardware-Based Receive Signaling ....................................................................................................91
Processor-Based Mode .......................................................................................................................96
Software Signaling Insertion-Enable Registers, E1 CAS Mode ........................................................100
Software Signaling Insertion-Enable Registers, T1 Mode .................................................................102
Hardware-Based Mode ......................................................................................................................102
PER-CHANNEL IDLE CODE GENERATION .............................................................. 103
16.1
17.
18.
IDLE-CODE PROGRAMMING EXAMPLES ..................................................................................... 104
CHANNEL BLOCKING REGISTERS .......................................................................... 108
ELASTIC STORES OPERATION ................................................................................ 111
18.1
RECEIVE SIDE ......................................................................................................................... 114
18.1.1
18.1.2
18.2
TRANSMIT SIDE ....................................................................................................................... 114
18.2.1
18.2.2
18.3
18.4
19.
20.
T1 Mode .............................................................................................................................................114
E1 Mode.............................................................................................................................................114
T1 Mode .............................................................................................................................................115
E1 Mode.............................................................................................................................................115
ELASTIC STORES INITIALIZATION .............................................................................................. 115
MINIMUM DELAY MODE ............................................................................................................ 115
G.706 INTERMEDIATE CRC-4 UPDATING (E1 MODE ONLY).................................. 116
T1 BIT-ORIENTED CODE (BOC) CONTROLLER ...................................................... 117
20.1
TRANSMIT BOC ....................................................................................................................... 117
Transmit a BOC................................................................................................................................................117
20.2
RECEIVE BOC ......................................................................................................................... 117
Receive a BOC.................................................................................................................................................117
21.
ADDITIONAL (SA) AND INTERNATIONAL (SI) BIT OPERATION (E1 ONLY).......... 120
21.1
21.2
21.3
22.
METHOD 1: HARDWARE SCHEME ............................................................................................. 120
METHOD 2: INTERNAL REGISTER SCHEME BASED ON DOUBLE-FRAME ...................................... 120
METHOD 3: INTERNAL REGISTER SCHEME BASED ON CRC4 MULTIFRAME ................................ 123
HDLC CONTROLLERS ............................................................................................... 133
22.1
22.2
22.2.1
22.3
22.3.1
22.3.2
22.3.3
22.3.4
22.3.5
22.4
22.5
22.5.1
22.5.2
22.5.3
BASIC OPERATION DETAILS ..................................................................................................... 133
HDLC CONFIGURATION ........................................................................................................... 133
FIFO Control ......................................................................................................................................137
HDLC MAPPING ...................................................................................................................... 138
Receive ..............................................................................................................................................138
Transmit .............................................................................................................................................140
FIFO Information ................................................................................................................................145
Receive Packet-Bytes Available ........................................................................................................145
HDLC FIFOs ......................................................................................................................................146
RECEIVE HDLC CODE EXAMPLE .............................................................................................. 147
LEGACY FDL SUPPORT (T1 MODE).......................................................................................... 147
Overview ............................................................................................................................................147
Receive Section .................................................................................................................................147
Transmit Section ................................................................................................................................149
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DS2156
22.6
23.
D4/SLC-96 OPERATION .......................................................................................................... 149
LINE INTERFACE UNIT (LIU) ..................................................................................... 150
23.1
23.2
LIU OPERATION ...................................................................................................................... 150
RECEIVER ............................................................................................................................... 150
23.2.1
23.2.2
23.2.3
23.3
TRANSMITTER.......................................................................................................................... 152
23.3.1
23.3.2
23.3.3
23.3.4
23.4
23.5
23.6
23.7
23.8
23.9
24.
Transmit Short-Circuit Detector/Limiter..............................................................................................152
Transmit Open-Circuit Detector .........................................................................................................152
Transmit BPV Error Insertion .............................................................................................................152
Transmit G.703 Synchronization Signal (E1 Mode)...........................................................................152
MCLK PRESCALER .................................................................................................................. 153
JITTER ATTENUATOR ............................................................................................................... 153
CMI (CODE MARK INVERSION) OPTION .................................................................................... 153
LIU CONTROL REGISTERS ....................................................................................................... 154
RECOMMENDED CIRCUITS........................................................................................................ 161
COMPONENT SPECIFICATIONS.................................................................................................. 163
UTOPIA BACKPLANE INTERFACE........................................................................... 168
24.1
DESCRIPTION .......................................................................................................................... 168
24.1.1
24.1.2
24.2
24.3
24.4
24.5
24.6
UTOPIA Side Transmit: Muxed Mode with One Transmit CLAV.......................................................171
UTOPIA Side Transmit: Direct Status Mode (Multitransmit CLAV) ...................................................174
Transmit Processing ..........................................................................................................................176
RECEIVE OPERATION ............................................................................................................... 177
24.6.1
24.6.2
24.6.3
24.7
24.8
24.9
25.
26.
List of Applicable Standards ..............................................................................................................168
Acronyms and Definitions ..................................................................................................................168
UTOPIA CLOCK MODES .......................................................................................................... 169
FULL T1/E1 MODE AND CLEAR-CHANNEL E1 MODE ................................................................. 169
FRACTIONAL T1/E1 MODE ........................................................................................................ 170
TRANSMIT OPERATION ............................................................................................................. 171
24.5.1
24.5.2
24.5.3
Receive Processing ...........................................................................................................................177
UTOPIA Side Receive: Muxed Mode with One Receive CLAV.........................................................179
UTOPIA Side Receive: Direct Status Mode (Multireceive CLAV) .....................................................180
REGISTER DEFINITIONS ........................................................................................................... 182
RECEIVE FIFO OVERRUN ........................................................................................................ 193
UTOPIA DIAGNOSTIC LOOPBACK ............................................................................................ 193
PROGRAMMABLE IN-BAND LOOP CODE GENERATION AND DETECTION ........ 194
BERT FUNCTION ........................................................................................................ 201
26.1
26.2
26.3
26.4
26.5
26.6
27.
STATUS ................................................................................................................................... 201
MAPPING ................................................................................................................................. 201
BERT REGISTER DESCRIPTIONS ............................................................................................. 203
BERT REPETITIVE PATTERN SET ............................................................................................. 207
BERT BIT COUNTER ............................................................................................................... 208
BERT ERROR COUNTER ......................................................................................................... 209
PAYLOAD ERROR-INSERTION FUNCTION (T1 MODE ONLY)................................ 211
27.1
NUMBER-OF-ERRORS REGISTERS ............................................................................................ 213
27.1.1
28.
28.1
28.2
29.
30.
31.
Receive Level Indicator and Threshold Interrupt ...............................................................................151
Receive G.703 Synchronization Signal (E1 Mode)............................................................................151
Monitor Mode .....................................................................................................................................151
Number-of-Errors Left Register..........................................................................................................214
INTERLEAVED PCM BUS OPERATION (IBO)........................................................... 215
CHANNEL INTERLEAVE ............................................................................................................. 215
FRAME INTERLEAVE ................................................................................................................. 215
EXTENDED SYSTEM INFORMATION BUS (ESIB).................................................... 218
PROGRAMMABLE BACKPLANE CLOCK SYNTHESIZER....................................... 222
FRACTIONAL T1/E1 SUPPORT ................................................................................. 222
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DS2156
31.1
31.2
32.
33.
TDM BACKPLANE MODE .......................................................................................................... 222
UTOPIA BACKPLANE MODE .................................................................................................... 223
USER-PROGRAMMABLE OUTPUT PINS.................................................................. 224
JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT ................ 225
33.1
33.2
DESCRIPTION .......................................................................................................................... 225
INSTRUCTION REGISTER .......................................................................................................... 228
SAMPLE/PRELOAD.........................................................................................................................................229
BYPASS ...........................................................................................................................................................229
EXTEST............................................................................................................................................................229
CLAMP .............................................................................................................................................................229
HIGHZ...............................................................................................................................................................229
IDCODE............................................................................................................................................................229
33.3
33.4
33.5
33.6
34.
34.1
34.2
35.
36.
36.1
36.2
36.3
36.4
36.5
36.6
37.
38.
38.1
38.2
TEST REGISTERS ..................................................................................................................... 230
BOUNDARY SCAN REGISTER .................................................................................................... 230
BYPASS REGISTER .................................................................................................................. 230
IDENTIFICATION REGISTER ....................................................................................................... 230
FUNCTIONAL TIMING DIAGRAMS ............................................................................ 234
T1 MODE ................................................................................................................................ 234
E1 MODE ................................................................................................................................ 239
OPERATING PARAMETERS ...................................................................................... 248
AC TIMING PARAMETERS AND DIAGRAMS ........................................................... 250
MULTIPLEXED BUS AC CHARACTERISTICS................................................................................ 250
NONMULTIPLEXED BUS AC CHARACTERISTICS ......................................................................... 253
RECEIVE-SIDE AC CHARACTERISTICS ...................................................................................... 256
TRANSMIT AC CHARACTERISTICS ............................................................................................ 259
UTOPIA TRANSMIT AC CHARACTERISTICS .............................................................................. 262
UTOPIA RECEIVE AC CHARACTERISTICS ................................................................................ 262
REVISION HISTORY ................................................................................................... 263
PACKAGE INFORMATION ......................................................................................... 264
100-PIN LQFP (56-G5002-000).............................................................................................. 264
100-BALL CSBGA (56-G6008-001) ........................................................................................ 265
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DS2156
LIST OF FIGURES
Figure 2-1. Block Diagram ........................................................................................................................ 14
Figure 2-2. Receive and Transmit LIU (TDM Backplane Enabled)........................................................... 15
Figure 2-3. Receive and Transmit LIU (UTOPIA Backplane Enabled) ..................................................... 16
Figure 2-4. Receive and Transmit Framer/HDLC ..................................................................................... 17
Figure 2-5. Backplane Interface (TDM Backplane Enabled) .................................................................... 18
Figure 2-6. Backplane Interface (UTOPIA Bus Enabled) ......................................................................... 19
Figure 3-1. 10mm CSBGA Pin Configuration (TDM Signals Shown) ....................................................... 38
Figure 6-1. Programming Sequence ........................................................................................................ 48
Figure 7-1. Clock Map (TDM Mode) ......................................................................................................... 52
Figure 15-1. Simplified Diagram of Receive Signaling Path ..................................................................... 90
Figure 15-2. Simplified Diagram of Transmit Signaling Path .................................................................... 96
Figure 19-1. CRC-4 Recalculate Method ............................................................................................... 116
Figure 23-1. Typical Monitor Application ................................................................................................ 151
Figure 23-2. CMI Coding ........................................................................................................................ 153
Figure 23-3. Basic Interface ................................................................................................................... 161
Figure 23-4. Protected Interface Using Internal Receive Termination.................................................... 162
Figure 23-5. E1 Transmit Pulse Template .............................................................................................. 164
Figure 23-6. T1 Transmit Pulse Template .............................................................................................. 164
Figure 23-7. Jitter Tolerance .................................................................................................................. 165
Figure 23-8. Jitter Tolerance (E1 Mode)................................................................................................. 165
Figure 23-9. Jitter Attenuation (T1 Mode)............................................................................................... 166
Figure 23-10. Jitter Attenuation (E1 Mode) ............................................................................................ 166
Figure 23-11. Optional Crystal Connections........................................................................................... 167
Figure 24-1. UTOPIA Clocking Configurations ....................................................................................... 169
Figure 24-2. Polling Phase and Selection Phase at Transmit Interface ................................................. 172
Figure 24-3. End and Restart of Cell at Transmit Interface ................................................................... 173
Figure 24-4. Transmission to PHY Paused for Three Cycles ................................................................. 174
Figure 24-5. Example of Direct Status Indication, Transmit Direction .................................................... 175
Figure 24-6. Transmit Cell Flow ............................................................................................................. 176
Figure 24-7. Cell-Delineation State Diagram .......................................................................................... 177
Figure 24-8. Header Correction State Machine ...................................................................................... 178
Figure 24-9. Polling Phase and Selection at Receive Interface.............................................................. 179
Figure 24-10. End and Restart of Cell Transmission at Receive Interface............................................. 180
Figure 24-11. Example of Direct Status Indication, Receive Direction ................................................... 181
Figure 26-1. Simplified Diagram of BERT in Network Direction ............................................................. 202
Figure 26-2. Simplified Diagram of BERT in Backplane Direction.......................................................... 202
Figure 28-1. IBO Example ...................................................................................................................... 217
Figure 29-1. ESIB Group of Four DS2156s ............................................................................................ 218
Figure 33-1. JTAG Functional Block Diagram ........................................................................................ 225
Figure 33-2. TAP Controller State Diagram............................................................................................ 228
Figure 34-1. Receive-Side D4 Timing .................................................................................................... 234
Figure 34-2. Receive-Side ESF Timing .................................................................................................. 234
Figure 34-3. Receive-Side Boundary Timing (with elastic store disabled) ............................................. 235
Figure 34-4. Receive-Side 1.544MHz Boundary Timing (with Elastic Store Enabled) ........................... 235
Figure 34-5. Receive-Side 2.048MHz Boundary Timing (with Elastic Store Enabled) ........................... 236
Figure 34-6. Transmit-Side D4 Timing ................................................................................................... 236
Figure 34-7. Transmit-Side ESF Timing ................................................................................................. 237
Figure 34-8. Transmit-Side Boundary Timing (with Elastic Store Disabled)........................................... 237
Figure 34-9. Transmit-Side 1.544MHz Boundary Timing (with Elastic Store Enabled) .......................... 238
Figure 34-10. Transmit-Side 2.048MHz Boundary Timing (with Elastic Store Enabled) ........................ 238
Figure 34-11. Receive-Side Timing ........................................................................................................ 239
Figure 34-12. Receive-Side Boundary Timing (with Elastic Store Disabled).......................................... 239
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Figure 34-13. Receive-Side Boundary Timing, RSYSCLK = 1.544MHz (Elastic Store Enabled)........... 240
Figure 34-14. Receive-Side Boundary Timing, RSYSCLK = 2.048MHz (Elastic Store Enabled)........... 240
Figure 34-15. Receive IBO Channel Interleave Mode Timing ................................................................ 241
Figure 34-16. Receive IBO Frame Interleave Mode Timing ................................................................... 242
Figure 34-17. G.802 Timing, E1 Mode Only ........................................................................................... 243
Figure 34-18. Transmit-Side Timing ....................................................................................................... 243
Figure 34-19. Transmit-Side Boundary Timing (Elastic Store Disabled) ................................................ 244
Figure 34-20. Transmit-Side Boundary Timing, TSYSCLK = 1.544MHz (Elastic Store Enabled) ......... 244
Figure 34-21. Transmit-Side Boundary Timing, TSYSCLK = 2.048MHz (Elastic Store Enabled) .......... 245
Figure 34-22. Transmit IBO Channel Interleave Mode Timing ............................................................... 246
Figure 34-23. Transmit IBO Frame Interleave Mode Timing .................................................................. 247
Figure 36-1. Intel Bus Read Timing (BTS = 0/MUX = 1) ........................................................................ 251
Figure 36-2. Intel Bus Write Timing (BTS = 0/MUX = 1)......................................................................... 251
Figure 36-3. Motorola Bus Timing (BTS = 1/MUX = 1)........................................................................... 252
Figure 36-4. Intel Bus Read Timing (BTS = 0/MUX = 0) ........................................................................ 254
Figure 36-5. Intel Bus Write Timing (BTS = 0/MUX = 0)......................................................................... 254
Figure 36-6. Motorola Bus Read Timing (BTS = 1/MUX = 0) ................................................................. 255
Figure 36-7. Motorola Bus Write Timing (BTS = 1/MUX = 0) ................................................................. 255
Figure 36-8. Receive-Side Timing .......................................................................................................... 257
Figure 36-9. Receive-Side Timing, Elastic Store Enabled...................................................................... 258
Figure 36-10. Receive Line Interface Timing.......................................................................................... 258
Figure 36-11. Transmit-Side Timing ....................................................................................................... 260
Figure 36-12. Transmit-Side Timing, Elastic Store Enabled................................................................... 261
Figure 36-13. Transmit Line Interface Timing......................................................................................... 261
Figure 36-14. UTOPIA Interface Setup and Hold Times ........................................................................ 262
Figure 36-15. UTOPIA Interface Delay Times ........................................................................................ 262
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LIST OF TABLES
Table 3-A. Pin Description Sorted by Pin Number (TDM Backplane Enabled) ........................................ 34
Table 3-B. Pin Description Sorted by Pin Number (UTOPIA Backplane Enabled)................................... 36
Table 4-A. Register Map Sorted by Address ............................................................................................ 39
Table 4-B. UTOPIA Register Map ............................................................................................................ 45
Table 8-A. T1 Alarm Criteria..................................................................................................................... 61
Table 9-A. E1 Sync/Resync Criteria ......................................................................................................... 63
Table 9-B. E1 Alarm Criteria..................................................................................................................... 68
Table 13-A. T1 Line Code Violation Counting Options ............................................................................. 83
Table 13-B. E1 Line-Code Violation Counting Options ............................................................................83
Table 13-C. T1 Path Code Violation Counting Arrangements .................................................................. 85
Table 13-D. T1 Frames Out-of-Sync Counting Arrangements ................................................................. 86
Table 15-A. Time Slot Numbering Schemes ............................................................................................ 97
Table 16-A. Idle-Code Array Address Mapping...................................................................................... 103
Table 16-B. GRIC and GTIC Functions .................................................................................................. 105
Table 18-A. Elastic Store Delay After Initialization ................................................................................. 115
Table 22-A. HDLC Controller Registers ................................................................................................. 134
Table 23-A. Transformer Specifications ................................................................................................. 163
Table 24-A. UTOPIA Clock Mode Configuration ....................................................................................170
Table 27-A. Transmit Error-Insertion Setup Sequence .......................................................................... 211
Table 27-B. Error Insertion Examples .................................................................................................... 213
Table 33-A. Instruction Codes for IEEE 1149.1 Architecture ................................................................. 229
Table 33-B. ID Code Structure ............................................................................................................... 230
Table 33-C. Device ID Codes................................................................................................................. 230
Table 33-D. Boundary Scan Control Bits................................................................................................ 231
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DS2156
1. MAIN FEATURES
The DS2156 contains all of the features of the previous generation of Dallas Semiconductor’s T1 and E1 SCTs plus
many new features such as a UTOPIA bus interface.
General
Programmable output clocks for fractional T1, E1,
H0, and H12 applications
Interleaving PCM bus operation
8-bit parallel control port, multiplexed or
nonmultiplexed, Intel or Motorola
IEEE 1149.1 JTAG-Boundary Scan
3.3V supply with 5V tolerant inputs and outputs
Pin compatible with DS2155, DS2152/DS2154,
and DS21x5Y SCT family
Signaling System 7 Support
RAI-CI, AIS-CI support
100-pin LQFP package (14mm x 14mm) (DS2156)
3.3V supply with 5V tolerant inputs and outputs
LQFP package that is pin compatible with
DS2152/DS2154, DS21352/DS21354,
DS21552/DS21554, and DS2155
Evaluation kits
IEEE 1149.1 JTAG boundary scan
Driver source code available from the factory
Line Interface
Requires only a 2.048MHz master clock for both
E1 and T1 operation with the option to use
1.544MHz for T1 operation
Fully software configurable
Short-haul and long-haul applications
Automatic receive sensitivity adjustments
Ranges include 0 to 43dB or 0 to 12dB for E1
applications and 0 to 13dB or 0 to 36dB for T1
applications
Receive level indication in 2.5dB steps from
-42.5dB to -2.5dB
Internal receive termination option for 75Ω, 100Ω,
and 120Ω lines
Internal transmit termination option for 75Ω, 100Ω,
and 120Ω lines
Monitor application gain settings of 20dB, 26dB,
and 32dB
G.703 receive synchronization-signal mode
Flexible transmit waveform generation
T1 DSX-1 line buildouts
T1 CSU line buildouts of -7.5dB, -15dB, and
-22.5dB
E1 waveforms include G.703 waveshapes for
both 75Ω coax and 120Ω twisted cables
AIS generation independent of loopbacks
Alternating ones and zeros generation
Square-wave output
Open-drain output option
NRZ format option
Transmitter power-down
Transmitter 50mA short-circuit limiter with
current-limit-exceeded indication
Transmit open-circuit-detected indication
Line interface function can be completely
decoupled from the framer/formatter
Clock Synthesizer
Output frequencies include 2.048MHz, 4.096MHz,
8.192MHz, and 16.384MHz
Derived from recovered receive clock
Jitter Attenuator
32-bit or 128-bit crystal-less jitter attenuator
Requires only a 2.048MHz master clock for both
E1 and T1 operation with the option to use
1.544MHz for T1 operation
Can be placed in either the receive or transmit path
or disabled
Limit trip indication
Framer/Formatter
Fully independent transmit and receive
functionality
Full receive and transmit path transparency
T1 framing formats include D4 (SLC-96) and ESF
Detailed alarm and status reporting with optional
interrupt support
Large path and line error counters for:
– T1: BPV, CV, CRC6, and framing bit errors
– E1: BPV, CV, CRC4, E-bit, and frame
alignment errors
Timed or manual update modes
DS1 idle code generation on a per-channel basis in
both transmit and receive paths
– User-defined
– Digital milliwatt
ANSI T1.403-1998 Support
RAI-CI detection and generation
AIS-CI detection and generation
E1ETS 300 011 RAI generation
G.965 V5.2 link detect
Ability to monitor one DS0 channel in both the
transmit and receive paths
In-band repeating pattern generators and detectors
– Three independent generators and detectors
– Patterns from 1 to 8 bits or 16 bits in length
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DS2156
RCL, RLOS, RRA, and RAIS alarms interrupt on
change-of-state
Flexible signaling support
– Software or hardware based
– Interrupt generated on change of signaling data
– Receive signaling freeze on loss-of-sync,
carrier loss, or frame slip
Addition of hardware pins to indicate carrier loss
and signaling freeze
Automatic RAI generation to ETS 300 011
specifications
Access to Sa and Si bits
Option to extend carrier loss criteria to a 1ms
period as per ETS 300 233
Japanese J1 support
– Ability to calculate and check CRC6 according
to the Japanese standard
– Ability to generate Yellow Alarm according to
the Japanese standard
TDM Bus
Dual two-frame independent receive and transmit
elastic stores
– Independent control and clocking
– Controlled slip capability with status
– Minimum delay mode supported
16.384MHz maximum backplane burst rate
Supports T1 to CEPT (E1) conversion
Programmable output clocks for fractional T1, E1,
H0, and H12 applications
Interleaving PCM bus operation
Hardware signaling capability
– Receive signaling reinsertion to a backplane
multiframe sync
– Availability of signaling in a separate PCM
data stream
– Signaling freezing
Ability to pass the T1 F-bit position through the
elastic stores in the 2.048MHz backplane mode
Access to the data streams in between the
framer/formatter and the elastic stores
User-selectable synthesized clock output
UTOPIA Bus
Supports fractional T1/E1 and arbitrary bit rates in
multiples of 64kbps (DS0/TS) up to 2.048Mbps
Supports clear E1
Compliant to the ATM forum specifications for
ATM over DS1 and E1, respectively
Standard UTOPIA-II interface to the ATM layer
Configurable UTOPIA address
Supports diagnostic loopback
Optional payload scrambling in transmit direction
and descrambling in receive direction as per the
ITU I.432 for the cell-based physical layer
Optional HEC insertion in transmit direction with
programmable COSET polynomial addition
Option of using either idle or unassigned cells for
cell-rate decoupling in transmit direction
1-Byte programmable pattern for payload of cells
used for cell-rate decoupling
Transmit FIFO depth configurable to either 2, 3, 4
cell deep, which provides control over cell latency
Transmit FIFO depth indication for 2-cell space
Optional single-bit HEC error insertion
HEC-based cell delineation
Optional single-bit HEC error correction in the
receive direction
Optional filtering of HEC errored cells received
Optional receive idle/unassigned cell filtering
Programmable loss-of-cell delineation (LCD)
integration and optional interrupt
Interrupt for FIFO overrun in receive direction
Saturating counts for:
– Number of error-free assigned cells received
and transmitted
– Number of correctable and uncorrectable HECerrored cells received
Optional internally generated clock (system clock
divided by 8) in diagnostic loopback mode
HDLC Controllers
Two independent HDLC controllers
Fast load and unload features for FIFOs
SS7 support for FISU transmit and receive
Independent 128-byte Rx and Tx buffers with
interrupt support
Access FDL, Sa, or single/multiple DS0 channels
DS0 access includes Nx64 or Nx56
Compatible with polled or interrupt driven
environments
Bit-oriented code (BOC) support
Test and Diagnostics
Programmable on-chip bit error-rate testing
Pseudorandom patterns including QRSS
User-defined repetitive patterns
Daly pattern
Error insertion single and continuous
Total bit and errored bit counts
Payload error insertion
Error insertion in the payload portion of the T1
frame in the transmit path
Errors can be inserted over the entire frame or
selected channels
Insertion options include continuous and absolute
number with selectable insertion rates
F-bit corruption for line testing
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DS2156
Control Port
8-bit parallel control port
Multiplexed or nonmultiplexed buses
Intel or Motorola formats
Supports polled or interrupt environments
Software access to device ID and silicon revision
Software reset supported
– Automatic clear on power-up
Hardware reset pin
Loopbacks: remote, local, analog, and per-channel
loopback
Extended System Information Bus
Host can read interrupt and alarm status on up to 8
ports with a single bus read
User-Programmable Output Pins
Four user-defined output pins for controlling
external logic
The DS2156 is compliant with the following standards:
ANSI:
T1.403-1995, T1.231–1993, T1.408
AT&T:
TR54016, TR62411
ITU:
G.703, G.704, G.706, G.736, G.775, G.823, G.932, I.431, O.151, Q.161
ITU-T:
Recommendation I.432–03/93 B-ISDN User-Network Interface—Physical Layer
Specification
ETSI:
ETS 300 011, ETS 300 166, ETS 300 233, CTR12, CTR4
Japanese:
JTG.703, JTI.431, JJ-20.11 (CMI Coding Only)
ATM Forum:
“DS1 Physical Layer Specification,” af-phy-0016.000, September 1994
ATM Forum:
“E1 Physical Layer Specification,” af-phy-0064.000, September 1996
ATM Forum:
“UTOPIA Level 2 Specification,” Version 1.0, af-phy-0039.000, June 1995
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DS2156
2. DETAILED DESCRIPTION
The DS2156 is a software-selectable T1, E1, or J1 single-chip transceiver (SCT) for short-haul and longhaul applications. The backplane is user-configurable for a TDM or UTOPIA II bus interface. The
DS2156 is composed of an LIU, framer, HDLC controllers, and a UTOPIA/TDM backplane interface,
and is controlled by an 8-bit parallel port configured for Intel or Motorola bus operations. The DS2156 is
pin and software compatible with the DS2155.
The LIU is composed of transmit and receive interfaces and a jitter attenuator. The transmit interface is
responsible for generating the necessary waveshapes for driving the network and providing the correct
source impedance depending on the type of media used. T1 waveform generation includes DSX-1 line
buildouts as well as CSU line buildouts of -7.5dB, -15dB, and -22.5dB. E1 waveform generation includes
G.703 waveshapes for both 75Ω coax and 120Ω twisted cables. The receive interface provides network
termination and recovers clock and data from the network. The receive sensitivity adjusts automatically to
the incoming signal and can be programmed for 0 to 43dB or 0 to 12dB for E1 applications and 0 to 30dB
or 0 to 36dB for T1 applications. The jitter attenuator removes phase jitter from the transmitted or
received signal. The crystal-less jitter attenuator requires only a 2.048MHz MCLK for both E1 and T1
applications (with the option of using a 1.544MHz MCLK in T1 applications) and can be placed in either
transmit or receive data paths. An additional feature of the LIU is a CMI coder/decoder for interfacing to
optical networks.
On the transmit side, clock, data, and frame-sync signals are provided to the framer by the backplane
interface section. The framer inserts the appropriate synchronization framing patterns, alarm information,
calculates and inserts the CRC codes, and provides the B8ZS/HDB3 (zero code suppression) and AMI
line coding. The receive-side framer decodes AMI, B8ZS, and HDB3 line coding, synchronizes to the
data stream, reports alarm information, counts framing/coding/CRC errors, and provides clock/data and
frame-sync signals to the backplane interface section.
Both the transmit and receive path have two HDLC controllers. The HDLC controllers transmit and
receive data through the framer block. The HDLC controllers can be assigned to any time slot, group of
time slots, portion of a time slot or to FDL (T1) or Sa bits (E1). Each controller has 128-byte FIFOs, thus
reducing the amount of processor overhead required to manage the flow of data. In addition, built-in
support for reducing the processor time is required in SS7 applications.
The backplane interface provides a versatile method of sending and receiving data from the host system.
Elastic stores provide a method for interfacing to asynchronous systems, converting from a T1/E1
network to a 2.048MHz, 4.096MHz, 8.192MHz, or N x 64kHz system backplane. The elastic stores also
manage slip conditions (asynchronous interface). An interleave bus option (IBO) is provided to allow up
to eight transceivers to share a high-speed backplane in TDM mode.
The parallel port provides access for control and configuration of the DS2156’s features. The extended
system information bus (ESIB) function allows up to eight transceivers to be accessed by a single read for
interrupt status or other user-selectable alarm status information. Diagnostic capabilities include
loopbacks, PRBS pattern generation/detection, and 16-bit loop-up and loop-down code generation and
detection.
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DS2156
Reader’s Note: This data sheet assumes a particular nomenclature of the T1 operating environment. In
each 125µs frame there are 24 8-bit channels plus a framing bit. It is assumed that the framing bit is sent
first followed by channel 1. Each channel is made up of eight bits that are numbered 1 to 8. Bit number 1
is the MSB and is transmitted first. Bit number 8 is the LSB and is transmitted last. The term “locked” is
used to refer to two clock signals that are phase- or frequency-locked or derived from a common clock
(i.e., a 1.544MHz clock can be locked to a 2.048MHz clock if they share the same 8kHz component).
Throughout this data sheet, the following abbreviations are used:
B8ZS
Bipolar with 8 Zero Substitution
BOC
CRC
Bit-Oriented Code
Cyclical Redundancy Check
D4
Superframe (12 frames per multiframe) Multiframe Structure
ESF
FDL
FPS
Extended Superframe (24 frames per multiframe) Multiframe Structure
Facility Data Link
Framing Pattern Sequence in ESF
Fs
Ft
HDLC
Signaling Framing Pattern in D4
Terminal Framing Pattern in D4
High-Level Data Link Control
MF
SLC–96
Multiframe
Subscriber Loop Carrier—96 Channels
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DS2156
2.1
Block Diagram
Figure 2-1 shows a simplified block diagram featuring the major components of the DS2156. Details are
shown in subsequent figures. About 30 device pins have dual functions depending on the selection of the
backplane, UTOPIA, or TDM. Some of the block diagrams depict a configuration based on the state of
the backplane selection. The block diagram is divided into three functional blocks: LIU, FRAMER, and
BACKPLANE INTERFACE.
Figure 2-1. Block Diagram
CLOCK
LIU
MUX
FRAMER
SINGALING
ALARM GEN
HDLCs
CRC GEN
HDB3 / B8ZS
EXTERNAL ACCESS
TO TRANSMIT SIGNALS
(TDM BACKPLANE ONLY)
JTAG
FRAMER
HOST INTERFACE
BACKPLANE
CLOCK SYNTH
BACKPLANE
INTERFACE
CIRCUIT
UTOPIA
or
TDM
BACKPLANE
INTERFACE
ESIB
DS2156
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BACKPLANE
HDB3 / B8ZS
SYNC
SINGALING
ALARM DET
HDLCs
PAYLOAD LOOPBACK
MUX
FRAMER LOOPBACK
TX
LIU
LOCAL LOOPBACK
T1/E1/J1
NETWORK
RX
LIU
REMOTE LOOPBACK
CLOCK
ADAPTER
JITTER ATTENUATOR
EXTERNAL ACCESS
TO RECEIVE SIGNALS
(TDM BACKPLANE ONLY)
DS2156
Figure 2-2. Receive and Transmit LIU (TDM Backplane Enabled)
RPOSI
RCLKI
RNEGI
REMOTE LOOPBACK
JITTER ATTENUATOR
TRANSMIT
OR RECEIVE PATH
TPOSO
TCLKO
TNEGO
TNEGI
TCLKI
TPOSI
LIUC
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RNEGO
RCLKO
RPOSO
8XCLK
LOCAL LOOPBACK
TRANSMIT
LINE I/F
TTIP
JACLK
32.768MHz
MUX
TPOS
TNEG
TCLK
TRING
RECEIVE
LINE I/F
RTIP
MUX
VCO / PLL
RPOS
RNEG
RCLK
RRING
XTALD
MCLK
RCL
DS2156
Figure 2-3. Receive and Transmit LIU (UTOPIA Backplane Enabled)
8XCLK
XTALD
MCLK
RCL
JACLK
VCO / PLL
32.768MHz
REMOTE LOOPBACK
JITTER ATTENUATOR
TRANSMIT
OR RECEIVE PATH
TTIP
TRANSMIT
LINE I/F
TRING
LOCAL LOOPBACK
RTIP
RECEIVE
LINE I/F
RRING
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RPOS
RNEG
RCLK
TPOS
TNEG
TCLK
DS2156
Figure 2-4. Receive and Transmit Framer/HDLC
RECEIVE
FRAMER
REC
HDLC #2
128 Byte
FIFO
128 Byte
FIFO
MAPPER
MAPPER
CLOCK
SYNC
SYNC
TRANSMIT
FRAMER
CLOCK
DATA
DATA
PAYLOAD LOOPBACK
TPOS
TNEG
TCLK
DATA
FRAMER LOOPBACK
RPOS
RNEG
RCLK
REC
HDLC #1
MAPPER
MAPPER
XMIT
HDLC #1
XMIT
HDLC #2
128 Byte
FIFO
128 Byte
FIFO
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CLOCK
SYNC
SYNC
CLOCK
DATA
DS2156
Figure 2-5. Backplane Interface (TDM Backplane Enabled)
Sa BIT/FDL
EXTRACTION
SIGNALING
BUFFER
DATA
RSIG
RSIGFR
RSYSCLK
RSER
RCLK
RSYNC
RMSYNC
ELASTIC
STORE
CLOCK
RLINK
RLCLK
SYNC
RFSYNC
RDATA
SYNC
DATA
Sa/FDL
INSERT
ELASTIC
STORE
CHANNEL
TIMING
RCHCLK
RCHBLK
SIGNALING
BUFFER
TSER
TSIG
TSSYNC
TSYSCLK
TSYNC
CLOCK
TESO
TDATA
TLCLK
TLINK
TCHCLK
TCHBLK
CHANNEL
TIMING
TCLK
MUX
JACLK
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TCLK
DS2156
Figure 2-6. Backplane Interface (UTOPIA Bus Enabled)
RSYNC
RDATA
RCLK
RCLK
UR-ENB
UR-SOC
UR-CLK
RCHCLK
RECEIVE
FRAMER
INTERFACE
DATA
CONTROL
SCRAMBLING
& RATE
DECOUPLING
CELL
STORAGE
FIFO
RECEIVE
UTOPIA BUS
INTERFACE
UR-CLAV0
SYNC
LOOPBACK
DATA
TRANSMIT
FRAMER
INTERFACE
CONTROL
SCRAMBLING
& RATE
DECOUPLING
CELL
STORAGE
FIFO
TRANSMIT
UTOPIA BUS
INTERFACE
8
UR-DATA0 TO
UR-DATA7
UT-CLAV0
UT-2CLAV0
5
UT-ADDR0 TO
UT-ADDR4
8
UT-DATA0 TO
UT-DATA7
SYNC
TCLK
UR-ADDR0 TO
UR-ADDR4
UT-ENB
UT-SOC
UT-CLK
TCHCLK
DATA
5
TCLK
UT-UTDO
TSYNC
TDATA
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DS2156
3. PIN FUNCTION DESCRIPTION
The DS2156 has a user-selectable TDM or UTOPIA backplane. Table 3-A and Table 3-B indicate which
pins have alternate functions depending on the backplane selected. Note that even when the UTOPIA
backplane is selected, the basic TDM signals such as clock, data, and frame-sync are available for both
the transmit and receive directions.
3.1
TDM Backplane
3.1.1 Transmit Side
Signal Name:
TCLK
Signal Description:
Transmit Clock
Signal Type:
Input
A 1.544MHz (T1) or a 2.048MHz (E1) primary clock. Used to clock data through the transmit-side formatter.
TCLK can be internally sourced from MCLK. This is the most flexible method and requires only a single clock
signal for both T1 or E1. If internal sourcing is used, then the TCLK pin should be connected low.
Signal Name:
TSER
Signal Description:
Transmit Serial Data
Signal Type:
Input
Transmit NRZ serial data. Sampled on the falling edge of TCLK when the transmit-side elastic store is disabled.
Sampled on the falling edge of TSYSCLK when the transmit-side elastic store is enabled.
Signal Name:
TCHCLK
Signal Description:
Transmit Channel Clock
Signal Type:
Output
A 192kHz (T1) or 256kHz (E1) clock that pulses high during the LSB of each channel. Can also be programmed to
output a gated transmit bit clock on a per-channel basis. Synchronous with TCLK when the transmit-side elastic
store is disabled. Synchronous with TSYSCLK when the transmit-side elastic store is enabled. Useful for parallelto-serial conversion of channel data.
Signal Name:
TCHBLK
Signal Description:
Transmit Channel Block
Signal Type:
Output
A user-programmable output that can be forced high or low during any of the channels. Synchronous with TCLK
when the transmit-side elastic store is disabled. Synchronous with TSYSCLK when the transmit-side elastic store is
enabled. Useful for blocking clocks to a serial UART or LAPD controller in applications where not all channels are
used such as Fractional T1, Fractional E1, 384kbps (H0), 768kbps, or ISDN–PRI. Also useful for locating
individual channels in drop-and-insert applications, for external per-channel loopback, and for per-channel
conditioning.
Signal Name:
TSYSCLK
Signal Description:
Transmit System Clock
Signal Type:
Input
1.544MHz, 2.048MHz, 4.096MHz, 8.192MHz, or 16.384MHz clock. Only used when the transmit-side elastic
store function is enabled. Should be connected low in applications that do not use the transmit-side elastic store.
See Section 28 for details on 4.096MHz, 8.192MHz, and 16.384MHz operation using the IBO.
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DS2156
Signal Name:
TLCLK
Signal Description:
Transmit Link Clock
Signal Type:
Output
Demand clock for the transmit link data [TLINK] input.
T1 Mode: A 4kHz or 2kHz (ZBTSI) clock.
E1 Mode: A 4kHz to 20kHz clock.
Signal Name:
TLINK
Signal Description:
Transmit Link Data
Signal Type:
Input
If enabled, this pin is sampled on the falling edge of TCLK for data insertion into either the FDL stream (ESF) or
the Fs-bit position (D4), or the Z-bit position (ZBTSI) or any combination of the Sa-bit positions (E1).
Signal Name:
TSYNC
Signal Description:
Transmit Sync
Signal Type:
Input/Output
A pulse at this pin establishes either frame or multiframe boundaries for the transmit side. Can be programmed to
output either a frame or multiframe pulse. If this pin is set to output pulses at frame boundaries, it can also be set by
IOCR1.3 to output double-wide pulses at signaling frames in T1 mode.
Signal Name:
TSSYNC
Signal Description:
Transmit System Sync
Signal Type:
Input
Only used when the transmit-side elastic store is enabled. A pulse at this pin establishes either frame or multiframe
boundaries for the transmit side. Should be connected low in applications that do not use the transmit-side elastic
store.
Signal Name:
TSIG
Signal Description:
Transmit Signaling Input
Signal Type:
Input
When enabled, this input samples signaling bits for insertion into outgoing PCM data stream. Sampled on the
falling edge of TCLK when the transmit-side elastic store is disabled. Sampled on the falling edge of TSYSCLK
when the transmit-side elastic store is enabled.
Signal Name:
TESO
Signal Description:
Transmit Elastic Store Data Output
Signal Type:
Output
Updated on the rising edge of TCLK with data out of the transmit-side elastic store whether the elastic store is
enabled or not. This pin is normally connected to TDATA.
Signal Name:
TDATA
Signal Description:
Transmit Data
Signal Type:
Input
Sampled on the falling edge of TCLK with data to be clocked through the transmit-side formatter. This pin is
normally connected to TESO.
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DS2156
Signal Name:
TPOSO
Signal Description:
Transmit Positive-Data Output
Signal Type:
Output
Updated on the rising edge of TCLKO with the bipolar data out of the transmit-side formatter. Can be programmed
to source NRZ data by the output data format (IOCR1.0) control bit. This pin is normally connected to TPOSI.
Signal Name:
TNEGO
Signal Description:
Transmit Negative-Data Output
Signal Type:
Output
Updated on the rising edge of TCLKO with the bipolar data out of the transmit-side formatter. This pin is normally
connected to TNEGI.
Signal Name:
TCLKO
Signal Description:
Transmit Clock Output
Signal Type:
Output
Buffered clock that is used to clock data through the transmit-side formatter (i.e., either TCLK or RCLKI). This pin
is normally connected to TCLKI.
Signal Name:
TPOSI
Signal Description:
Transmit Positive-Data Input
Signal Type:
Input
Sampled on the falling edge of TCLKI for data to be transmitted out onto the T1 line. Can be internally connected
to TPOSO by connecting the LIUC pin high. TPOSI and TNEGI can be connected together in NRZ applications.
Signal Name:
TNEGI
Signal Description:
Transmit Negative-Data Input
Signal Type:
Input
Sampled on the falling edge of TCLKI for data to be transmitted out onto the T1 line. Can be internally connected
to TNEGO by connecting the LIUC pin high. TPOSI and TNEGI can be connected together in NRZ applications.
Signal Name:
TCLKI
Signal Description:
Transmit Clock Input
Signal Type:
Input
Line interface transmit clock. Can be internally connected to TCLKO by connecting the LIUC pin high.
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DS2156
3.1.2 Receive Side
Signal Name:
RLINK
Signal Description:
Receive Link Data
Signal Type:
Output
T1 Mode: Updated with either FDL data (ESF) or Fs bits (D4) or Z bits (ZBTSI) one RCLK before the start of a
frame.
E1 Mode: Updated with the full E1 data stream on the rising edge of RCLK.
Signal Name:
RLCLK
Signal Description:
Receive Link Clock
Signal Type:
Output
T1 Mode: A 4kHz or 2kHz (ZBTSI) clock for the RLINK output.
E1 Mode: A 4kHz to 20kHz clock.
Signal Name:
RCLK
Signal Description:
Receive Clock
Signal Type:
Output
1.544MHz (T1) or 2.048MHz (E1) clock that is used to clock data through the receive-side framer.
Signal Name:
RCHCLK
Signal Description:
Receive Channel Clock
Signal Type:
Output
A 192kHz (T1) or 256kHz (E1) clock that pulses high during the LSB of each channel. Synchronous with RCLK
when the receive-side elastic store is disabled. Synchronous with RSYSCLK when the receive-side elastic store is
enabled. Useful for parallel-to-serial conversion of channel data.
Signal Name:
RCHBLK
Signal Description:
Receive Channel Block
Signal Type:
Output
A user-programmable output that can be forced high or low during any of the 24 T1 or 32 E1 channels.
Synchronous with RCLK when the receive-side elastic store is disabled. Synchronous with RSYSCLK when the
receive-side elastic store is enabled. Useful for blocking clocks to a serial UART or LAPD controller in
applications where not all channels are used such as fractional service, 384kbps service, 768kbps, or ISDN–PRI.
Also useful for locating individual channels in drop-and-insert applications, for external per-channel loopback, and
for per-channel conditioning. See Section 17 for details.
Signal Name:
RSER
Signal Description:
Receive Serial Data
Signal Type:
Output
Received NRZ serial data. Updated on rising edges of RCLK when the receive-side elastic store is disabled.
Updated on the rising edges of RSYSCLK when the receive-side elastic store is enabled.
Signal Name:
RSYNC
Signal Description:
Receive Sync
Signal Type:
Input/Output
An extracted pulse, one RCLK wide, is output at this pin that identifies either frame (IOCR1.5 = 0) or multiframe
(IOCR1.5 = 1) boundaries. If set to output frame boundaries, then through IOCR1.6, RSYNC can also be set to
output double-wide pulses on signaling frames in T1 mode. If the receive-side elastic store is enabled, then this pin
can be enabled to be an input through IOCR1.4, at which a frame or multiframe boundary pulse is applied.
Signal Name:
RFSYNC
Signal Description:
Receive Frame Sync
Signal Type:
Output
An extracted 8kHz pulse, one RCLK wide, is output at this pin that identifies frame boundaries.
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DS2156
Signal Name:
RMSYNC
Signal Description:
Receive Multiframe Sync
Signal Type:
Output
An extracted pulse, one RCLK wide (elastic store disabled) or one RSYSCLK wide (elastic store enabled), is
output at this pin that identifies multiframe boundaries.
Signal Name:
RDATA
Signal Description:
Receive Data
Signal Type:
Output
Updated on the rising edge of RCLK with the data out of the receive-side framer.
Signal Name:
RSYSCLK
Signal Description:
Receive System Clock
Signal Type:
Input
1.544MHz, 2.048MHz, 4.096MHz, or 8.192MHz clock. Only used when the receive-side elastic store function is
enabled. Should be connected low in applications that do not use the receive-side elastic store. See Section 28 for
details on 4.096MHz and 8.192MHz operation using the IBO.
Signal Name:
RSIG
Signal Description:
Receive Signaling Output
Signal Type:
Output
Outputs signaling bits in a PCM format. Updated on rising edges of RCLK when the receive-side elastic store is
disabled. Updated on the rising edges of RSYSCLK when the receive-side elastic store is enabled.
Signal Name:
RLOS/LOTC
Signal Description:
Receive Loss-of-Sync/Loss-of-Transmit Clock
Signal Type:
Output
A dual function output that is controlled by the CCR1.0 control bit. This pin can be programmed to either toggle
high when the synchronizer is searching for the frame and multiframe or to toggle high if the TCLK pin has not
been toggled for 5µs.
Signal Name:
RCL
Signal Description:
Receive Carrier Loss
Signal Type:
Output
Set high when the line interface detects a carrier loss.
Signal Name:
RSIGF
Signal Description:
Receive Signaling Freeze
Signal Type:
Output
Set high when the signaling data is frozen by either automatic or manual intervention. Used to alert downstream
equipment of the condition.
Signal Name:
BPCLK
Signal Description:
Backplane Clock
Signal Type:
Output
A user-selectable synthesized clock output that is referenced to the clock that is output at the RCLK pin.
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DS2156
Signal Name:
RPOSO
Signal Description:
Receive Positive-Data Output
Signal Type:
Output
Updated on the rising edge of RCLKO with bipolar data out of the line interface. This pin is normally connected to
RPOSI.
Signal Name:
RNEGO
Signal Description:
Receive Negative-Data Output
Signal Type:
Output
Updated on the rising edge of RCLKO with the bipolar data out of the line interface. This pin is normally
connected to RPOSI.
Signal Name:
RCLKO
Signal Description:
Receive Clock Output
Signal Type:
Output
Buffered recovered clock from the network. This pin is normally connected to RCLKI.
Signal Name:
RPOSI
Signal Description:
Receive Positive-Data Input
Signal Type:
Input
Sampled on the falling edge of RCLKI for data to be clocked through the receive-side framer. RPOSI and RNEGI
can be connected together for an NRZ interface. Can be internally connected to RPOSO by connecting the LIUC
pin high.
Signal Name:
RNEGI
Signal Description:
Receive Negative-Data Input
Signal Type:
Input
Sampled on the falling edge of RCLKI for data to be clocked through the receive-side framer. RPOSI and RNEGI
can be connected together for an NRZ interface. Can be internally connected to RNEGO by connecting the LIUC
pin high.
Signal Name:
RCLKI
Signal Description:
Receive Clock Input
Signal Type:
Input
Clock used to clock data through the receive-side framer. This pin is normally connected to RCLKO. Can be
internally connected to RCLKO by connecting the LIUC pin high.
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DS2156
3.2
UTOPIA Bus
3.2.1 Receive Side
Signal Name:
UR-ADDR0 to UR-ADDR4
Signal Description:
Receive UTOPIA Address
Signal Type:
Input
5-bit UTOPIA address bus driven from ATM layer to select the appropriate UTOPIA port. RX_UTOP_ADDR4 is
the MSB; RX_UTOP_ADDR0 is the LSB.
Signal Name:
UR-ENB
Signal Description:
Receive UTOPIA Enable
Signal Type:
Input
Active-low signal asserted by the ATM layer to indicate that UR-DATAx and UR-SOC are sampled at the end of
the next cycle.
Signal Name:
UR-SOC
Signal Description:
Receive UTOPIA Start of Cell
Signal Type:
Output
Active-high signal asserted by the DS2156 when UR-DATAx contains the first valid byte of a cell and is enabled
only in cycles following those with UR-ENB asserted and cell transfer is in progress.
Signal Name:
UR-DATA0 to UR-DATA7
Signal Description:
Receive UTOPIA Data Bus
Signal Type:
Output
This byte-wide data bus is driven by the DS2156 in response to the selection of one of the UTOPIA ports by the
ATM layer for cell transfer. This bus is tri-statable and is enabled only in cycles following those with UR-ENB
asserted and cell transfer is in progress for a port. UR-DATA7 is the MSB; UR-DATA0 is the LSB.
Signal Name:
UR-CLAV
Signal Description:
Receive UTOPIA Cell Available
Signal Type:
Output
The active-high UR-CLAV signal is asserted if a complete cell is available for transfer to the ATM layer for the
polled port. If UR-ADDRx does not match with any one of UTOPIA port addresses, this signal is tri-stated at the
chip level using the control lines detailed below. UR-CLAV0 is driven in multiplexed bus with 1CLAV polling
mode as well as direct status mode.
Signal Name:
UR-CLK
Signal Description:
Receive UTOPIA Clock
Signal Type:
Input
Receive UTOPIA bus clock.
26 of 265
DS2156
3.2.2 Transmit Side
Signal Name:
UT-ADDR0 to UT-ADDR4
Signal Description:
Transmit UTOPIA Address
Signal Type:
Input
This 5-bit wide bus is driven by the ATM layer to poll and select the appropriate UTOPIA port. UT-ADDR4 is the
MSB; UT-ADDR0 is the LSB.
Signal Name:
UT-ENB
Signal Description:
Transmit UTOPIA Enable
Signal Type:
Input
Active-low enable signal asserted by ATM layer during cycles when UT-DATAx contains valid cell data.
Signal Name:
UT-SOC
Signal Description:
Transmit UTOPIA Start of Cell
Signal Type:
Input
Active-high signal asserted by ATM layer when UT-DATAx contains the first valid byte of the cell.
Signal Name:
UT-DATA0 to UT-DATA7
Signal Description:
Transmit UTOPIA Data Bus
Signal Type:
Input
Byte-wide true data driven from ATM layer to one of the selected ports. UT-DATA7 is the MSB; UT-DATA0 is
the LSB.
Signal Name:
UT-CLAV
Signal Description:
Transmit UTOPIA Cell Available
Signal Type:
Output
This active-high UT-CLAV signal is asserted by the DS2156 if it has a cell space available to accommodate a
complete cell from the ATM layer to the polled port.
Signal Name:
UT-2CLAV
Signal Description:
Transmit UTOPIA 2 Cells Available
Signal Type:
Output
This active-high signal is asserted by the DS2156 to indicate that the transmitter can accommodate two cells. UT2CLAV0 is driven in multiplexed bus with 1CLAV mode as well as direct status mode for port 0. The timing of
this signal follows as that of UT-CLAV. This bus is not tri-statable.
Signal Name:
UT-UTDO
Signal Description:
UTOPIA Transmit Data Output
Signal Type:
Output
Access to the data prior to the transmit formatter. Updated on the rising edge of TCLK. This output is normally
connected to TDATA.
Signal Name:
UT-CLK
Signal Description:
Receive UTOPIA Clock
Signal Type:
Input
Transmit UTOPIA bus clock.
27 of 265
DS2156
3.3
Parallel Control Port Pins
INT
Signal Name:
Signal Description:
Interrupt
Signal Type:
Output
Flags host controller during conditions and events defined in the status registers. Active-low, open-drain output.
Signal Name:
TSTRST
Signal Description:
Tri-State Control and Device Reset
Signal Type:
Input
A dual function pin. A 0-to-1 transition issues a hardware reset to the DS2156 register set. A reset clears all
configuration registers. Configuration register contents are set to 0. Leaving TSTRST high tri-states all output and
I/O pins (including the parallel control port). Set low for normal operation. Useful in board-level testing.
MUX
Signal Name:
Signal Description:
Bus Operation
Signal Type:
Input
Set low to select nonmultiplexed bus operation. Set high to select multiplexed bus operation.
Signal Name:
AD0 to AD7
Signal Description:
Data Bus [D0 to D7] or Address/Data Bus
Signal Type:
Input/Output
In nonmultiplexed bus operation (MUX = 0), these serve as the data bus. In multiplexed bus operation (MUX = 1),
these pins serve as an 8-bit multiplexed address/data bus.
Signal Name:
A0 to A6
Signal Description:
Address Bus
Signal Type:
Input
In nonmultiplexed bus operation (MUX = 0), these serve as the address bus. In multiplexed bus operation
(MUX = 1), these pins are not used and should be connected low.
Signal Name:
BTS
Signal Description:
Bus Type Select
Signal Type:
Input
Strap high to select Motorola bus timing; strap low to select Intel bus timing. This pin controls the function of the
RD (DS), ALE (AS), and WR (R/W) pins.
If BTS = 1, then these pins assume the function listed in parentheses ().
Signal Name:
RD (DS)
Signal Description:
Read Input, Data Strobe
Signal Type:
Input
RD and DS are active-low signals. DS active HIGH when MUX = 1. See Bus Timing Diagrams.
28 of 265
DS2156
CS
Signal Name:
Signal Description:
Chip Select
Signal Type:
Input
Must be low to read or write to the device. CS is an active-low signal.
Signal Name:
ALE(AS)/A7
Signal Description:
Address Latch Enable (Address Strobe) or A7
Signal Type:
Input
In nonmultiplexed bus operation (MUX = 0), serves as the upper address bit. In multiplexed bus operation
(MUX = 1), serves to demultiplex the bus on a positive-going edge.
Signal Name:
WR (R/W)
Signal Description:
Write Input(Read/Write)
Signal Type:
Input
WR is an active-low signal.
Signal Name:
TUSEL
Signal Description:
TDM/UTOPIA Backplane Select
Signal Type:
Input
Low to enable TDM backplane. High to enable UTOPIA backplane.
3.4
Extended System Information Bus
Signal Name:
ESIBS0
Signal Description:
Extended System Information Bus Select 0
Signal Type:
Input/Output
Used to group two to eight DS2156s into a bus-sharing mode for alarm and status reporting. See Section 29 for
more details.
Signal Name:
ESIBS1
Signal Description:
Extended System Information Bus Select 1
Signal Type:
Input/Output
Used to group two to eight DS2156s into a bus-sharing mode for alarm and status reporting. See Section 29 for
more details.
Signal Name:
ESIBRD
Signal Description:
Extended System Information Bus Read
Signal Type:
Input/Output
Used to group two to eight DS2156s into a bus-sharing mode for alarm and status reporting. See Section 29 for
more details.
29 of 265
DS2156
3.5
User Output Port Pins
Signal Name:
UOP0
Signal Description:
User Output Port 0
Signal Type:
Output
This output port pin can be set low or high by the CCR4.0 control bit. This pin is forced low on power-up and after
any device reset.
Signal Name:
UOP1
Signal Description:
User Output Port 1
Signal Type:
Output
This output port pin can be set low or high by the CCR4.1 control bit. This pin is forced low on power-up and after
any device reset.
Signal Name:
UOP2
Signal Description:
User Output Port 2
Signal Type:
Output
This output port pin can be set low or high by the CCR4.2 control bit. This pin is forced low on power-up and after
any device reset.
Signal Name:
UOP3
Signal Description:
User Output Port 3
Signal Type:
Output
This output port pin can be set low or high by the CCR4.3 control bit. This pin is forced low on power-up and after
any device reset.
30 of 265
DS2156
3.6
JTAG Test Access Port Pins
Signal Name:
Signal Description:
Signal Type:
JTRST
IEEE 1149.1 Test Reset
Input
JTRST is used to asynchronously reset the test access port controller. After power-up, JTRST must be toggled from
low to high. This action sets the device into the JTAG DEVICE ID mode. Normal device operation is restored by
pulling JTRST low. JTRST is pulled high internally by a 10kΩ resistor operation.
Signal Name:
JTMS
Signal Description:
IEEE 1149.1 Test Mode Select
Signal Type:
Input
This pin is sampled on the rising edge of JTCLK and is used to place the test access port into the various defined
IEEE 1149.1 states. This pin has a 10kΩ pullup resistor.
Signal Name:
JTCLK
Signal Description:
IEEE 1149.1 Test Clock Signal
Signal Type:
Input
This signal is used to shift data into JTDI on the rising edge and out of JTDO on the falling edge.
Signal Name:
JTDI
Signal Description:
IEEE 1149.1 Test Data Input
Signal Type:
Input
Test instructions and data are clocked into this pin on the rising edge of JTCLK. This pin has a 10kΩ pullup
resistor.
Signal Name:
JTDO
Signal Description:
IEEE 1149.1 Test Data Output
Signal Type:
Output
Test instructions and data are clocked out of this pin on the falling edge of JTCLK. If not used, this pin should be
left unconnected.
31 of 265
DS2156
3.7
Line Interface Pins
Signal Name:
MCLK
Signal Description:
Signal Type:
Master Clock Input
Input
A (50ppm) clock source is applied at this pin. This clock is used internally for both clock/data recovery and for the
jitter attenuator for T1 and E1 modes. A quartz crystal of 2.048MHz can be applied across MCLK and XTALD
instead of the clock source. The clock rate can be 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz. When using
the DS2156 in T1-only operation, a 1.544MHz (50ppm) clock source can be used.
Signal Name:
XTALD
Signal Description:
Signal Type:
Quartz Crystal Driver
Output
A quartz crystal of 2.048MHz (optional 1.544MHz in T1-only operation) can be applied across MCLK and
XTALD instead of a clock source at MCLK. Leave open circuited if a clock source is applied at MCLK.
Signal Name:
8XCLK
Signal Description:
Eight Times Clock (8x)
Signal Type:
Output
An 8x clock that is locked to the recovered network clock provided from the clock/data recovery block (if
the jitter attenuator is enabled on the receive side) or from the TCLKI pin (if the jitter attenuator is
enabled on the transmit side).
Signal Name:
LIUC
Signal Description:
Signal Type:
Line Interface Connect
Input
Connect low to separate the line interface circuitry from the framer/formatter circuitry and activate the
TPOSI/TNEGI/TCLKI/RPOSI/RNEGI/RCLKI pins. Connect high to connect the line interface circuitry to the
framer/formatter circuitry and deactivate the TPOSI/TNEGI/TCLKI/RPOSI/RNEGI/RCLKI pins. When LIUC is
connected high, the TPOSI/TNEGI/TCLKI/RPOSI/RNEGI/RCLKI pins should be connected low.
Signal Name:
RTIP and RRING
Signal Description:
Signal Type:
Receive Tip and Ring
Input
Analog inputs for clock recovery circuitry. These pins connect through a 1:1 transformer to the network. See
Section 23 for details.
Signal Name:
TTIP and TRING
Signal Description:
Signal Type:
Transmit Tip and Ring
Output
Analog line driver outputs. These pins connect through a 1:2 step-up transformer to the network. See Section 23 for
details.
32 of 265
DS2156
3.8
Supply Pins
Signal Name:
DVDD
Signal Description:
Digital Positive Supply
Signal Type:
Supply
3.3V ±5%. Should be connected to the RVDD and TVDD pins.
Signal Name:
RVDD
Signal Description:
Receive Analog Positive Supply
Signal Type:
Supply
3.3V ±5%. Should be connected to the DVDD and TVDD pins.
Signal Name:
TVDD
Signal Description:
Transmit Analog Positive Supply
Signal Type:
Supply
3.3V ±5%. Should be connected to the RVDD and DVDD pins.
Signal Name:
DVSS
Signal Description:
Digital Signal Ground
Signal Type:
Supply
Should be connected to the RVSS and TVSS pins.
Signal Name:
RVSS
Signal Description:
Receive Analog Signal Ground
Signal Type:
Supply
0V. Should be connected to DVSS and TVSS.
Signal Name:
TVSS
Signal Description:
Transmit Analog Signal Ground
Signal Type:
Supply
0V. Should be connected to DVSS and RVSS.
33 of 265
DS2156
3.9
L and G Package Pinout
The DS2156 is available in either a 100-pin LQFP (L) or 10mm CSBGA, 0.8mm pitch (G) package.
Table 3-A. Pin Description Sorted by Pin Number (TDM Backplane Enabled)
BOLD entries indicate pins that have an alternate function when UTOPIA bus interface is enabled.
PIN
LQFP
CSBGA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19, 20, 24
21
22
23
25
26
27, 28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44, 61, 81, 83
45, 60, 80, 84
46
47
48
A1
B2
C3
B1
D4
C2
C1
D3
D2
D1
E3
E2
E1
E4
E5
F1
F2
F3
F4, G1, J1
G2
H1
G3
H2
K1
J2, H3
K2
G4
J3
K3
H4
J4
K4
H5
J5
K5
G5
F5
K6
J6
H6
K7, F8, B8, C7
G6, G10, D7, B7
J7
K8
H7
SYMBOL
TYPE
RCHBLK
JTMS
BPCLK
JTCLK
JTRST
RCL
JTDI
UOP0
UOP1
JTDO
BTS
LIUC
8XCLK
TSTRST
UOP2
RTIP
RRING
RVDD
RVSS
MCLK
XTALD
UOP3
INT
TUSEL
N.C.
TTIP
TVSS
TVDD
TRING
TCHBLK
TLCLK
TLINK
ESIBS0
TSYNC
TPOSI
TNEGI
TCLKI
TCLKO
TNEGO
TPOSO
DVDD
DVSS
TCLK
TSER
TSIG
O
I
O
I
I
O
I
O
O
O
I
I
O
I
O
I
I
—
—
I
O
O
O
—
—
O
–
–
O
O
O
I
I/O
I/O
I
I
I
O
O
O
—
—
I
I
I
34 of 265
FUNCTION
Receive Channel Block
IEEE 1149.1 Test Mode Select
Backplane Clock
IEEE 1149.1 Test Clock Signal
IEEE 1149.1 Test Reset
Receive Carrier Loss
IEEE 1149.1 Test Data Input
User Output 0
User Output 1
IEEE 1149.1 Test Data Output
Bus Type Select
Line Interface Connect
Eight Times Clock
Test/Reset
User Output 2
Receive Analog Tip Input
Receive Analog Ring Input
Receive Analog Positive Supply
Receive Analog Signal Ground
Master Clock Input
Quartz Crystal Driver
User Output 3
Interrupt
Backplane Interface Select
Reserved for Factory Test
Transmit Analog Tip Output
Transmit Analog Signal Ground
Transmit Analog Positive Supply
Transmit Analog Ring Output
Transmit Channel Block
Transmit Link Clock
Transmit Link Data
Extended System Information Bus 0
Transmit Sync
Transmit Positive-Data Input
Transmit Negative-Data Input
Transmit Clock Input
Transmit Clock Output
Transmit Negative-Data Output
Transmit Positive-Data Output
Digital Positive Supply
Digital Signal Ground
Transmit Clock
Transmit Serial Data
Transmit Signaling Input
DS2156
PIN
LQFP
CSBGA
49
50
51
52
53
54
55
56
57
58
59
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
82
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
K9
J8
K10
J9
H8
J10
G7
H9
H10
G8
G9
F9
F10
F7
F6
E10
E9
E8
D10
E7
D9
C10
D8
B10
C9
A10
B9
C8
A9
A8
A7
C6
B6
A6
D6
E6
A5
B5
C5
A4
D5
B4
A3
C4
A2
B3
SYMBOL
TYPE
TESO
TDATA
TSYSCLK
TSSYNC
TCHCLK
ESIBS1
MUX
D0/AD0
D1/AD1
D2/AD2
D3/AD3
D4/AD4
D5/AD5
D6/AD6
D7/AD7
A0
A1
A2
A3
A4
A5
A6
ALE (AS)/A7
RD (DS)
CS
ESIBRD
WR (R/W)
RLINK
RLCLK
RCLK
RDATA
RPOSI
RNEGI
RCLKI
RCLKO
RNEGO
RPOSO
RCHCLK
RSIGF
RSIG
RSER
RMSYNC
RFSYNC
RSYNC
RLOS/LOTC
RSYSCLK
O
I
I
I
O
I/O
I
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I
I
I
I
I
I
I
I
I
I
I/O
I
O
O
O
O
I
I
I
O
O
O
O
O
O
O
O
O
I/O
O
I
35 of 265
FUNCTION
Transmit Elastic Store Output
Transmit Data
Transmit System Clock
Transmit System Sync
Transmit Channel Clock
Extended System Information Bus 1
Bus Operation
Data Bus Bit0/Address/Data Bus Bit 0
Data Bus Bit1/Address/Data Bus Bit 1
Data Bus Bit 2/Address/Data Bus 2
Data Bus Bit 3/Address/Data Bus Bit 3
Data Bus Bit4/Address/Data Bus Bit 4
Data Bus Bit 5/Address/Data Bus Bit 5
Data Bus Bit 6/Address/Data Bus Bit 6
Data Bus Bit 7/Address/Data Bus Bit 7
Address Bus Bit 0
Address Bus Bit 1
Address Bus Bit 2
Address Bus Bit 3
Address Bus Bit 4
Address Bus Bit 5
Address Bus Bit 6
Address Latch Enable/Address Bus Bit 7
Read Input (Data Strobe)
Chip Select
Extended System Information Bus Read
Write Input (Read/Write)
Receive Link Data
Receive Link Clock
Receive Clock
Receive Data
Receive Positive-Data Input
Receive Negative-Data Input
Receive Clock Input
Receive Clock Output
Receive Negative-Data Output
Receive Positive-Data Output
Receive Channel Clock
Receive Signaling-Freeze Output
Receive Signaling Output
Receive Serial Data
Receive Multiframe Sync
Receive Frame Sync
Receive Sync
Receive Loss-of-Sync/Loss-of-Transmit Clock
Receive System Clock
DS2156
Table 3-B. Pin Description Sorted by Pin Number (UTOPIA Backplane
Enabled)
BOLD entries indicate pins that have an alternate function when the TDM bus interface is enabled.
PIN
LQFP
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19, 20, 24
21
22
23
25
26
27, 28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44, 61, 81, 83
45, 60, 80, 84
46
47
48
CSBGA
A1
B2
C3
B1
D4
C2
C1
D3
D2
D1
E3
E2
E1
E4
E5
F1
F2
F3
F4, G1, J1
G2
H1
G3
H2
K1
J2, H3
K2
G4
J3
K3
H4
J4
K4
H5
J5
K5
G5
F5
K6
J6
H6
K7, F8, B8,
C7
G6, G10, D7,
B7
J7
K8
H7
SYMBOL
TYPE
UR-SOC
JTMS
UR-ENB
JTCLK
JTRST
RCL
JTDI
UT-SOC
UT-ENB
JTDO
BTS
UT-CLAV
8XCLK
TSTRST
UOP2
RTIP
RRING
RVDD
RVSS
MCLK
XTALD
UT-ADDR0
INT
TUSEL
N.C.
TTIP
TVSS
TVDD
TRING
UT-ADDR1
UT-ADDR2
UT-ADDR3
ESIBS0
TSYNC
UT-ADDR4
UT-DATA0
UT-DATA1
UT-DATA2
UT-DATA3
UT-DATA4
O
I
I
I
I
O
I
I
I
O
I
O
O
I
I
I
—
—
I
O
I
O
I
—
O
—
—
O
I
I
I
I/O
I/O
I
I
I
I
I
I
UTOPIA Receive Start of Cell
IEEE 1149.1 Test Mode Select
UTOPIA Receive Enable
IEEE 1149.1 Test Clock Signal
IEEE 1149.1 Test Reset
Receive Carrier Loss
IEEE 1149.1 Test Data Input
UTOPIA Transmit Start of Cell
UTOPIA Transmit Enable
IEEE 1149.1 Test Data Output
Bus Type Select
UTOPIA Transmit Cell Available
Eight Times Clock
Test/Reset
User Output Pin 2
Receive Analog Tip Input
Receive Analog Ring Input
Receive Analog Positive Supply
Receive Analog Signal Ground
Master Clock Input
Quartz Crystal Driver
UTOPIA Transmit Address Bus Bit 0
Interrupt
Backplane Interface Select
No Connection. Reserved for Factory Test
Transmit Analog Tip Output
Transmit Analog Signal Ground
Transmit Analog Positive Supply
Transmit Analog Ring Output
UTOPIA Transmit Address Bus Bit 1
UTOPIA Transmit Address Bus Bit 2
UTOPIA Transmit Address Bus Bit 3
Extended System Information Bus 0
Transmit Sync
UTOPIA Transmit Address Bus Bit 4
UTOPIA Transmit Data Bus Bit 0
UTOPIA Transmit Data Bus Bit 1
UTOPIA Transmit Data Bus Bit 2
UTOPIA Transmit Data Bus Bit 3
UTOPIA Transmit Data Bus Bit 4
DVDD
—
Digital Positive Supply
DVSS
—
Digital Signal Ground
TCLK
UT-DATA5
UT-DATA6
I
I
I
36 of 265
DESCRIPTION
Transmit Clock
UTOPIA Transmit Data Bus Bit 5
UTOPIA Transmit Data Bus Bit 6
DS2156
PIN
LQFP
49
50
51
52
53
54
55
56
57
58
59
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
82
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
CSBGA
K9
J8
K10
J9
H8
J10
G7
H9
H10
G8
G9
F9
F10
F7
F6
E10
E9
E8
D10
E7
D9
C10
D8
B10
C9
A10
B9
C8
A9
A8
A7
C6
B6
A6
D6
E6
A5
B5
C5
A4
D5
B4
A3
C4
A2
B3
SYMBOL
TYPE
UT-UTDO
TDATA
UT-DATA7
UT-CLK
UR-CLK
ESIBS1
MUX
D0/AD0
D1/AD1
D2/AD2
D3/AD3
D4/AD4
D5/AD5
D6/AD6
D7/AD7
A0
A1
A2
A3
A4
A5
A6
ALE (AS)/A7
RD (DS)
CS
ESIBRD
WR (R/W)
UR-DATA0
UR-DATA1
RCLK
RDATA
UR-DATA2
UR-DATA3
UR-DATA4
UR-DATA5
UR-DATA6
UR-DATA7
UR-ADDR0
UR-ADDR1
UR-ADDR2
UR-CLAV
UR-ADDR3
UR-ADDR4
RSYNC
RLOS/LOTC
UT-2CLAV
O
I
I
I
I
I/O
I
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I
I
I
I
I
I
I
I
I
I
I/O
I
O
O
O
O
O
O
O
O
O
O
I
I
I
O
I
I
I/O
O
O
37 of 265
DESCRIPTION
UTOPIA Transmit Data Output
Transmit Data
UTOPIA Transmit Data Bus Bit 7
UTOPIA Transmit Clock
UTOPIA Receive Clock
Extended System Information Bus 1
Bus Operation
Data Bus Bit0/Address/Data Bus Bit 0
Data Bus Bit1/Address/Data Bus Bit 1
Data Bus Bit 2/Address/Data Bus 2
Data Bus Bit 3/Address/Data Bus Bit 3
Data Bus Bit4/Address/Data Bus Bit 4
Data Bus Bit 5/Address/Data Bus Bit 5
Data Bus Bit 6/Address/Data Bus Bit 6
Data Bus Bit 7/Address/Data Bus Bit 7
Address Bus Bit 0
Address Bus Bit 1
Address Bus Bit 2
Address Bus Bit 3
Address Bus Bit 4
Address Bus Bit 5
Address Bus Bit 6
Address Latch Enable/Address Bus Bit 7
Read Input (Data Strobe)
Chip Select
Extended System Information Bus Read
Write Input (Read/Write)
UTOPIA Receive Data Bus Bit 0
UTOPIA Receive Data Bus Bit 1
Receive Clock
Receive Data
UTOPIA Receive Data Bus Bit 2
UTOPIA Receive Data Bus Bit 3
UTOPIA Receive Data Bus Bit 4
UTOPIA Receive Data Bus Bit 5
UTOPIA Receive Data Bus Bit 6
UTOPIA Receive Data Bus Bit 7
UTOPIA Receive Address Bus Bit 0
UTOPIA Receive Address Bus Bit 1
UTOPIA Receive Address Bus Bit 2
UTOPIA Receive Cell Available
UTOPIA Receive Address Bus Bit 3
UTOPIA Receive Address Bus Bit 4
Receive Sync
Receive Loss-of-Sync/Loss-of-Transmit Clock
UTOPIA Transmit 2 Cells Available
DS2156
3.10 10mm CSBGA Pin Configuration
Figure 3-1. 10mm CSBGA Pin Configuration (TDM Signals Shown)
1
A
B
C
D
E
F
G
H
J
K
2
3
4
5
6
7
8
9
10
RCHBLK
RLOS/
LOTC
RFSYNC
RSIG
RPOSO
RCLKI
RDATA
RCLK
RLCLK
ESIBRD
JTCLK
JTMS
RSYSCLK
RMSYNC
RCHCLK
RNEGI
DVSS
DVDD
WR
(R/W)
RD
(DS)
JTDI
RCL
BPCLK
RSYNC
RSIGF
RPOSI
DVDD
RLINK
CS
A6
JTDO
UOP1
UOP0
JTRST
RSER
RCLKO
DVSS
ALE(AS)/
A7
A5
A3
8XCLK
LIUC
BTS
TSTRST
UOP2
RNEGO
A4
A2
A1
A0
RTIP
RRING
RVDD
RVSS
TCLKI
D7/AD7
D6/AD6
DVDD
D4/AD4
D5/AD5
RVSS
MCLK
UOP3
TVSS
TNEGI
DVSS
MUX
D2/AD2
D3/AD3
DVSS
XTALD
INT
N.C.
TCHBLK
ESIBS0
TPOSO
TSIG
TCHCLK
D0/AD0
D1/AD1
RVSS
N.C.
TVDD
TLCLK
TSYNC
TNEGO
TCLK
TDATA
TSSYNC
ESIBS1
TUSEL
TTIP
TRING
TLINK
TPOSI
TCLKO
DVDD
TSER
TESO
TSYSCLK
TOP VIEW
38 of 265
DS2156
4. PARALLEL PORT
The SCT is controlled by either a nonmultiplexed (MUX = 0) or a multiplexed (MUX = 1) bus through an
external microcontroller or microprocessor. The SCT can operate with either Intel or Motorola bus timing
configurations. If the BTS pin is connected low, Intel timing is selected; if connected high, Motorola
timing is selected. All Motorola bus signals are listed in parentheses (). See the timing diagrams in AC
Electrical Characteristics in Section 36 for more details.
4.1
Register Map
Table 4-A. Register Map Sorted by Address
ADDRESS
xxh
00
01
02
03
04
05
06
07
08
09
0A
0B
0C
0D
0E
0F
10
11
12
13
14
15
16
17
18
19
1A
1B
1C
1D
1E
1F
20
21
22
23
24
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
R
R/W
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
REGISTER NAME
Master Mode Register
I/O Configuration Register 1
I/O Configuration Register 2
T1 Receive Control Register 1
T1 Receive Control Register 2
T1 Transmit Control Register 1
T1 Transmit Control Register 2
T1 Common Control Register 1
Software Signaling Insertion Enable 1
Software Signaling Insertion Enable 2
Software Signaling Insertion Enable 3
Software Signaling Insertion Enable 4
T1 Receive Digital Milliwatt Enable Register 1
T1 Receive Digital Milliwatt Enable Register 2
T1 Receive Digital Milliwatt Enable Register 3
Device Identification Register
Information Register 1
Information Register 2
Information Register 3
Interrupt Information Register 1
Interrupt Information Register 2
Status Register 1
Interrupt Mask Register 1
Status Register 2
Interrupt Mask Register 2
Status Register 3
Interrupt Mask Register 3
Status Register 4
Interrupt Mask Register 4
Status Register 5
Interrupt Mask Register 5
Status Register 6
Interrupt Mask Register 6
Status Register 7
Interrupt Mask Register 7
Status Register 8
39 of 265
SYMBOL
PAGE
MSTRREG
IOCR1
IOCR2
T1RCR1
T1RCR2
T1TCR1
T1TCR2
T1CCR1
SSIE1
SSIE2
SSIE3
SSIE4
T1RDMR1
T1RDMR2
T1RDMR3
IDR
INFO1
INFO2
INFO3
49
76
77
53
54
55
56
57
100
100
101
101
59
59
59
70
60
158
67
IIR1
IIR2
SR1
IMR1
SR2
IMR2
SR3
IMR3
SR4
IMR4
SR5
IMR5
SR6
IMR6
SR7
IMR7
SR8
51
51
159
160
70
71
72
73
74
75
113
113
142
143
142
143
119
DS2156
ADDRESS
xxh
R/W
REGISTER NAME
SYMBOL
PAGE
25
26
27
28
29
2A
2B
2C
2D
2E
2F
30
31
32
33
34
35
36
37
38
39
3A
3B
3C
3D
3E
3F
40
41
42
43
44
45
46
47
48
49
4A
4B
4C
4D
4E
4F
50
51
52
53
R/W
R/W
R/W
R/W
W
W
W
W
R/W
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
R
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Interrupt Mask Register 8
Status Register 9
Interrupt Mask Register 9
Per-Channel Pointer Register
Per-Channel Data Register 1
Per-Channel Data Register 2
Per-Channel Data Register 3
Per-Channel Data Register 4
Information Register 4
Information Register 5
Information Register 6
Information Register 7
HDLC #1 Receive Control
HDLC #2 Receive Control
E1 Receive Control Register 1
E1 Receive Control Register 2
E1 Transmit Control Register 1
E1 Transmit Control Register 2
BOC Control Register
Receive Signaling Change-of-State Information 1
Receive Signaling Change-of-State Information 2
Receive Signaling Change-of-State Information 3
Receive Signaling Change-of-State Information 4
Receive Signaling Change-of-State Interrupt Enable 1
Receive Signaling Change-of-State Interrupt Enable 2
Receive Signaling Change-of-State Interrupt Enable 3
Receive Signaling Change-of-State Interrupt Enable 4
Signaling Control Register
Error Count Configuration Register
Line-Code Violation Count Register 1
Line-Code Violation Count Register 2
Path Code Violation Count Register 1
Path Code Violation Count Register 2
Frames Out-of-Sync Count Register 1
Frames Out-of-Sync Count Register 2
E-Bit Count Register 1
E-Bit Count Register 2
Loopback Control Register
Per-Channel Loopback Enable Register 1
Per-Channel Loopback Enable Register 2
Per-Channel Loopback Enable Register 3
Per-Channel Loopback Enable Register 4
Elastic Store Control Register
Transmit Signaling Register 1
Transmit Signaling Register 2
Transmit Signaling Register 3
Transmit Signaling Register 4
IMR8
SR9
IMR9
PCPR
PCDR1
PCDR2
PCDR3
PCDR4
INFO4
INFO5
INFO6
INFO7
H1RC
H2RC
E1RCR1
E1RCR2
E1TCR1
E1TCR2
BOCC
RSINFO1
RSINFO2
RSINFO3
RSINFO4
RSCSE1
RSCSE2
RSCSE3
RSCSE4
SIGCR
ERCNT
LCVCR1
LCVCR2
PCVCR1
PCVCR2
FOSCR1
FOSCR2
EBCR1
EBCR2
LBCR
PCLR1
PCLR2
PCLR3
PCLR4
ESCR
TS1
TS2
TS3
TS4
119
205
206
46
47
47
47
47
144
144
144
67
136
136
62
63
64
65
118
95
95
95
95
95
95
95
95
92
82
84
84
85
85
86
86
87
87
78
80
80
81
81
112
98
98
98
98
40 of 265
DS2156
ADDRESS
xxh
54
55
56
57
58
59
5A
5B
5C
5D
5E
5F
60
61
62
63
64
65
66
67
68
69
6A
6B
6C
6D
6E
6F
70
71
72
73
74
75
76
77
78
79
7A
7B
7C
7D
7E
7F
80
81
82
R/W
REGISTER NAME
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R
R/W
R
R/W
R/W
R/W
R/W
Transmit Signaling Register 5
Transmit Signaling Register 6
Transmit Signaling Register 7
Transmit Signaling Register 8
Transmit Signaling Register 9
Transmit Signaling Register 10
Transmit Signaling Register 11
Transmit Signaling Register 12
Transmit Signaling Register 13
Transmit Signaling Register 14
Transmit Signaling Register 15
Transmit Signaling Register 16
Receive Signaling Register 1
Receive Signaling Register 2
Receive Signaling Register 3
Receive Signaling Register 4
Receive Signaling Register 5
Receive Signaling Register 6
Receive Signaling Register 7
Receive Signaling Register 8
Receive Signaling Register 9
Receive Signaling Register 10
Receive Signaling Register 11
Receive Signaling Register 12
Receive Signaling Register 13
Receive Signaling Register 14
Receive Signaling Register 15
Receive Signaling Register 16
Common Control Register 1
Common Control Register 2
Common Control Register 3
Common Control Register 4
Transmit Channel Monitor Select
Transmit DS0 Monitor Register
Receive Channel Monitor Select
Receive DS0 Monitor Register
Line Interface Control 1
Line Interface Control 2
Line Interface Control 3
Line Interface Control 4
W
R/W
R/W
R/W
R/W
Idle Array Address Register
Per-Channel Idle Code Value Register
Transmit Idle Code Enable Register 1
Transmit Idle Code Enable Register 2
Transmit Idle Code Enable Register 3
41 of 265
SYMBOL
PAGE
TS5
TS6
TS7
TS8
TS9
TS10
TS11
TS12
TS13
TS14
TS15
TS16
RS1
RS2
RS3
RS4
RS5
RS6
RS7
RS8
RS9
RS10
RS11
RS12
RS13
RS14
RS15
RS16
CCR1
CCR2
CCR3
CCR4
TDS0SEL
TDS0M
RDS0SEL
RDS0M
LIC1
LIC2
LIC3
LIC4
98
98
98
98
98
98
98
98
98
98
98
98
93
93
93
93
93
93
93
93
93
93
93
93
93
93
93
93
69
222
223
224
88
88
89
89
154
155
156
157
IAAR
PCICR
TCICE1
TCICE2
TCICE3
105
105
106
106
106
DS2156
ADDRESS
xxh
R/W
83
84
85
86
87
88
89
8A
8B
8C
8D
8E
8F
90
91
92
93
94
95
96
97
98
99
9A
9B
9C
9D
9E
9F
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
AA
AB
AC
AD
AE
AF
B0
B1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
W
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
W
R
R
R/W
R/W
REGISTER NAME
Transmit Idle Code Enable Register 4
Receive Idle Code Enable Register 1
Receive Idle Code Enable Register 2
Receive Idle Code Enable Register 3
Receive Idle Code Enable Register 4
Receive Channel Blocking Register 1
Receive Channel Blocking Register 2
Receive Channel Blocking Register 3
Receive Channel Blocking Register 4
Transmit Channel Blocking Register 1
Transmit Channel Blocking Register 2
Transmit Channel Blocking Register 3
Transmit Channel Blocking Register 4
HDLC #1 Transmit Control
HDLC #1 FIFO Control
HDLC #1 Receive Channel Select 1
HDLC #1 Receive Channel Select 2
HDLC #1 Receive Channel Select 3
HDLC #1 Receive Channel Select 4
HDLC #1 Receive Time Slot Bits/Sa Bits Select
HDLC #1 Transmit Channel Select1
HDLC #1 Transmit Channel Select2
HDLC #1 Transmit Channel Select3
HDLC #1 Transmit Channel Select4
HDLC #1 Transmit Time Slot Bits/Sa Bits Select
HDLC #1 Receive Packet Bytes Available
HDLC #1 Transmit FIFO
HDLC #1 Receive FIFO
HDLC #1 Transmit FIFO Buffer Available
HDLC #2 Transmit Control
HDLC #2 FIFO Control
HDLC #2 Receive Channel Select 1
HDLC #2 Receive Channel Select 2
HDLC #2 Receive Channel Select 3
HDLC #2 Receive Channel Select 4
HDLC #2 Receive Time Slot Bits/Sa Bits Select
HDLC #2 Transmit Channel Select1
HDLC #2 Transmit Channel Select2
HDLC #2 Transmit Channel Select3
HDLC #2 Transmit Channel Select4
HDLC #2 Transmit Time Slot Bits/Sa Bits Select
HDLC #2 Receive Packet Bytes Available
HDLC #2 Transmit FIFO
HDLC #2 Receive FIFO
HDLC #2 Transmit FIFO Buffer Available
Extend System Information Bus Control Register 1
Extend System Information Bus Control Register 2
42 of 265
SYMBOL
PAGE
TCICE4
RCICE1
RCICE2
RCICE3
RCICE4
RCBR1
RCBR2
RCBR3
RCBR4
TCBR1
TCBR2
TCBR3
TCBR4
H1TC
H1FC
H1RCS1
H1RCS2
H1RCS3
H1RCS4
H1RTSBS
H1TCS1
H1TCS2
H1TCS3
H1TCS4
H1TTSBS
H1RPBA
H1TF
H1RF
H1TFBA
H2TC
H2FC
H2RCS1
H2RCS2
H2RCS3
H2RCS4
H2RTSBS
H2TCS1
H2TCS2
H2TCS3
H2TCS4
H2TTSBS
H2RPBA
H2TF
H2RF
H2TFBA
ESIBCR1
ESIBCR2
106
107
107
107
107
108
108
109
109
110
110
110
110
135
137
138
138
138
138
139
140
140
140
140
141
145
146
146
145
135
137
138
138
138
138
139
140
140
140
140
141
145
146
146
145
219
220
DS2156
ADDRESS
xxh
B2
B3
B4
B5
B6
B7
B8
B9
BA
BB
BC
BD
BE
BF
C0
C1
C2
C3
C4
C5
C6
C7
C8
C9
CA
CB
CC
CD
CE
CF
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
DA
DB
DC
DD
DE
DF
E0
R/W
REGISTER NAME
SYMBOL
PAGE
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
R/W
R/W
Extend System Information Bus Register 1
Extend System Information Bus Register 2
Extend System Information Bus Register 3
Extend System Information Bus Register 4
In-Band Code Control Register
Transmit Code Definition Register 1
Transmit Code Definition Register 2
Receive Up Code Definition Register 1
Receive Up Code Definition Register 2
Receive Down Code Definition Register 1
Receive Down Code Definition Register 2
In-Band Receive Spare Control Register
Receive Spare Code Definition Register 1
Receive Spare Code Definition Register 2
Receive FDL Register
Transmit FDL Register
Receive FDL Match Register 1
Receive FDL Match Register 2
ESIB1
ESIB2
ESIB3
ESIB4
IBCC
TCD1
TCD2
RUPCD1
RUPCD2
RDNCD1
RDNCD2
RSCC
RSCD1
RSCD2
RFDL
TFDL
RFDLM1
RFDLM2
221
221
221
221
195
196
196
197
197
198
198
199
200
200
148
149
148
148
R/W
R
R
R
R
R
R
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Interleave Bus Operation Control Register
Receive Align Frame Register
Receive Nonalign Frame Register
Receive Si Align Frame
Receive Si Nonalign Frame
Receive Remote Alarm Bits
Receive Sa4 Bits
Receive Sa5 Bits
Receive Sa6 Bits
Receive Sa7 Bits
Receive Sa8 Bits
Transmit Align Frame Register
Transmit Nonalign Frame Register
Transmit Si Align Frame
Transmit Si Nonalign Frame
Transmit Remote Alarm Bits
Transmit Sa4 Bits
Transmit Sa5 Bits
Transmit Sa6 Bits
Transmit Sa7 Bits
Transmit Sa8 Bits
Transmit Sa Bit Control Register
BERT Alternating Word Count Rate
BERT Repetitive Pattern Set Register 1
BERT Repetitive Pattern Set Register 2
BERT Repetitive Pattern Set Register 3
BERT Repetitive Pattern Set Register 4
BERT Control Register 1
IBOC
RAF
RNAF
RSiAF
RSiNAF
RRA
RSa4
RSa5
RSa6
RSa7
RSa8
TAF
TNAF
TSiAF
TSiNAF
TRA
TSa4
TSa5
TSa6
TSa7
TSa8
TSACR
BAWC
BRP1
BRP2
BRP3
BRP4
BC1
216
121
121
123
124
124
125
125
126
126
127
122
122
127
128
128
129
129
130
130
131
132
206
207
207
207
207
203
43 of 265
DS2156
ADDRESS
xxh
E1
E2
E3
E4
E5
E6
E7
E8
E9
EA
EB
EC
ED
EE
EF
F0*
F1–F9*
FA–FF*
R/W
REGISTER NAME
R/W
BERT Control Register 2
R
R
R
R
R
R
R
R/W
R/W
R/W
R/W
R
R
—
—
—
BERT Bit Count Register 1
BERT Bit Count Register 2
BERT Bit Count Register 3
BERT Bit Count Register 4
BERT Error Count Register 1
BERT Error Count Register 2
BERT Error Count Register 3
BERT Interface Control Register
Error Rate Control Register
Number-of-Errors 1
Number-of-Errors 2
Number-of-Errors Left 1
Number-of-Errors Left 2
Test Register
Test Register
Test Register
*TEST1 to TEST16 registers are used only by the factory.
44 of 265
SYMBOL
PAGE
BC2
204
BBC1
BBC2
BBC3
BBC4
BEC1
BEC2
BEC3
BIC
ERC
NOE1
NOE2
NOEL1
NOEL2
TEST
TEST
TEST
208
208
208
208
209
209
209
210
212
213
213
214
214
—
—
—
DS2156
4.2
UTOPIA Bus Registers
When the UTOPIA bus is enabled, register space 50h–6A is mapped to the UTOPIA function.
Table 4-B. UTOPIA Register Map
ADDRESS
xxh
50
51
52
53
54
55
56
57
58, 59,
5A–5F
60
61
62
63
64
65
66
67
68
69
6A
6B–6F
R/W
R/W
R/W
W
R
R
R/W
R/W
R/W
—
R/W
R/W
R/W
W
R
R
R
R
R
R
R/W
—
REGISTER
Transmit Configuration Register
Transmit PMON Counter-Latch Enable Register
Transmit Assigned Cell Counter MSB
Transmit Assigned Cell Counter LSB
Transmit Idle/Unassigned Payload Byte
Transmit HEC Error-Insertion Pattern
Transmit Control Register 1
Transmit Control Register 2
Reserved
Receive Configuration Register
Receive LCD Integration Period Register
Receive PMON Counter-Latch Enable Register
Receive Correctable HEC Latch Register
Receive Uncorrectable HEC MSB
Receive Uncorrectable HEC LSB
Receive Assigned Cell Counter MSB
Receive Assigned Cell Counter LSB
Receive Status Register
Receive Control Register 1
Receive Control Register 2
Reserved
45 of 265
SYMBOL
PAGE
U_TCFR
U_TPCLE
U_TACC1
U_TACC2
U_TIUPB
U_THEPR
U_TCR1
U_TCR2
182
183
183
183
184
184
185
186
—
—
U_RCFR
U_RLCDIP
U_RPCE
U_RCHEC
U_RUHEC1
U_RUHEC2
U_RACC1
U_RACC2
U_RSR
U_RCR1
U_RCR2
—
186
187
187
188
188
188
189
189
190
191
192
—
DS2156
5. SPECIAL PER-CHANNEL REGISTER OPERATION
Some of the features described in the data sheet that operate on a per-channel basis use a special method
for channel selection. There are five registers involved: per-channel pointer register (PCPR) and perchannel data registers 1–4 (PCDR1–4). The user selects which function or functions are to be applied on a
per-channel basis by setting the appropriate bit(s) in the PCPR register. The user then writes to the PCDR
registers to select the channels for that function. The following is an example of mapping the transmit and
receive BERT function to channels 9–12, 20, and 21.
Write
Write
Write
Write
Write
11h
00h
0fh
18h
00h
to
to
to
to
to
PCPR
PCDR1
PCDR2
PCDR3
PCDR4
The user may write to the PCDR1-4 with muliple functions in the PCPR register selected, but can only
read the values from the PCDR1-4 registers for a single function at a time. More information about how
to use these per-channel features can be found in their respective sections in the data sheet.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RSAOICS
0
PCPR
Per-Channel Pointer Register
28h
6
RSRCS
0
5
RFCS
0
4
BRCS
0
3
THSCS
0
2
PEICS
0
Bit 0/Bert Transmit Channel Select (BTCS)
Bit 1/Transmit Fractional Channel Select (TFCS)
Bit 2/Payload Error Insert Channel Select (PEICS)
Bit 3/Transmit Hardware Signaling Channel Select (THSCS)
Bit 4/Bert Receive Channel Select (BRCS)
Bit 5/Receive Fractional Channel Select (RFCS)
Bit 6/Receive Signaling Reinsertion Channel Select (RSRCS)
Bit 7/Receive Signaling All-Ones Insertion Channel Select (RSAOICS)
46 of 265
1
TFCS
0
0
BTCS
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
CH8
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
CH16
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
CH24
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
CH32
PCDR1
Per-Channel Data Register 1
29h
6
—
CH7
5
—
CH6
4
—
CH5
3
—
CH4
2
—
CH3
1
—
CH2
0
—
CH1
3
—
CH12
2
—
CH11
1
—
CH10
0
—
CH9
3
—
CH20
2
—
CH19
1
—
CH18
0
—
CH17
3
—
CH28
2
—
CH27
1
—
CH26
0
—
CH25
PCDR2
Per-Channel Data Register 2
2Ah
6
—
CH15
5
—
CH14
4
—
CH13
PCDR3
Per-Channel Data Register 3
2Bh
6
—
CH23
5
—
CH22
4
—
CH21
PCDR4
Per-Channel Data Register 4
2Ch
6
—
CH31
5
—
CH30
4
—
CH29
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DS2156
6. PROGRAMMING MODEL
The DS2156 register map is divided into three groups: T1 specific features, E1 specific features, and
common features. The typical programming sequence begins with issuing a reset to the DS2156, selecting
T1 or E1 operation in the master mode register, enabling T1 or E1 functions and enabling the common
functions. The act of resetting the DS2156 automatically clears all configuration and status registers.
Therefore, it is not necessary to load unused registers with 0s.
Figure 6-1. Programming Sequence
POWER-ON
ISSUE RESET
SELECT T1 OR E1 OPERATION
IN MASTER MODE REGISTER
PROGRAM E1 SPECIFIC REGISTERS
PROGRAM T1 SPECIFIC REGISTERS
PROGRAM COMMON REGISTERS
DS2156 OPERATIONAL
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DS2156
6.1
Power-Up Sequence
The DS2156 contains an on-chip power-up reset function that automatically clears the writeable register
space immediately after power is supplied to the DS2156. The user can issue a chip reset at any time.
Issuing a reset disrupts traffic flowing through the DS2156 until the device is reprogrammed. The reset
can be issued through hardware using the TSTRST pin or through software using the SFTRST function in
the master mode register. The LIRST (LIC2.6) should be toggled from 0 to 1 to reset the line interface
circuitry. (It takes the DS2156 about 40ms to recover from the LIRST bit being toggled.) Finally, after the
TSYSCLK and RSYSCLK inputs are stable, the receive and transmit elastic stores should be reset (this
step can be skipped if the elastic stores are disabled).
6.1.1 Master Mode Register
Register Name:
Register Description:
Register Address:
MSTRREG
Master Mode Register
00h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
URST
0
3
TEST1
0
2
TEST0
0
1
T1/E1
0
0
SFTRST
0
Bit 0/Software-Issued Reset (SFTRST). A 0-to-1 transition causes the register space in the DS2156 to be cleared.
A reset clears all configuration and status registers. The bit automatically clears itself when the reset has completed.
Bit 1/DS2156 Operating Mode (T1/E1). Used to select the operating mode of the framer/formatter (digital)
portion of the 2156. The operating mode of the LIU must also be programmed.
0 = T1 operation
1 = E1 operation
Bits 2, 3/Test Mode Bits (TEST0, TEST1). Test modes are used to force the output pins of the DS2156 into
known states. This can facilitate the checkout of assemblies during the manufacturing process and also be used to
isolate devices from shared buses.
TEST1
TEST0
Effect On Output Pins
0
0
1
1
0
1
0
1
Operate normally
Force all output pins into tri-state (including all I/O pins and parallel port pins)
Force all output pins low (including all I/O pins except parallel port pins)
Force all output pins high (including all I/O pins except parallel port pins)
Bit 4/UTOPIA Reset (URST). A 0-to-1 transition causes the UTOPIA interface to reset.
Bits 5 to 7/Unused, must be set to 0 for proper operation
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DS2156
6.2
Interrupt Handling
Various alarms, conditions, and events in the DS2156 can cause interrupts. For simplicity, these are all
referred to as events in this explanation. All status registers can be programmed to produce interrupts.
Each status register has an associated interrupt mask register. For example, SR1 (status register 1) has an
interrupt control register called IMR1 (interrupt mask register 1). Status registers are the only sources of
interrupts in the DS2156. On power-up, all writeable registers are automatically cleared. Since bits in the
IMRx registers have to be set = 1 to allow a particular event to cause an interrupt, no interrupts can occur
until the host selects which events are to product interrupts. Since there are potentially many sources of
interrupts on the DS2156, several features are available to help sort out and identify which event is
causing an interrupt. When an interrupt occurs, the host should first read the IIR1 and IIR2 registers
(interrupt information registers) to identify which status register (or registers) is producing the interrupt.
Once that is determined, the individual status register or registers can be examined to determine the exact
source. In multiple port configurations, two to eight DS2156s can be connected together by the 3-wire
ESIB feature. This allows multiple DS2156s to be interrogated by a single CPU port read cycle. The host
can determine the synchronization status, or interrupt status of up to eight devices with a single read. The
ESIB feature also allows the user to select from various events to be examined through this method. For
more information, see Section 29.
The U_RSR register in the UTOPIA sections works slightly different than all other status registers. Only
two of the bits in this register are capable of generating interrupts, U_RSR.0 and U_RSR.1. These two
bits, unlike the other status register bits, are only set if the corresponding mask bits U_RCR2.3 and
U_RCR2.4 are set.
Once an interrupt has occurred, the interrupt handler routine should set the INTDIS bit (CCR3.6) to stop
further activity on the interrupt pin. After all interrupts have been determined and processed, the interrupt
hander routine should re-enable interrupts by setting the INTDIS bit = 0.
6.3
Status Registers
When a particular event or condition has occurred (or is still occurring in the case of conditions), the
appropriate bit in a status register is set to a 1. All of the status registers operate in a latched fashion. This
means that if an event or condition occurs a bit is set to a 1. It remains set until the user reads that bit. An
event bit is cleared when it is read and it is not set again until the event has occurred again. Condition bits
such as RBL, RLOS, etc., remain set if the alarm is still present.
The user always proceeds a read of any of the status registers with a write. The byte written to the register
informs the DS2156 which bits the user wishes to read and have cleared. The user writes a byte to one of
these registers, with a 1 in the bit positions the user wishes to read and a 0 in the bit positions the user
does not wish to obtain the latest information on. When a 1 is written to a bit location, the read register is
updated with the latest information. When a 0 is written to a bit position, the read register is not updated
and the previous value is held. A write to the status registers is immediately followed by a read of the
same register. This write-read scheme allows an external microcontroller or microprocessor to
individually poll certain bits without disturbing the other bits in the register. This operation is key in
controlling the DS2156 with higher order languages.
Status register bits are divided into two groups, condition bits and event bits. Condition bits are typically
network conditions such as loss-of-sync or all-ones detect. Event bits are typically markers such as the
one-second timer, elastic store slip, etc. Each status register bit is labeled as a condition or event bit.
Some of the status registers have bits for both the detection of a condition and the clearance of the
50 of 265
DS2156
condition. For example, SR2 has a bit that is set when the device goes into a loss-of-sync state (SR2.0, a
condition bit) and a bit that is set (SR2.4, an event bit) when the loss-of-sync condition clears (goes in
sync). Some of the status register bits (condition bits) do not have a separate bit for the “condition clear”
event but rather the status bit can produce interrupts on both edges, setting and clearing. These bits are
marked as double interrupt bits. An interrupt is produced when the condition occurs and when it clears.
6.4
Information Registers
Information registers operate the same as status registers except they cannot cause interrupts. They are all
latched except for INFO7 and some of the bits in INFO5 and INFO6. INFO7 register is a read-only
register. It reports the status of the E1 synchronizer in real time. INFO7 and some of the bits in INFO6
and INFO5 are not latched and it is not necessary to precede a read of these bits with a write.
6.5
Interrupt Information Registers
The interrupt information registers provide an indication of which status registers (SR1 through SR9) are
generating an interrupt. When an interrupt occurs, the host can read IIR1 and IIR2 to quickly identify
which of the nine status registers are causing the interrupt.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
SR8
0
IIR1
Interrupt Information Register 1
14h
6
SR7
0
5
SR6
0
4
SR5
0
3
SR4
0
Register Name:
Register Description:
Register Address:
IIR2
Interrupt Information Register 2
15h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
51 of 265
2
SR3
0
1
SR2
0
0
SR1
0
2
—
0
1
U_RSR
0
0
SR9
0
DS2156
7. CLOCK MAP
Figure 7-1 shows the clock map of the DS2156. The routing for the transmit and receive clocks are shown
for the various loopback modes and jitter attenuator positions. Although there is only one jitter attenuator,
which can be placed in the receive or transmit path, two are shown for simplification and clarity.
Figure 7-1. Clock Map (TDM Mode)
MCLK
TSYSCLK
MCLKS = 0
MCLKS = 1
PRE-SCALER
LIC4.MPS0
LIC4.MPS1
2.048 TO 1.544
SYNTHESIZER
LIC2.3
DJA = 1
8 x PLL
LOCAL
LOOPBACK
RCL = 1
RXCLK
JITTER ATTENUATOR
SEE LIC1 REGISTER
LLB = 0
LTCA
RCL = 0
JAS = 0
AND
DJA = 0
REMOTE
LOOPBACK
FRAMER
LOOPBACK
FLB = 0
LLB = 1
TO
LIU
JAS = 0
OR
DJA = 1
TXCLK
JAS = 1
OR
DJA = 1
PAYLOAD
LOOPBACK
(SEE NOTES)
BPCLK
SYNTH
RECEIVE
FRAMER
BPCLK
RCLK
FLB = 1
RLB = 1
LTCA
JAS = 1
AND
DJA = 0
8XCLK
DJA = 0
RLB = 0
PLB = 1
TRANSMIT
FORMATTER
PLB = 0
TCLK
MUX
A
B
C
TCLK
The TCLK MUX is dependent on the state of the TCSS0 and TCSS1 bits in the LIC1 register and the
state of the TCLK pin.
TCSS1
TCSS0
0
0
0
1
1
0
1
1
Transmit Clock Source
The TCLK pin (C) is always the source of transmit clock.
Switch to the recovered clock (B) when the signal at the TCLK pin
fails to transition after one channel time.
Use the scaled signal (A) derived from MCLK as the transmit clock.
The TCLK pin is ignored.
Use the recovered clock (B) as the transmit clock. The TCLK pin is
ignored.
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DS2156
8. T1 FRAMER/FORMATTER CONTROL AND STATUS REGISTERS
The T1 framer portion of the DS2156 is configured through a set of nine control registers. Typically, the
control registers are only accessed when the system is first powered up. Once the DS2156 has been
initialized, the control registers only need to be accessed when there is a change in the system
configuration. There are two receive control registers (T1RCR1 and T1RCR2), two transmit control
registers (T1TCR1 and T1TCR2), and a common control register (T1CCR1). Each of these registers is
described in this section.
8.1
T1 Control Registers
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
T1RCR1
T1 Receive Control Register 1
03h
6
ARC
0
5
OOF1
0
4
OOF2
0
3
SYNCC
0
2
SYNCT
0
1
SYNCE
0
0
RESYNC
0
Bit 0/Resynchronize (RESYNC). When toggled from low to high, a resynchronization of the receive-side framer
is initiated. Must be cleared and set again for a subsequent resync.
Bit 1/Sync Enable (SYNCE)
0 = auto resync enabled
1 = auto resync disabled
Bit 2/Sync Time (SYNCT)
0 = qualify 10 bits
1 = qualify 24 bits
Bit 3/Sync Criteria (SYNCC)
In D4 Framing Mode:
0 = search for Ft pattern, then search for Fs pattern
1 = cross couple Ft and Fs pattern
In ESF Framing Mode:
0 = search for FPS pattern only
1 = search for FPS and verify with CRC6
Bits 4, 5/Out-of-Frame Select Bits (OOF2, OOF1)
OOF2
OOF1
0
0
1
1
0
1
0
1
Out-Of-Frame Criteria
2/4 frame bits in error
2/5 frame bits in error
2/6 frame bits in error
2/6 frame bits in error
Bit 6/Auto Resync Criteria (ARC)
0 = resync on OOF or RCL event
1 = resync on OOF only
Bit 7/Unused, must be set to 0 for proper operation
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
T1RCR2
T1 Receive Control Register 2
04h
6
RFM
0
5
RB8ZS
0
4
RSLC96
0
3
RZSE
0
2
RZBTSI
0
1
RJC
0
0
RD4YM
0
Bit 0/Receive-Side D4 Yellow Alarm Select (RD4YM)
0 = 0s in bit 2 of all channels
1 = a 1 in the S-bit position of frame 12 (J1 Yellow Alarm Mode)
Bit 1/Receive Japanese CRC6 Enable (RJC)
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)
1 = use Japanese standard JT–G704 CRC6 calculation
Bit 2/Receive-Side ZBTSI Support Enable (RZBTSI). Allows ZBTSI information to be output on RLINK pin.
0 = ZBTSI disabled
1 = ZBTSI enabled
Bit 3/Receive FDL Zero-Destuffer Enable (RZSE). Set this bit to 0 if using the internal HDLC/BOC controller
instead of the legacy support for the FDL. See Section 22.5 for details.
0 = zero destuffer disabled
1 = zero destuffer enabled
Bit 4/Receive SLC-96 Enable (RSLC96). Only set this bit to a 1 in D4/SLC-96 framing applications. See Section
22.6 for details.
0 = SLC-96 disabled
1 = SLC-96 enabled
Bit 5/Receive B8ZS Enable (RB8ZS)
0 = B8ZS disabled
1 = B8ZS enabled
Bit 6/Receive Frame Mode Select (RFM)
0 = D4 framing mode
1 = ESF framing mode
Bit 7/Unused, must be set to 0 for proper operation
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TJC
0
T1TCR1
T1 Transmit Control Register 1
05h
6
TFPT
0
5
TCPT
0
4
TSSE
0
3
GB7S
0
2
TFDLS
0
1
TBL
0
0
TYEL
0
Bit 0/Transmit Yellow Alarm (TYEL)
0 = do not transmit yellow alarm
1 = transmit yellow alarm
Bit 1/Transmit Blue Alarm (TBL)
0 = transmit data normally
1 = transmit an unframed all-ones code at TPOS and TNEG
Bit 2/TFDL Register Select (TFDLS)
0 = source FDL or Fs-bits from the internal TFDL register (legacy FDL support mode)
1 = source FDL or Fs-bits from the internal HDLC controller or the TLINK pin
Bit 3/Global Bit 7 Stuffing (GB7S)
0 = allow the SSIEx registers to determine which channels containing all 0s are to be bit 7 stuffed
1 = force bit 7 stuffing in all 0-byte channels regardless of how the SSIEx registers are programmed
Bit 4/Transmit Software Signaling Enable (TSSE).
0 = do not source signaling data from the TSx registers regardless of the SSIEx registers. The SSIEx
registers still define which channels are to have B7 stuffing preformed.
1 = source signaling data as enabled by the SSIEx registers
Bit 5/Transmit CRC Pass-Through (TCPT)
0 = source CRC6 bits internally
1 = CRC6 bits sampled at TSER during F-bit time
Bit 6/Transmit F-Bit Pass-Through (TFPT)
0 = F bits sourced internally
1 = F bits sampled at TSER
Bit 7/Transmit Japanese CRC6 Enable (TJC)
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)
1 = use Japanese standard JT–G704 CRC6 calculation
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TB8ZS
0
T1TCR2
T1 Transmit Control Register 2
06h
6
TSLC96
0
5
TZSE
0
4
FBCT2
0
3
FBCT1
0
2
TD4YM
0
1
TZBTSI
0
0
TB7ZS
0
Bit 0/Transmit-Side Bit 7 Zero-Suppression Enable (TB7ZS)
0 = no stuffing occurs
1 = bit 7 forced to a 1 in channels with all 0s
Bit 1/Transmit-Side ZBTSI Support Enable (TZBTSI). Allows ZBTSI information to be input on TLINK pin.
0 = ZBTSI disabled
1 = ZBTSI enabled
Bit 2/Transmit-Side D4 Yellow Alarm Select (TD4YM)
0 = 0s in bit 2 of all channels
1 = a 1 in the S-bit position of frame 12
Bit 3/F-Bit Corruption Type 1 (FBCT1). A low-to-high transition of this bit causes the next three consecutive Ft
(D4 framing mode) or FPS (ESF framing mode) bits to be corrupted causing the remote end to experience a loss of
synchronization.
Bit 4/F-Bit Corruption Type 2 (FBCT2). Setting this bit high enables the corruption of one Ft (D4 framing mode)
or FPS (ESF framing mode) bit in every 128 Ft or FPS bits as long as the bit remains set.
Bit 5/Transmit FDL Zero-Stuffer Enable (TZSE). Set this bit to 0 if using the internal HDLC controller instead
of the legacy support for the FDL. See Section 15 for details.
0 = zero stuffer disabled
1 = zero stuffer enabled
Bit 6/Transmit SLC-96/Fs-Bit Insertion Enable (TSLC96). Only set this bit to a 1 in D4 framing applications.
Must be set to 1 to source the Fs pattern from the TFDL register. See Section 22.6 for details.
0 = SLC-96/Fs-bit insertion disabled
1 = SLC-96/Fs-bit insertion enabled
Bit 7/Transmit B8ZS Enable (TB8ZS)
0 = B8ZS disabled
1 = B8ZS enabled
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
T1CCR1
T1 Common Control Register 1
07h
6
—
0
5
—
0
4
TRAI-CI
0
3
TAIS-CI
0
2
TFM
0
1
PDE
0
0
TLOOP
0
Bit 0/Transmit Loop-Code Enable (TLOOP). See Section 25 for details.
0 = transmit data normally
1 = replace normal transmitted data with repeating code as defined in registers TCD1 and TCD2
Bit 1/Pulse Density Enforcer Enable (PDE). The framer always examines the transmit and receive data streams
for violations of these, which are required by ANSI T1.403: No more than 15 consecutive 0s and at least N 1s in
each and every time window of 8 x (N + 1) bits, where N = 1 through 23. Violations for the transmit and receive
data streams are reported in the INFO1.6 and INFO1.7 bits, respectively. When this bit is set to 1, the DS2156
forces the transmitted stream to meet this requirement no matter the content of the transmitted stream. When
running B8ZS, this bit should be set to 0 since B8ZS encoded data streams cannot violate the pulse density
requirements.
0 = disable transmit pulse density enforcer
1 = enable transmit pulse density enforcer
Bit 2/Transmit Frame Mode Select (TFM)
0 = D4 framing mode
1 = ESF framing mode
Bit 3/Transmit AIS-CI Enable (TAIS-CI). Setting this bit and the TBL bit (T1TCR1.1) causes the AIS-CI code
to be transmitted at TPOSO and TNEGO, as defined in ANSI T1.403.
0 = do not transmit the AIS-CI code
1 = transmit the AIS-CI code (T1TCR1.1 must also be set = 1)
Bit 4/Transmit RAI-CI Enable (TRAI-CI). Setting this bit causes the ESF RAI-CI code to be transmitted in the
FDL bit position.
0 = do not transmit the ESF RAI-CI code
1 = transmit the ESF RAI-CI code
Bits 5 to 7/Unused, must be set to 0 for proper operation
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DS2156
8.2
T1 Transmit Transparency
The software signaling insertion-enable registers, SSIE1–SSIE4, can be used to select signaling insertion
from the transmit signaling registers, TS1–TS12, on a per-channel basis. Setting a bit in the SSIEx
register allows signaling data to be sourced from the signaling registers for that channel.
In transparent mode, bit 7 stuffing and/or robbed-bit signaling is prevented from overwriting the data in
the channels. If a DS0 is programmed to be clear, no robbed-bit signaling is inserted nor does the channel
have bit 7 stuffing performed. However, in the D4 framing mode, bit 2 is overwritten by a 0 when a
Yellow Alarm is transmitted. Also, the user has the option to globally override the SSIEx registers from
determining which channels are to have bit 7 stuffing performed. If the T1TCR1.3 and T1TCR2.0 bits are
set to 1, then all 24 T1 channels have bit 7 stuffing performed on them, regardless of how the SSIEx
registers are programmed. In this manner, the SSIEx registers are only affecting the channels that are to
have robbed-bit signaling inserted into them.
8.3
AIS-CI and RAI-CI Generation and Detection
The DS2156 can transmit and detect the RAI-CI and AIS-CI codes in T1 mode. These codes are
compatible with and do not interfere with the standard RAI (Yellow) and AIS (Blue) alarms. These codes
are defined in ANSI T1.403.
The AIS-CI code (alarm indication signal-customer installation) is the same for both ESF and D4
operation. Setting the TAIS-CI bit in the T1CCR1 register and the TBL bit in the T1TCR1 register causes
the DS2156 to transmit the AIS-CI code. The RAIS-CI status bit in the SR4 register indicates the
reception of an AIS-CI signal.
The RAI-CI (remote alarm indication-customer installation) code for T1 ESF operation is a special form
of the ESF Yellow Alarm (an unscheduled message). Setting the RAIS-CI bit in the T1CCR1 register
causes the DS2156 to transmit the RAI-CI code. The RAI-CI code causes a standard Yellow Alarm to be
detected by the receiver. When the host processor detects a Yellow Alarm, it can then test the alarm for
the RAI-CI state by checking the BOC detector for the RAI-CI flag. That flag is a 011111 code in the 6bit BOC message.
The RAI-CI code for T1 D4 operation is a 10001011 flag in all 24 time slots. To transmit the RAI-CI
code the host sets all 24 channels to idle with a 10001011 idle code. Since this code meets the
requirements for a standard T1 D4 Yellow Alarm, the host can use the receive channel monitor function
to detect the 100001011 code whenever a standard Yellow Alarm is detected.
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DS2156
8.4
T1 Receive-Side Digital-Milliwatt Code Generation
Receive-side digital-milliwatt code generation involves using the receive digital-milliwatt registers
(T1RDMR1/2/3) to determine which of the 24 T1 channels of the T1 line going to the backplane should
be overwritten with a digital-milliwatt pattern. The digital-milliwatt code is an 8-byte repeating pattern
that represents a 1kHz sine wave (1E/0B/0B/1E/9E/8B/8B/9E). Each bit in the T1RDMRx registers
represents a particular channel. If a bit is set to a 1, then the receive data in that channel is replaced with
the digital-milliwatt code. If a bit is set to 0, no replacement occurs.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH8
0
T1RDMR1
T1 Receive Digital-Milliwatt Enable Register 1
0Ch
6
CH7
0
5
CH6
0
4
CH5
0
3
CH4
0
2
CH3
0
1
CH2
0
0
CH1
0
Bits 0 to 7/Receive Digital-Milliwatt Enable for Channels 1 to 8 (CH1 to CH8)
0 = do not affect the receive data associated with this channel
1 = replace the receive data associated with this channel with digital-milliwatt code
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH16
0
T1RDMR2
T1 Receive Digital-Milliwatt Enable Register 2
0Dh
6
CH15
0
5
CH14
0
4
CH13
0
3
CH12
0
2
CH11
0
1
CH10
0
0
CH9
0
Bits 0 to 7/Receive Digital-Milliwatt Enable for Channels 9 to 16 (CH9 to CH16)
0 = do not affect the receive data associated with this channel
1 = replace the receive data associated with this channel with digital-milliwatt code
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH24
0
T1RDMR3
T1 Receive Digital-Milliwatt Enable Register 3
0Eh
6
CH23
0
5
CH22
0
4
CH21
0
3
CH20
0
2
CH19
0
1
CH18
0
0
CH17
0
Bits 0 to 7/Receive Digital-Milliwatt Enable for Channels 17 to 24 (CH17 to CH24)
0 = do not affect the receive data associated with this channel
1 = replace the receive data associated with this channel with digital-milliwatt code
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RPDV
0
INFO1
Information Register 1
10h
6
TPDV
0
5
COFA
0
4
8ZD
0
3
16ZD
0
2
SEFE
0
1
B8ZS
0
0
FBE
0
Bit 0/Frame Bit-Error Event (FBE). Set when an Ft (D4) or FPS (ESF) framing bit is received in error.
Bit 1/B8ZS Codeword Detect Event (B8ZS). Set when a B8ZS codeword is detected at RPOS and RNEG
independent of whether the B8ZS mode is selected or not by T1TCR2.7. Useful for automatically setting the line
coding.
Bit 2/Severely Errored Framing Event (SEFE). Set when two out of six framing bits (Ft or FPS) are received in
error.
Bit 3/Sixteen Zero-Detect Event (16ZD). Set when a string of at least 16 consecutive 0s (regardless of the length
of the string) have been received at RPOSI and RNEGI.
Bit 4/Eight Zero-Detect Event (8ZD). Set when a string of at least eight consecutive 0s (regardless of the length
of the string) have been received at RPOSI and RNEGI.
Bit 5/Change-of-Frame Alignment Event (COFA). Set when the last resync resulted in a change-of-frame or
multiframe alignment.
Bit 6/Transmit Pulse-Density Violation Event (TPDV). Set when the transmit data stream does not meet the
ANSI T1.403 requirements for pulse density.
Bit 7/Receive Pulse-Density Violation Event (RPDV). Set when the receive data stream does not meet the ANSI
T1.403 requirements for pulse density.
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DS2156
Table 8-A. T1 Alarm Criteria
ALARM
Blue Alarm (AIS)
(Note 1)
Yellow Alarm (RAI)
D4 Bit 2 Mode
(T1RCR2.0 = 0)
SET CRITERIA
When over a 3ms window, five or
fewer 0s are received
When bit 2 of 256 consecutive
channels is set to 0 for at least 254
occurrences
CLEAR CRITERIA
When over a 3ms window, six or
more 0s are received
When bit 2 of 256 consecutive
channels is set to 0 for fewer than
254 occurrences
D4 12th F-Bit Mode
(T1RCR2.0 = 1; this mode is also
referred to as the “Japanese Yellow
Alarm”)
When the 12th framing bit is set to 1
for two consecutive occurrences
When the 12th framing bit is set to
0 for two consecutive occurrences
ESF Mode
When 16 consecutive patterns of
00FF appear in the FDL
When 14 or fewer patterns of 00FF
hex out of 16 possible appear in the
FDL
Red Alarm (LRCL)
(Also referred to as loss of signal)
When 192 consecutive 0s are
received
When 14 or more 1s out of 112
possible bit positions are received
Note 1: The definition of Blue Alarm (or AIS) is an unframed all-ones signal. Blue Alarm detectors should be able to operate properly in the
presence of a 10E-3 error rate and they should not falsely trigger on a framed all-1s signal. Blue Alarm criteria in the DS2156 has been
set to achieve this performance. It is recommended that the RBL bit be qualified with the RLOS bit.
Note 2: ANSI specifications use a different nomenclature than the DS2156 does. The following terms are equivalent:
RBL = AIS
RCL = LOS
RLOS = LOF
RYEL = RAI
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DS2156
9. E1 FRAMER/FORMATTER CONTROL AND STATUS REGISTERS
The E1 framer portion of the DS2156 is configured by a set of four control registers. Typically, the
control registers are only accessed when the system is first powered up. Once the DS2156 has been
initialized, the control registers need only to be accessed when there is a change in the system
configuration. There are two receive control registers (E1RCR1 and E1RCR2) and two transmit control
registers (E1TCR1 and E1TCR2). There are also four status and information registers. Each of these eight
registers is described in this section.
9.1
E1 Control Registers
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RSERC
0
E1RCR1
E1 Receive Control Register 1
33h
6
RSIGM
0
5
RHDB3
0
4
RG802
0
3
RCRC4
0
2
FRC
0
1
SYNCE
0
0
RESYNC
0
Bit 0/Resync (RESYNC). When toggled from low to high, a resync is initiated. Must be cleared and set again for a
subsequent resync.
Bit 1/Sync Enable (SYNCE)
0 = auto resync enabled
1 = auto resync disabled
Bit 2/Frame Resync Criteria (FRC)
0 = resync if FAS received in error three consecutive times
1 = resync if FAS or bit 2 of non-FAS is received in error three consecutive times
Bit 3/Receive CRC4 Enable (RCRC4)
0 = CRC4 disabled
1 = CRC4 enabled
Bit 4/Receive G.802 Enable (RG802). See Section 16 for details.
0 = do not force RCHBLK high during bit 1 of time slot 26
1 = force RCHBLK high during bit 1 of time slot 26
Bit 5/Receive HDB3 Enable (RHDB3)
0 = HDB3 disabled
1 = HDB3 enabled
Bit 6/Receive Signaling Mode Select (RSIGM)
0 = CAS signaling mode
1 = CCS signaling mode
Bit 7/RSER Control (RSERC)
0 = allow RSER to output data as received under all conditions
1 = force RSER to 1 under loss-of-frame alignment conditions
62 of 265
DS2156
Table 9-A. E1 Sync/Resync Criteria
FRAME OR
MULTIFRAME
LEVEL
SYNC CRITERIA
RESYNC CRITERIA
ITU SPEC.
Three consecutive incorrect
FAS received
FAS present in frame N and
N + 2; FAS not present in
frame N + 1
FAS
Two valid MF alignment
words found within 8ms
Valid MF alignment word
found and previous time slot
16 contains code other than
all 0s
CRC4
CAS
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
Sa8S
0
Alternate: (E1RCR1.2 = 1) The
above criteria is met or three
consecutive incorrect bit 2 of
non-FAS received
915 or more CRC4 codewords
out of 1000 received in error
Two consecutive MF
alignment words received in
error
G.706
4.1.1
4.1.2
G.706
4.2 and 4.3.2
G.732
5.2
E1RCR2
E1 Receive Control Register 2
34h
6
Sa7S
0
5
Sa6S
0
4
Sa5S
0
3
Sa4S
0
2
—
0
1
—
0
0
RCLA
0
Bit 0/Receive Carrier-Loss (RCL) Alternate Criteria (RCLA). Defines the criteria for a receive carrier-loss
condition for both the framer and LIU.
0 = RCL declared upon 255 consecutive 0s (125µs)
1 = RCL declared upon 2048 consecutive 0s (1ms)
Bits 1, 2/Unused, must be set to 0 for proper operation
Bit 3/Sa4 Bit Select (Sa4S). Set to 1 to have RLCLK pulse at the Sa4 bit position; set to 0 to force RLCLK low
during Sa4 bit position. See Section 34 for details.
Bit 4/Sa5 Bit Select (Sa5S). Set to 1 to have RLCLK pulse at the Sa5 bit position; set to 0 to force RLCLK low
during Sa5 bit position. See Section 34 for details.
Bit 5/Sa6 Bit Select (Sa6S). Set to 1 to have RLCLK pulse at the Sa6 bit position; set to 0 to force RLCLK low
during Sa6 bit position. See Section 34 for details.
Bit 6/Sa7 Bit Select (Sa7S). Set to 1 to have RLCLK pulse at the Sa7 bit position; set to 0 to force RLCLK low
during Sa7 bit position. See Section 34 for details.
Bit 7/Sa8 Bit Select (Sa8S). Set to 1 to have RLCLK pulse at the Sa8 bit position; set to 0 to force RLCLK low
during Sa8 bit position. See Section 34 for details.
63 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TFPT
0
E1TCR1
E1 Transmit Control Register 1
35h
6
T16S
0
5
TUA1
0
4
TSiS
0
3
TSA1
0
2
THDB3
0
1
TG802
0
0
TCRC4
0
Bit 0/Transmit CRC4 Enable (TCRC4)
0 = CRC4 disabled
1 = CRC4 enabled
Bit 1/Transmit G.802 Enable (TG802). See Section 34 for details.
0 = do not force TCHBLK high during bit 1 of time slot 26
1 = force TCHBLK high during bit 1 of time slot 26
Bit 2/Transmit HDB3 Enable (THDB3)
0 = HDB3 disabled
1 = HDB3 enabled
Bit 3/Transmit Signaling All Ones (TSA1)
0 = normal operation
1 = force time slot 16 in every frame to all ones
Bit 4/Transmit International Bit Select (TSiS)
0 = sample Si bits at TSER pin
1 = source Si bits from TAF and TNAF registers (in this mode, E1TCR1.7 must be set to 0)
Bit 5/Transmit Unframed All Ones (TUA1)
0 = transmit data normally
1 = transmit an unframed all-ones code at TPOSO and TNEGO
Bit 6/Transmit Time Slot 16 Data Select (T16S). See Section 15.2 for details.
0 = time slot 16 determined by the SSIEx registers and the THSCS function in the PCPR register
1 = source time slot 16 from TS1 to TS16 registers
Bit 7/Transmit Time Slot 0 Pass-Through (TFPT)
0 = FAS bits/Sa bits/remote alarm sourced internally from the TAF and TNAF registers
1 = FAS bits/Sa bits/remote alarm sourced from TSER
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
Sa8S
0
E1TCR2
E1 Transmit Control Register 2
36h
6
Sa7S
0
5
Sa6S
0
4
Sa5S
0
3
Sa4S
0
2
AEBE
0
1
AAIS
0
0
ARA
0
Bit 0/Automatic Remote Alarm Generation (ARA)
0 = disabled
1 = enabled
Bit 1/Automatic AIS Generation (AAIS)
0 = disabled
1 = enabled
Bit 2/Automatic E-Bit Enable (AEBE)
0 = E-bits not automatically set in the transmit direction
1 = E-bits automatically set in the transmit direction
Bit 3/Sa4 Bit Select (Sa4S). Set to 1 to source the Sa4 bit from the TLINK pin; set to 0 to not source the Sa4 bit.
See Section 34 for details.
Bit 4/Sa5 Bit Select (Sa5S). Set to 1 to source the Sa5 bit from the TLINK pin; set to 0 to not source the Sa5 bit.
See Section 34 for details.
Bit 5/Sa6 Bit Select (Sa6S). Set to 1 to source the Sa6 bit from the TLINK pin; set to 0 to not source the Sa6 bit.
See Section 34 for details.
Bit 6/Sa7 Bit Select (Sa7S). Set to 1 to source the Sa7 bit from the TLINK pin; set to 0 to not source the Sa7 bit.
See Section 34 for details.
Bit 7/Sa8 Bit Select (Sa8S). Set to 1 to source the Sa8 bit from the TLINK pin; set to 0 to not source the Sa8 bit.
See Section 34 for details.
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DS2156
9.2
Automatic Alarm Generation
The device can be programmed to automatically transmit AIS or remote alarm. When automatic AIS
generation is enabled (E1TCR2.1 = 1), the device monitors the receive-side framer to determine if any of
the following conditions are present: loss-of-receive frame synchronization, AIS alarm (all ones)
reception, or loss-of-receive carrier (or signal). The framer forces either an AIS or remote alarm if any
one or more of these conditions is present.
When automatic RAI generation is enabled (E1TCR2.0 = 1), the framer monitors the receive side to
determine if any of the following conditions are present: loss-of-receive-frame synchronization, AIS
alarm (all ones) reception, loss-of-receive carrier (or signal), or if CRC4 multiframe synchronization
cannot be found within 128ms of FAS synchronization (if CRC4 is enabled). If any one or more of these
conditions is present, then the framer transmits an RAI alarm. RAI generation conforms to ETS 300 011
specifications and a constant remote alarm is transmitted if the DS2156 cannot find CRC4 multiframe
synchronization within 400ms as per G.706.
Note: It is an invalid state to have both automatic AIS generation and automatic remote alarm generation
enabled at the same time.
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DS2156
9.3
E1 Information Registers
Register Name:
Register Description:
Register Address:
INFO3
Information Register 3
12h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
2
CRCRC
0
1
FASRC
0
0
CASRC
0
Bit 0/CAS Resync Criteria Met Event (CASRC). Set when two consecutive CAS MF alignment words are
received in error.
Bit 1/FAS Resync Criteria Met Event (FASRC). Set when three consecutive FAS words are received in error.
Bit 2/CRC Resync Criteria Met Event (CRCRC). Set when 915/1000 codewords are received in error.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CSC5
0
INFO7
Information Register 7 (Real-Time, Non-Latched Register)
30h
6
CSC4
0
5
CSC3
0
4
CSC2
0
3
CSC0
0
2
FASSA
0
1
CASSA
0
0
CRC4SA
0
Bit 0/CRC4 MF Sync Active (CRC4SA). Set while the synchronizer is searching for the CRC4 MF alignment
word. This is a read-only, non-latched, real-time bit. It is not necessary to precede the read of this bit with a write.
Bit 1/CAS MF Sync Active (CASSA). Set while the synchronizer is searching for the CAS MF alignment word.
This is a read-only, non-latched, real-time bit. It is not necessary to precede the read of this bit with a write.
Bit 2/FAS Sync Active (FASSA). Set while the synchronizer is searching for alignment at the FAS level. This is a
read-only, non-latched, real-time bit. It is not necessary to precede the read of this bit with a write.
Bits 3 to 7/CRC4 Sync Counter Bits (CSC0, CSC2 to CSC4). The CRC4 sync counter increments each time the
8ms CRC4 multiframe search times out. The counter is cleared when the framer has successfully obtained
synchronization at the CRC4 level. The counter can also be cleared by disabling the CRC4 mode (E1RCR1.3 = 0).
This counter is useful for determining the amount of time the framer has been searching for synchronization at the
CRC4 level. ITU G.706 suggests that if synchronization at the CRC4 level cannot be obtained within 400ms, then
the search should be abandoned and proper action taken. The CRC4 sync counter rolls over. CSC0 is the LSB of
the 6-bit counter. (Note: The bit next to LSB is not accessible. CSC1 is omitted to allow resolution to >400ms
using 5 bits.) These are read-only, non-latched, real-time bits. It is not necessary to precede the read of these bits
with a write.
67 of 265
DS2156
Table 9-B. E1 Alarm Criteria
ALARM
RLOS
RCL
RRA
RUA1
RDMA
V52LNK
SET CRITERIA
CLEAR CRITERIA
An RLOS condition exists on power-up
prior to initial synchronization, when a
resync criteria has been met, or when a
manual resync has been initiated by
E1RCR1.0
255 or 2048 consecutive 0s received as
determined by E1RCR2.0
Bit 3 of nonalign frame set to 1 for three
consecutive occasions
Fewer than three 0s in two frames (512
bits)
Bit 6 of time slot 16 in frame 0 has been set
for two consecutive multiframes
At least 32 1s in 255-bit times
are received
Bit 3 of nonalign frame set to
0 for three consecutive
occasions
More than two 0s in two
frames (512 bits)
Two out of three Sa7 bits are 0
ITU
SPECIFICATION
G.775/G.962
O.162
2.1.4
O.162
1.6.1.2
G.965
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DS2156
10.
COMMON CONTROL AND STATUS REGISTERS
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
MCLKS
0
CCR1
Common Control Register 1
70h
6
CRC4R
0
5
SIE
0
4
ODM
0
3
DICAI
0
2
TCSS1
0
1
TCSS0
0
0
RLOSF
0
Bit 0/Function of the RLOS/LOTC Output (RLOSF)
0 = receive loss of sync (RLOS)
1 = loss-of-transmit clock (LOTC)
Bit 1/Transmit Clock Source Select Bit 0 (TCSS0)
Bit 2/Transmit Clock Source Select Bit 0 (TCSS1)
TCSS1
TCSS0
Transmit Clock Source
0
0
0
1
1
0
1
1
The TCLK pin is always the source of transmit clock.
Switch to the clock present at RCLK when the signal at the TCLK pin
fails to transition after 1 channel time.
Use the scaled signal present at MCLK as the transmit clock. The
TCLK pin is ignored.
Use the signal present at RCLK as the transmit clock. The TCLK pin is
ignored.
Bit 3/Disable Idle Code Auto Increment (DICAI). Selects/deselects the auto-increment feature for the transmit
and receive idle code array address register. See Section 16.
0 = addresses in IAAR register automatically increment on every read/write operation to the PCICR
register
1 = addresses in IAAR register do not automatically increment
Bit 4/Output Data Mode (ODM)
0 = pulses at TPOSO and TNEGO are one full TCLKO period wide
1 = pulses at TPOSO and TNEGO are one-half TCLKO period wide
Bit 5/Signaling Integration Enable (SIE)
0 = signaling changes of state reported on any change in selected channels
1 = signaling must be stable for three multiframes in order for a change of state to be reported
Bit 6/CRC-4 Recalculate (CRC4R)
0 = transmit CRC-4 generation and insertion operates in normal mode
1 = transmit CRC-4 generation operates according to G.706 intermediate path recalculation method
Bit 7/MCLK Source (MCLKS). Selects the source of MCLK
0 = MCLK is source from the MCLK pin
1 = MCLK is source from the TSYSCLK pin
69 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
ID7
1
IDR
Device Identification Register
0Fh
6
ID6
1
5
ID5
0
4
ID4
0
3
ID3
0
2
ID2
0
1
ID1
0
0
ID0
0
Bits 0 to 3/Chip Revision Bits (ID0 to ID3). The lower four bits of the IDR are used to display the die revision of
the chip. IDO is the LSB of a decimal code that represents the chip revision.
Bits 4 to 7/Device ID (ID4 to ID7). The upper four bits of the IDR are used to display the DS2156 ID.
10.1 T1/E1 Status Registers
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RYELC
0
SR2
Status Register 2
18h
6
RUA1C
0
5
FRCLC
0
4
RLOSC
0
3
RYEL
0
2
RUA1
0
1
FRCL
0
0
RLOS
0
Bit 0/Receive Loss-of-Sync Condition (RLOS). Set when the DS2156 is not synchronized to the received data
stream.
Bit 1/Framer Receive Carrier-Loss Condition (FRCL). Set when 255 (or 2048 if E1RCR2.0 = 1) E1 mode or
192 T1 mode consecutive 0s have been detected at RPOSI and RNEGI.
Bit 2/Receive Unframed All-Ones (T1 Blue Alarm, E1 AIS) Condition (RUA1). Set when an unframed all 1s
code is received at RPOSI and RNEGI.
Bit 3/Receive Yellow Alarm Condition (RYEL) (T1 Only). Set when a Yellow Alarm is received at RPOSI and
RNEGI.
Bit 4/Receive Loss-of-Sync Clear Event (RLOSC). Set when the framer achieves synchronization; remains set
until read.
Bit 5/Framer Receive Carrier-Loss Clear Event (FRCLC). Set when the carrier loss condition at RPOSI and
RNEGI is no longer detected.
Bit 6/Receive Unframed All-Ones Clear Event (RUA1C). Set when the unframed all 1s condition is no longer
detected.
Bit 7/Receive Yellow Alarm Clear Event (RYELC) (T1 Only). Set when the receive Yellow Alarm condition is
no longer detected.
70 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RYELC
0
IMR2
Interrupt Mask Register 2
19h
6
RUA1C
0
5
FRCLC
0
4
RLOSC
0
3
RYEL
0
2
RUA1
0
Bit 0/Receive Loss-of-Sync Condition (RLOS)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 1/Framer Receive Carrier Loss Condition (FRCL)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 2/Receive Unframed All-Ones (Blue Alarm) Condition (RUA1)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 3/Receive Yellow Alarm Condition (RYEL)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 4/Receive Loss-of-Sync Clear Event (RLOSC)
0 = interrupt masked
1 = interrupt enabled
Bit 5/Framer Receive Carrier Loss Condition Clear (FRCLC)
0 = interrupt masked
1 = interrupt enabled
Bit 6/Receive Unframed All-Ones Condition Clear Event (RUA1C)
0 = interrupt masked
1 = interrupt enabled
Bit 7/Receive Yellow Alarm Clear Event (RYELC)
0 = interrupt masked
1 = interrupt enabled
71 of 265
1
FRCL
0
0
RLOS
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
LSPARE
0
SR3
Status Register 3
1Ah
6
LDN
0
5
LUP
0
4
LOTC
0
3
LORC
0
2
V52LNK
0
1
RDMA
0
0
RRA
0
Bit 0/Receive Remote Alarm Condition (RRA) (E1 Only). Set when a remote alarm is received at RPOSI and
RNEGI. This is a double interrupt bit. See Section 6.3.
Bit 1/Receive Distant MF Alarm Condition (RDMA) (E1 Only). Set when bit 6 of time slot 16 in frame 0 has
been set for two consecutive multiframes. This alarm is not disabled in the CCS signaling mode. This is a double
interrupt bit. See Section 6.3.
Bit 2/V5.2 Link Detected Condition (V52LNK) (E1 Only). Set on detection of a V5.2 link identification signal
(G.965). This is a double interrupt bit. See Section 6.3.
Bit 3/Loss-of-Receive Clock Condition (LORC). Set when the RCLKI pin has not transitioned for one channel
time. This is a double interrupt bit. See Section 6.3.
Bit 4/Loss-of-Transmit Clock Condition (LOTC). Set when the TCLK pin has not transitioned for one channel
time. Forces the LOTC pin high if enabled by CCR1.0. This is a double interrupt bit. See Section 6.3.
Bit 5/Loop-Up Code Detected Condition (LUP) (T1 Only). Set when the loop-up code as defined in the
RUPCD1/2 register is being received. See Section 25 for details. This is a double interrupt bit. See Section 6.3.
Bit 6/Loop-Down Code Detected Condition (LDN) (T1 Only). Set when the loop down code as defined in the
RDNCD1/2 register is being received. See Section 25 for details. This is a double interrupt bit. See Section 6.3.
Bit 7/Spare Code Detected Condition (LSPARE) (T1 Only). Set when the spare code as defined in the RSCD1/2
registers is being received. See Section 25 for details. This is a double interrupt bit. See Section 6.3.
72 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
LSPARE
0
IMR3
Interrupt Mask Register 3
1Bh
6
LDN
0
5
LUP
0
4
LOTC
0
3
LORC
0
2
V52LNK
0
Bit 0/Receive Remote Alarm Condition (RRA)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 1/Receive Distant MF Alarm Condition (RDMA)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 2/V5.2 Link Detected Condition (V52LNK)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 3/Loss-of-Receive Clock Condition (LORC)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 4/Loss-of-Transmit Clock Condition (LOTC)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 5/Loop-Up Code-Detected Condition (LUP)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 6/Loop-Down Code-Detected Condition (LDN)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 7/Spare Code Detected Condition (LSPARE)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
73 of 265
1
RDMA
0
0
RRA
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RAIS-CI
0
SR4
Status Register 4
1Ch
6
RSAO
0
5
RSAZ
0
4
TMF
0
3
TAF
0
2
RMF
0
1
RCMF
0
0
RAF
0
Bit 0/Receive Align Frame Event (RAF) (E1 Only). Set every 250µs at the beginning of align frames. Used to
alert the host that Si and Sa bits are available in the RAF and RNAF registers.
Bit 1/Receive CRC4 Multiframe Event (RCMF) (E1 Only). Set on CRC4 multiframe boundaries; continues to
set every 2ms on an arbitrary boundary if CRC4 is disabled.
Bit 2/Receive Multiframe Event (RMF)
E1 Mode: Set every 2ms (regardless if CAS signaling is enabled or not) on receive multiframe boundaries.
Used to alert the host that signaling data is available.
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.
Bit 3/Transmit Align Frame Event (TAF) (E1 Only). Set every 250µs at the beginning of align frames. Used to
alert the host that the TAF and TNAF registers need to be updated.
Bit 4/Transmit Multiframe Event (TMF)
E1 Mode: Set every 2ms (regardless if CRC4 is enabled) on transmit multiframe boundaries. Used to alert
the host that signaling data needs to be updated.
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.
Bit 5/Receive Signaling All-Zeros Event (RSAZ) (E1 Only). Set when over a full MF, time slot 16 contains
all 0s.
Bit 6/Receive Signaling All-Ones Event (RSAO) (E1 Only). Set when the contents of time slot 16 contains fewer
than three 0s over 16 consecutive frames. This alarm is not disabled in the CCS signaling mode.
Bit 7/Receive AIS-CI Event (RAIS-CI) (T1 Only). Set when the receiver detects the AIS-CI pattern as defined in
ANSI T1.403.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RAIS-CI
0
IMR4
Interrupt Mask Register 4
1Dh
6
RSAO
0
5
RSAZ
0
4
TMF
0
3
TAF
0
Bit 0/Receive Align Frame Event (RAF)
0 = interrupt masked
1 = interrupt enabled
Bit 1/Receive CRC4 Multiframe Event (RCMF)
0 = interrupt masked
1 = interrupt enabled
Bit 2/Receive Multiframe Event (RMF)
0 = interrupt masked
1 = interrupt enabled
Bit 3/Transmit Align Frame Event (TAF)
0 = interrupt masked
1 = interrupt enabled
Bit 4/Transmit Multiframe Event (TMF)
0 = interrupt masked
1 = interrupt enabled
Bit 5/Receive Signaling All-Zeros Event (RSAZ)
0 = interrupt masked
1 = interrupt enabled
Bit 6/Receive Signaling All-Ones Event (RSAO)
0 = interrupt masked
1 = interrupt enabled
Bit 7/Receive AIS-CI Event (RAIS-CI)
0 = interrupt masked
1 = interrupt enabled
75 of 265
2
RMF
0
1
RCMF
0
0
RAF
0
DS2156
11.
I/O PIN CONFIGURATION OPTIONS
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RSMS
0
IOCR1
I/O Configuration Register 1
01h
6
RSMS2
0
5
RSMS1
0
4
RSIO
0
3
TSDW
0
2
TSM
0
1
TSIO
0
0
ODF
0
Bit 0/Output Data Format (ODF)
0 = bipolar data at TPOSO and TNEGO
1 = NRZ data at TPOSO; TNEGO = 0
Bit 1/TSYNC I/O Select (TSIO)
0 = TSYNC is an input
1 = TSYNC is an output
Bit 2/TSYNC Mode Select (TSM). Selects frame or multiframe mode for the TSYNC pin. See the timing
diagrams in Section 34.
0 = frame mode
1 = multiframe mode
Bit 3/TSYNC Double-Wide (TSDW). (Note: This bit must be set to 0 when IOCR1.2 = 1 or when IOCR1.1 = 0.)
0 = do not pulse double-wide in signaling frames
1 = do pulse double-wide in signaling frames
Bit 4/RSYNC I/O Select (RSIO). (Note: This bit must be set to 0 when ESCR.0 = 0.)
0 = RSYNC is an output
1 = RSYNC is an input (only valid if elastic store enabled)
Bit 5/RSYNC Mode Select 1(RSMS1). Selects frame or multiframe pulse when RSYNC pin is in output mode. In
input mode (elastic store must be enabled), multiframe mode is only useful when receive signaling reinsertion is
enabled. See the timing diagrams in Section 34.
0 = frame mode
1 = multiframe mode
Bit 6/RSYNC Mode Select 2 (RSMS2)
T1 Mode: RSYNC pin must be programmed in the output frame mode (IOCR1.5 = 0, IOCR1.4 = 0).
0 = do not pulse double-wide in signaling frames
1 = do pulse double-wide in signaling frames
E1 Mode: RSYNC pin must be programmed in the output multiframe mode (IOCR1.5 = 1, IOCR1.4 = 0).
0 = RSYNC outputs CAS multiframe boundaries
1 = RSYNC outputs CRC4 multiframe boundaries
Bit 7/RSYNC Multiframe Skip Control (RSMS). Useful in framing format conversions from D4 to ESF. This
function is not available when the receive-side elastic store is enabled. RSYNC must be set to output multiframe
pulses (IOCR1.5 = 1 and IOCR1.4 = 0).
0 = RSYNC outputs a pulse at every multiframe
1 = RSYNC outputs a pulse at every other multiframe
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RCLKINV
0
IOCR2
I/O Configuration Register 2
02h
6
TCLKINV
0
5
RSYNCINV
0
4
TSYNCINV
0
3
TSSYNCINV
0
2
H100EN
0
1
TSCLKM
0
Bit 0/RSYSCLK Mode Select (RSCLKM)
0 = if RSYSCLK is 1.544MHz
1 = if RSYSCLK is 2.048MHz or IBO enabled (See Section 28 for details on IBO function.)
Bit 1/TSYSCLK Mode Select (TSCLKM)
0 = if TSYSCLK is 1.544MHz
1 = if TSYSCLK is 2.048MHz or IBO enabled (See Section 28 for details on IBO function.)
Bit 2/H.100 SYNC Mode (H100EN)
0 = normal operation
1 = SYNC shift
Bit 3/TSSYNC Invert (TSSYNCINV)
0 = no inversion
1 = invert
Bit 4/TSYNC Invert (TSYNCINV)
0 = no inversion
1 = invert
Bit 5/RSYNC Invert (RSYNCINV)
0 = no inversion
1 = invert
Bit 6/TCLK Invert (TCLKINV)
0 = no inversion
1 = invert
Bit 7/RCLK Invert (RCLKINV)
0 = no inversion
1 = invert
77 of 265
0
RSCLKM
0
DS2156
12.
LOOPBACK CONFIGURATION
Register Name:
Register Description:
Register Address:
LBCR
Loopback Control Register
4Ah
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
LIUC
0
3
LLB
0
2
RLB
0
1
PLB
0
0
FLB
0
Bit 0/Framer Loopback (FLB). This loopback is useful in testing and debugging applications. In FLB, the
DS2156 loops data from the transmit side back to the receive side. When FLB is enabled, the following occurs:
1) T1 Mode: An unframed all-ones code is transmitted at TPOSO and TNEGO.
E1 Mode: Normal data is transmitted at TPOSO and TNEGO.
2) Data at RPOSI and RNEGI is ignored.
3) All receive-side signals take on timing synchronous with TCLK instead of RCLKI.
Please note that it is not acceptable to have RCLK connected to TCLK during this loopback because this
causes an unstable condition.
0 = loopback disabled
1 = loopback enabled
Bit 1/Payload Loopback (PLB). When PLB is enabled, the following occurs:
1)
2)
3)
4)
Data is transmitted from the TPOSO and TNEGO pins synchronous with RCLK instead of TCLK.
All the receive side signals continue to operate normally.
Data at the TSER, TDATA, and TSIG pins is ignored.
The TLCLK signal becomes synchronous with RCLK instead of TCLK.
0 = loopback disabled
1 = loopback enabled
T1 Mode. Normally, this loopback is only enabled when ESF framing is being performed but can also be
enabled in D4 framing applications. In a PLB situation, the DS2156 loops the 192 bits of payload data
(with BPVs corrected) from the receive section back to the transmit section. The FPS framing pattern,
CRC6 calculation, and the FDL bits are not looped back; they are reinserted by the DS2156.
E1 Mode. In a PLB situation, the DS2156 loops the 248 bits of payload data (with BPVs corrected) from
the receive section back to the transmit section. The transmit section modifies the payload as if it was input
at TSER. The FAS word; Si, Sa, and E bits; and CRC4 are not looped back; they are reinserted by the
DS2156.
Bit 2/Remote Loopback (RLB). In this loopback, data input by the RPOSI and RNEGI pins is transmitted back to
the TPOSO and TNEGO pins. Data continues to pass through the receive-side framer of the DS2156 as it would
normally. Data from the transmit-side formatter is ignored. See Figure 2-1 for more details.
0 = loopback disabled
1 = loopback enabled
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DS2156
Bit 3/Local Loopback (LLB). In this loopback, data continues to be transmitted as normal through the transmit
side of the SCT. Data being received at RTIP and RRING are replaced with the data being transmitted. Data in this
loopback passes through the jitter attenuator. See Figure 2-2 for more details.
0 = loopback disabled
1 = loopback enabled
Bit 4/Line Interface Unit Mux Control (LIUC). This is a software version of the LIUC pin. When the LIUC pin
is connected high, the LIUC bit has control. When the LIUC pin is connected low, the framer and LIU are
separated and the LIUC bit has no effect
0 = if LIUC pin connected high, LIU internally connected to framer block and deactivate the
TPOSI/TNEGI/TCLKI/RPOSI/RNEGI/RCLKI pins
1 = if LIUC pin connected high, disconnect LIU from framer block and activate the
TPOSI/TNEGI/TCLKI/RPOSI/RNEGI/RCLKI pins
LIUC Pin
0
0
1
1
LIUC Bit
0
1
0
1
Condition
LIU and framer separated
LIU and framer separated
LIU and framer connected
LIU and framer separated
Bits 5 to 7/Unused, must be set to 0 for proper operation
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DS2156
12.1 Per-Channel Loopback
The per-channel loopback registers (PCLRs) determine which channels (if any) from the backplane
should be replaced with the data from the receive side or, i.e., off of the T1 or E1 line. If this loopback is
enabled, then transmit and receive clocks and frame syncs must be synchronized. One method to
accomplish this is to connect RCLK to TCLK and RFSYNC to TSYNC. There are no restrictions on
which channels can be looped back or on how many channels can be looped back.
Each of the bit positions in the per-channel loopback registers (PCLR1/PCLR2/PCLR3/PCLR4)
represents a DS0 channel in the outgoing frame. When these bits are set to a 1, data from the
corresponding receive channel replaces the data on TSER for that channel.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH8
0
PCLR1
Per-Channel Loopback Enable Register 1
4Bh
6
CH7
0
5
CH6
0
4
CH5
0
3
CH4
0
2
CH3
0
1
CH2
0
0
CH1
0
Bits 0 to 7/Per-Channel Loopback Enable for Channels 1 to 8 (CH1 to CH8)
0 = loopback disabled
1 = enable loopback; source data from the corresponding receive channel
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH16
0
PCLR2
Per-Channel Loopback Enable Register 2
4Ch
6
CH15
0
5
CH14
0
4
CH13
0
3
CH12
0
2
CH11
0
1
CH10
0
Bits 0 to 7/Per-Channel Loopback Enable for Channels 9 to 16 (CH9 to CH16)
0 = loopback disabled
1 = enable loopback; source data from the corresponding receive channel
80 of 265
0
CH9
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH24
0
PCLR3
Per-Channel Loopback Enable Register 3
4Dh
6
CH23
0
5
CH22
0
4
CH21
0
3
CH20
0
2
CH19
0
1
CH18
0
0
CH17
0
Bits 0 to 7/Per-Channel Loopback Enable for Channels 17 to 24 (CH17 to CH24)
0 = loopback disabled
1 = enable loopback; source data from the corresponding receive channel
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH32
0
PCLR4
Per-Channel Loopback Enable Register 4
4Eh
6
CH31
0
5
CH30
0
4
CH29
0
3
CH28
0
2
CH27
0
1
CH26
0
Bits 0 to 7/Per-Channel Loopback Enable for Channels 25 to 32 (CH25 to CH32)
0 = loopback disabled
1 = enable loopback; source data from the corresponding receive channel
81 of 265
0
CH25
0
DS2156
13.
ERROR COUNT REGISTERS
The DS2156 contains four counters that are used to accumulate line-coding errors, path errors, and
synchronization errors. Counter update options include one-second boundaries, 42ms (T1 mode only),
62ms (E1 mode only), or manual. See Error-Counter Configuration Register (ERCNT). When updated
automatically, the user can use the interrupt from the timer to determine when to read these registers. All
four counters saturate at their respective maximum counts, and they do not roll over. Note: Only the linecode violation count register has the potential to overflow, but the bit error would have to exceed 10E-2
before this would occur.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
ERCNT
Error-Counter Configuration Register
41h
6
MECU
0
5
ECUS
0
4
EAMS
0
3
VCRFS
0
2
FSBE
0
1
MOSCRF
0
0
LCVCRF
0
Bit 0/T1 Line-Code Violation Count Register Function Select (LCVCRF)
0 = do not count excessive 0s
1 = count excessive 0s
Bit 1/Multiframe Out-of-Sync Count Register Function Select (MOSCRF)
0 = count errors in the framing bit position
1 = count the number of multiframes out-of-sync
Bit 2/PCVCR Fs-Bit Error-Report Enable (FSBE)
0 = do not report bit errors in Fs-bit position; only Ft-bit position
1 = report bit errors in Fs-bit position as well as Ft-bit position
Bit 3/E1 Line-Code Violation Count Register Function Select (VCRFS)
0 = count bipolar violations (BPVs)
1 = count code violations (CVs)
Bit 4/Error-Accumulation Mode Select (EAMS)
0 = ERCNT.5 determines accumulation time
1 = ERCNT.6 determines accumulation time
Bit 5/Error-Counter Update Select (ECUS)
T1 Mode:
0 = update error counters once a second
1 = update error counters every 42ms (333 frames)
E1 Mode:
0 = update error counters once a second
1 = update error counters every 62.5ms (500 frames)
Bit 6/Manual Error-Counter Update (MECU). When enabled by ERCNT.4, the changing of this bit from a 0 to
a 1 allows the next clock cycle to load the error-counter registers with the latest counts and reset the counters. The
user must wait a minimum of 1.5 RCLK clock periods before reading the error count registers to allow for proper
update.
Bit 7/Unused, must be set to 0 for proper operation
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DS2156
13.1 Line-Code Violation Count Register (LCVCR)
13.1.1
T1 Operation
T1 code violations are defined as bipolar violations (BPVs) or excessive 0s. If the B8ZS mode is set for
the receive side, then B8ZS codewords are not counted. This counter is always enabled; it is not disabled
during receive loss-of-synchronization (RLOS = 1) conditions. Table 13-A shows what the LCVCRs
count.
Table 13-A. T1 Line Code Violation Counting Options
COUNT EXCESSIVE
ZEROS?
(ERCNT.0)
No
Yes
No
Yes
B8ZS ENABLED?
(T1RCR2.5)
No
No
Yes
Yes
COUNTED IN THE LCVCRs
BPVs
BPVs + 16 consecutive 0s
BPVs (B8ZS codewords not counted)
BPVs + 8 consecutive 0s
13.1.2 E1 Operation
Either bipolar violations or code violations can be counted. Bipolar violations are defined as consecutive
marks of the same polarity. In this mode, if the HDB3 mode is set for the receive side, then HDB3
codewords are not counted as BPVs. If ERCNT.3 is set, then the LVC counts code violations as defined
in ITU O.161. Code violations are defined as consecutive bipolar violations of the same polarity. In most
applications, the framer should be programmed to count BPVs when receiving AMI code and to count
CVs when receiving HDB3 code. This counter increments at all times and is not disabled by loss-of-sync
conditions. The counter saturates at 65,535 and does not roll over. The bit-error rate on an E1 line would
have to be greater than 10-2 before the VCR would saturate (Table 13-B).
Table 13-B. E1 Line-Code Violation Counting Options
E1 CODE VIOLATION SELECT
(ERCNT.3)
0
1
COUNTED IN THE LCVCRs
BPVs
CVs
83 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
LCVC15
0
LCVCR1
Line-Code Violation Count Register 1
42h
6
LCVC14
0
5
LCVC13
0
4
LCVC12
0
3
LCVC11
0
2
LCVC10
0
1
LCVC9
0
0
LCCV8
0
Bits 0 to 7/Line-Code Violation Counter Bits 8 to 15 (LCVC8 to LCVC15). LCV15 is the MSB of the 16-bit
code violation count.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
LCVC7
0
LCVCR2
Line-Code Violation Count Register 2
43h
6
LCVC6
0
5
LCVC5
0
4
LCVC4
0
3
LCVC3
0
2
LCVC2
0
1
LCVC1
0
0
LCVC0
0
Bits 0 to 7/Line-Code Violation Counter Bits 0 to 7 (LCVC0 to LCVC7). LCV0 is the LSB of the 16-bit code
violation count.
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DS2156
13.2 Path Code Violation Count Register (PCVCR)
13.2.1 T1 Operation
The path code violation count register records Ft, Fs, or CRC6 errors in T1 frames. When the receive side
of a framer is set to operate in the T1 ESF framing mode, PCVCR records errors in the CRC6 codewords.
When set to operate in the T1 D4 framing mode, PCVCR counts errors in the Ft framing bit position.
Through the ERCNT.2 bit, a framer can be programmed to also report errors in the Fs framing bit
position. The PCVCR is disabled during receive loss-of-synchronization (RLOS = 1) conditions. Table
13-C shows what errors the PCVCR counts.
Table 13-C. T1 Path Code Violation Counting Arrangements
FRAMING MODE
COUNT Fs ERRORS?
D4
D4
ESF
No
Yes
Don’t Care
COUNTED
IN THE PCVCRs
Errors in the Ft pattern
Errors in both the Ft and Fs patterns
Errors in the CRC6 codewords
13.2.2 E1 Operation
The path code violation-count register records CRC4 errors. Since the maximum CRC4 count in a onesecond period is 1000, this counter cannot saturate. The counter is disabled during loss-of-sync at either
the FAS or CRC4 level; it continues to count if loss-of-multiframe sync occurs at the CAS level.
Path code violation-count register 1 (PCVCR1) is the most significant word and PCVCR2 is the least
significant word of a 16-bit counter that records path violations (PVs).
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
PCVC15
0
PCVCR1
Path Code Violation Count Register 1
44h
6
PCVC14
0
5
PCVC13
0
4
PCVC12
0
3
PCVC11
0
2
PCVC10
0
1
PCVC9
0
0
PCVC8
0
Bits 0 to 7/Path Code Violation Counter Bits 8 to 15 (PCVC8 to PCVC15). PCVC15 is the MSB of the 16-bit
path code violation count.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
PCVC7
0
PCVCR2
Path Code Violation Count Register 2
45h
6
PCVC6
0
5
PCVC5
0
4
PCVC4
0
3
PCVC3
0
2
PCVC2
0
1
PCVC1
0
0
PCVC0
0
Bits 0 to 7/Path Code Violation Counter Bits 0 to 7 (PCVC0 to PCVC7). PCVC0 is the LSB of the 16-bit path
code violation count.
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DS2156
13.3 Frames Out-of-Sync Count Register (FOSCR)
13.3.1 T1 Operation
The FOSCR is used to count the number of multiframes that the receive synchronizer is out of sync. This
number is useful in ESF applications needing to measure the parameters loss-of-frame count (LOFC) and
ESF error events as described in AT&T publication TR54016. When the FOSCR is operated in this
mode, it is not disabled during receive loss-of-synchronization (RLOS = 1) conditions. The FOSCR has
an alternate operating mode whereby it counts either errors in the Ft framing pattern (in the D4 mode) or
errors in the FPS framing pattern (in the ESF mode). When the FOSCR is operated in this mode, it is
disabled during receive loss-of-synchronization (RLOS = 1) conditions. Table 13-D shows what the
FOSCR is capable of counting.
Table 13-D. T1 Frames Out-of-Sync Counting Arrangements
FRAMING MODE
(T1RCR1.3)
D4
D4
ESF
ESF
COUNT MOS OR
F-BIT ERRORS
(ERCNT.1)
MOS
F-Bit
MOS
F-Bit
COUNTED IN THE FOSCRs
Number of multiframes out-of-sync
Errors in the Ft pattern
Number of multiframes out-of-sync
Errors in the FPS pattern
13.3.2 E1 Operation
The FOSCR counts word errors in the FAS in time slot 0. This counter is disabled when RLOS is high.
FAS errors are not counted when the framer is searching for FAS alignment and/or synchronization at
either the CAS or CRC4 multiframe level. Since the maximum FAS word error count in a one-second
period is 4000, this counter cannot saturate.
The frames out-of-sync count register 1 (FOSCR1) is the most significant word and FOSCR2 is the least
significant word of a 16-bit counter that records frames out-of-sync.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
FOS15
0
FOSCR1
Frames Out-of-Sync Count Register 1
46h
6
FOS14
0
5
FOS13
0
4
FOS12
0
3
FOS11
0
2
FOS10
0
1
FOS9
0
0
FOS8
0
Bits 0 to 7/Frames Out-of-Sync Counter Bits 8 to 15 (FOS8 to FOS15). FOS15 is the MSB of the 16-bit frames
out-of-sync count.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
FOS7
0
FOSCR2
Frames Out-of-Sync Count Register 2
47h
6
FOS6
0
5
FOS5
0
4
FOS4
0
3
FOS3
0
2
FOS2
0
1
FOS1
0
0
FOS0
0
Bits 0 to 7/Frames Out-of-Sync Counter Bits 0 to 7 (FOS0 to FOS7). FOS0 is the LSB of the 16-bit frames outof-sync count.
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DS2156
13.4 E-Bit Counter (EBCR)
This counter is only available in E1 mode. E-bit count register 1 (EBCR1) is the most significant word
and EBCR2 is the least significant word of a 16-bit counter that records far-end block errors (FEBE) as
reported in the first bit of frames 13 and 15 on E1 lines running with CRC4 multiframe. These count
registers increment once each time the received E-bit is set to 0. Since the maximum E-bit count in a onesecond period is 1000, this counter cannot saturate. The counter is disabled during loss-of-sync at either
the FAS or CRC4 level; it continues to count if loss-of-multiframe sync occurs at the CAS level.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
EB15
0
EBCR1
E-Bit Count Register 1
48h
6
EB14
0
5
EB13
0
4
EB12
0
3
EB11
0
2
EB10
0
1
EB9
0
0
EB8
0
Bits 0 to 7/E-Bit Counter Bits 8 to 15 (EB8 to EB15). EB15 is the MSB of the 16-bit E-bit count.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
EB7
0
EBCR2
E-Bit Count Register 2
49h
6
EB6
0
5
EB5
0
4
EB4
0
3
EB3
0
2
EB2
0
1
EB1
0
0
EB0
0
Bits 0 to 7/E-Bit Counter Bits 0 to 7 (EB0 to EB7). EB0 is the LSB of the 16-bit E-bit count.
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DS2156
14.
DS0 MONITORING FUNCTION
The DS2156 has the ability to monitor one DS0 64kbps channel in the transmit direction and one DS0
channel in the receive direction at the same time. In the transmit direction, the user determines which
channel is to be monitored by properly setting the TCM0 to TCM4 bits in the TDS0SEL register. In the
receive direction, the RCM0 to RCM4 bits in the RDS0SEL register need to be properly set. The DS0
channel pointed to by the TCM0 to TCM4 bits appear in the transmit DS0 monitor (TDS0M) register.
The DS0 channel pointed to by the RCM0 to RCM4 bits appear in the receive DS0 (RDS0M) register.
The TCM4 to TCM0 and RCM4 to RCM0 bits should be programmed with the decimal decode of the
appropriate T1or E1 channel. T1 channels 1 through 24 map to register values 0 through 23. E1 channels
1 through 32 map to register values 0 through 31. For example, if DS0 channel 6 in the transmit direction
and DS0 channel 15 in the receive direction needed to be monitored, then the following values would be
programmed into TDS0SEL and RDS0SEL:
TCM4 = 0
TCM3 = 0
TCM2 = 1
TCM1 = 0
TCM0 = 1
RCM4 = 0
RCM3 = 1
RCM2 = 1
RCM1 = 1
RCM0 = 0
Register Name:
Register Description:
Register Address:
TDS0SEL
Transmit Channel Monitor Select
74h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
TCM4
0
3
TCM3
0
2
TCM2
0
1
TCM1
0
0
TCM0
0
Bits 0 to 4/Transmit Channel Monitor Bits (TCM0 to TCM4). TCM0 is the LSB of a 5-bit channel select that
determines which transmit channel data appear in the TDS0M register.
Bits 5 to 7/Unused, must be set to 0 for proper operation
Register Name:
Register Description:
Register Address:
TDS0M
Transmit DS0 Monitor Register
75h
Bit #
Name
Default
6
B2
0
7
B1
0
5
B3
0
4
B4
0
3
B5
0
2
B6
0
1
B7
0
0
B8
0
Bits 0 to 7/Transmit DS0 Channel Bits (B1 to B8). Transmit channel data that has been selected by the transmit
channel monitor select register. B8 is the LSB of the DS0 channel (last bit to be transmitted).
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DS2156
Register Name:
Register Description:
Register Address:
RDS0SEL
Receive Channel Monitor Select
76h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
RCM4
0
3
RCM3
0
2
RCM2
0
1
RCM1
0
0
RCM0
0
Bits 0 to 4/Receive Channel Monitor Bits (RCM0 to RCM4). RCM0 is the LSB of a 5-bit channel select that
determines which receive DS0 channel data appear in the RDS0M register.
Bits 5 to 7/Unused, must be set to 0 for proper operation
Register Name:
Register Description:
Register Address:
RDS0M
Receive DS0 Monitor Register
77h
Bit #
Name
Default
6
B2
0
7
B1
0
5
B3
0
4
B4
0
3
B5
0
2
B6
0
1
B7
0
0
B8
0
Bits 0 to 7/Receive DS0 Channel Bits (B1 to B8). Receive channel data that has been selected by the receive
channel monitor select register. B8 is the LSB of the DS0 channel (last bit to be received).
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DS2156
15.
SIGNALING OPERATION
There are two methods to access receive signaling data and provide transmit signaling data, processorbased (software-based) or hardware-based. Processor-based refers to access through the transmit and
receive signaling registers RS1–RS16 and TS1–TS16. Hardware-based refers to the TSIG and RSIG pins.
Both methods can be used simultaneously.
15.1 Receive Signaling
Figure 15-1. Simplified Diagram of Receive Signaling Path
PER-CHANNEL
CONTROL
T1/E1 DATA STREAM
SIGNALING
EXTRACTION
RECEIVE SIGNALING
REGISTERS
CHANGE-OF-STATE
INDICATION
REGISTERS
ALL-ONES
REINSERTION
CONTROL
SIGNALING
BUFFERS
RSER
RSYNC
RSIG
15.1.1 Processor-Based Signaling
The robbed-bit signaling (T1) or TS16 CAS signaling (E1) is sampled in the receive data stream and
copied into the receive signaling registers, RS1–RS16. In T1 mode, only RS1–RS12 are used. The
signaling information in these registers is always updated on multiframe boundaries. This function is
always enabled.
15.1.1.1 Change-of-State
To avoid constant monitoring of the receive signaling registers, the DS2156 can be programmed to alert
the host when any specific channel or channels undergo a change of their signaling state.
RSCSE1–RSCSE4 for E1 and RSCSE1–RSCSE3 for T1 are used to select which channels can cause a
change-of-state indication. The change-of-state is indicated in status register 5 (SR1.5). If signaling
integration (CCR1.5) is enabled, then the new signaling state must be constant for three multiframes
before a change-of-state is indicated. The user can enable the INT pin to toggle low upon detection of a
change in signaling by setting the IMR1.5 bit. The signaling integration mode is global and cannot be
enabled on a channel-by-channel basis.
The user can identity which channels have undergone a signaling change-of-state by reading the
RSINFO1–RSINFO4 registers. The information from these registers inform the user which RSx register
to read for the new signaling data. All changes are indicated in the RSINFO1–RSINFO4 registers
regardless of the RSCSE1–RSCSE4 registers.
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DS2156
15.1.2 Hardware-Based Receive Signaling
In hardware-based signaling the signaling data can be obtained from the RSER pin or the RSIG pin.
RSIG is a signaling PCM stream output on a channel-by-channel basis from the signaling buffer. The
signaling data, T1 robbed bit or E1 TS16, is still present in the original data stream at RSER. The
signaling buffer provides signaling data to the RSIG pin and also allows signaling data to be reinserted
into the original data stream in a different alignment that is determined by a multiframe signal from the
RSYNC pin. In this mode, the receive elastic store can be enabled or disabled. If the receive elastic store
is enabled, then the backplane clock (RSYSCLK) can be either 1.544MHz or 2.048MHz. In the ESF
framing mode, the ABCD signaling bits are output on RSIG in the lower nibble of each channel. The
RSIG data is updated once a multiframe (3ms) unless a freeze is in effect. In the D4 framing mode, the
AB signaling bits are output twice on RSIG in the lower nibble of each channel. Hence, bits 5 and 6
contain the same data as bits 7 and 8, respectively, in each channel. The RSIG data is updated once a
multiframe (1.5ms) unless a freeze is in effect. See the timing diagrams in Section 34 for some examples.
15.1.2.1 Receive Signaling Reinsertion at RSER
In this mode, the user provides a multiframe sync at the RSYNC pin and the signaling data is reinserted
based on this alignment. In T1 mode, this results in two copies of the signaling data in the RSER data
stream, the original signaling data and the realigned data. This is of little consequence in voice channels.
Reinsertion can be avoided in data channels since this feature is activated on a per-channel basis. In this
mode, the elastic store must be enabled; however, the backplane clock can be either 1.544MHz or
2.048MHz.
Signaling reinsertion can be enabled on a per-channel basis by setting the RSRCS bit high in the PCPR
register. The channels that will have signaling reinserted are selected by writing to the PCDR1–PCDR3
registers for T1 mode and PCDR1–PCDR4 registers for E1 mode. In E1 mode, the user generally selects
all channels or none for reinsertion. In E1 mode, signaling reinsertion on all channels can be enabled with
a single bit, SIGCR.7 (GRSRE). This bit allows the user to reinsert all signaling channels without having
to program all channels through the per-channel function.
15.1.2.2 Force Receive Signaling All Ones
In T1 mode, the user can, on a per-channel basis, force the robbed-bit signaling bit positions to a 1 by
using the per-channel register (Section 5). The user sets the BTCS bit in the PCPR register. The channels
that will be forced to 1 are selected by writing to the PCDR1–PCDR3 registers.
15.1.2.3 Receive Signaling Freeze
The signaling data in the four multiframe signaling buffers is frozen in a known good state upon either a
loss of synchronization (OOF event), carrier loss, or frame slip. This action meets the requirements of
BellCore TR–TSY–000170 for signaling freezing. To allow this freeze action to occur, the RFE control
bit (SIGCR.4) should be set high. The user can force a freeze by setting the RFF control bit (SIGCR.3)
high. The RSIGF output pin provides a hardware indication that a freeze is in effect. The four-multiframe
buffer provides a three-multiframe delay in the signaling bits provided at the RSIG pin (and at the RSER
pin if receive signaling reinsertion is enabled). When freezing is enabled (RFE = 1), the signaling data is
held in the last-known good state until the corrupting error condition subsides. When the error condition
subsides, the signaling data is held in the old state for at least an additional 9ms (or 4.5ms in D4 framing
mode) before updating with new signaling data.
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DS2156
Register Name:
Register Description:
Register Address:
SIGCR
Signaling Control Register
40h
Bit #
Name
Default
6
—
0
7
GRSRE
0
5
—
0
4
RFE
0
3
RFF
0
2
RCCS
0
1
TCCS
0
0
FRSAO
0
Bit 0/Force Receive Signaling All Ones (FRSAO). In T1 mode, this bit forces all signaling data at the RSIG and
RSER pin to all ones. This bit has no effect in E1 mode.
0 = normal signaling data at RSIG and RSER
1 = force signaling data at RSIG and RSER to all ones
Bit 1/Transmit Time Slot Control for CAS Signaling (TCCS). Controls the order that signaling is transmitted
from the transmit signaling registers. This bit should be set = 0 in T1 mode.
0 = signaling data is CAS format
1 = signaling data is CCS format
Bit 2/Receive Time Slot Control for CAS Signaling (RCCS). Controls the order that signaling is placed into the
receive signaling registers. This bit should be set = 0 in T1 mode.
0 = signaling data is CAS format
1 = signaling data is CCS format
Bit 3/Receive Force Freeze (RFF). Freezes receive-side signaling at RSIG (and RSER if receive signaling
reinsertion is enabled); overrides receive freeze enable (RFE). See Section 15.1.2.3 for details.
0 = do not force a freeze event
1 = force a freeze event
Bit 4/Receive Freeze Enable (RFE). See Section 15.1.2.3 for details.
0 = no freezing of receive signaling data occurs
1 = allow freezing of receive signaling data at RSIG (and RSER if receive signaling reinsertion is enabled)
Bits 5, 6/Unused, must be set to 0 for proper operation
Bit 7/Global Receive Signaling Reinsertion Enable (GRSRE). This bit allows the user to reinsert all signaling
channels without programming all channels through the per-channel function.
0 = do not reinsert all signaling
1 = reinsert all signaling
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DS2156
Register Name:
Register Description:
Register Address:
(MSB)
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
Register Name:
Register Description:
Register Address:
(MSB)
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
RS1 to RS12
Receive Signaling Registers (T1 Mode, ESF Format)
60h to 6Bh
CH2-C
CH4-C
CH6-C
CH8-C
CH10-C
CH12-C
CH14-C
CH16-C
CH18-C
CH20-C
CH22-C
CH24-C
CH2-D
CH4-D
CH6-D
CH8-D
CH10-D
CH12-D
CH14-D
CH16-D
CH18-D
CH20-D
CH22-D
CH24-D
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
CH1-C
CH3-C
CH5-C
CH7-C
CH9-C
CH11-C
CH13-C
CH15-C
CH17-C
CH19-C
CH21-C
CH23-C
(LSB)
CH1-D
CH3-D
CH5-D
CH7-D
CH9-D
CH11-D
CH13-D
CH15-D
CH17-D
CH19-D
CH21-D
CH23-D
RS1
RS2
RS3
RS4
RS5
RS6
RS7
RS8
RS9
RS10
RS11
RS12
RS1 to RS12
Receive Signaling Registers (T1 Mode, D4 Format)
60h to 6Bh
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
(LSB)
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
Note: In D4 format, TS1–TS12 contain signaling data for two frames. Bold type indicates data for second frame.
93 of 265
RS1
RS2
RS3
RS4
RS5
RS6
RS7
RS8
RS9
RS10
RS11
RS12
DS2156
Register Name:
Register Description:
Register Address:
(MSB)
0
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH26-A
CH28-A
CH30-A
0
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
CH26-B
CH28-B
CH30-B
Register Name:
Register Description:
Register Address:
(MSB)
1
9
17
25
33
41
49
57
65
73
81
89
97
105
113
121
2
10
18
26
34
42
50
58
66
74
82
90
98
106
114
122
RS1 to RS16
Receive Signaling Registers (E1 Mode, CAS Format)
60h to 6Fh
0
CH2-C
CH4-C
CH6-C
CH8-C
CH10-C
CH12-C
CH14-C
CH16-C
CH18-C
CH20-C
CH22-C
CH24-C
CH26-C
CH28-C
CH30-C
0
CH2-D
CH4-D
CH6-D
CH8-D
CH10-D
CH12-D
CH14-D
CH16-D
CH18-D
CH20-D
CH22-D
CH24-D
CH26-D
CH28-D
CH30-D
X
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
CH25-A
CH27-A
CH29-A
Y
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
CH25-B
CH27-B
CH29-B
X
CH1-C
CH3-C
CH5-C
CH7-C
CH9-C
CH11-C
CH13-C
CH15-C
CH17-C
CH19-C
CH21-C
CH23-C
CH25-C
CH27-C
CH29-C
(LSB)
X
CH1-D
CH3-D
CH5-D
CH7-D
CH9-D
CH11-D
CH13-D
CH15-D
CH17-D
CH19-D
CH21-D
CH23-D
CH25-D
CH27-D
CH29-D
RS1
RS2
RS3
RS4
RS5
RS6
RS7
RS8
RS9
RS10
RS11
RS12
RS13
RS14
RS15
RS16
RS1 to RS16
Receive Signaling Registers (E1 Mode, CCS Format)
60h to 6Fh
3
11
19
27
35
43
51
59
67
75
83
91
99
107
115
123
4
12
20
28
36
44
52
60
68
76
84
92
100
108
116
124
5
13
21
29
37
45
53
61
69
77
85
93
101
109
117
125
6
14
22
30
38
46
54
62
70
78
86
94
102
110
118
126
94 of 265
7
15
23
31
39
47
55
63
71
79
87
95
103
111
119
127
(LSB)
8
16
24
32
40
48
56
64
72
80
88
96
104
112
120
128
RS1
RS2
RS3
RS4
RS5
RS6
RS7
RS8
RS9
RS10
RS11
RS12
RS13
RS14
RS15
RS16
DS2156
Register Name:
Register Description:
Register Address:
(MSB)
CH8
CH16
CH24
CH7
CH15
CH23
RSCSE1, RSCSE2, RSCSE3, RSCSE4
Receive Signaling Change-of-State Interrupt Enable
3Ch, 3Dh, 3Eh, 3Fh
CH6
CH14
CH22
CH30
CH5
CH13
CH21
CH29
CH4
CH12
CH20
CH28
CH3
CH11
CH19
CH27
CH2
CH10
CH18
CH26
(LSB)
CH1
CH9
CH17
CH25
RSCSE1
RSCSE2
RSCSE3
RSCSE4
Setting any of the CH1–CH30 bits in the RSCSE1–RSCSE4 registers causes an interrupt when that channel’s
signaling data changes state.
Register Name:
Register Description:
Register Address:
(MSB)
CH8
CH16
CH24
CH7
CH15
CH23
RSINFO1, RSINFO2, RSINFO3, RSINFO4
Receive Signaling Change-of-State Information
38h, 39h, 3Ah, 3Bh
CH6
CH14
CH22
CH30
CH5
CH13
CH21
CH29
CH4
CH12
CH20
CH28
CH3
CH11
CH19
CH27
CH2
CH10
CH18
CH26
(LSB)
CH1
CH9
CH17
CH25
RSINFO1
RSINFO2
RSINFO3
RSINFO4
When a channel’s signaling data changes state, the respective bit in registers RSINFO1–4 is set. An interrupt is
generated if the channel was also enabled as an interrupt source by setting the appropriate bit in RSCSE1–4. The
bit remains set until read.
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DS2156
15.2 Transmit Signaling
Figure 15-2. Simplified Diagram of Transmit Signaling Path
TRANSMIT
SIGNALING
REGISTERS
1
0
0
T1/E1 DATA
STREAM
TSER
0
1
1
B7
SIGNALING
BUFFERS
TSIG
T1TCR1.4
PER-CHANNEL
CONTROL
PER-CHANNEL
CONTROL
PCPR.3
SSIE1 - SSIE4
ONLY APPLIES TO T1 MODE
15.2.1 Processor-Based Mode
In processor-based mode, signaling data is loaded into the transmit signaling registers (TS1–TS16) by the
host interface. On multiframe boundaries, the contents of these registers are loaded into a shift register for
placement in the appropriate bit position in the outgoing data stream. The user can employ the transmit
multiframe interrupt in status register 4 (SR4.4) to know when to update the signaling bits. The user need
not update any transmit signaling register for which there is no change-of-state for that register.
Each transmit signaling register contains the robbed-bit signaling (T1) or TS16 CAS signaling (E1) for
two time slots that are inserted into the outgoing stream, if enabled to do so through T1TCR1.4 (T1
mode) or E1TCR1.6 (E1 mode). In T1 mode, only TS1–TS12 are used.
Signaling data can be sourced from the TS registers on a per-channel basis by using the software
signaling insertion enable registers, SSIE1–SSIE4.
15.2.1.1 T1 Mode
In T1 ESF framing mode, there are four signaling bits per channel (A, B, C, and D). TS1–TS12 contain a
full multiframe of signaling data. In T1 D4 framing mode, there are only two signaling bits per channel
(A and B). In T1 D4 framing mode, the framer uses the C and D bit positions as the A and B bit positions
for the next multiframe. In D4 mode, two multiframes of signaling data can be loaded into TS1–TS12.
The framer loads the contents of TS1–TS12 into the outgoing shift register every other D4 multiframe. In
D4 mode, the host should load new contents into TS1–TS12 on every other multiframe boundary and no
later than 120µs after the boundary.
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DS2156
15.2.1.2 E1 Mode
In E1 mode, TS16 carries the signaling information. This information can be in either CCS (common
channel signaling) or CAS (channel associated signaling) format. The 32 time slots are referenced by two
different channel number schemes in E1. In “Channel” numbering, TS0–TS31 are labeled channels 1
through 32. In “Phone Channel” numbering, TS1–TS15 are labeled channel 1 through channel 15 and
TS17–TS31 are labeled channel 15 through channel 30.
Table 15-A. Time Slot Numbering Schemes
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
TS
Channel 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Phone
Channel
97 of 265
DS2156
Register Name:
Register Description:
Register Address:
(MSB)
0
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH26-A
CH28-A
CH30-A
0
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
CH26-B
CH28-B
CH30-B
Register Name:
Register Description:
Register Address:
(MSB)
1
9
17
25
33
41
49
57
65
73
81
89
97
105
113
121
2
10
18
26
34
42
50
58
66
74
82
90
98
106
114
122
TS1 to TS16
Transmit Signaling Registers (E1 Mode, CAS Format)
50h to 5Fh
0
CH2-C
CH4-C
CH6-C
CH8-C
CH10-C
CH12-C
CH14-C
CH16-C
CH18-C
CH20-C
CH22-C
CH24-C
CH26-C
CH28-C
CH30-C
0
CH2-D
CH4-D
CH6-D
CH8-D
CH10-D
CH12-D
CH14-D
CH16-D
CH18-D
CH20-D
CH22-D
CH24-D
CH26-D
CH28-D
CH30-D
X
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
CH25-A
CH27-A
CH29-A
Y
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
CH25-B
CH27-B
CH29-B
X
CH1-C
CH3-C
CH5-C
CH7-C
CH9-C
CH11-C
CH13-C
CH15-C
CH17-C
CH19-C
CH21-C
CH23-C
CH25-C
CH27-C
CH29-C
(LSB)
X
CH1-D
CH3-D
CH5-D
CH7-D
CH9-D
CH11-D
CH13-D
CH15-D
CH17-D
CH19-D
CH21-D
CH23-D
CH25-D
CH27-D
CH29-D
TS1
TS2
TS3
TS4
TS5
TS6
TS7
TS8
TS9
TS10
TS11
TS12
TS13
TS14
TS15
TS16
TS1 to TS16
Transmit Signaling Registers (E1 Mode, CCS Format)
50h to 5Fh
3
11
19
27
35
43
51
59
67
75
83
91
99
107
115
123
4
12
20
28
36
44
52
60
68
76
84
92
100
108
116
124
5
13
21
29
37
45
53
61
69
77
85
93
101
109
117
125
6
14
22
30
38
46
54
62
70
78
86
94
102
110
118
126
98 of 265
7
15
23
31
39
47
55
63
71
79
87
95
103
111
119
127
(LSB)
8
16
24
32
40
48
56
64
72
80
88
96
104
112
120
128
TS1
TS2
TS3
TS4
TS5
TS6
TS7
TS8
TS9
TS10
TS11
TS12
TS13
TS14
TS15
TS16
DS2156
Register Name:
Register Description:
Register Address:
(MSB)
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
Register Name:
Register Description:
Register Address:
(MSB)
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
TS1 to TS12
Transmit Signaling Registers (T1 Mode, ESF Format)
50h to 5Bh
CH2-C
CH4-C
CH6-C
CH8-C
CH10-C
CH12-C
CH14-C
CH16-C
CH18-C
CH20-C
CH22-C
CH24-C
CH2-D
CH4-D
CH6-D
CH8-D
CH10-D
CH12-D
CH14-D
CH16-D
CH18-D
CH20-D
CH22-D
CH24-D
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
CH1-C
CH3-C
CH5-C
CH7-C
CH9-C
CH11-C
CH13-C
CH15-C
CH17-C
CH19-C
CH21-C
CH23-C
(LSB)
CH1-D
CH3-D
CH5-D
CH7-D
CH9-D
CH11-D
CH13-D
CH15-D
CH17-D
CH19-D
CH21-D
CH23-D
TS1
TS2
TS3
TS4
TS5
TS6
TS7
TS8
TS9
TS10
TS11
TS12
TS1 to TS12
Transmit Signaling Registers (T1 Mode, D4 Format)
50h to 5Bh
CH2-A
CH4-A
CH6-A
CH8-A
CH10-A
CH12-A
CH14-A
CH16-A
CH18-A
CH20-A
CH22-A
CH24-A
CH2-B
CH4-B
CH6-B
CH8-B
CH10-B
CH12-B
CH14-B
CH16-B
CH18-B
CH20-B
CH22-B
CH24-B
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
CH1-A
CH3-A
CH5-A
CH7-A
CH9-A
CH11-A
CH13-A
CH15-A
CH17-A
CH19-A
CH21-A
CH23-A
(LSB)
CH1-B
CH3-B
CH5-B
CH7-B
CH9-B
CH11-B
CH13-B
CH15-B
CH17-B
CH19-B
CH21-B
CH23-B
Note: In D4 format, TS1–TS12 contain signaling data for two frames. Bold type indicates data for second frame.
99 of 265
TS1
TS2
TS3
TS4
TS5
TS6
TS7
TS8
TS9
TS10
TS11
TS12
DS2156
15.2.2 Software Signaling Insertion-Enable Registers, E1 CAS Mode
In E1 CAS mode, the CAS signaling alignment/alarm byte can be sourced from the transmit signaling
registers along with the signaling data.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH7
0
SSIE1
Software Signaling Insertion Enable 1
08h
6
CH6
0
5
CH5
0
4
CH4
0
3
CH3
0
2
CH2
0
1
CH1
0
0
UCAW
0
Bit 0/Upper CAS Align/Alarm Word (UCAW). Selects the upper CAS align/alarm pattern (0000) to be sourced
from the upper 4 bits of the TS1 register.
0 = do not source the upper CAS align/alarm pattern from the TS1 register
1 = source the upper CAS align/alarm pattern from the TS1 register
Bits 1 to 7/Software Signaling-Insertion Enable for Channels 1 to 7 (CH1 to CH7). These bits determine
which channels are to have signaling inserted from the transmit signaling registers.
0 = do not source signaling data from the TSx registers for this channel
1 = source signaling data from the TSx registers for this channel
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH15
0
SSIE2
Software Signaling Insertion Enable 2
09h
6
CH14
0
5
CH13
0
4
CH12
0
3
CH11
0
2
CH10
0
1
CH9
0
0
CH8
0
Bits 0 to 7/Software Signaling Insertion Enable for Channels 8 to 15 (CH8 to CH15). These bits determine
which channels are to have signaling inserted from the transmit signaling registers.
0 = do not source signaling data from the TSx registers for this channel
1 = source signaling data from the TSx registers for this channel
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH22
0
SSIE3
Software Signaling Insertion Enable 3
0Ah
6
CH21
0
5
CH20
0
4
CH19
0
3
CH18
0
2
CH17
0
1
CH16
0
0
LCAW
0
Bit 0/Lower CAS Align/Alarm Word (LCAW). Selects the lower CAS align/alarm bits (xyxx) to be sourced
from the lower 4 bits of the TS1 register.
0 = do not source the lower CAS align/alarm bits from the TS1 register
1 = source the lower CAS alarm align/bits from the TS1 register
Bits 1 to 7/Software Signaling Insertion Enable for LCAW and Channels 16 to 22 (CH16 to CH22). These
bits determine which channels are to have signaling inserted from the transmit signaling registers.
0 = do not source signaling data from the TSx registers for this channel
1 = source signaling data from the TSx registers for this channel
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH30
0
SSIE4
Software Signaling Insertion Enable 4
0Bh
6
CH29
0
5
CH28
0
4
CH27
0
3
CH26
0
2
CH25
0
1
CH24
0
0
CH23
0
Bits 0 to 7/Software Signaling Insertion Enable for Channels 22 to 30 (CH23 to CH30). These bits determine
which channels are to have signaling inserted from the transmit signaling registers.
0 = do not source signaling data from the TSx registers for this channel
1 = source signaling data from the TSx registers for this channel
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DS2156
15.2.3 Software Signaling Insertion-Enable Registers, T1 Mode
In T1 mode, only registers SSIE1–SSIE3 are used since there are only 24 channels in a T1 frame.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH8
0
SSIE1
Software Signaling Insertion Enable 1
08h
6
CH7
0
5
CH6
0
4
CH5
0
3
CH4
0
2
CH3
0
1
CH2
0
0
CH1
0
Bits 0 to 7/Software Signaling Insertion Enable for Channels 1 to 8 (CH1 to CH8). These bits determine which
channels are to have signaling inserted from the transmit signaling registers.
0 = do not source signaling data from the TSx registers for this channel
1 = source signaling data from the TSx registers for this channel
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH16
0
SSIE2
Software Signaling-Insertion Enable 2
09h
6
CH15
0
5
CH14
0
4
CH13
0
3
CH12
0
2
CH11
0
1
CH10
0
0
CH9
0
Bits 0 to 7/Software Signaling Insertion Enable for Channels 9 to 16 (CH9 to CH16). These bits determine
which channels are to have signaling inserted from the transmit signaling registers.
0 = do not source signaling data from the TSx registers for this channel
1 = source signaling data from the TSx registers for this channel
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH24
0
SSIE3
Software Signaling-Insertion Enable 3
0Ah
6
CH23
0
5
CH22
0
4
CH21
0
3
CH20
0
2
CH19
0
1
CH18
0
0
CH17
0
Bits 0 to 7/Software Signaling Insertion Enable for Channels 17 to 24 (CH17 to CH24). These bits determine
which channels are to have signaling inserted from the transmit signaling registers.
0 = do not source signaling data from the TSx registers for this channel
1 = source signaling data from the TSx registers for this channel
15.2.4
Hardware-Based Mode
In hardware-based mode, signaling data is input through the TSIG pin. This signaling PCM stream is
buffered and inserted to the data stream being input at the TSER pin.
Signaling data can be inserted on a per-channel basis by the transmit hardware-signaling channel-select
(THSCS) function. The user has the ability to control which channels are to have signaling data from the
TSIG pin inserted into them on a per-channel basis. See Section 5 for details on using this per-channel
(THSCS) feature. The signaling insertion capabilities of the framer are available whether the transmitside elastic store is enabled or disabled. If the elastic store is enabled, the backplane clock (TSYSCLK)
can be either 1.544MHz or 2.048MHz. Also, if the elastic is enabled in conjunction with transmit
hardware signaling, CCR3.7 must be set = 0.
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DS2156
16.
PER-CHANNEL IDLE CODE GENERATION
Channel data can be replaced by an idle code on a per-channel basis in the transmit and receive
directions. When operated in the T1 mode, only the first 24 channels are used by the DS2156, the
remaining channels, CH25–CH32, are not used.
The DS2156 contains a 64-byte idle code array accessed by the idle array address register (IAAR) and the
per-channel idle code register (PCICR). The contents of the array contain the idle codes to be substituted
into the appropriate transmit or receive channels. This substitution can be enabled and disabled on a perchannel basis by the transmit-channel idle code-enable registers (TCICE1–4) and receive-channel idle
code-enable registers (RCICE1–4).
To program idle codes, first select a channel by writing to the IAAR register. Then write the idle code to
the PCICR register. For successive writes there is no need to load the IAAR with the next consecutive
address. The IAAR register automatically increments after a write to the PCICR register. The auto
increment feature can be used for read operations as well. Bits 6 and 7 of the IAAR register can be used
to block write a common idle code to all transmit or receive positions in the array with a single write to
the PCICR register. Bits 6 and 7 of the IAAR register should not be used for read operations. TCICE1–4
and RCICE1–4 are used to enable idle code replacement on a per-channel basis.
Table 16-A. Idle-Code Array Address Mapping
BITS 0 to 5 OF IAAR
REGISTER
0
1
2
—
—
30
31
32
33
34
—
—
62
63
MAPS TO CHANNEL
Transmit Channel 1
Transmit Channel 2
Transmit Channel 3
—
—
Transmit Channel 31
Transmit Channel 32
Receive Channel 1
Receive Channel 2
Receive Channel 3
—
—
Receive Channel 31
Receive Channel 32
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DS2156
16.1 Idle-Code Programming Examples
Example 1
Sets transmit channel 3 idle code to 7Eh.
Write IAAR = 02h ;select channel 3 in the array
Write PCICR = 7Eh ;set idle code to 7Eh
Example 2
Sets transmit channels 3, 4, 5, and 6 idle code to 7Eh and enables transmission of idle codes for those channels.
Write
Write
Write
Write
Write
Write
IAAR = 02h
PCICR = 7Eh
PCICR = 7Eh
PCICR = 7Eh
PCICR = 7Eh
TCICE1 = 3Ch
;select channel 3 in the array
;set channel 3 idle code to 7Eh
;set channel 4 idle code to 7Eh
;set channel 5 idle code to 7Eh
;set channel 6 idle code to 7Eh
;enable transmission of idle codes for channels 3,4,5, and 6
Example 3
Sets transmit channels 3, 4, 5, and 6 idle code to 7Eh, EEh, FFh, and 7Eh, respectively.
Write
Write
Write
Write
Write
IAAR = 02h
PCICR = 7Eh
PCICR = EEh
PCICR = FFh
PCICR = 7Eh
Example 4
Sets all transmit idle codes to 7Eh.
Write IAAR = 4xh
Write PCICR = 7Eh
Example 5
Sets all receive and transmit idle codes to 7Eh and enables idle code substitution in all E1 transmit and receive
channels.
Write IAAR = Cxh
Write PCICR = 7Eh
Write TCICE1 = FEh
Write TCICE2 = FFh
Write TCICE3 = FEh
Write
Write
Write
Write
Write
TCICE4
RCICE1
RCICE2
RCICE3
RCICE4
=
=
=
=
=
FFh
FEh
FFh
FEh
FFh
;enable block write to all transmit and receive positions in the array
;7Eh is idle code
;enable idle code substitution for transmit channels 2 through 8
;Although an idle code was programmed for channel 1 by the block write
;function above, enabling it for channel 1 would step on the frame
;alignment, alarms, and Sa bits
;enable idle code substitution for transmit channels 9 through 16
;enable idle code substitution for transmit channels 18 through 24
;Although an idle code was programmed for channel 17 by the block write
;function above, enabling it for channel 17 would step on the CAS frame
;alignment, and signaling information
;enable idle code substitution for transmit channels 25 through 32
;enable idle code substitution for receive channels 2 through 8
;enable idle code substitution for receive channels 9 through 16
;enable idle code substitution for receive channels 18 through 24
;enable idle code substitution for receive channels 25 through 32
104 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
GRIC
0
IAAR
Idle Array Address Register
7Eh
6
GTIC
0
5
IAA5
0
4
IAA4
0
3
IAA3
0
2
IAA2
0
1
IAA1
0
0
IAA0
0
Bits 0 to 5/Channel Pointer Address Bits (IAA0 to IAA5). These bits select the channel to be programmed with
the idle code defined in the PCICR register. IAA0 is the LSB of the 5-bit channel code. Channel 1 is 01h.
Bit 6/Global Transmit-Idle Code (GTIC). Setting this bit causes all transmit channels to be set to the idle code
written to the PCICR register. This bit must be set = 0 for read operations. The value in bits IAA0–IAA5 must be a
valid transmit channel (01h to 20h for E1 mode; 01h to 18h for T1 mode).
Bit 7/Global Receive-Idle Code (GRIC). Setting this bit causes all receive channels to be set to the idle code
written to the PCICR register. This bit must be set = 0 for read operations. The value in bits IAA0–IAA5 must be a
valid transmit channel (01h to 20h for E1 mode; 01h to 18h for T1 mode).
Table 16-B. GRIC and GTIC Functions
GRIC
0
0
1
1
GTIC
0
1
0
1
FUNCTION
Updates a single transmit or receive channel
Updates all transmit channels
Updates all receive channels
Updates all transmit and receive channels
Register Name:
Register Description:
Register Address:
PCICR
Per-Channel Idle Code Register
7Fh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Bits 0 to 7/Per-Channel Idle-Code Bits (C0 to C7). This register defines the idle code to be programmed in the
channel selected by the IAAR register. C0 is the LSB of the idle code (this bit is transmitted last).
105 of 265
DS2156
The transmit-channel idle-code enable registers (TCICE1/2/3/4) are used to determine which of the 24 T1 or 32 E1
channels from the backplane to the T1 or E1 line should be overwritten with the code placed in the per-channel
code array.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH8
0
TCICE1
Transmit-Channel Idle-Code Enable Register 1
80h
6
CH7
0
5
CH6
0
4
CH5
0
3
CH4
0
2
CH3
0
1
CH2
0
0
CH1
0
Bits 0 to 7/Transmit Channels 1 to 8 Code Insertion Control Bits (CH1 to CH8)
0 = do not insert data from the idle-code array into the transmit data stream
1 = insert data from the idle-code array into the transmit data stream
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH16
0
TCICE2
Transmit-Channel Idle-Code Enable Register 2
81h
6
CH15
0
5
CH14
0
4
CH13
0
3
CH12
0
2
CH11
0
1
CH10
0
0
CH9
0
Bits 0 to 7/Transmit Channels 9 to 16 Code Insertion Control Bits (CH9 to CH16)
0 = do not insert data from the idle-code array into the transmit data stream
1 = insert data from the idle code-array into the transmit data stream
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH24
0
TCICE3
Transmit-Channel Idle-Code Enable Register 3
82h
6
CH23
0
5
CH22
0
4
CH21
0
3
CH20
0
2
CH19
0
1
CH18
0
0
CH17
0
Bits 0 to 7/Transmit Channels 17 to 24 Code Insertion Control Bits (CH17 to CH24)
0 = do not insert data from the idle-code array into the transmit data stream
1 = insert data from the idle code-array into the transmit data stream
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH32
0
TCICE4
Transmit-Channel Idle-Code Enable Register 4
83h
6
CH31
0
5
CH30
0
4
CH29
0
3
CH28
0
2
CH27
0
1
CH26
0
Bits 0 to 7/Transmit Channels 25 to 32 Code Insertion Control Bits (CH25 to CH32)
0 = do not insert data from the idle-code array into the transmit data stream
1 = insert data from the idle-code array into the transmit data stream
106 of 265
0
CH25
0
DS2156
The receive-channel idle-code enable registers (RCICE1/2/3/4) are used to determine which of the 24 T1 or 32 E1
channels from the backplane to the T1 or E1 line should be overwritten with the code placed in the per-channel
code array.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH8
0
RCICE1
Receive-Channel Idle-Code Enable Register 1
84h
6
CH7
0
5
CH6
0
4
CH5
0
3
CH4
0
2
CH3
0
1
CH2
0
0
CH1
0
Bits 0 to 7/Receive Channels 1 to 8 Code Insertion Control Bits (CH1 to CH8)
0 = do not insert data from the idle-code array into the receive data stream
1 = insert data from the idle-code array into the receive data stream
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH16
0
RCICE2
Receive-Channel Idle-Code Enable Register 2
85h
6
CH15
0
5
CH14
0
4
CH13
0
3
CH12
0
2
CH11
0
1
CH10
0
0
CH9
0
Bits 0 to 7/Receive Channels 9 to 16 Code Insertion Control Bits (CH9 to CH16)
0 = do not insert data from the idle-code array into the receive data stream
1 = insert data from the idle-code array into the receive data stream
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH24
0
RCICE3
Receive-Channel Idle-Code Enable Register 3
86h
6
CH23
0
5
CH22
0
4
CH21
0
3
CH20
0
2
CH19
0
1
CH18
0
0
CH17
0
Bits 0 to 7/Receive Channels 17 to 24 Code Insertion Control Bits (CH17 to CH24)
0 = do not insert data from the idle-code array into the receive data stream
1 = insert data from the idle-code array into the receive data stream
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH32
0
RCICE4
Receive-Channel Idle-Code Enable Register 4
87h
6
CH31
0
5
CH30
0
4
CH29
0
3
CH28
0
2
CH27
0
1
CH26
0
Bits 0 to 7/Receive Channels 25 to 32 Code Insertion Control Bits (CH25 to CH32)
0 = do not insert data from the idle-code array into the receive data stream
1 = insert data from the idle-code array into the receive data stream
107 of 265
0
CH25
0
DS2156
17.
CHANNEL BLOCKING REGISTERS
The receive channel blocking registers (RCBR1/RCBR2/RCBR3/RCBR4) and the transmit channel
blocking registers (TCBR1/TCBR2/TCBR3/TCBR4) control RCHBLK and TCHBLK pins, respectively.
The RCHBLK and TCHBLK pins are user-programmable outputs that can be forced either high or low
during individual channels. These outputs can be used to block clocks to a USART or LAPD controller in
ISDN-PRI applications. When the appropriate bits are set to a 1, the RCHBLK and TCHBLK pins are
held high during the entire corresponding channel time. Channels 25 through 32 are ignored when the
DS2156 is operated in the T1 mode.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH8
0
RCBR1
Receive Channel Blocking Register 1
88h
6
CH7
0
5
CH6
0
4
CH5
0
3
CH4
0
2
CH3
0
1
CH2
0
0
CH1
0
Bits 0 to 7/Receive Channels 1 to 8 Channel Blocking Control Bits (CH1 to CH8)
0 = force the RCHBLK pin to remain low during this channel time
1 = force the RCHBLK pin high during this channel time
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH16
0
RCBR2
Receive Channel Blocking Register 2
89h
6
CH15
0
5
CH14
0
4
CH13
0
3
CH12
0
2
CH11
0
1
CH10
0
Bits 0 to 7/Receive Channels 9 to 16 Channel Blocking Control Bits (CH9 to CH16)
0 = force the RCHBLK pin to remain low during this channel time
1 = force the RCHBLK pin high during this channel time
108 of 265
0
CH9
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH24
0
RCBR3
Receive Channel Blocking Register 3
8Ah
6
CH23
0
5
CH22
0
4
CH21
0
3
CH20
0
2
CH19
0
1
CH18
0
0
CH17
0
Bits 0 to 7/Receive Channels 17 to 24 Channel Blocking Control Bits (CH17 to CH24)
0 = force the RCHBLK pin to remain low during this channel time
1 = force the RCHBLK pin high during this channel time
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH32
0
RCBR4
Receive Channel Blocking Register 4
8Bh
6
CH31
0
5
CH30
0
4
CH29
0
3
CH28
0
2
CH27
0
1
CH26
0
Bits 0 to 7/Receive Channels 25 to 32 Channel Blocking Control Bits (CH25 to CH32)
0 = force the RCHBLK pin to remain low during this channel time
1 = force the RCHBLK pin high during this channel time
109 of 265
0
CH25
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH8
0
TCBR1
Transmit Channel Blocking Register 1
8Ch
6
CH7
0
5
CH6
0
4
CH5
0
3
CH4
0
2
CH3
0
1
CH2
0
0
CH1
0
Bits 0 to 7/Transmit Channels 1 to 8 Channel Blocking Control Bits (CH1 to CH8)
0 = force the TCHBLK pin to remain low during this channel time
1 = force the TCHBLK pin high during this channel time
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH16
0
TCBR2
Transmit Channel Blocking Register 2
8Dh
6
CH15
0
5
CH14
0
4
CH13
0
3
CH12
0
2
CH11
0
1
CH10
0
0
CH9
0
Bits 0 to 7/Transmit Channels 9 to 16 Channel Blocking Control Bits (CH9 to CH16)
0 = force the TCHBLK pin to remain low during this channel time
1 = force the TCHBLK pin high during this channel time
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH24
0
TCBR3
Transmit Channel Blocking Register 3
8Eh
6
CH23
0
5
CH22
0
4
CH21
0
3
CH20
0
2
CH19
0
1
CH18
0
0
CH17
0
Bits 0 to 7/Transmit Channels 17 to 24 Channel Blocking Control Bits (CH17 to CH24)
0 = force the TCHBLK pin to remain low during this channel time
1 = force the TCHBLK pin high during this channel time
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
CH32
0
TCBR4
Transmit Channel Blocking Register 4
8Fh
6
CH31
0
5
CH30
0
4
CH29
0
3
CH28
0
2
CH27
0
1
CH26
0
0
CH25
0
Bits 0 to 7/Transmit Channels 25 to 32 Channel Blocking Control Bits (CH25 to CH32)
0 = force the TCHBLK pin to remain low during this channel time
1 = force the TCHBLK pin high during this channel time
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DS2156
18.
ELASTIC STORES OPERATION
The elastic store function is unavailable when UTOPIA backplane is enabled.
The DS2156 contains dual two-frame elastic stores, one for the receive direction and one for the transmit
direction. Both elastic stores are fully independent. The transmit and receive-side elastic stores can be
enabled/disabled independently of each other. Also, each elastic store can interface to either a 1.544MHz
or 2.048MHz/4.096MHz/8.192MHz/16.384MHz backplane without regard to the backplane rate the other
elastic store is interfacing to.
The elastic stores have two main purposes. Firstly, they can be used for rate conversion. When the
DS2156 is in the T1 mode, the elastic stores can rate-convert the T1 data stream to a 2.048MHz
backplane. In E1 mode, the elastic store can rate-convert the E1 data stream to a 1.544MHz backplane.
Secondly, they can be used to absorb the differences in frequency and phase between the T1 or E1 data
stream and an asynchronous (i.e., not locked) backplane clock, which can be 1.544MHz or 2.048MHz. In
this mode, the elastic stores manage the rate difference and perform controlled slips, deleting or repeating
frames of data in order to manage the difference between the network and the backplane.
The elastic stores can also be used to multiplex T1 or E1 data streams into higher backplane rates, which
is the IBO discussed in Section 28.
111 of 265
DS2156
Register Name:
Register Description:
Register Address:
ESCR
Elastic Store Control Register
4Fh
Bit #
Name
Default
6
TESR
0
7
TESALGN
0
5
TESMDM
0
4
TESE
0
3
RESALGN
0
2
RESR
0
1
RESMDM
0
0
RESE
0
Bit 0/Receive Elastic Store Enable (RESE)
0 = elastic store is bypassed
1 = elastic store is enabled
Bit 1/Receive Elastic Store Minimum-Delay Mode (RESMDM). See Section 18.4 for details.
0 = elastic stores operate at full two-frame depth
1 = elastic stores operate at 32-bit depth
Bit 2/Receive Elastic Store Reset (RESR). Setting this bit from a 0 to a 1 forces the read and write pointers into
opposite frames, maximizing the delay through the receive elastic store. It should be toggled after RSYSCLK has
been applied and is stable. See Section 18.3 for details. Do not leave this bit set HIGH.
Bit 3/Receive Elastic Store Align (RESALGN). Setting this bit from a 0 to a 1 forces the receive elastic store’s
write/read pointers to a minimum separation of half a frame. No action is taken if the pointer separation is already
greater or equal to half a frame. If pointer separation is less than half a frame, the command is executed and the
data is disrupted. It should be toggled after RSYSCLK has been applied and is stable. Must be cleared and set again
for a subsequent align. See Section 18.3 for details.
Bit 4/Transmit Elastic Store Enable (TESE)
0 = elastic store is bypassed
1 = elastic store is enabled
Bit 5/Transmit Elastic Store Minimum-Delay Mode (TESMDM). See Section 18.4 for details.
0 = elastic stores operate at full two-frame depth
1 = elastic stores operate at 32-bit depth
Bit 6/Transmit Elastic Store Reset (TESR). Setting this bit from a 0 to a 1 forces the read and write pointers into
opposite frames, maximizing the delay through the transmit elastic store. Transmit data is lost during the reset. It
should be toggled after TSYSCLK has been applied and is stable. See Section 18.3 for details. Do not leave this bit
set HIGH.
Bit 7/Transmit Elastic Store Align (TESALGN). Setting this bit from a 0 to a 1 forces the transmit elastic store’s
write/read pointers to a minimum separation of half a frame. No action is taken if the pointer separation is already
greater or equal to half a frame. If pointer separation is less than half a frame, the command is executed and the
data is disrupted. It should be toggled after TSYSCLK has been applied and is stable. It must be cleared and set
again for a subsequent align. See Section 18.3 for details.
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DS2156
Register Name:
Register Description:
Register Address:
SR5
Status Register 5
1Eh
Bit #
Name
Default
6
—
0
7
—
0
5
TESF
0
4
TESEM
0
3
TSLIP
0
2
RESF
0
1
RESEM
0
0
RSLIP
0
Bit 0/Receive Elastic Store Slip-Occurrence Event (RSLIP). Set when the receive elastic store has either
repeated or deleted a frame.
Bit 1/Receive Elastic Store Empty Event (RESEM). Set when the receive elastic store buffer empties and a
frame is repeated.
Bit 2/Receive Elastic Store Full Event (RESF). Set when the receive elastic store buffer fills and a frame is
deleted.
Bit 3/Transmit Elastic Store Slip-Occurrence Event (TSLIP). Set when the transmit elastic store has either
repeated or deleted a frame.
Bit 4/Transmit Elastic Store Empty Event (TESEM). Set when the transmit elastic store buffer empties and a
frame is repeated.
Bit 5/Transmit Elastic Store Full Event (TESF). Set when the transmit elastic store buffer fills and a frame is
deleted.
Register Name:
Register Description:
Register Address:
IMR5
Interrupt Mask Register 5
1Fh
Bit #
Name
Default
6
—
0
7
—
0
5
TESF
0
4
TESEM
0
3
TSLIP
0
Bit 0/Receive Elastic Store Slip-Occurrence Event (RSLIP)
0 = interrupt masked
1 = interrupt enabled
Bit 1/Receive Elastic Store Empty Event (RESEM)
0 = interrupt masked
1 = interrupt enabled
Bit 2/Receive Elastic Store Full Event (RESF)
0 = interrupt masked
1 = interrupt enabled
Bit 3/Transmit Elastic Store Slip-Occurrence Event (TSLIP)
0 = interrupt masked
1 = interrupt enabled
Bit 4/Transmit Elastic Store Empty Event (TESEM)
0 = interrupt masked
1 = interrupt enabled
Bit 5/Transmit Elastic Store Full Event (TESF)
0 = interrupt masked
1 = interrupt enabled
113 of 265
2
RESF
0
1
RESEM
0
0
RSLIP
0
DS2156
18.1 Receive Side
See the IOCR1 and IOCR2 registers for information about clock and I/O configurations.
If the receive-side elastic store is enabled, then the user must provide either a 1.544MHz or 2.048MHz
clock at the RSYSCLK pin. For higher rate system clock applications, see the Interleaved PCM Bus
Operation in Section 28. The user has the option of either providing a frame/multiframe sync at the
RSYNC pin or having the RSYNC pin provide a pulse on frame/multiframe boundaries. If signaling
reinsertion is enabled, signaling data in TS16 is realigned to the multiframe sync input on RSYNC.
Otherwise, a multiframe sync input on RSYNC is treated as a simple frame boundary by the elastic store.
The framer always indicates frame boundaries on the network side of the elastic store by the RFSYNC
output, whether the elastic store is enabled or not. Multiframe boundaries are always indicated by the
RMSYNC output. If the elastic store is enabled, then RMSYNC outputs the multiframe boundary on the
backplane side of the elastic store.
18.1.1 T1 Mode
If the user selects to apply a 2.048MHz clock to the RSYSCLK pin, then the data output at RSER is
forced to all 1s every fourth channel and the F-bit is passed into the MSB of TS0. Hence, channels 1 (bits
1–7), 5, 9, 13, 17, 21, 25, and 29 [time slots 0 (bits 1–7), 4, 8, 12, 16, 20, 24, and 28] are forced to a 1.
Also, in 2.048MHz applications, the RCHBLK output is forced high during the same channels as the
RSER pin. This is useful in T1-to-E1 conversion applications. If the two-frame elastic buffer either fills
or empties, a controlled slip occurs. If the buffer empties, then a full frame of data is repeated at RSER,
and the SR5.0 and SR5.1 bits are set to a 1. If the buffer fills, then a full frame of data is deleted, and the
SR5.0 and SR5.2 bits are set to a 1.
18.1.2 E1 Mode
If the elastic store is enabled, then either CAS or CRC4 multiframe boundaries are indicated through the
RMSYNC output. If the user selects to apply a 1.544MHz clock to the RSYSCLK pin, then every fourth
channel of the received E1 data is deleted and an F-bit position, which is forced to 1, is inserted. Hence,
channels 1, 5, 9, 13, 17, 21, 25, and 29 (time slots 0, 4, 8, 12, 16, 20, 24, and 28) are deleted from the
received E1 data stream. Also, in 1.544MHz applications, the RCHBLK output is not active in channels
25 through 32 (i.e., RCBR4 is not active). If the two-frame elastic buffer either fills or empties, a
controlled slip occurs. If the buffer empties, then a full frame of data is repeated at RSER, and the SR5.0
and SR5.1 bits are set to a 1. If the buffer fills, then a full frame of data is deleted, and the SR5.0 and
SR5.2 bits are set to a 1.
18.2 Transmit Side
See the IOCR1 and IOCR2 registers for information about clock and I/O configurations.
The operation of the transmit elastic store is very similar to the receive side. If the transmit-side elastic
store is enabled, a 1.544MHz or 2.048MHz clock can be applied to the TSYSCLK input. For higher rate
system clock applications, see Interleaved PCM Bus Operation in Section 28. Controlled slips in the
transmit elastic store are reported in the SR5.3 bit, and the direction of the slip is reported in the SR5.4
and SR5.5 bits. If hardware signaling insertion is not enabled, CCR3.7 should be set = 1.
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DS2156
18.2.1 T1 Mode
If the user selects to apply a 2.048MHz clock to the TSYSCLK pin, then the data input at TSER is
ignored every fourth channel. Therefore channels 1, 5, 9, 13, 17, 21, 25, and 29 (time slots 0, 4, 8, 12, 16,
20, 24, and 28) are ignored. The user can supply frame or multiframe sync pulse to the TSSYNC input.
Also, in 2.048MHz applications, the TCHBLK output is forced high during the channels ignored by the
framer.
18.2.2 E1 Mode
A 1.544MHz or 2.048MHz clock can be applied to the TSYSCLK input. The user must supply a frame
sync pulse or a multiframe sync pulse to the TSSYNC input.
18.3 Elastic Stores Initialization
There are two elastic store initializations that can be used to improve performance in certain applications,
elastic store reset and elastic store align. Both of these involve the manipulation of the elastic store’s read
and write pointers and are useful primarily in synchronous applications (RSYSCLK/TSYSCLK are
locked to RCLK/TCLK, respectively) (Table 18-A).
Table 18-A. Elastic Store Delay After Initialization
INITIALIZATION
Receive Elastic Store Reset
Transmit Elastic Store Reset
Receive Elastic Store Align
Transmit Elastic Store Align
REGISTER BIT
ESCR.2
ESCR.6
ESCR.3
ESCR.7
DELAY
8 Clocks < Delay < 1 Frame
1 Frame < Delay < 2 Frames
½ Frame < Delay < 1 ½ Frames
½ Frame < Delay < 1 ½ Frames
18.4 Minimum Delay Mode
Elastic store minimum delay mode can be used when the elastic store’s system clock is locked to its
network clock (i.e., RCLK locked to RSYSCLK for the receive side and TCLK locked to TSYSCLK for
the transmit side). ESCR.5 and ESCR.1 enable the transmit and receive elastic store minimum delay
modes. When enabled, the elastic stores are forced to a maximum depth of 32 bits instead of the normal
two-frame depth. This feature is useful primarily in applications that interface to a 2.048MHz bus.
Certain restrictions apply when minimum delay mode is used. In addition to the restriction mentioned
above, RSYNC must be configured as an output when the receive elastic store is in minimum delay
mode; TSYNC must be configured as an output when transmit minimum delay mode is enabled. In a
typical application, RSYSCLK and TSYSCLK are locked to RCLK, and RSYNC (frame output mode) is
connected to TSSYNC (frame input mode). All of the slip contention logic in the framer is disabled (since
slips cannot occur). On power-up, after the RSYSCLK and TSYSCLK signals have locked to their
respective network clock signals, the elastic store reset bits (ESCR.2 and ESCR.6) should be toggled
from a 0 to a 1 to ensure proper operation.
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DS2156
19.
G.706 INTERMEDIATE CRC-4 UPDATING (E1 MODE ONLY)
The DS2156 can implement the G.706 CRC-4 recalculation at intermediate path points. When this mode
is enabled, the data stream presented at TSER already has the FAS/NFAS, CRC multiframe alignment
word, and CRC-4 checksum in time slot 0. The user can modify the Sa bit positions. This change in data
content is used to modify the CRC-4 checksum. This modification, however, does not corrupt any error
information the original CRC-4 checksum may contain. In this mode of operation, TSYNC must be
configured to multiframe mode. The data at TSER must be aligned to the TSYNC signal. If TSYNC is an
input, then the user must assert TSYNC aligned at the beginning of the multiframe relative to TSER. If
TSYNC is an output, the user must multiframe-align the data presented to TSER.
Figure 19-1. CRC-4 Recalculate Method
TPOSO/TNEGO
INSERT
NEW CRC-4
CODE
EXTRACT
OLD CRC-4
CODE
TSER
+
CRC-4
CALCULATOR
XOR
MODIFY
Sa BIT
POSITIONS
NEW Sa BIT
DATA
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DS2156
20.
T1 BIT-ORIENTED CODE (BOC) CONTROLLER
The DS2156 contains a BOC generator on the transmit side and a BOC detector on the receive side. The
BOC function is available only in T1 mode.
20.1 Transmit BOC
Bits 0 to 5 in the TFDL register contain the BOC message to be transmitted. Setting BOCC.0 = 1 causes
the transmit BOC controller to immediately begin inserting the BOC sequence into the FDL bit position.
The transmit BOC controller automatically provides the abort sequence. BOC messages are transmitted as
long as BOCC.0 is set.
Transmit a BOC
1) Write 6-bit code into the TFDL register.
2) Set the SBOC bit in BOCC = 1.
20.2 Receive BOC
The receive BOC function is enabled by setting BOCC.4 = 1. The RFDL register now operates as the
receive BOC message and information register. The lower six bits of the RFDL register (BOC message
bits) are preset to all 1s. When the BOC bits change state, the BOC change-of-state indicator, SR8.0,
alerts the host. The host then reads the RFDL register to get the BOC status and message. A change-ofstate occurs when either a new BOC code has been present for a time determined by the receive BOC
filter bits RBF0 and RBF1 in the BOCC register, or a nonvalid code is being received.
Receive a BOC
1) Set integration time through BOCC.1 and BOCC.2.
2) Enable the receive BOC function (BOCC.4 = 1).
3) Enable interrupt (IMR8.0 = 1).
4) Wait for interrupt to occur.
5) Read the RFDL register.
6) If SR2.7 = 1, then a valid BOC message was received.
– The lower six bits of the RFDL register comprise the message.
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DS2156
Register Name:
Register Description:
Register Address:
BOCC
BOC Control Register
37h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
RBOCE
0
3
RBR
0
2
RBF1
0
1
RBF0
0
0
SBOC
0
Bit 0/Send BOC (SBOC). Set = 1 to transmit the BOC code placed in bits 0 to 5 of the TFDL register.
Bits 1 and 2/Receive BOC Filter Bits (RBF0, RBF1). The BOC filter sets the number of consecutive patterns that
must be received without error prior to an indication of a valid message.
RBF1
RBF0
0
0
1
1
0
1
0
1
Consecutive BOC Codes for
Valid Sequence Identification
None
3
5
7
Bit 3/Receive BOC Reset (RBR). A 0-to-1 transition resets the BOC circuitry. Must be cleared and set again for a
subsequent reset.
Bit 4/Receive BOC Enable (RBOCE). Enables the receive BOC function. The RFDL register reports the received
BOC code and two information bits when this bit is set.
0 = receive BOC function disabled
1 = receive BOC function enabled; the RFDL register reports BOC messages and information
Bits 5 to 7/Unused, must be set to 0 for proper operation
Register Name:
Register Description:
Register Address:
RFDL
Receive FDL Register
C0h
Bit #
Name
Default
6
—
0
7
—
0
5
RBOC5
0
4
RBOC4
0
3
RBOC3
0
RFDL register bit definitions when BOCC.4 = 1:
Bit 0/BOC Bit 0 (RBOC0)
Bit 1/BOC Bit 1 (RBOC1)
Bit 2/BOC Bit 2 (RBOC2)
Bit 3/BOC Bit 3 (RBOC3)
Bit 4/BOC Bit 4 (RBOC4)
Bit 5/BOC Bit 5 (RBOC5)
Bits 6, 7/This bit position is unused when BOCC.4 = 1.
118 of 265
2
RBOC2
0
1
RBOC1
0
0
RBOC0
0
DS2156
Register Name:
Register Description:
Register Address:
SR8
Status Register 8
24h
Bit #
Name
Default
6
—
0
7
—
0
5
BOCC
0
4
RFDLAD
0
3
RFDLF
0
2
TFDLE
0
1
RMTCH
0
0
RBOC
0
Bit 0/Receive BOC Detector Change-of-State Event (RBOC). Set whenever the BOC detector sees a change of
state to a valid BOC. The setting of this bit prompts the user to read the RFDL register.
Bit 1/Receive FDL Match Event (RMTCH). Set whenever the contents of the RFDL register matches RFDLM1
or RFDLM2.
Bit 2/TFDL Register Empty Event (TFDLE). Set when the transmit FDL buffer (TFDL) empties.
Bit 3/RFDL Register Full Event (RFDLF). Set when the receive FDL buffer (RFDL) fills to capacity.
Bit 4/RFDL Abort Detect Event (RFDLAD). Set when eight consecutive 1s are received on the FDL.
Bit 5/BOC Clear Event (BOCC). Set when 30 FDL bits occur without an abort sequence.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
IMR8
Interrupt Mask Register 8
25h
6
—
0
5
BOCC
0
4
RFDLAD
0
3
RFDLF
0
Bit 0/Receive BOC Detector Change-of-State Event (RBOC)
0 = interrupt masked
1 = interrupt enabled
Bit 1/Receive FDL Match Event (RMTCH)
0 = interrupt masked
1 = interrupt enabled
Bit 2/TFDL Register Empty Event (TFDLE)
0 = interrupt masked
1 = interrupt enabled
Bit 3/RFDL Register Full Event (RFDLF)
0 = interrupt masked
1 = interrupt enabled
Bit 4/RFDL Abort Detect Event (RFDLAD)
0 = interrupt masked
1 = interrupt enabled
Bit 5/BOC Clear Event (BOCC)
0 = interrupt masked
1 = interrupt enabled
119 of 265
2
TFDLE
0
1
RMTCH
0
0
RBOC
0
DS2156
21. ADDITIONAL (SA) AND INTERNATIONAL (SI) BIT OPERATION (E1
ONLY)
When operated in the E1 mode, the DS2156 provides three methods for accessing the Sa and the Si bits.
The first method involves a hardware scheme that uses the RLINK/RLCLK and TLINK/TLCLK pins
(Section 21.1). The second method involves using the internal RAF/RNAF and TAF/TNAF registers
(Section 21.2). The third method, which is covered in Section 21.3, involves an expanded version of the
second method.
21.1 Method 1: Hardware Scheme
On the receive side, all of the received data is reported at the RLINK pin. Using the E1RCR2 register, the
user can control the RLCLK pin to pulse during any combination of Sa bits. This allows the user to create
a clock that can be used to capture the needed Sa bits. If RSYNC is programmed to output a frame
boundary, it identifies the Si bits.
On the transmit side, the individual Sa bits can be either sourced from the internal TNAF register (Section
21.2) or externally from the TLINK pin. Using the E1TCR2 register, the framer can be programmed to
source any combination of the Sa bits from the TLINK pin. Si bits can be sampled through the TSER pin
if by setting E1TCR1.4 = 0.
21.2 Method 2: Internal Register Scheme Based on Double-Frame
On the receive side, the RAF and RNAF registers always report the data as it received in the Sa and Si bit
locations. The RAF and RNAF registers are updated on align-frame boundaries. The setting of the receive
align frame bit in Status Register 4 (SR4.0) indicates that the contents of the RAF and RNAF have been
updated. The host can use the SR4.0 bit to know when to read the RAF and RNAF registers. The host has
250µs to retrieve the data before it is lost.
On the transmit side, data is sampled from the TAF and TNAF registers with the setting of the transmit
align frame bit in Status Register 4 (SR4.3). The host can use the SR4.3 bit to know when to update the
TAF and TNAF registers. It has 250µs to update the data or else the old data is retransmitted. If the TAF
and TNAF registers are only being used to source the align frame and nonalign frame-sync
patterns, then the host need only write once to these registers. Data in the Si bit position is
overwritten if either the framer is (1) programmed to source the Si bits from the TSER pin, (2) in the
CRC4 mode, or (3) has automatic E-bit insertion enabled. Data in the Sa bit position is overwritten if any
of the E1TCR2.3 to E1TCR2.7 bits are set to 1.
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DS2156
Register Name:
Register Description:
Register Address:
RAF
Receive Align Frame Register
C6h
Bit #
Name
Default
6
0
0
7
Si
0
5
0
0
4
1
0
3
1
0
2
0
0
1
1
0
0
1
0
2
Sa6
0
1
Sa7
0
0
Sa8
0
Bit 0/Frame Alignment Signal Bit (1)
Bit 1/Frame Alignment Signal Bit (1)
Bit 2/Frame Alignment Signal Bit (0)
Bit 3/Frame Alignment Signal Bit (1)
Bit 4/Frame Alignment Signal Bit (1)
Bit 5/Frame Alignment Signal Bit (0)
Bit 6/Frame Alignment Signal Bit (0)
Bit 7/International Bit (Si)
Register Name:
Register Description:
Register Address:
RNAF
Receive Nonalign Frame Register
C7h
Bit #
Name
Default
6
1
0
7
Si
0
5
A
0
4
Sa4
0
3
Sa5
0
Bit 0/Additional Bit 8 (Sa8)
Bit 1/Additional Bit 7 (Sa7)
Bit 2/Additional Bit 6 (Sa6)
Bit 3/Additional Bit 5 (Sa5)
Bit 4/Additional Bit 4 (Sa4)
Bit 5/Remote Alarm (A)
Bit 6/Frame Nonalignment Signal Bit (1)
Bit 7/International Bit (Si)
121 of 265
DS2156
Register Name:
Register Description:
Register Address:
TAF
Transmit Align Frame Register
D0h
Bit #
Name
Default
6
0
0
7
Si
0
5
0
0
4
1
1
3
1
1
2
0
0
1
1
1
0
1
1
2
Sa6
0
1
Sa7
0
0
Sa8
0
Bit 0/Frame Alignment Signal Bit (1)
Bit 1/Frame Alignment Signal Bit (1)
Bit 2/Frame Alignment Signal Bit (0)
Bit 3/Frame Alignment Signal Bit (1)
Bit 4/Frame Alignment Signal Bit (1)
Bit 5/Frame Alignment Signal Bit (0)
Bit 6/Frame Alignment Signal Bit (0)
Bit 7/International Bit (Si)
Register Name:
Register Description:
Register Address:
TNAF
Transmit Nonalign Frame Register
D1h
Bit #
Name
Default
6
1
1
7
Si
0
5
A
0
4
Sa4
0
3
Sa5
0
Bit 0/Additional Bit 8 (Sa8)
Bit 1/Additional Bit 7 (Sa7)
Bit 2/Additional Bit 6 (Sa6)
Bit 3/Additional Bit 5 (Sa5)
Bit 4/Additional Bit 4 (Sa4)
Bit 5/Remote Alarm [used to transmit the alarm (A)]
Bit 6/Frame Nonalignment Signal Bit (1)
Bit 7/International Bit (Si)
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DS2156
21.3 Method 3: Internal Register Scheme Based on CRC4 Multiframe
The receive side contains a set of eight registers (RSiAF, RSiNAF, RRA, and RSa4–RSa8) that report the
Si and Sa bits as they are received. These registers are updated with the setting of the receive CRC4
multiframe bit in Status Register 2 (SR4.1). The host can use the SR4.1 bit to know when to read these
registers. The user has 2ms to retrieve the data before it is lost. The MSB of each register is the first
received. See the following register descriptions for more details.
The transmit side also contains a set of eight registers (TSiAF, TSiNAF, TRA, and TSa4–TSa8) that,
through the transmit Sa bit control register (TSaCR), can be programmed to insert Si and Sa data. Data is
sampled from these registers with the setting of the transmit multiframe bit in Status Register 2 (SR4.4).
The host can use the SR4.4 bit to know when to update these registers. It has 2ms to update the data or
else the old data is retransmitted. The MSB of each register is the first bit transmitted. See the following
register descriptions for more details.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
SiF14
0
RSiAF
Received Si Bits of the Align Frame
C8h
6
SiF12
0
5
SiF10
0
4
SiF8
0
3
SiF6
0
Bit 0/Si Bit of Frame 0 (SiF0)
Bit 1/Si Bit of Frame 2 (SiF2)
Bit 2/Si Bit of Frame 4 (SiF4)
Bit 3/Si Bit of Frame 6 (SiF6)
Bit 4/Si Bit of Frame 8 (SiF8)
Bit 5/Si Bit of Frame 10 (SiF10)
Bit 6/Si Bit of Frame 12 (SiF12)
Bit 7/Si Bit of Frame 14 (SiF14)
123 of 265
2
SiF4
0
1
SiF2
0
0
SiF0
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
SiF15
0
RSiNAF
Received Si Bits of the Nonalign Frame
C9h
6
SiF13
0
5
SiF11
0
4
SiF9
0
3
SiF7
0
2
SiF5
0
1
SiF3
0
0
SiF1
0
Bit 0/Si Bit of Frame 1 (SiF1)
Bit 1/Si Bit of Frame 3 (SiF3)
Bit 2/Si Bit of Frame 5 (SiF5)
Bit 3/Si Bit of Frame 7 (SiF7)
Bit 4/Si Bit of Frame 9 (SiF9)
Bit 5/Si Bit of Frame 11 (SiF11)
Bit 6/Si Bit of Frame 13 (SiF13)
Bit 7/Si Bit of Frame 15 (SiF15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RRAF15
0
RRA
Received Remote Alarm
Cah
6
RRAF13
0
5
RRAF11
0
4
RRAF9
0
3
RRAF7
0
Bit 0/Remote Alarm Bit of Frame 1 (RRAF1)
Bit 1/Remote Alarm Bit of Frame 3 (RRAF3)
Bit 2/Remote Alarm Bit of Frame 5 (RRAF5)
Bit 3/Remote Alarm Bit of Frame 7 (RRAF7)
Bit 4/Remote Alarm Bit of Frame 9 (RRAF9)
Bit 5/Remote Alarm Bit of Frame 11 (RRAF11)
Bit 6/Remote Alarm Bit of Frame 13 (RRAF13)
Bit 7/Remote Alarm Bit of Frame 15 (RRAF15)
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2
RRAF5
0
1
RRAF3
0
0
RRAF1
0
DS2156
Register Name:
Register Description:
Register Address:
RSa4
Received Sa4 Bits
CBh
Bit #
Name
Default
6
RSa4F13
0
7
RSa4F15
0
5
RSa4F11
0
4
RSa4F9
0
3
RSa4F7
0
2
RSa4F5
0
1
RSa4F3
0
0
RSa4F1
0
Bit 0/Sa4 Bit of Frame 1 (RSa4F1)
Bit 1/Sa4 Bit of Frame 3 (RSa4F3)
Bit 2/Sa4 Bit of Frame 5 (RSa4F5)
Bit 3/Sa4 Bit of Frame 7 (RSa4F7)
Bit 4/Sa4 Bit of Frame 9 (RSa4F9)
Bit 5/Sa4 Bit of Frame 11 (RSa4F11)
Bit 6/Sa4 Bit of Frame 13 (RSa4F13)
Bit 7/Sa4 Bit of Frame 15 (RSa4F15)
Register Name:
Register Description:
Register Address:
RSa5
Received Sa5 Bits
CCh
Bit #
Name
Default
6
RSa5F13
0
7
RSa5F15
0
5
RSa5F11
0
4
RSa5F9
0
3
RSa5F7
0
Bit 0/Sa5 Bit of Frame 1 (RSa5F1)
Bit 1/Sa5 Bit of Frame 3 (RSa5F3)
Bit 2/Sa5 Bit of Frame 5 (RSa5F5)
Bit 3/Sa5 Bit of Frame 7 (RSa5F7)
Bit 4/Sa5 Bit of Frame 9 (RSa5F9)
Bit 5/Sa5 Bit of Frame 11 (RSa5F11)
Bit 6/Sa5 Bit of Frame 13 (RSa5F13)
Bit 7/Sa5 Bit of Frame 15 (RSa5F15)
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2
RSa5F5
0
1
RSa5F3
0
0
RSa5F1
0
DS2156
Register Name:
Register Description:
Register Address:
RSa6
Received Sa6 Bits
CDh
Bit #
Name
Default
6
RSa6F13
0
7
RSa6F15
0
5
RSa6F11
0
4
RSa6F9
0
3
RSa6F7
0
2
RSa6F5
0
1
RSa6F3
0
0
RSa6F1
0
Bit 0/Sa6 Bit of Frame 1 (RSa6F1)
Bit 1/Sa6 Bit of Frame 3 (RSa6F3)
Bit 2/Sa6 Bit of Frame 5 (RSa6F5)
Bit 3/Sa6 Bit of Frame 7 (RSa6F7)
Bit 4/Sa6 Bit of Frame 9 (RSa6F9)
Bit 5/Sa6 Bit of Frame 11 (RSa6F11)
Bit 6/Sa6 Bit of Frame 13 (RSa6F13)
Bit 7/Sa6 Bit of Frame 15 (RSa6F15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RSa7F15
0
RSa7
Received Sa7 Bits
CEh
6
Rsa7F13
0
5
RSa7F11
0
4
RSa7F9
0
3
RSa7F7
0
Bit 0/Sa7 Bit of Frame 1 (RSa7F1)
Bit 1/Sa7 Bit of Frame 3 (RSa7F3)
Bit 2/Sa7 Bit of Frame 5 (RSa7F5)
Bit 3/Sa7 Bit of Frame 7 (RSa7F7)
Bit 4/Sa7 Bit of Frame 9 (RSa7F9)
Bit 5/Sa7 Bit of Frame 11 (RSa7F11)
Bit 6/Sa7 Bit of Frame 13 (RSa7F13)
Bit 7/Sa7 Bit of Frame 15 (RSa4F15)
126 of 265
2
RSa7F5
0
1
RSa7F3
0
0
RSa7F1
0
DS2156
Register Name:
Register Description:
Register Address:
RSa8
Received Sa8 Bits
CFh
Bit #
Name
Default
6
RSa8F13
0
7
RSa8F15
0
5
RSa8F11
0
4
RSa8F9
0
3
RSa8F7
0
2
RSa8F5
0
1
RSa8F3
0
1
TSiF2
0
0
TSiF0
0
Bit 0/Sa8 Bit of Frame 1 (RSa8F1)
Bit 1/Sa8 Bit of Frame 3 (RSa8F3)
Bit 2/Sa8 Bit of Frame 5 (RSa8F5)
Bit 3/Sa8 Bit of Frame 7 (RSa8F7)
Bit 4/Sa8 Bit of Frame 9 (RSa8F9)
Bit 5/Sa8 Bit of Frame 11 (RSa8F11)
Bit 6/Sa8 Bit of Frame 13 (RSa8F13)
Bit 7/Sa8 Bit of Frame 15 (RSa8F15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TSiF14
0
TSiAF
Transmit Si Bits of the Align Frame
D2h
6
TSiF12
0
5
TSiF10
0
4
TSiF8
0
3
TSiF6
0
Bit 0/Si Bit of Frame 0 (TSiF0)
Bit 1/Si Bit of Frame 2 (TSiF2)
Bit 2/Si Bit of Frame 4 (TSiF4)
Bit 3/Si Bit of Frame 6 (TSiF6)
Bit 4/Si Bit of Frame 8 (TSiF8)
Bit 5/Si Bit of Frame 10 (TSiF10)
Bit 6/Si Bit of Frame 12 (TSiF12)
Bit 7/Si Bit of Frame 14 (TSiF14)
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2
TSiF4
0
0
RSa8F1
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TSiF15
0
TSiNAF
Transmit Si Bits of the Nonalign Frame
D3h
6
TSiF13
0
5
TSiF11
0
4
TSiF9
0
3
TSiF7
0
2
TSiF5
0
1
TSiF3
0
0
TSiF1
0
Bit 0/Si Bit of Frame 1 (TSiF1)
Bit 1/Si Bit of Frame 3 (TSiF3)
Bit 2/Si Bit of Frame 5 (TSiF5)
Bit 3/Si Bit of Frame 7 (TSiF7)
Bit 4/Si Bit of Frame 9 (TSiF9)
Bit 5/Si Bit of Frame 11 (TSiF11)
Bit 6/Si Bit of Frame 13 (TSiF13)
Bit 7/Si Bit of Frame 15 (TSiF15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TRAF15
0
TRA
Transmit Remote Alarm
D4h
6
TRAF13
0
5
TRAF11
0
4
TRAF9
0
3
TRAF7
0
Bit 0/Remote Alarm Bit of Frame 1 (TRAF1)
Bit 1/Remote Alarm Bit of Frame 3 (TRAF3)
Bit 2/Remote Alarm Bit of Frame 5 (TRAF5)
Bit 3/Remote Alarm Bit of Frame 7 (TRAF7)
Bit 4/Remote Alarm Bit of Frame 9 (TRAF9)
Bit 5/Remote Alarm Bit of Frame 11 (TRAF11)
Bit 6/Remote Alarm Bit of Frame 13 (TRAF13)
Bit 7/Remote Alarm Bit of Frame 15 (TRAF15)
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2
TRAF5
0
1
TRAF3
0
0
TRAF1
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TSa4F15
0
TSa4
Transmit Sa4 Bits
D5h
6
TSa4F13
0
5
TSa4F11
0
4
TSa4F9
0
3
TSa4F7
0
2
TSa4F5
0
1
TSa4F3
0
0
TSa4F1
0
Bit 0/Sa4 Bit of Frame 1 (TSa4F1)
Bit 1/Sa4 Bit of Frame 3 (TSa4F3)
Bit 2/Sa4 Bit of Frame 5 (TSa4F5)
Bit 3/Sa4 Bit of Frame 7 (TSa4F7)
Bit 4/Sa4 Bit of Frame 9 (TSa4F9)
Bit 5/Sa4 Bit of Frame 11 (TSa4F11)
Bit 6/Sa4 Bit of Frame 13 (TSa4F13)
Bit 7/Sa4 Bit of Frame 15 (TSa4F15)
Register Name:
Register Description:
Register Address:
TSa5
Transmitted Sa5 Bits
D6h
Bit #
Name
Default
6
TSa5F13
0
7
TSa5F15
0
5
TSa5F11
0
4
TSa5F9
0
Bit 0/Sa5 Bit of Frame 1 (TSa5F1)
Bit 1/Sa5 Bit of Frame 3 (TSa5F3)
Bit 2/Sa5 Bit of Frame 5 (TSa5F5)
Bit 3/Sa5 Bit of Frame 7 (TSa5F7)
Bit 4/Sa5 Bit of Frame 9 (TSa5F9)
Bit 5/Sa5 Bit of Frame 11 (TSa5F11)
Bit 6/Sa5 Bit of Frame 13 (TSa5F13)
Bit 7/Sa5 Bit of Frame 15 (TSa5F15)
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3
TSa5F7
0
2
TSa5F5
0
1
TSa5F3
0
0
TSa5F1
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TSa6F15
0
TSa6
Transmit Sa6 Bits
D7h
6
TSa6F13
0
5
TSa6F11
0
4
TSa6F9
0
3
TSa6F7
0
2
TSa6F5
0
1
TSa6F3
0
0
TSa6F1
0
Bit 0/Sa6 Bit of Frame 1 (TSa6F1)
Bit 1/Sa6 Bit of Frame 3 (TSa6F3)
Bit 2/Sa6 Bit of Frame 5 (TSa6F5)
Bit 3/Sa6 Bit of Frame 7 (TSa6F7)
Bit 4/Sa6 Bit of Frame 9 (TSa6F9)
Bit 5/Sa6 Bit of Frame 11 (TSa6F11)
Bit 6/Sa6 Bit of Frame 13 (TSa6F13)
Bit 7/Sa6 Bit of Frame 15 (TSa6F15)
Register Name:
Register Description:
Register Address:
TSa7
Transmit Sa7 Bits
D8h
Bit #
Name
Default
6
TSa7F13
0
7
TSa7F15
0
5
TSa7F11
0
4
TSa7F9
0
Bit 0/Sa7 Bit of Frame 1 (TSa7F1)
Bit 1/Sa7 Bit of Frame 3 (TSa7F3)
Bit 2/Sa7 Bit of Frame 5 (TSa7F5)
Bit 3/Sa7 Bit of Frame 7 (TSa7F7)
Bit 4/Sa7 Bit of Frame 9 (TSa7F9)
Bit 5/Sa7 Bit of Frame 11 (TSa7F11)
Bit 6/Sa7 Bit of Frame 13 (TSa7F13)
Bit 7/Sa7 Bit of Frame 15 (TSa4F15)
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3
TSa7F7
0
2
TSa7F5
0
1
TSa7F3
0
0
TSa7F1
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TSa8F15
0
TSa8
Transmit Sa8 Bits
D9h
6
TSa8F13
0
5
TSa8F11
0
4
TSa8F9
0
3
TSa8F7
0
Bit 0/Sa8 Bit of Frame 1 (TSa8F1)
Bit 1/Sa8 Bit of Frame 3 (TSa8F3)
Bit 2/Sa8 Bit of Frame 5 (TSa8F5)
Bit 3/Sa8 Bit of Frame 7 (TSa8F7)
Bit 4/Sa8 Bit of Frame 9 (TSa8F9)
Bit 5/Sa8 Bit of Frame 11 (TSa8F11)
Bit 6/Sa8 Bit of Frame 13 (TSa8F13)
Bit 7/Sa8 Bit of Frame 15 (TSa8F15)
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2
TSa8F5
0
1
TSa8F3
0
0
TSa8F1
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
SiAF
0
TSACR
Transmit Sa Bit Control Register
DAh
6
SiNAF
0
5
RA
0
4
Sa4
0
3
Sa5
0
2
Sa6
0
1
Sa7
0
Bit 0/Additional Bit 8 Insertion Control Bit (Sa8)
0 = do not insert data from the TSa8 register into the transmit data stream
1 = insert data from the TSa8 register into the transmit data stream
Bit 1/Additional Bit 7 Insertion Control Bit (Sa7)
0 = do not insert data from the TSa7 register into the transmit data stream
1 = insert data from the TSa7 register into the transmit data stream
Bit 2/Additional Bit 6 Insertion Control Bit (Sa6)
0 = do not insert data from the TSa6 register into the transmit data stream
1 = insert data from the TSa6 register into the transmit data stream
Bit 3/Additional Bit 5 Insertion Control Bit (Sa5)
0 = do not insert data from the TSa5 register into the transmit data stream
1 = insert data from the TSa5 register into the transmit data stream
Bit 4/Additional Bit 4 Insertion Control Bit (Sa4)
0 = do not insert data from the TSa4 register into the transmit data stream
1 = insert data from the TSa4 register into the transmit data stream
Bit 5/Remote Alarm Insertion Control Bit (RA)
0 = do not insert data from the TRA register into the transmit data stream
1 = insert data from the TRA register into the transmit data stream
Bit 6/International Bit in Nonalign Frame Insertion Control Bit (SiNAF)
0 = do not insert data from the TSiNAF register into the transmit data stream
1 = insert data from the TSiNAF register into the transmit data stream
Bit 7/International Bit in Align Frame Insertion Control Bit (SiAF)
0 = do not insert data from the TSiAF register into the transmit data stream
1 = insert data from the TSiAF register into the transmit data stream
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0
Sa8
0
DS2156
22.
HDLC CONTROLLERS
This device has two enhanced HDLC controllers, HDLC #1 and HDLC #2. Each controller is
configurable for use with time slots, Sa4 to Sa8 bits (E1 mode), or the FDL (T1 mode). Each HDLC
controller has 128-byte buffers in the transmit and receive paths. When used with time slots, the user can
select any time slot or multiple time slots, contiguous or noncontiguous, as well as any specific bits
within the time slot(s) to assign to the HDLC controllers.
The user must not map both transmit HDLC controllers to the same Sa bits, time slots or, in T1 mode,
map both controllers to the FDL. HDLC #1 and HDLC #2 are identical in operation and therefore the
following operational description refers only to a singular controller.
The HDLC controller performs the entire necessary overhead for generating and receiving performance
report messages (PRMs) as described in ANSI T1.403 and the messages as described in AT&T TR54016.
The HDLC controller automatically generates and detects flags, generates and checks the CRC check
sum, generates and detects abort sequences, stuffs and destuffs zeros, and byte aligns to the data stream.
The 128-byte buffers in the HDLC controller are large enough to allow a full PRM to be received or
transmitted without host intervention.
22.1 Basic Operation Details
The HDLC registers are divided into four groups: control/configuration, status/information, mapping, and
FIFOs. Table 22-A lists these registers by group.
22.2 HDLC Configuration
The HxTC and HxRC registers perform the basic configuration of the HDLC controllers. Operating
features such as CRC generation, zero stuffer, transmit and receive HDLC mapping options, and idle
flags are selected here. These registers also reset the HDLC controllers.
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DS2156
Table 22-A. HDLC Controller Registers
REGISTER
FUNCTION
CONTROL AND CONFIGURATION
H1TC, HDLC #1 Transmit Control Register
General control over the transmit HDLC
H2TC, HDLC #2 Transmit Control Register
controllers
H1RC, HDLC #1 Receive Control Register
General control over the receive HDLC
H2RC, HDLC #2 Receive Control Register
controllers
H1FC, HDLC #1 FIFO Control Register
Sets high watermark for receiver and low
H2FC, HDLC #2 FIFO Control Register
watermark for transmitter
STATUS AND INFORMATION
SR6, HDLC #1 Status Register
Key status information for both transmit and
SR7, HDLC #2 Status Register
receive directions
IMR6, HDLC #1 Interrupt Mask Register
Selects which bits in the status registers (SR7
IMR7, HDLC #2 Interrupt Mask Register
and SR8) cause interrupts
INFO4, HDLC #1 and #2 Information Register
Information about HDLC controller
INFO5, HDLC #1 Information Register
INFO6, HDLC #2 Information Register
Indicates the number of bytes that can be read
H1RPBA, HDLC #1 Receive Packet Bytes
from the receive FIFO
Available Register
H2RPBA, HDLC #2 Receive Packet Bytes
Available Register
Indicates the number of bytes that can be
H1TFBA, HDLC #1 Transmit FIFO Buffer
written to the transmit FIFO
Available Register
H2TFBA, HDLC #2 Transmit FIFO Buffer
Available Register
MAPPING
H1RCS1, H1RCS2, H1RCS3, H1RCS4, HDLC Selects which channels are mapped to the
receive HDLC controller
#1 Receive Channel Select Registers
H2RCS1, H2RCS2, H2RCS3, H2RCS4, HDLC
#2 Receive Channel Select Registers
H1RTSBS, HDLC #1 Receive TS/Sa Bit Select
Selects which bits in a channel are used or
Register
which Sa bits are used by the receive HDLC
H2RTSBS, HDLC #2 Receive TS/Sa Bit Select
controller
Register
Selects which channels are mapped to the
H1TCS1, H1TCS2, H1TCS3, H1TCS4, HDLC
transmit HDLC controller
#1 Transmit Channel Select Registers
H2TCS1, H2TCS2, H2TCS3, H2TCS4, HDLC
#2 Transmit Channel Select Registers
H1TTSBS, HDLC # 1 Transmit TS/Sa Bit Select Selects which bits in a channel are used or
which Sa bits are used by the transmit HDLC
Register
H2TTSBS, HDLC # 2 Transmit TS/Sa Bit Select controller
Register
FIFOs
H1RF, HDLC #1 Receive FIFO Register
Access to 128-byte receive FIFO
H2RF, HDLC #1 Receive FIFO Register
H1TF, HDLC #1 Transmit FIFO Register
Access to 128-byte transmit FIFO
H2TF, HDLC #2 Transmit FIFO Register
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
NOFS
0
H1TC, H2TC
HDLC #1 Transmit Control
HDLC #2 Transmit Control
90h, A0h
6
TEOML
0
5
THR
0
4
THMS
0
3
TFS
0
2
TEOM
0
1
TZSD
0
0
TCRCD
0
Bit 0/Transmit CRC Defeat (TCRCD). A 2-byte CRC code is automatically appended to the outbound message.
This bit can be used to disable the CRC function.
0 = enable CRC generation (normal operation)
1 = disable CRC generation
Bit 1/Transmit Zero-Stuffer Defeat (TZSD). The zero-stuffer function automatically inserts a 0 in the message
field (between the flags) after five consecutive 1s to prevent the emulation of a flag or abort sequence by the data
pattern. The receiver automatically removes (destuffs) any 0 after five 1s in the message field.
0 = enable the zero stuffer (normal operation)
1 = disable the zero stuffer
Bit 2/Transmit End of Message (TEOM). Should be set to a 1 just before the last data byte of an HDLC packet is
written into the transmit FIFO at HxTF. If not disabled through TCRCD, the transmitter automatically appends a 2byte CRC code to the end of the message.
Bit 3/Transmit Flag/Idle Select (TFS). This bit selects the intermessage fill character after the closing and before
the opening flags (7Eh).
0 = 7Eh
1 = FFh
Bit 4/Transmit HDLC Mapping Select (THMS)
0 = transmit HDLC assigned to channels
1 = transmit HDLC assigned to FDL (T1 mode), Sa bits (E1 mode)
Bit 5/Transmit HDLC Reset (THR). Resets the transmit HDLC controller and flushes the transmit FIFO. An
abort followed by 7Eh or FFh flags/idle is transmitted until a new packet is initiated by writing new data into the
FIFO. Must be cleared and set again for a subsequent reset.
0 = normal operation
1 = reset transmit HDLC controller and flush the transmit FIFO
Bit 6/Transmit End of Message and Loop (TEOML). To loop on a message, this bit should be set to a 1 just
before the last data byte of an HDLC packet is written into the transmit FIFO. The message repeats until the user
clears this bit or a new message is written to the transmit FIFO. If the host clears the bit, the looping message
completes, then flags are transmitted until a new message is written to the FIFO. If the host terminates the loop by
writing a new message to the FIFO, the loop terminates, one or two flags are transmitted, and the new message
starts. If not disabled through TCRCD, the transmitter automatically appends a 2-byte CRC code to the end of all
messages. This is useful for transmitting consecutive SS7 FISUs without host intervention.
Bit 7/Number of Flags Select (NOFS)
0 = send one flag between consecutive messages
1 = send two flags between consecutive messages
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RHR
0
H1RC, H2RC
HDLC #1 Receive Control
HDLC #2 Receive Control
31h, 32h
6
RHMS
0
5
—
0
4
—
0
3
—
0
2
—
0
1
—
0
0
RSFD
0
Bit 0/Receive SS7 Fill-In Signal Unit Delete (RSFD)
0 = normal operation; all FISUs are stored in the receive FIFO and reported to the host.
1 = When a consecutive FISU having the same BSN the previous FISU is detected, it is deleted without
host intervention.
Bits 1 to 5/Unused, must be set to 0 or proper operation
Bit 6/Receive HDLC Mapping Select (RHMS)
0 = receive HDLC assigned to channels
1 = receive HDLC assigned to FDL (T1 mode), Sa bits (E1 mode)
Bit 7/Receive HDLC Reset (RHR). Resets the receive HDLC controller and flushes the receive FIFO. Must be
cleared and set again for a subsequent reset.
0 = normal operation
1 = reset receive HDLC controller and flush the receive FIFO
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DS2156
22.2.1
FIFO Control
The FIFO control register (HxFC) controls and sets the watermarks for the transmit and receive FIFOs.
Bits 3, 4, and 5 set the transmit low watermark and the lower 3 bits set the receive high watermark.
When the transmit FIFO empties below the low watermark, the TLWM bit in the appropriate HDLC
status register SR6 or SR7 is set. TLWM is a real-time bit and remains set as long as the transmit FIFO’s
read pointer is below the watermark. If enabled, this condition can also cause an interrupt through the INT
pin.
When the receive FIFO fills above the high watermark, the RHWM bit in the appropriate HDLC status
register is set. RHWM is a real-time bit and remains set as long as the receive FIFO’s write pointer is
above the watermark. If enabled, this condition can also cause an interrupt through the INT pin.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
H1FC, H2FC
HDLC # 1 FIFO Control
HDLC # 2 FIFO Control
91h, A1h
6
—
0
5
TFLWM2
0
4
TFLWM1
0
3
TFLWM0
0
2
RFHWM2
0
Bits 0 to 2/Receive FIFO High-Watermark Select (RFHWM0 to RFHWM2)
RFHWM2
RFHWM1
RFHWM0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Receive FIFO Watermark
(bytes)
4
16
32
48
64
80
96
112
Bits 3 to 5/Transmit FIFO Low-Watermark Select (TFLWM0 to TFLWM2)
TFLWM2
TFLWM1
TFLWM0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Transmit FIFO Watermark
(bytes)
4
16
32
48
64
80
96
112
Bits 6, 7/Unused, must be set to 0 for proper operation
137 of 265
1
RFHWM1
0
0
RFHWM0
0
DS2156
22.3 HDLC Mapping
22.3.1 Receive
The HDLC controllers must be assigned a space in the T1/E1 bandwidth in which they transmit and
receive data. The controllers can be mapped to either the FDL (T1), Sa bits (E1), or to channels. If
mapped to channels, then any channel or combination of channels, contiguous or not, can be assigned to
an HDLC controller. When assigned to a channel(s), any combination of bits within the channel(s) can be
avoided.
The HxRCS1–HxRCS4 registers are used to assign the receive controllers to channels 1–24 (T1) or
1–32 (E1) according to the following table:
Register
HxRCS1
HxRCS2
HxRCS3
HxRCS4
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RHCS7
0
Channels
1–8
9–16
17–24
25–32
H1RCS1, H1RCS2, H1RCS3, H1RCS4
H2RCS1, H2RCS2, H2RCS3, H2RCS4
HDLC # 1 Receive Channel Select x
HDLC # 2 Receive Channel Select x
92h, 93h, 94h, 95h
A2h, A3h, A4h, A5h
6
RHCS6
0
5
RHCS5
0
4
RHCS4
0
3
RHCS3
0
2
RHCS2
0
1
RHCS1
0
Bit 0/Receive HDLC Channel Select Bit 0 (RHCS0). Select Channel 1, 9, 17, or 25.
Bit 1/Receive HDLC Channel Select Bit 1 (RHCS1). Select Channel 2, 10, 18, or 26.
Bit 2/Receive HDLC Channel Select Bit 2 (RHCS2). Select Channel 3, 11, 19, or 27.
Bit 3/Receive HDLC Channel Select Bit 3 (RHCS3). Select Channel 4, 12, 20, or 28.
Bit 4/Receive HDLC Channel Select Bit 4 (RHCS4). Select Channel 5, 13, 21, or 29.
Bit 5/Receive HDLC Channel Select Bit 5 (RHCS5). Select Channel 6, 14, 22, or 30.
Bit 6/Receive HDLC Channel Select Bit 6 (RHCS6). Select Channel 7, 15, 23, or 31.
Bit 7/Receive HDLC Channel Select Bit 7 (RHCS7). Select Channel 8, 16, 24, or 32.
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0
RHCS0
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RCB8SE
0
H1RTSBS, H2RTSBS
HDLC # 1 Receive Time Slot Bits/Sa Bits Select
HDLC # 2 Receive Time Slot Bits/Sa Bits Select
96h, A6h
6
RCB7SE
0
5
RCB6SE
0
4
RCB5SE
0
3
RCB4SE
0
2
RCB3SE
0
1
RCB2SE
0
0
RCB1SE
0
Bit 0/Receive Channel Bit 1 Suppress Enable/Sa8 Bit Enable (RCB1SE ). LSB of the channel. Set to 1 to stop
this bit from being used.
Bit 1/Receive Channel Bit 2 Suppress Enable/Sa7 Bit Enable (RCB2SE). Set to 1 to stop this bit from being
used.
Bit 2/Receive Channel Bit 3 Suppress Enable/Sa6 Bit Enable (RCB3SE). Set to 1 to stop this bit from being
used.
Bit 3/Receive Channel Bit 4 Suppress Enable/Sa5 Bit Enable (RCB4SE). Set to 1 to stop this bit from being
used.
Bit 4/Receive Channel Bit 5 Suppress Enable/Sa4 Bit Enable (RCB5SE). Set to 1 to stop this bit from being
used.
Bit 5/Receive Channel Bit 6 Suppress Enable (RCB6SE). Set to 1 to stop this bit from being used.
Bit 6/Receive Channel Bit 7 Suppress Enable (RCB7SE). Set to 1 to stop this bit from being used.
Bit 7/Receive Channel Bit 8 Suppress Enable (RCB8SE). MSB of the channel. Set to 1 to stop this bit from
being used.
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DS2156
22.3.2 Transmit
The HxTCS1–HxTCS4 registers are used to assign the transmit controllers to channels 1–24 (T1) or
1–32 (E1) according to the following table.
Register
HxTCS1
HxTCS2
HxTCS3
HxTCS4
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
THCS7
0
Channels
1–8
9–16
17–24
25–32
H1TCS1, H1TCS2, H1TCS3, H1TCS4
H2TCS1, H2TCS2, H2TCS3, H2TCS4
HDLC # 1 Transmit Channel Select
HDLC # 2 Transmit Channel Select
97h, 98h, 99h, 9Ah
A7h, A8h, A9h, AAh
6
THCS6
0
5
THCS5
0
4
THCS4
0
3
THCS3
0
2
THCS2
0
1
THCS1
0
Bit 0/Transmit HDLC Channel Select Bit 0 (THCS0). Select Channel 1, 9, 17, or 25.
Bit 1/Transmit HDLC Channel Select Bit 1 (THCS1). Select Channel 2, 10, 18, or 26.
Bit 2/Transmit HDLC Channel Select Bit 2 (THCS2). Select Channel 3, 11, 19, or 27.
Bit 3/Transmit HDLC Channel Select Bit 3 (THCS3). Select Channel 4, 12, 20, or 28.
Bit 4/Transmit HDLC Channel Select Bit 4 (THCS4). Select Channel 5, 13, 21, or 29.
Bit 5/Transmit HDLC Channel Select Bit 5 (THCS5). Select Channel 6, 14, 22, or 30.
Bit 6/Transmit HDLC Channel Select Bit 6 (THCS6). Select Channel 7, 15, 23, or 31.
Bit 7/Transmit HDLC Channel Select Bit 7 (THCS7). Select Channel 8, 16, 24, or 32.
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0
THCS0
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TCB8SE
0
H1TTSBS, H2TTSBS
HDLC # 1 Transmit Time Slot Bits/Sa Bits Select
HDLC # 2 Transmit Time Slot Bits/Sa Bits Select
9Bh, ABh
6
TCB7SE
0
5
TCB6SE
0
4
TCB5SE
0
3
TCB4SE
0
2
TCB3SE
0
1
TCB2SE
0
0
TCB1SE
0
Bit 0/Transmit Channel Bit 1 Suppress Enable/Sa8 Bit Enable (TCB1SE). LSB of the channel. Set to 1 to stop
this bit from being used.
Bit 1/Transmit Channel Bit 2 Suppress Enable/Sa7 Bit Enable (TCB1SE). Set to 1 to stop this bit from being
used.
Bit 2/Transmit Channel Bit 3 Suppress Enable/Sa6 Bit Enable (TCB1SE). Set to 1 to stop this bit from being
used.
Bit 3/Transmit Channel Bit 4 Suppress Enable/Sa5 Bit Enable (TCB1SE). Set to 1 to stop this bit from being
used.
Bit 4/Transmit Channel Bit 5 Suppress Enable/Sa4 Bit Enable (TCB1SE). Set to 1 to stop this bit from being
used.
Bit 5/Transmit Channel Bit 6 Suppress Enable (TCB1SE). Set to 1 to stop this bit from being used.
Bit 6/Transmit Channel Bit 7 Suppress Enable (TCB1SE). Set to 1 to stop this bit from being used.
Bit 7/Transmit Channel Bit 8 Suppress Enable (TCB1SE). MSB of the channel. Set to 1 to stop this bit from
being used.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
SR6, SR7
HDLC #1 Status Register 6
HDLC #2 Status Register 7
20h, 22h
6
TMEND
0
5
RPE
0
4
RPS
0
3
RHWM
0
2
RNE
0
1
TLWM
0
0
TNF
0
Bit 0/Transmit FIFO Not Full Condition (TNF). Set when the transmit 128-byte FIFO has at least 1 byte
available.
Bit 1/Transmit FIFO Below Low-Watermark Condition (TLWM). Set when the transmit 128-byte FIFO
empties beyond the low watermark as defined by the transmit low-watermark register (TLWMR).
Bit 2/Receive FIFO Not Empty Condition (RNE). Set when the receive 128-byte FIFO has at least 1 byte
available for a read.
Bit 3/Receive FIFO Above High-Watermark Condition (RHWM). Set when the receive 128-byte FIFO fills
beyond the high watermark as defined by the receive high-watermark register (RHWMR).
Bit 4/Receive Packet-Start Event (RPS). Set when the HDLC controller detects an opening byte. This is a latched
bit and is cleared when read.
Bit 5/Receive Packet-End Event (RPE). Set when the HDLC controller detects either the finish of a valid
message (i.e., CRC check complete) or when the controller has experienced a message fault such as a CRC
checking error, or an overrun condition, or an abort has been seen. This is a latched bit and is cleared when read.
Bit 6/Transmit Message-End Event (TMEND). Set when the transmit HDLC controller has finished sending a
message. This is a latched bit and is cleared when read.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
IMR6, IMR7
HDLC # 1 Interrupt Mask Register 6
HDLC # 2 Interrupt Mask Register 7
21h, 23h
6
TMEND
0
5
RPE
0
4
RPS
0
3
RHWM
0
2
RNE
0
Bit 0/Transmit FIFO Not Full Condition (TNF)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 1/Transmit FIFO Below Low-Watermark Condition (TLWM)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 2/Receive FIFO Not Empty Condition (RNE)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 3/Receive FIFO Above High-Watermark Condition (RHWM)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising edge only
Bit 4/Receive Packet-Start Event (RPS)
0 = interrupt masked
1 = interrupt enabled
Bit 5/Receive Packet-End Event (RPE)
0 = interrupt masked
1 = interrupt enabled
Bit 6/Transmit Message-End Event (TMEND)
0 = interrupt masked
1 = interrupt enabled
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1
TLWM
0
0
TNF
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
INFO5, INFO6
HDLC #1 Information Register
HDLC #2 Information Register
2Eh, 2Fh
6
—
0
5
TEMPTY
0
4
TFULL
0
3
REMPTY
0
2
PS2
0
1
PS1
0
0
PS0
0
Bits 0 to 2/Receive Packet Status (PS0 to PS2). These are real-time bits indicating the status as of the last read of
the receive FIFO.
PS2
PS1
PS0
Packet Status
0
0
0
In Progress
0
0
1
Packet OK: Packet ended with correct CRC codeword
0
1
0
0
1
1
1
0
0
CRC Error: A closing flag was detected, preceded by a corrupt CRC
codeword
Abort: Packet ended because an abort signal was detected (seven or
more 1s in a row).
Overrun: HDLC controller terminated reception of packet because
receive FIFO is full.
Bit 3/Receive FIFO Empty (REMPTY). A real-time bit that is set high when the receive FIFO is empty.
Bit 4/Transmit FIFO Full (TFULL). A real-time bit that is set high when the FIFO is full.
Bit 5/Transmit FIFO Empty (TEMPTY). A real-time bit that is set high when the FIFO is empty.
Register Name:
Register Description:
Register Address:
INFO4
HDLC Event Information Register #4
2Dh
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
H2UDR
0
2
H2OBT
0
1
H1UDR
0
0
H1OBT
0
Bit 0/HDLC #1 Opening Byte Event (H1OBT). Set when the next byte available in the receive FIFO is the first
byte of a message.
Bit 1/HDLC #1 Transmit FIFO Underrun Event (H1UDR). Set when the transmit FIFO empties out without
having seen the TMEND bit set. An abort is automatically sent. This bit is latched and is cleared when read.
Bit 2/HDLC #2 Opening Byte Event (H2OBT). Set when the next byte available in the receive FIFO is the first
byte of a message.
Bit 3/HDLC #2 Transmit FIFO Underrun Event (H2UDR). Set when the transmit FIFO empties out without
having seen the TMEND bit set. An abort is automatically sent. This bit is latched and is cleared when read.
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DS2156
22.3.3 FIFO Information
The transmit FIFO buffer-available register indicates the number of bytes that can be written into the
transmit FIFO. The count form this register informs the host as to how many bytes can be written into the
transmit FIFO without overflowing the buffer.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TFBA7
0
H1TFBA, H2TFBA
HDLC # 1 Transmit FIFO Buffer Available
HDLC # 2 Transmit FIFO Buffer Available
9Fh, Afh
6
TFBA6
0
5
TFBA5
0
4
TFBA4
0
3
TFBA3
0
2
TFBA2
0
1
TFBA1
0
0
TFBA0
0
Bits 0 to 7/Transmit FIFO Bytes Available (TFBAO to TFBA7). TFBA0 is the LSB.
22.3.4
Receive Packet-Bytes Available
The lower 7 bits of the receive packet-bytes available register indicates the number of bytes (0 through
127) that can be read from the receive FIFO. The value indicated by this register (lower seven bits)
informs the host as to how many bytes can be read from the receive FIFO without going past the end of a
message. This value refers to one of four possibilities: the first part of a packet, the continuation of a
packet, the last part of a packet, or a complete packet. After reading the number of bytes indicated by this
register, the host then checks the HDLC information register for detailed message status.
If the value in the HxRPBA register refers to the beginning portion of a message or continuation of a
message, then the MSB of the HxRPBA register returns a value of 1. This indicates that the host can
safely read the number of bytes returned by the lower seven bits of the HxRPBA register, but there is no
need to check the information register since the packet has not yet terminated (successfully or otherwise).
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
MS
0
H1RPBA, H2RPBA
HDLC # 1 Receive Packet Bytes Available
HDLC # 2 Receive Packet Bytes Available
9Ch, ACh
6
RPBA6
0
5
RPBA5
0
4
RPBA4
0
3
RPBA3
0
2
RPBA2
0
1
RPBA1
0
0
RPBA0
0
Bits 0 to 6/Receive FIFO Packet Bytes Available Count (RPBA0 to RPBA6). RPBA0 is the LSB.
Bit 7/Message Status (MS)
0 = bytes indicated by RPBA0 through RPBA6 are the end of a message. Host must check the INFO5 or
INFO6 register for details.
1 = bytes indicated by RPBA0 through RPBA6 are the beginning or continuation of a message. The host
does not need to check the INFO5 or INFO6 register.
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DS2156
22.3.5
HDLC FIFOs
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
THD7
0
H1TF, H2TF
HDLC # 1 Transmit FIFO
HDLC # 2 Transmit FIFO
9Dh, ADh
6
THD6
0
5
THD5
0
4
THD4
0
3
THD3
0
2
THD2
0
1
THD1
0
0
THD0
0
Bit 0/Transmit HDLC Data Bit 0 (THD0). LSB of an HDLC packet data byte.
Bit 1/Transmit HDLC Data Bit 1 (THD1)
Bit 2/Transmit HDLC Data Bit 2 (THD2)
Bit 3/Transmit HDLC Data Bit 3 (THD3)
Bit 4/Transmit HDLC Data Bit 4 (THD4)
Bit 5/Transmit HDLC Data Bit 5 (THD5)
Bit 6/Transmit HDLC Data Bit 6 (THD6)
Bit 7/Transmit HDLC Data Bit 7 (THD7). MSB of an HDLC packet data byte.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RHD7
0
H1RF, H2RF
HDLC # 1 Receive FIFO
HDLC # 2 Receive FIFO
9Eh, AEh
6
RHD6
0
5
RHD5
0
4
RHD4
0
3
RHD3
0
2
RHD2
0
1
RHD1
0
Bit 0/Receive HDLC Data Bit 0 (RHD0). LSB of an HDLC packet data byte.
Bit 1/Receive HDLC Data Bit 1 (RHD1)
Bit 2/Receive HDLC Data Bit 2 (RHD2)
Bit 3/Receive HDLC Data Bit 3 (RHD3)
Bit 4/Receive HDLC Data Bit 4 (RHD4)
Bit 5/Receive HDLC Data Bit 5 (RHD5)
Bit 6/Receive HDLC Data Bit 6 (RHD6)
Bit 7/Receive HDLC Data Bit 7 (RHD7). MSB of an HDLC packet data byte.
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0
RHD0
0
DS2156
22.4 Receive HDLC Code Example
The following is an example of a receive HDLC routine:
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
Reset receive HDLC controller.
Set HDLC mode, mapping, and high watermark.
Start new message buffer.
Enable RPE and RHWM interrupts.
Wait for interrupt.
Disable RPE and RHWM interrupts.
Read HxRPBA register. N = HxRPBA (lower 7 bits are byte count, MSB is status).
Read (N and 7Fh) bytes from receive FIFO and store in message buffer.
Read INFO5 register.
If PS2, PS1, PS0 = 000, then go to Step 4.
If PS2, PS1, PS0 = 001, then packet terminated OK, save present message buffer.
If PS2, PS1, PS0 = 010, then packet terminated with CRC error.
If PS2, PS1, PS0 = 011, then packet aborted.
If PS2, PS1, PS0 = 100, then FIFO overflowed.
Go to Step 3.
22.5 Legacy FDL Support (T1 Mode)
22.5.1 Overview
To provide backward compatibility to the older DS21x52 T1 device, the DS2156 maintains the circuitry
that existed in the previous generation of the T1 framer. In new applications, it is recommended that the
HDLC controllers and BOC controller described in Section 20 and 22 are used.
22.5.2 Receive Section
In the receive section, the recovered FDL bits or Fs bits are shifted bit-by-bit into the receive FDL
register (RFDL). Because the RFDL is 8 bits in length, it fills up every 2ms (8 x 250µs). The framer
signals an external microcontroller that the buffer has filled through the SR8.3 bit. If enabled through
IMR8.3, the INT pin toggles low, indicating that the buffer has filled and needs to be read. The user has
2ms to read this data before it is lost. If the byte in the RFDL matches either of the bytes programmed
into the RFDLM1 or RFDLM2 registers, then the SR8.1 bit is set to a 1 and the INT pin toggles low if
enabled through IMR8.1. This feature allows an external microcontroller to ignore the FDL or Fs pattern
until an important event occurs.
The framer also contains a zero destuffer, which is controlled through the T1RCR2.3 bit. In both ANSI
T1.403 and TR54016, communications on the FDL follows a subset of an LAPD protocol. The LAPD
protocol states that no more than five 1s should be transmitted in a row so that the data does not resemble
an opening or closing flag (01111110) or an abort signal (11111111). If enabled through T1RCR2.3, the
DS2156 automatically looks for five 1s in a row, followed by a 0. If it finds such a pattern, it
automatically removes the zero. If the zero destuffer sees six or more 1s in a row followed by a 0, the 0 is
not removed. The T1RCR2.3 bit should always be set to a 1 when the DS2156 is extracting the FDL.
Refer to Application Note 335: DS2141A, DS2151 Controlling the FDL for information about using the
DS2156 in FDL applications in this legacy support mode.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RFDL7
0
RFDL
Receive FDL Register
C0h
6
RFDL6
0
5
RFDL5
0
4
RFDL4
0
3
RFDL3
0
2
RFDL2
0
1
RFDL1
0
0
RFDL0
0
The receive FDL register (RFDL) reports the incoming FDL or the incoming Fs bits. The LSB is received first.
Bit 0/Receive FDL Bit 0 (RFDL0). LSB of the received FDL code.
Bit 1/Receive FDL Bit 1 (RFDL1)
Bit 2/Receive FDL Bit 2 (RFDL2)
Bit 3/Receive FDL Bit 3 (RFDL3)
Bit 4/Receive FDL Bit 4 (RFDL4)
Bit 5/Receive FDL Bit 5 (RFDL5)
Bit 6/Receive FDL Bit 6 (RFDL6)
Bit 7/Receive FDL Bit 7 (RFDL7). MSB of the received FDL code.
Register Name:
Register Description:
Register Address:
RFDLM1, RFDLM2
Receive FDL Match Register 1
Receive FDL Match Register 2
C2h, C3h
Bit #
Name
Default
6
RFDLM6
0
7
RFDLM7
0
5
RFDLM5
0
4
RFDLM4
0
3
RFDLM3
0
Bit 0/Receive FDL Match Bit 0 (RFDLM0). LSB of the FDL match code.
Bit 1/Receive FDL Match Bit 1 (RFDLM1)
Bit 2/Receive FDL Match Bit 2 (RFDLM2)
Bit 3/Receive FDL Match Bit 3 (RFDLM3)
Bit 4/Receive FDL Match Bit 4 (RFDLM4)
Bit 5/Receive FDL Match Bit 5 (RFDLM5)
Bit 6/Receive FDL Match Bit 6 (RFDLM6)
Bit 7/Receive FDL Match Bit 7 (RFDLM7). MSB of the FDL match code.
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2
RFDLM2
0
1
RFDLM1
0
0
RFDLM0
0
DS2156
22.5.3 Transmit Section
The transmit section shifts out into the T1 data stream either the FDL (in the ESF framing mode) or the
Fs bits (in the D4 framing mode) contained in the transmit FDL register (TFDL). When a new value is
written to the TFDL, it is multiplexed serially (LSB first) into the proper position in the outgoing T1 data
stream. After the full 8 bits have been shifted out, the framer signals the host microcontroller by setting
the SR8.2 bit to a 1 that the buffer is empty and that more data is needed. The INT also toggles low if
enabled through IMR8.2. The user has 2ms to update the TFDL with a new value. If the TFDL is not
updated, the old value in the TFDL is transmitted once again. The framer also contains a zero stuffer that
is controlled through the T1TCR2.5 bit. In both ANSI T1.403 and TR54016, communications on the FDL
follows a subset of an LAPD protocol. The LAPD protocol states that no more than five 1s should be
transmitted in a row so that the data does not resemble an opening or closing flag (01111110) or an abort
signal (11111111). If enabled through T1TCR2.5, the framer automatically looks for five 1s in a row. If it
finds such a pattern, it automatically inserts a 0 after the five 1s. The T1TCR2.5 bit should always be set
to a 1 when the framer is inserting the FDL.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TFDL7
0
TFDL
Transmit FDL Register
C1h
6
TFDL6
0
5
TFDL5
0
4
TFDL4
0
3
TFDL3
0
2
TFDL2
0
1
TFDL1
0
0
TFDL0
0
Note: Also used to insert Fs framing pattern in D4 framing mode.
The transmit FDL register (TFDL) contains the FDL information that is to be inserted on a byte basis into the
outgoing T1 data stream. The LSB is transmitted first.
Bit 0/Transmit FDL Bit 0 (TFDL0). LSB of the transmit FDL code.
Bit 1/Transmit FDL Bit 1 (TFDL1)
Bit 2/Transmit FDL Bit 2 (TFDL2)
Bit 3/Transmit FDL Bit 3 (TFDL3)
Bit 4/Transmit FDL Bit 4 (TFDL4)
Bit 5/Transmit FDL Bit 5 (TFDL5)
Bit 6/Transmit FDL Bit 6 (TFDL6)
Bit 7/Transmit FDL Bit 7 (TFDL7). MSB of the transmit FDL code.
22.6 D4/SLC-96 Operation
In the D4 framing mode, the framer uses the TFDL register to insert the Fs framing pattern. To allow the
device to properly insert the Fs framing pattern, the TFDL register at address C1h must be programmed to
1Ch and the following bits must be programmed as shown:
T1TCR1.2 = 0 (source Fs data from the TFDL register)
T1TCR2.6 = 1 (allow the TFDL register to load on multiframe boundaries)
Since the SLC-96 message fields share the Fs-bit position, the user can access these message fields
through the TFDL and RFDL registers. Refer to Application Note 345: DS2141A, DS2151, DS2152 SLC96 for a detailed description about implementing an SLC-96 function.
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23.
LINE INTERFACE UNIT (LIU)
The LIU contains three sections: the receiver that handles clock and data recovery, the transmitter that
waveshapes and drives the T1 line, and the jitter attenuator. These three sections are controlled by the line
interface control registers (LIC1–LIC4), which are described in the following sections. The LIU has its
own T1/E1 mode-select bit and can operate independently of the framer function.
The DS2156 can switch between T1 or E1 networks without changing any external components on either
the transmit or receive side. Figure 23-3 shows a network connection using minimal components. In this
configuration, the DS2156 can connect to T1, J1, or E1 (75Ω or 120Ω) without any component change.
The receiver can adjust the 120Ω termination to 100Ω or 75Ω. The transmitter can adjust its output
impedance to provide high return-loss characteristics for 120Ω, 100Ω, and 75Ω lines. Other components
can be added to this configuration to meet safety and network protection requirements (Section 23.8).
23.1 LIU Operation
The analog AMI/HDB3 waveform off the E1 line or the AMI/B8ZS waveform off of the T1 line is
transformer-coupled into the RTIP and RRING pins of the DS2156. The user has the option to use
internal termination, software selectable for 75Ω/100Ω/120Ω applications, or external termination. The
LIU recovers clock and data from the analog signal and passes it through the jitter-attenuation mux
outputting the received line clock at RCLKO and bipolar or NRZ data at RPOSO and RNEGO. The
DS2156 contains an active filter that reconstructs the analog-received signal for the nonlinear losses that
occur in transmission. The receive circuitry also is configurable for various monitor applications. The
device has a usable receive sensitivity of 0dB to -43dB for E1 and 0dB to -36dB for T1, which allow the
device to operate on 0.63mm (22AWG) cables up to 2.5km (E1) and 6k feet (T1) in length. Data input at
TPOSI and TNEGI is sent through the jitter-attenuation mux to the waveshaping circuitry and line driver.
The DS2156 drives the E1 or T1 line from the TTIP and TRING pins through a coupling transformer.
The line driver can handle both CEPT 30/ISDN-PRI lines for E1 and long-haul (CSU) or short-haul
(DSX-1) lines for T1.
23.2 Receiver
The DS2156 contains a digital clock recovery system. The DS2156 couples to the receive E1 or T1
twisted pair (or coaxial cable in 75Ω E1 applications) through a 1:1 transformer. See Table 23-A for
transformer details. The DS2156 has the option of using software-selectable termination requiring only a
single fixed pair of termination resistors.
The DS2156’s LIU is designed to be fully software selectable for E1 and T1, requiring no change to any
external resistors for the receive side. The receive side allows the user to configure the DS2156 for 75Ω,
100Ω, or 120Ω receive termination by setting the RT1 (LIC4.1) and RT0 (LIC4.0) bits. When using the
internal termination feature, the resistors labeled R in Figure 23-3 should be 60Ω each. If external
termination is used, RT1 and RT0 should be set to 0 and the resistors labeled R in Figure 23-3 should be
37.5Ω, 50Ω, or 60Ω each, depending on the line impedance.
There are two ranges of user-selectable receive sensitivity for T1 and E1. The EGL bit of LIC1 (LIC1.4)
selects the full or limited sensitivity. The resultant E1 or T1 clock derived from MCLK is multiplied by
16 through an internal PLL and fed to the clock recovery system. The clock recovery system uses the
clock from the PLL circuit to form a 16-times over-sampler that is used to recover the clock and data.
This over-sampling technique offers outstanding performance to meet jitter tolerance specifications
shown in Figure 23-7.
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DS2156
Normally, the clock that is output at the RCLK pin is the recovered clock from the E1 AMI/HDB3 or T1
AMI/B8ZS waveform presented at the RTIP and RRING inputs. If the jitter attenuator is placed in the
receive path (as is the case in most applications), the jitter attenuator restores the RCLK to an
approximate 50% duty cycle. If the jitter attenuator is either placed in the transmit path or is disabled, the
RCLK output can exhibit slightly shorter high cycles of the clock. This is because of the highly oversampled digital-clock recovery circuitry. See the Receive AC Timing Characteristics in Section 36.3 for
more details. When no signal is present at RTIP and RRING, a receive carrier loss (RCL) condition
occurs and the RCLK is derived from the JACLK source.
23.2.1
Receive Level Indicator and Threshold Interrupt
The DS2156 reports the signal strength at RTIP and RRING in 2.5dB increments through RL3–RL0
located in Information Register 2 (INFO2). This feature is helpful when trouble-shooting lineperformance problems. The DS2156 can initiate an interrupt whenever the input falls below a certain
level through the input-level under-threshold indicator (SR1.7). Using the RLT0–RLT4 bits of the CCR4
register, the user can set a threshold in 2.5dB increments. The SR1.7 bit is set whenever the input level at
RTIP and RRING falls below the threshold set by the value in RLT0–RLT4. The level must remain
below the programmed threshold for approximately 50ms for this bit to be set.
23.2.2
Receive G.703 Synchronization Signal (E1 Mode)
The DS2156 is capable of receiving a 2.048MHz square-wave synchronization clock as specified in
Section 13 of ITU G.703, October 1998. In order to use the DS2156 in this mode, set the receive
synchronization clock enable (LIC3.2) = 1.
23.2.3
Monitor Mode
Monitor applications in both E1 and T1 require various flat gain settings for the receive-side circuitry.
The DS2156 can be programmed to support these applications through the monitor mode control bits
MM1 and MM0 in the LIC3 register (Figure 23-1).
Figure 23-1. Typical Monitor Application
PRIMARY
T1/E1 TERMINATING
DEVICE
T1/E1 LINE
Rm
Rm
X
F
M
R
MONITOR
PORT JACK
Rt
DS2156
SECONDARY T1/E1
TERMINATING
DEVICE
151 of 265
DS2156
23.3 Transmitter
The DS2156 uses a phase-lock loop along with a precision digital-to-analog converter (DAC) to create
the waveforms that are transmitted onto the E1 or T1 line. The waveforms created by the DS2156 meet
the latest ETSI, ITU, ANSI, and AT&T specifications. The user selects which waveform is generated by
setting the ETS bit (LIC2.7) for E1 or T1 operation, then programming the L2/L1/L0 bits in register LIC1
for the appropriate application.
A 2.048MHz or 1.544MHz clock is required at TCLKI for transmitting data presented at TPOSI and
TNEGI. Normally these pins are connected to TCLKO, TPOSO, and TNEGO. However, the LIU can
operate in an independent fashion. ITU specification G.703 requires an accuracy of ±50ppm for both T1
and E1. TR62411 and ANSI specifications require an accuracy of ±32ppm for T1 interfaces. The clock
can be sourced internally from RCLK or JACLK. See LIC2.3, LIC4.4, and LIC4.5 for details. Because of
the nature of the transmitter’s design, very little jitter (less than 0.005UIP-P broadband from 10Hz to
100kHz) is added to the jitter present on TCLK. Also, the waveforms created are independent of the duty
cycle of TCLK. The transmitter in the DS2156 couples to the E1 or T1 transmit twisted pair (or coaxial
cable in some E1 applications) through a 1:2 step-up transformer. For the device to create the proper
waveforms, the transformer used must meet the specifications listed in Table 23-A. The DS2156 has the
option of using software-selectable transmit termination.
23.3.1 Transmit Short-Circuit Detector/Limiter
The DS2156 has an automatic short-circuit limiter that limits the source current to 50mA (RMS) into a
1Ω load. This feature can be disabled by setting the SCLD bit (LIC2.1) = 1. TCLE (INFO2.5) provides a
real-time indication of when the current limiter is activated. If the current limiter is disabled, TCLE
indicates that a short-circuit condition exists. Status Register SR1.2 provides a latched version of the
information, which can be used to activate an interrupt when enabled by the IMR1 register. The TPD bit
(LIC1.0) powers down the transmit line driver and tri-states the TTIP and TRING pins.
23.3.2 Transmit Open-Circuit Detector
The DS2156 can also detect when the TTIP or TRING outputs are open circuited. TOCD (INFO2.4)
provides a real-time indication of when an open circuit is detected. SR1 provides a latched version of the
information (SR1.1), which can be used to activate an interrupt when enabled by the IMR1 register.
23.3.3 Transmit BPV Error Insertion
When IBPV (LIC2.5) is transitioned from a 0 to a 1, the device waits for the next occurrence of three
consecutive 1s to insert a BPV. IBPV must be cleared and set again for another BPV error insertion.
23.3.4 Transmit G.703 Synchronization Signal (E1 Mode)
The DS2156 can transmit the 2.048MHz square-wave synchronization clock as specified in Section 13 of
ITU G.703, October 1998. In order to transmit the 2.048MHz clock, when in E1 mode, set the transmit
synchronization clock enable (LIC3.1) = 1.
152 of 265
DS2156
23.4 MCLK Prescaler
A 16.384MHz, 8.192MHz, 4.096MHz, 2.048MHz, or 1.544MHz clock must be applied at MCLK. ITU
specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI
specifications require an accuracy of ±32ppm for T1 interfaces. A prescaler divides the 16MHz, 8MHz,
or 4MHz clock down to 2.048MHz. There is an on-board PLL for the jitter attenuator, which converts the
2.048MHz clock to a 1.544MHz rate for T1 applications. Setting JAMUX (LIC2.3) to a logic 0 bypasses
this PLL.
23.5 Jitter Attenuator
The DS2156 contains an on-board jitter attenuator that can be set to a depth of either 32 or 128 bits
through the JABDS bit (LIC1.2). The 128-bit mode is used in applications where large excursions of
wander are expected. The 32-bit mode is used in delay-sensitive applications. The characteristics of the
attenuation are shown in Figure 23-9. The jitter attenuator can be placed in either the receive path or the
transmit path by appropriately setting or clearing the JAS bit (LIC1.3). Setting the DJA bit (LIC1.1)
disables (in effect, removes) the jitter attenuator. On-board circuitry adjusts either the recovered clock
from the clock/data recovery block or the clock applied at the TCLK pin to create a smooth jitter-free
clock that is used to clock data out of the jitter attenuator FIFO. It is acceptable to provide a
gapped/bursty clock at the TCLK pin if the jitter attenuator is placed on the transmit side. If the incoming
jitter exceeds either 120UIP-P (buffer depth is 128 bits) or 28UIP-P (buffer depth is 32 bits), then the
DS2156 divides the internal nominal 32.768MHz (E1) or 24.704MHz (T1) clock by either 15 or 17
instead of the normal 16 to keep the buffer from overflowing. When the device divides by either 15 or 17,
it also sets the jitter attenuator limit trip (JALT) bit in Status Register 1 (SR1.4).
23.6 CMI (Code Mark Inversion) Option
The DS2156 provides a CMI interface for connection to optical transports. This interface is a unipolar
1T2B signal type. Ones are encoded as either a logical 1 or 0 level for the full duration of the clock
period. Zeros are encoded as a 0-to-1 transition at the middle of the clock period.
Figure 23-2. CMI Coding
CLOCK
DATA
1
1
0
1
0
0
1
CMI
Transmit and receive CMI are enabled through LIC4.7. When this register bit is set, the TTIP pin outputs
CMI-coded data at normal levels. This signal can be used to directly drive an optical interface. When
CMI is enabled, the user can also use HDB3/B8ZS coding. When this register bit is set, the RTIP pin
becomes a unipolar CMI input. The CMI signal is processed to extract and align the clock with data.
153 of 265
DS2156
23.7 LIU Control Registers
Register Name:
Register Description:
Register Address:
LIC1
Line Interface Control 1
78h
Bit #
Name
Default
6
L1
0
7
L2
0
5
L0
0
4
EGL
0
3
JAS
0
2
JABDS
0
1
DJA
0
0
TPD
0
Bit 0/Transmit Power-Down (TPD)
0 = powers down the transmitter and tri-states the TTIP and TRING pins
1 = normal transmitter operation
Bit 1/Disable Jitter Attenuator (DJA)
0 = jitter attenuator enabled
1 = jitter attenuator disabled
Bit 2/Jitter Attenuator Buffer Depth Select (JABDS)
0 = 128 bits
1 = 32 bits (use for delay-sensitive applications)
Bit 3/Jitter Attenuator Select (JAS)
0 = place the jitter attenuator on the receive side
1 = place the jitter attenuator on the transmit side
Bit 4/Receive Equalizer Gain Limit (EGL). This bit controls the sensitivity of the receive equalizer.
T1 Mode
0 = -36dB (long haul)
1 = 15dB (limited long haul)
E1 Mode
0 = -10dB (short haul)
1 = -43dB (long haul)
Bits 5 to 7/Line Buildout Select (L0 to L2). When using the internal termination, the user needs only to select 000
for 75Ω operation or 001 for 120Ω operation below. This selects the proper voltage levels for 75Ω or 120Ω
operation. Using TT0 and TT1 of the LICR4 register, the user can then select the proper internal source
termination. Line buildouts 100 and 101 are for backwards compatibility with older products only.
E1 Mode
L2
0
0
1
1
L1
0
0
0
0
L0
0
1
0
1
Application
75Ω normal
120Ω normal
75Ω with high return loss*
120Ω with high return loss*
N (1)
1:2
1:2
1:2
1:2
*TT0 and TT1 of LIC4 register must be set to 0 in this configuration.
154 of 265
Return Loss
NM
NM
21dB
21dB
Rt (1) (Ω)
0
0
6.2
11.6
DS2156
T1 Mode
L2
0
0
0
0
1
1
1
1
L1
0
0
1
1
0
0
1
1
L0
0
1
0
1
0
1
0
1
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
ETS
0
Application
DSX-1 (0ft to 133ft) / 0dB CSU
DSX-1 (133ft to 266ft)
DSX-1 (266ft to 399ft)
DSX-1 (399ft to 533ft)
DSX-1 (533ft to 655ft)
-7.5dB CSU
-15dB CSU
-22.5dB CSU
N (1)
1:2
1:2
1:2
1:2
1:2
1:2
1:2
1:2
Return Loss
NM
NM
NM
NM
NM
NM
NM
NM
Rt (1) (Ω)
0
0
0
0
0
0
0
0
LIC2
Line Interface Control 2
79h
6
LIRST
0
5
IBPV
0
4
TUA1
0
3
JAMUX
0
2
—
0
1
SCLD
0
0
CLDS
0
Bit 0/Custom Line Driver Select (CLDS). Setting this bit to a 1 redefines the operation of the transmit line
driver. When this bit is set to a 1 and LIC1.5 = LIC1.6 = LIC1.7 = 0, the device generates a square wave at the
TTIP and TRING outputs instead of a normal waveform. When this bit is set to a 1 and LIC1.5 = LIC1.6 = LIC1.7
≠ 0, the device forces TTIP and TRING outputs to become open-drain drivers instead of their normal push-pull
operation. This bit should be set to 0 for normal operation of the device.
Bit 1/Short-Circuit Limit Disable (ETS = 1) (SCLD). Controls the 50mA (RMS) current limiter.
0 = enable 50mA current limiter
1 = disable 50mA current limiter
Bit 2/Unused, must be set to 0 for proper operation
Bit 3/Jitter Attenuator Mux (JAMUX). Controls the source for JACLK.
0 = JACLK sourced from MCLK (2.048MHz or 1.544MHz at MCLK)
1 = JACLK sourced from internal PLL (2.048MHz at MCLK)
Bit 4/Transmit Unframed All Ones (TUA1). The polarity of this bit is set such that the device transmits an allones pattern on power-up or device reset. This bit must be set to a 1 to allow the device to transmit data. The
transmission of this data pattern is always timed off of the JACLK.
0 = transmit all ones at TTIP and TRING
1 = transmit data normally
Bit 5/Insert BPV (IBPV). A 0-to-1 transition on this bit causes a single BPV to be inserted into the transmit data
stream. Once this bit has been toggled from a 0 to a 1, the device waits for the next occurrence of three consecutive
1s to insert the BPV. This bit must be cleared and set again for a subsequent error to be inserted.
Bit 6/Line Interface Reset (LIRST). Setting this bit from a 0 to a 1 initiates an internal reset that resets the clock
recovery state machine and recenters the jitter attenuator. Normally this bit is only toggled on power-up. Must be
cleared and set again for a subsequent reset.
Bit 7/E1/T1 Select (ETS)
0 = T1 mode selected
1 = E1 mode selected
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
LIC3
Line Interface Control 3
7Ah
6
TCES
0
5
RCES
0
4
MM1
0
3
MM0
0
2
RSCLKE
0
1
TSCLKE
0
0
TAOZ
0
Bit 0/Transmit Alternate Ones and Zeros (TAOZ). Transmit a …101010… pattern (customer disconnect
indication signal) at TTIP and TRING. The transmission of this data pattern is always timed off of TCLK.
0 = disabled
1 = enabled
Bit 1/Transmit Synchronization G.703 Clock Enable (TSCLKE)
0 = disable 1.544MHz (T1)/2.048MHz (E1) transmit synchronization clock
1 = enable 1.544MHz (T1)/2.048MHz (E1) transmit synchronization clock
Bit 2/Receive Synchronization G.703 Clock Enable (RSCLKE)
0 = disable 1.544MHz (T1)/2.048MHz (E1) synchronization receive mode
1 = enable 1.544MHz (T1)/2.048MHz (E1) synchronization receive mode
Bits 3 to 4/Monitor Mode (MM0 to MM1)
MM1
MM0
0
0
1
1
0
1
0
1
Internal Linear Gain Boost
(dB)
Normal operation (no boost)
20
26
32
Bit 5/Receive-Clock Edge Select (RCES). Selects which RCLKO edge to update RPOSO and RNEGO.
0 = update RPOSO and RNEGO on rising edge of RCLKO
1 = update RPOSO and RNEGO on falling edge of RCLKO
Bit 6/Transmit-Clock Edge Select (TCES). Selects which TCLKI edge to sample TPOSI and TNEGI.
0 = sample TPOSI and TNEGI on falling edge of TCLKI
1 = sample TPOSI and TNEGI on rising edge of TCLKI
Bit 7/Unused, must be set to 0 for proper operation
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
LIC4
Line Interface Control 4
7Bh
7
CMIE
0
6
CMII
0
5
MPS1
0
4
MPS0
0
3
TT1
0
2
TT0
0
Bits 0, 1/Receive Termination Select (RT0, RT1)
RT1
0
0
1
1
RT0
0
1
0
1
Internal Receive-Termination Configuration
Internal receive-side termination disabled
Internal receive-side 75Ω enabled
Internal receive-side 100Ω enabled
Internal receive-side 120Ω enabled
Bits 2, 3/Transmit Termination Select (TT0, TT1)
TT1
0
0
1
1
TT0
0
1
0
1
Internal Transmit-Termination Configuration
Internal transmit-side termination disabled
Internal transmit -side 75Ω enabled
Internal transmit -side 100Ω enabled
Internal transmit -side 120Ω enabled
Bits 4, 5/MCLK Prescaler for T1 Mode
MCLK
(MHz)
1.544
3.088
6.176
12.352
2.048
4.096
8.192
16.384
MPS1
MPS0
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
JAMUX
(LIC2.3)
0
0
0
0
1
1
1
1
Bits 4, 5/MCLK Prescaler for E1 Mode
MCLK
(MHz)
2.048
4.096
8.192
16.384
MPS1
MPS0
0
0
1
1
0
1
0
1
JAMUX
(LIC2.3)
0
0
0
0
Bit 6/CMI Invert (CMII)
0 = CMI normal at TTIP and RTIP
1 = invert CMI signal at TTIP and RTIP
Bit 7/CMI Enable (CMIE)
0 = disable CMI mode
1 = enable CMI mode
157 of 265
1
RT1
0
0
RT0
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
BSYNC
0
INFO2
Information Register 2
11h
6
BD
0
5
TCLE
0
4
TOCD
0
3
RL3
0
2
RL2
0
1
RL1
0
0
RL0
0
Bits 0 to 3/Receive Level Bits (RL0 to RL3). Real-time bits
RL3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
RL2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
RL1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
RL0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Receive Level (dB)
Greater than -2.5
-2.5 to -5.0
-5.0 to -7.5
-7.5 to -10.0
-10.0 to -12.5
-12.5 to -15.0
-15.0 to -17.5
-17.5 to -20.0
-20.0 to -22.5
-22.5 to -25.0
-25.0 to -27.5
-27.5 to -30.0
-30.0 to -32.5
-32.5 to -35.0
-35.0 to -37.5
Less than -37.5
Bit 4/Transmit Open-Circuit Detect (TOCD). A real-time bit that is set when the device detects that the TTIP
and TRING outputs are open-circuited.
Bit 5/Transmit Current-Limit Exceeded (TCLE). A real-time bit that is set when the 50mA (RMS) current
limiter is activated, whether the current limiter is enabled or not.
Bit 6/BOC Detected (BD). A real-time bit that is set high when the BOC detector is presently seeing a valid
sequence and set low when no BOC is currently being detected.
Bit 7/BERT Real-Time Synchronization Status (BSYNC). Real-time status of the synchronizer (this bit is not
latched). This bit is set when the incoming pattern matches for 32 consecutive bit positions. It is cleared when six
or more bits out of 64 are received in error. Refer to BSYNC in the BERT status register, SR9, for an interruptgenerating version of this signal.
158 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
ILUT
0
SR1
Status Register 1
16h
6
TIMER
0
5
RSCOS
0
4
JALT
0
3
LRCL
0
2
TCLE
0
1
TOCD
0
0
LOLITC
0
Bit 0/Loss of Line-Interface Transmit-Clock Condition (LOLITC). Set when TCLKI has not transitioned for
one channel time. This is a double interrupt bit (Section 6.2).
Bit 1/Transmit Open-Circuit Detect Condition (TOCD). Set when the device detects that the TTIP and TRING
outputs are open-circuited. This is a double interrupt bit (Section 6.2).
Bit 2/Transmit Current-Limit Exceeded Condition (TCLE). Set when the 50mA (RMS) current limiter is
activated, whether the current limiter is enabled or not. This is a double interrupt bit (Section 6.2).
Bit 3/Line Interface Receive Carrier-Loss Condition (LRCL). Set when the carrier signal is lost. This is a
double interrupt bit (Section 6.2).
Bit 4/Jitter Attenuator Limit Trip Event (JALT). Set when the jitter attenuator FIFO reaches to within 4 bits of
its useful limit. This bit is cleared when read. Useful for debugging jitter attenuation operation.
Bit 5/Receive Signaling Change-of-State Event (RSCOS). Set when any channel selected by the receive
signaling change-of-state interrupt-enable registers (RSCSE1 through RSCSE4) changes signaling state.
Bit 6/Timer Event (TIMER). Follows the error-counter update interval as determined by the ECUS bit in the
error-counter configuration register (ERCNT).
T1: set on increments of 1 second or 42ms based on RCLK
E1: set on increments of 1 second or 62.5ms based on RCLK
Bit 7/Input Level Under Threshold (ILUT). This bit is set whenever the input level at RTIP and RRING falls
below the threshold set by the value in CCR4.4 through CCR4.7. The level must remain below the programmed
threshold for approximately 50ms for this bit to be set. This is a double interrupt bit (Section 6.2).
159 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
ILUT
0
IMR1
Interrupt Mask Register 1
17h
6
TIMER
0
5
RSCOS
0
4
JALT
0
3
LRCL
0
2
TCLE
0
Bit 0/Loss-of-Transmit Clock Condition (LOLITC)
0 = interrupt masked
1 = interrupt enabled—generates interrupts on rising and falling edges
Bit 1/Transmit Open-Circuit Detect Condition (TOCD)
0 = interrupt masked
1 = interrupt enabled—generates interrupts on rising and falling edges
Bit 2/Transmit Current-Limit Exceeded Condition (TCLE)
0 = interrupt masked
1 = interrupt enabled—generates interrupts on rising and falling edges
Bit 3/Line Interface Receive Carrier-Loss Condition (LRCL)
0 = interrupt masked
1 = interrupt enabled—generates interrupts on rising and falling edges
Bit 4/Jitter Attenuator Limit Trip Event (JALT)
0 = interrupt masked
1 = interrupt enabled
Bit 5/Receive Signaling Change-of-State Event (RSCOS)
0 = interrupt masked
1 = interrupt enabled
Bit 6/Timer Event (TIMER)
0 = interrupt masked
1 = interrupt enabled
Bit 7/Input Level Under Threshold (ILUT)
0 = interrupt masked
1 = interrupt enabled
160 of 265
1
TOCD
0
0
LOLITC
0
DS2156
23.8 Recommended Circuits
Figure 23-3. Basic Interface
VDD
DS2156
2:1
TTIP
TRANSMIT
LINE
C
DVDD
0.1µF 0.01µF
DVSS
TRING TVDD
1:1
RTIP
RECEIVE
LINE
0.1µF
10µF
+
TVSS
RVDD
0.1µF 10µF
+
RRING RVSS
R
R
0.1µF
Note 1: All resistor values are ±1%.
Note 2: Resistors R should be set to 60Ω each if the internal receive-side termination feature is enabled. When this feature is disabled, R =
37.5Ω for 75Ω coaxial E1 lines, 60Ω for 120Ω twisted-pair E1 lines, or 50Ω for 100Ω twisted-pair T1 lines.
Note 3: C = 1µF ceramic.
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DS2156
Figure 23-4. Protected Interface Using Internal Receive Termination
VDD
D1 D2
2:1
TRANSMIT
LINE
DS2156
TTIP
F1
S1
C1
DVDD
0.1µF 0.01µF
DVSS
0.1µF
X2
F2
VDD
D4
D3
TRING
TVDD
0.1µF
10µF
+
TVSS
VDD
D5
D6
1:1
RECEIVE
LINE
0.1µF
D8
F4
RVSS
RTIP
S2
F3
RVDD
X1
RRING
D7
60
60
0.1µF
Note 1: All resistor values are ±1%.
Note 2: X1 and X2 are very low DCR transformers.
Note 3: C1 = 1µF ceramic.
Note 4: S1 and S2 are 6V transient suppressers.
Note 5: D1–D8 are Schottky diodes.
Note 6: The optional fuses, F1–F4, prevent AC power line crosses from compromising the transformers.
Note 7: The 68µF is used to keep the local power-plane potential within tolerance during a surge.
162 of 265
0.1µF 10µF
+
68µF
+
DS2156
23.9 Component Specifications
Table 23-A. Transformer Specifications
SPECIFICATION
Turns Ratio 3.3V Applications
Primary Inductance
Leakage Inductance
Intertwining Capacitance
Transmit Transformer DC Resistance
Primary (Device Side)
Secondary
Receive Transformer DC Resistance
Primary (Device Side)
Secondary
RECOMMENDED VALUE
1:1 (receive) and 1:2 (transmit) ±2%
600µH (min)
1.0µH (max)
40pF (max)
1.0Ω (max)
2.0Ω (max)
1.2Ω (max)
1.2Ω (max)
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DS2156
Figure 23-5. E1 Transmit Pulse Template
1.2
SCALED AMPLITUDE
(IN 75Ω SYSTEMS, 1.0 ON THE SCALE = 2.37VPEAK
IN 120Ω SYSTEMS, 1.0 ON THE SCALE = 3.00VPEAK)
1.1
269ns
1.0
0.9
0.8
0.7
G.703
TEMPLATE
194ns
0.6
0.5
219ns
0.4
0.3
0.2
0.1
0
-0.1
-0.2
-250
-200
-150
-100
-50
0
50
100
150
200
250
TIME (ns)
Figure 23-6. T1 Transmit Pulse Template
1.2
1.0
-0.77
-0.39
-0.27
-0.27
-0.12
0.00
0.27
0.35
0.93
1.16
0.9
0.8
0.7
NORMALIZED AMPLITUDE
MINIMUM CURVE
UI
Time Amp.
MAXIMUM CURVE
UI
Time Amp.
1.1
0.6
-500
-255
-175
-175
-75
0
175
225
600
750
0.05
0.05
0.80
1.15
1.15
1.05
1.05
-0.07
0.05
0.05
0.5
-0.77
-0.23
-0.23
-0.15
0.00
0.15
0.23
0.23
0.46
0.66
0.93
1.16
-500
-150
-150
-100
0
100
150
150
300
430
600
750
-0.05
-0.05
0.50
0.95
0.95
0.90
0.50
-0.45
-0.45
-0.20
-0.05
-0.05
0.4
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
T1.102/87, T1.403,
CB 119 (OCT. 79), AND
I.431 TEMPLATE
-0.4
-0.5
-500
-400
-300
-200
-100
0
100
200
TIME (ns)
164 of 265
300
400
500
600
700
DS2156
Figure 23-7. Jitter Tolerance
UNIT INTERVALS (UIP-P)
1k
DS2156
TOLERANCE
100
TR 62411 (DEC. 90)
10
ITU-T G.823
1
0.1
1
10
100
1k
FREQUENCY (Hz)
10k
100k
Figure 23-8. Jitter Tolerance (E1 Mode)
UNIT INTERVALS (UIP-P)
1k
DS2155
TOLERANCE
100
40
10
1.5
1
MINIMUM TOLERANCE
LEVEL AS PER
0.2
ITU G.823
0.1
1
10
20
100
1k
FREQUENCY (Hz)
165 of 265
2.4k
10k
18k
100k
DS2156
Figure 23-9. Jitter Attenuation (T1 Mode)
-20dB
C
ve
ur
A
TR 62411 (Dec. 90)
Prohibited Area
-40dB
rve
Cu
JITTER ATTENUATION (dB)
0dB
B
DS2156
T1 MODE
-60dB
1
10
100
1K
FREQUENCY (Hz)
10K
100K
Figure 23-10. Jitter Attenuation (E1 Mode)
JITTER ATTENUATION (dB)
0dB
TBR12
Prohibited
Area
ITU G.7XX
Prohibited Area
-20dB
DS2156
E1 MODE
-40dB
-60dB
1
10
100
1K
FREQUENCY (Hz)
166 of 265
10K
100K
DS2156
Figure 23-11. Optional Crystal Connections
DS2156
XTALD
1.544MHz/2.048MHz
MCLK
C1
C2
Note 1: C1 and C2 should be 5pF lower than two times the nominal loading capacitance of the crystal to adjust for the input capacitance of the
DS2156.
167 of 265
DS2156
24.
UTOPIA BACKPLANE INTERFACE
24.1 Description
The DS2156’s UTOPIA interface maps the ATM cells in a T1/E1 frame in the transmit direction as per
ATM Forum Specifications af-phy-0016.000 [1] and af-phy-0064.000 [2] and recovers them in the
receive direction from a similar mapping. In the receive direction, the cell delineation mechanism used
for finding ATM cell boundaries within a T1/E1 frame is performed as per ITU-T I.432 [4]. The terms
“physical layer (PHY)” and “line side” are used synonymously in this document and refer to the device
interface with the line side of the DS2156. The terms “ATM layer” and “system side” are used
synonymously and refer to the UTOPIA-II interface of the DS2156.
The transmit section receives cells from the ATM layer through the UTOPIA-II interface. It writes the
cells into a 4-cell-deep transmit FIFO that is used for rate decoupling. The FIFO’s depth is programmable
to two, three, or four ATM cells. The cells are mapped into the T1/E1 frame as per [1] and [2]. The
DS2156 can be configured to perform valid HEC insertion and payload scrambling.
The receive section delineates the cells from the data received from the PHY layer as per [4]. Once cells
are delineated, they are written into a 4-cell-deep receive FIFO used for rate decoupling. The receive
section interfaces with the ATM layer through the UTOPIA-II interface. It can also be configured to
perform payload descrambling and idle/unassigned cell filtering. Single-bit HEC error correction is also
supported.
24.1.1 List of Applicable Standards
1) ATM Forum “DS1 Physical Layer Specification,” af-phy-0016.000, September 1994
2) ATM Forum “E1 Physical Layer Specification,” af-phy-0064.000, September 1996
3) ATM Forum “UTOPIA Level 2 Specification,” Version 1.0, af-phy-0039.000, June 1995
4) B-ISDN User-Network Interface—Physical Layer Specification—ITU-T Recommendation I.432–
03/93
24.1.2
Acronyms and Definitions
ACRONYM
ATM
CRC
HEC
LCD
OAM
OCD
PMON
UTOPIA
DEFINITION
Asynchronous Transfer Mode
Cyclic Redundancy Check
Header Error Check
Loss-of-Cell Delineation
Operations Administration and Maintenance
Out-of-Loss Delineation
Performance Monitoring
Universal Test and Operations PHY Interface for ATM
168 of 265
DS2156
24.2 UTOPIA Clock Modes
When the UTOPIA backplane is enabled, the user can select from several clocking modes: full T1/E1,
clear-channel E1, or fractional T1/E1. Because ATM bytes are byte-aligned in the frame, clear-channel
mode is only available in E1 operation. See Table 24-A for the various register configurations. Figure
24-1 shows a simplified diagram of the clock, data, and sync connections between the framer and the
UTOPIA block.
Figure 24-1. UTOPIA Clocking Configurations
CCR3.4
RECEIVE
FRAMER
RCLK
GAPPED
CLOCK
1
CLOCK
0
FRAME SYNC
SYNC
DATA
DATA
NETWORK
RECEIVE
UTOPIA BLOCK
UTOPIA
BACKPLANE
CCR3.5
TRANSMIT
FRAMER
TCLK
1
GAPPED
CLOCK
0
FRAME SYNC
DATA
CLOCK
SYNC
TRANSMIT
UTOPIA BLOCK
DATA
TCLK
24.3 Full T1/E1 Mode and Clear-Channel E1 Mode
In full T1/E1 mode, the framer is programmed to provide a constant clock (RCLK for the receiver and
TCLK for the transmitter) to the UTOPIA block by setting CCR3.4 and CCR3.5 = 1. The framer also
provides frame-sync pulses to the UTOPIA block. The UTOPIA block is programmed to use the clock
and sync signals by setting U_TCR2.1 and U_RCR2.1 = 0. In this mode the UTOPIA block uses the sync
signal to byte align the transmit data stream and locate the F-bit position in T1 operation and TS0 and
TS16 in E1 operation.
In T1 mode, the receive and transmit UTOPIA blocks always use the frame-sync pulse to gap out the Fbit position.
In E1 mode, the transmit UTOPIA block can be programmed to gap out TS0 and TS16 by setting
U_TCR1.3 = 0, or use the full 256 bits of the frame by setting U_TCR1.3 = 1. Using the full 256 bits of
the frame is referred to as clear-channel mode and is only available in E1 mode. In full E1 mode, the
receive UTOPIA block always uses the frame-sync pulse to gap out TS0 and TS16. In order for the
receive UTOPIA block to operate in clear-channel mode, set U_RCR2.1 = 1 while in full clock mode or
use the fractional mode of operation described in Section 24.4 with all channels selected.
169 of 265
DS2156
24.4 Fractional T1/E1 mode
In fractional T1/E1 mode, the framer is programmed to provide a gapped clock by setting CCR3.4 and
CCR3.5 = 0. The gapped clocks are synchronous with RCLK and TCLK. The UTOPIA block is
programmed to use the clock and ignore the sync signals by setting U_TCR2.1 and U_RCR2.1 = 1. In
this mode, the user can program the clock to be active during any time slot or group of time slots by using
the transmit and receive fractional channel-select function in the per-channel pointer register (PCPR). See
Section 5 for details on using this feature. In T1 mode, the F-bit is automatically gapped. In E1 mode, the
user must program the clock to be gapped during TS0 and/or TS16 if desired.
Table 24-A. UTOPIA Clock Mode Configuration
MODE
Full T1
mode, F-bit
position
gapped
Full E1
mode, TS0
and TS16
gapped
Full E1
mode, clearchannel
(transmit)
Full E1
mode, clearchannel
(receive)
Method #1
Full E1
mode, clearchannel
(receive)
Method #2
U_TCFR.0
CCR3.4
U_RCFR.0
CCR3.5
U_TCR2.3
U_TCR2.1
U_RCR2.1
0
1
1
X
0
0
1
1
1
0
0
0
1
—
1
1
0
0
1
1
—
X
—
1
1
0
—
X
—
1
Fractional T1
mode
0
0
0
X
1
1
Fractional E1
mode
1
0
0
X
1
1
170 of 265
COMMENTS
Clear-channel
operation is not
available in T1
mode
Transmit framer
must be set to TS0
pass-through mode
E1TCR1.7 = 1 and
transmit-signaling
insertion disabled
Use PCPR and
PCDR1–PCDR4
registers to make
all receive channels
active
Use PCPR and
PCDR1–PCDR4
registers to select
active transmit and
receive channels
Use PCPR and
PCDR1–PCDR4
registers to select
active transmit and
receive channels
DS2156
24.5 Transmit Operation
The DS2156 interface to the ATM layer is fully compliant to the ATM Forum’s UTOPIA Level 2
specification [3]. Either direct status or multiplexed with 1CLAV mode is supported. The DS2156 can be
configured to use any address, 0 to 3, as its UTOPIA port address, and uses a 4-cell buffer for cell-rate
decoupling. The depth of the transmit FIFO is configurable to 2, 3, or 4 cells. When a port is polled and
has cell space available, the DS2156 generates a cell available signal for that port. Additionally, the
DS2156 generates a 2-cell space availability indication for each port. Note that this “2CLAV” indication
follows the timing and polling cycles of UT-CLAV.
Figure 24-2 shows the polling and cell transfer cycles for DS2156s used in a multiport configuration.
Note that UT-SOC must be aligned with the first byte transfer. The DS2156 uses UT-SOC to detect the
first byte of a cell. If a spurious UT-SOC comes during a cell transfer, then the DS2156 aligns with the
latest UT-SOC and ignores the bytes (partial cell) received thus far.
24.5.1
UTOPIA Side Transmit: Muxed Mode with One Transmit CLAV
In the following functional description, a PHY is a single DS2156 and PHYs are multiple DS2156s.
In Level 2 UTOPIA, only one PHY at a time is selected for a cell transfer. However, another PHY can be
polled for its UT-CLAV status while the selected PHY transfers data. The ATM layer polls the UTCLAV status of a PHY by placing its address on the transmit UTOPIA bus. The PHY drives UT-CLAV
during each cycle following one with its address on the UT-ADDRx lines. The ATM layer selects a PHY
for transfer by placing the port address of the PHY onto UT-ADDRx, when UT-ENB is deasserted during
the current clock cycle, and asserted during the next clock cycle. All PHYs only examine the value on
UT-ADDRx for selection purposes when UT-ENB is deasserted. The PHY is selected starting from the
cycle after its address is on the UT-ADDRx lines and UT-ENB is deasserted. And ending in the cycle,
another PHY is addressed for selection and UT-ENB is deasserted. Once a PHY is selected, the cell
transfer is accomplished as described by the cell-level handshake of UTOPIA Level 1. To operate a PHY
in a single PHY environment, the address pins should be set to the value programmed by the management
interface.
Figure 24-2 shows an example where PHYs are polled until the end of a cell transmission cycle. The UTCLAV signal shows that PHYs N - 3 and N + 3 can accept cells and PHY N + 3 is selected. The PHY is
selected with the rising clock edge #16. Immediately after the beginning of cell transmission to
PHY N + 3, the ATM layer starts polling again. Using the 2-clock polling cycles shown, up to 26 PHYs
can be polled. This maximum value can only be reached if all responses occur in minimum delays, e.g.,
as shown, where, with clock edge #15, the response of the last PHY is obtained, immediately followed by
the UT-ENB pulse to the PHYs. If an ATM implementation needs additional clock cycles to select the
PHY, fewer than 26 PHY can be polled during one cell cycle. Note that if the ATM would decide to
select PHY N again for the next cell transmission, it could leave the UT-ENB line asserted and start
transmitting the next cell with clock edge #15. This results in a back-to-back cell transmission.
171 of 265
DS2156
Figure 24-2. Polling Phase and Selection Phase at Transmit Interface
SELECTION
POLLING
UT-CLK
UT-ADDRx
1
2
N+2
UT-CLAV
3
1F
4
N-3
5
1F
6
N-2
N-3
N+2
7
1F
POLLING
8
9
N-1
N-2
1F
10
N+3
11
1F
12
N+1
N+3
N-1
13
1F
14
N
N+1
15
1F
16
N+3
17
1F
N
N+3
P48
H1
18
N+1
19
1F
20
N-1
N+1
UT-ENB
UT-DATAx
P35
P36
P37
P38
P39
P40
P41
P42
P43
P44
P45
P46
P47
H2
H3
H4
UT-SOC
CELL XMIT TO:
PHY N
PHY N+3
Note that the active PHY (PHY N) is polled in octet P48. At this time, according to the UTOPIA Level 1
specification, the UT-CLAV signal of the PHY indicates the possibility of a subsequent cell transfer.
Polling of PHY N before octet P44 would be possible but it does not indicate availability of the next cell.
172 of 265
DS2156
The example in Figure 24-3 shows where the transmission of cells though the transmit interface is
stopped by the ATM, as no PHY is ready to accept cells. Polling continues. Several clock cycles later one
PHY gets ready to accept a cell. During the transmission pause, the UT-DATAx and UT-SOC can go into
high-impedance state as shown. UT-ENB is held in deasserted state. When a PHY is found that is ready to
accept a cell (PHY_N + 3 in this case), the address of this PHY must be applied again to select it. This is
necessary because of the 2-clock polling cycle, where the PHY is detected at the clock edge #15. At this
time, the address of PHY N + 3 is no longer on the bus and therefore must be applied again in the next
clock cycle. PHY N + 3 is selected with clock edge #16.
Figure 24-3. End and Restart of Cell at Transmit Interface
SELECTION
DETECTION
POLLING
UT-CLK
UT-ADDRx
1
2
N+1
UT-CLAV
3
1F
4
N
N+1
5
1F
N
6
N+3
7
1F
N+3
POLLING
8
N+2
9
1F
N+2
10
N-1
11
1F
N-1
12
N
13
1F
N
14
N+3
15
1F
N+3
16
N+3
17
1F
18
N-2
N+3
19
1F
20
N-3
N-2
UT-ENB
UT-DATAx
P45
P46
P47
P48
H1
H2
H3
UT-SOC
CELL XMIT TO:
PHY N
PHY N+3
173 of 265
H4
DS2156
Figure 24-4 shows an example where the ATM must pause the data transmission, since it has no data
available (in this case, for three clock cycles). This is done by deasserting UT-ENB and (optionally)
setting UT-DATAx and UT-SOC into a high-impedance state. Polling can continue. In the last clock
cycle before restarting the transmission, the address “M” of the previously selected PHY is put on the
UT-ADDRx bus to reselect PHY M again.
Figure 24-4. Transmission to PHY Paused for Three Cycles
SELECTION
POLLING
UT-CLK
UT-ADDRx
UT-CLAV
1
2
N
3
1F
4
N+1
N
5
1F
N+1
POLLING
6
N-4
7
1F
8
9
M
1F
M
N-4
10
N+2
11
1F
12
N+3
N+2
13
1F
N+3
UT-ENB
UT-DATAx
P31 P32 P33 P34
P35 P36 P37 P38 P39
UT-SOC
CELL XMIT TO:
PHY M
PAUSE
XMIT
PHY M
24.5.2
UTOPIA Side Transmit: Direct Status Mode (Multitransmit CLAV)
The DS2156 supports direct status mode per [3] for a maximum of four PHY ports connected to one
ATM layer. For each PHY port, the status signals UR-CLAV and UT-CLAV are permanently available
according to UTOPIA Level 1 specification. PHY devices with up to four PHY ports on-chip have up to
four UR-CLAV and up to four UT-CLAV status signals, one pair of UR-CLAV and UT-CLAV for each
PHY port.
Status signals and cell transfers are independent of each other. No address information is needed to obtain
status information. Address information must be valid only for selecting a PHY port prior to one or
multiple cell transfers. With respect to the status signals UR-CLAV and UT-CLAV, this mode of
operation corresponds to that of four individual PHY devices according to UTOPIA Level 1. With respect
to the cell transfer, this mode of operation corresponds to that as described in other parts of this
document. The ATM layer selects a PHY port for cell transfer by placing the desired port on the address
lines (UR-ADDRx, UT-ADDRx), while the enable signal (UR-ENB, UT-ENB) is deasserted. All PHY
ports examine only the value on the address lines for possible selection when the enable signal is
deasserted. In case the ATM suspends transmission for a specific PHY port during a cell transfer, no cells
to/from other PHY ports can be transferred during this time.
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DS2156
Figure 24-5 shows an example of direct status for the transmit direction. Signals UT-CLAV[3:0] are
associated to PHY port addresses #4, #3, #2, and #1. There is no need for a unique null device, thus “X =
don’t care” represents any address between 0 and 31 on the address lines UT-ADDRx or any data on the
data bus. The polling of PHY ports starts while no cell transfer takes place. The ATM layer has pending
cells for all four PHY ports (one individual queue for each PHY port) but all four PHY ports cannot
accept a cell. With rising clock edge #2, PHY port #1 indicates that it can accept a complete cell
(UT-CLAV0 asserted). The ATM layer detects this at clock edge #3. It selects that PHY port by placing
address #1 on the address lines with rising clock edge #3. PHY port #1 detects this at clock edge #4. At
clock edge #5, PHY port #1 detects UT-ENB asserted, therefore cell transfer for PHY port #1 starts with
rising clock edge #5 (byte H1).
Figure 24-5. Example of Direct Status Indication, Transmit Direction
UT-CLK
UT-ADDRx
1
2
3
X
UT-CLAV(1)
PORT #1
UT-CLAV(2)
PORT #2
UT-CLAV(3)
PORT #3
UT-CLAV(4)
PORT #4
4
5
1
6
52
X
53
54
55
56
57
X = Don't Care
58
59
3
X
X
H1
N-4
UT-ENB
UT-SOC
UT-DATAx
X
H1
H2
P44 P45 P46 P47 P48
Port #1 Transfer
Port #3
At clock edge #5, the ATM layer detects a cell available at PHY port #3 (UT-CLAV2 asserted). With
rising clock edge #52, PHY port #1 indicates that it cannot accept an additional cell by deasserting UTCLAV0. Thus, at clock edge #57, the ATM layer detects only UT-CLAV2 asserted (UT-CLAV1 and UTCLAV3 remain deasserted). The ATM layer deselects PHY port #1 and selects PHY port #3 for cell
transfer with rising clock edge #57 by placing address #3 on the address lines and deasserting UT-ENB.
PHY port #1 and PHY port #3 detect this at clock edge #58. At clock edge #59, PHY port #3 detects
UT-ENB asserted, therefore cell transfer for PHY port #3 starts with rising clock edge #59 (byte H1). For
additional examples, refer to [3].
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DS2156
24.5.3 Transmit Processing
The DS2156 can optionally insert a valid HEC byte in the cell header, or it can be programmed to
transparently transmit the HEC byte from ATM layer. When inserting a valid HEC byte, COSET (0x55)
addition can be optionally disabled. The generator polynomial used is 1 + X + X2 + X8. For
idle/unassigned cell insertion (used for cell-rate decoupling), the DS2156 inserts a valid HEC byte with or
without COSET addition, depending on the TCRDS bit (U_TCR1.3). The DS2156 can optionally
scramble payload bytes, depending on the TPSE bit (U_TCR1.4) register bit. The polynomial used for
scrambling is X43 + 1. For debugging purposes, the DS2156 can be configured to introduce a single-bit
HEC error in the cell header of cells transmitted in a controlled manner. If configured in HEC errorinsertion mode, it inserts HEC errors in HEC ON PERIOD number of cells and turns off HEC error
insertion for HEC OFF PERIOD number of cells set in the transmit HEC error-pattern register
(U_THEPR). This process repeats periodically, until HEC error insertion is disabled through U_TCR1.1.
Figure 24-6. Transmit Cell Flow
UTOPIA II
Data Input
Unassigned
Cell
Idle
Cell
Transmit
FIFO
Tx_Crd_sel
Tx_Coset_enb
HEC Insertion
ON
HEC Insertion
ON/OFF
Payload
Scrambling
ON/OFF
HEC_OFF_period
HEC Error
Insertion
ON/OFF
Cell Data
to Framer (PHY)
176 of 265
HEC_insert_enb
Tx_Coset_enb
Scrambling_enb
HEC_err_insert_enb
HEC_ON_period
DS2156
24.6 Receive Operation
The receive interface of the DS2156 is fully compliant with the ATM Forum’s UTOPIA Level 2
specifications [3]. The DS2156 can be configured to use any address in the range 0 to 31 as its UTOPIA
port addresses. If the receive FIFO is not empty, the cell-available signal is asserted. After cell transfer
from a port, the external cell-available signal updates based on the receive FIFO fill level only after oneclock cycle from cell-transfer completion. During this one-clock cycle, cell available indication for this
port is kept in the deasserted state. One-clock minimum latency between two cell transfers from the same
UTOPIA port is needed by the DS2156 to update its internal cell pointers.
24.6.1 Receive Processing
The received bits, after ignoring framing overhead bits, are checked for possible HEC pattern. The
polynomial used for HEC check is G(X) = 1 + X + X2 + X8, as recommended in [4]. The COSET
subtraction (0x55) can be optionally disabled by clearing the register bit U_RCR1.0.
The cell boundaries in the incoming bit stream are identified based on HEC. Figure 24-7 shows the celldelineation state machine. The cell-delineation state machine is initially in HUNT state. In HUNT state, it
performs bit-by-bit hunting for correct HEC. If correct HEC is found, it transitions to the PRESYNC state
where it cell-by-cell checks for correct HEC patterns. If DELTA consecutive correct patterns are received
in PRESYNC, the cell-delineation state machine transits to SYNC state. Otherwise, it goes to HUNT
state itself and starts bit-by-bit hunting. In SYNC state, if ALPHA consecutive incorrect HEC patterns are
received, cell delineation is lost and it goes to HUNT state. In PRESYNC and SYNC states, only cell-bycell checking for proper HEC pattern is performed. ALPHA and DELTA are 7 and 6, respectively.
Figure 24-7. Cell-Delineation State Diagram
Bit by bit
HUNT
ALPHA
consecutive
incorrect HEC
Correct HEC
Incorrect
HEC
PRESYNC
DELTA
consecutive
correct HEC
SYNC
Cell by cell
177 of 265
Cell
by
cell
DS2156
The persistence of an out-of-cell delineation (OCD) event is integrated into loss-of-cell delineation
(LCD), based on programmable integration time period (receive LCD integration-period register). If OCD
persists for the programmed time, LCD is declared. LCD is deasserted only when cell delineation persists
in SYNC for the same programmed time. Whenever there is a change in LCD status, namely “into LCD”
or “out of LCD,” an external interrupt is optionally generated by the microprocessor interface based on
the corresponding mask bit U_RCR2.4. The persistence is checked every system clock period divided by
16,383. The default value of receive LCD integration period register provides an integration time of
102ms in E1 mode and 135ms in T1 mode.
If a single-bit header-error correction is enabled, the receiver mode of operation state machine follows the
state machine given in Figure 24-8. Single-bit correction is done only if correction is enabled and the state
machine is in “correction mode” of operation at the start-of-cell transfer. Receiver mode of operation is
valid only when cell delineation is in SYNC state. 8-bit correctable and 12-bit uncorrectable HEC-errored
cell counters are maintained as saturating counters.
Figure 24-8. Header Correction State Machine
Multi-bit error
detected
(cell discarded)
No error
detected
(no action)
Correction
mode
No error detected
(no action)
Detection
mode
Error detected
(cell discarded)
Single bit error detected
(correction)
.
HEC error correction is accomplished based on the receiver mode of operation. In correction mode, only
single-bit errors can be corrected and the receiver switches to detection mode. In detection mode, all cells
with detected header errors are discarded, provided the U_RCR1.3 bit is set = 0. When a header is
examined and found not to be in error, the receiver switches to correction mode. The term “no action” in
Figure 24-8 means no correction is performed and no cell is discarded.
The payload bytes of the cell are optionally descrambled using the self-synchronizing descrambler
polynomial X43 + 1, as given in [4]. The descrambling can be enabled through the U_RCR1.2 bit.
Descrambling is activated if cell delineation is in PRESYNC or SYNC state. The cell header is not
affected by descrambling.
After descrambling and single-bit header-error correction, the cells are written into the receive FIFO as
long as cell delineation is in SYNC and the receive FIFO is not full. Idle and/or unassigned cells can be
optionally filtered by properly programming the receive control register bits. Uncorrectable HEC-errored
cells are normally filtered and are not written into the receive FIFO unless U_RCR1.3 is set. Note that if
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HEC error correction is disabled, all HEC-errored cells are termed as uncorrectable HEC-errored cells. A
16-bit count of the number of cells that can be written into receive FIFO is maintained, which saturates at
FFFFh. Note that, whether or not ATM layer dequeues cells from the receive FIFO, this counter
increments if valid cells are received. This counter is cleared by the microprocessor interface once it is
latched. A 2k x 8 receive FIFO that holds 4-cell buffer space per port is maintained for rate decoupling.
24.6.2 UTOPIA Side Receive: Muxed Mode with One Receive CLAV
The DS2156 drives the internal cell-available signals onto the external CLAV lines based on the
configured polling mode. In direct status mode, only four ports are supported. If a port is conducting a
cell transfer, its CLAV is kept asserted until the last byte is transferred to the ATM layer. This supports
interfacing with the octet-level ATM layer also. Cell-available status for any fresh cell corresponding to a
port has to be polled by the ATM layer only after the current cell transfer to the port is completed. The
multiplexed bus with 1CLAV polling mode cycle is depicted in Figure 24-9 in which N, N + 2, N - 3, N 2, N - 1, N + 3, and N + 1 are considered part of DS2156 UTOPIA ports. During reception of a cell from
PHY N, the other PHYs are polled. It turns out that PHY N - 3 and PHY N + 3 have cells available, and
PHY N + 3 is ultimately selected. (Remember that the PHY number values are for example only). Just
like the transmit interface, the 2-clock polling cycles allow up to 26 PHYs to be polled in the 8-bit mode.
Figure 24-9. Polling Phase and Selection at Receive Interface
SELECTION
POLLING
UR-CLK
UR-ADDRx
UR-CLAV
1
N+2
2
1F
N+2
3
N-3
4
1F
N-3
5
N-2
6
1F
N-2
POLLING
7
8
N-1
1F
N-1
9
N+3
10
1F
11
N+1
N+3
12
1F
N+1
13
N-1
14
1F
15
N+3
N-1
16
1F
17
N+1
N+3
18
1F
19
N-1
N+1
UR_ENB
UR-DATAx
P35 P36 P37 P38 P39 P40 P41 P42 P43 P44 P45 P46 P47 P48
H1
H2
H3
UR-SOC
CELL RCV FROM:
PHY N
PHY N+3
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DS2156
Figure 24-10 shows a case when, after the end of transmission of a cell from PHY N, no other PHY has a
cell available. Therefore, UR-ENB remains asserted as the ATM assumes a cell-available from PHY N.
With clock edge #9, it turns out that PHY N also has no cell available, as UR-SOC remains low. The
ATM then deasserts UR-ENB while the polling of the PHYs continues. With clock edge #15,
PHY N - 3 is found to have a cell for transmission. Thus, address N - 3 is applied and the PHY N - 3 is
selected with clock edge #16. Additional receive interface examples are available in [3].
Figure 24-10. End and Restart of Cell Transmission at Receive Interface
DETECTION
SELECTION
POLLING
UR-CLK
UR-ADDRx
UR-CLAV
1
2
N-3
3
1F
N-3
4
N+1
5
1F
N+1
6
N-1
7
1F
POLLING
8
N
N-1
9
1F
10
N+3
N
11
1F
N+3
12
N-1
13
1F
N-1
14
N-3
15
1F
N-3
16
N-3
17
1F
18
N+1
N-3
19
1F
20
N+2
N+1
UR-ENB
UR-DATAx
P42 P43 P44 P45 P46 P47 P48
XX
H1
H2
H3
UR-SOC
CELL RCV FROM:
PHY N
PHY N-3
24.6.3 UTOPIA Side Receive: Direct Status Mode (Multireceive CLAV)
Up to a maximum of four PHY ports can be connected to one ATM layer. For each PHY port, the status
signals UR-CLAV and UT-CLAV are permanently available according to UTOPIA Level 1 specification.
Status signals and cell transfers are independent of each other. No address information is needed to obtain
status information. Address information must be valid only for selecting a PHY port prior to one or
multiple cell transfers. With respect to the status signals UR-CLAV and UT-CLAV, this mode of
operation corresponds to that of four individual PHY devices according to UTOPIA Level 1. With respect
to the cell transfer, this mode of operation corresponds to that as described in this document and [3]. The
ATM layer selects a PHY port for cell transfer by placing the desired port on the address lines
(UR-ADDRx, UT-ADDRx), while the enable signal (UR-ENB, UT-ENB) is deasserted. All PHY ports
only examine the value on the address lines for possible selection when the enable signal is deasserted. In
case the ATM suspends transmission for a specific PHY port during a cell transfer, no cells to/from other
PHY ports can be transferred during this time.
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An example for the receive direction is shown in Figure 24-11. The status signals UR-CLAVx are
associated to PHY port addresses #4, #3, #2, and #1. There is no need for a unique null device so “X =
don’t care” on the address lines UR-ADDRx.
In Figure 24-11, the polling of PHY ports starts while no cell transfer takes place. The ATM layer
monitors all four status signals UR-CLAVx. At clock edge #3 it detects a cell available at PHY port #1,
UR-CLAV(1) asserted. It selects that PHY port by placing address #1 on the address lines with rising
clock edge #3. PHY port #1 detects this at clock edge #4. At clock edge #5, PHY port #1 detects
UR-ENB asserted, thus cell transfer for PHY port #1 starts with rising clock edge #5.
At clock edge #5 the ATM layer detects a cell available at PHY port #3, UR-CLAV(3) asserted. Not
knowing whether PHY port #1 may have another cell available or not, the ATM layer deselects PHY port
#1 and selects PHY port #3 for cell transfer with rising clock edge #57 by placing address #3 on the
address lines and deasserting UR-ENB. PHY port #1 and PHY port #3 detect this at clock edge #58. At
clock edge #59, PHY port #3 detects UR-ENB asserted, thus cell transfer starts with rising clock edge
#59. At clock edge #111, no cell is available at PHY ports #1, #2, and #4. The ATM layer keeps
UR-ENB asserted and detects at clock edge #113 the first byte of another cell available from PHY port
#3, UR-CLAV(3) asserted. Thus, cell transfer takes place starting with rising clock edge #112. At clock
edge #164, again, no cell is available at PHY ports #1, #2, and #4. The ATM layer keeps the UR-ENB
asserted and also detects at clock edge #166 no cell available from PHY port #3, UR-CLAV(3)
deasserted. Thus, the ATM layer deselects PHY port #3 by deasserting UR-ENB with rising clock edge
#166.
Figure 24-11. Example of Direct Status Indication, Receive Direction
UR-CLK
UR-ADDRx
1
2
X
UR-CLAV(1)
PORT #1
UR-CLAV(2)
PORT #2
UR-CLAV(3)
PORT #3
UR-CLAV(4)
PORT #4
3
4
1
5
6
X
57
58
3
59
60
111
112
113
114
164
165
X
X
166
X
UR-ENB
UR-SOC
UR-DATAx
H1
P48
Cell Transfer
(port #1)
H1
P48
Cell Transfer
(port #3)
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H1
H2
Cell Transfer
(port #3)
P48
X
167
DS2156
24.7 Register Definitions
The CCR2 register is used to configure the UTOPIA port address. The upper five bits of the CCR2
register contain the port address 0–31. The lower three bits are used for the backplane clock function. See
Programmable Backplane Clock Synthesizer in Section 30.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TRPA4
0
CCR2
Common Control Register 2
71h
6
TRPA3
0
5
TRPA2
0
4
TRPA1
0
3
TRPA0
0
2
BPCS1
0
1
BPCS0
0
0
BPEN
0
Bit 0/BPEN. See Section 30 for more information.
Bit 1/BPCS0. See Section 30 for more information.
Bit 2/BPCS1. See Section 30 for more information.
Bits 3 to 7/Transmit and Receive Port Address 0 to 4 (TRPA0 to TRPA4). The 5-bit value in this register is
used to assign the UTOPIA interface 1 of 32 port addresses.
Register Name:
Register Description:
Register Address:
U_TCFR
UTOPIA Transmit Configuration Register
50h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
1
3
—
0
2
—
0
1
TPM
0
Bit 0/Transmit Port Configuration (TPC)
0 = T1 mode
1 = E1 mode
Bit 1/Transmit Poll Mode (TPM). Transmit UTOPIA polling mode configuration
0 = multiplexed with 1CLAV mode
1 = direct status
Bits 2 to 7/Unassigned, must be set to 0 for proper operation
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0
TPC
0
DS2156
Register Name:
Register Description:
Register Address:
U_TPCL
UTOPIA Transmit PMON Counter Latch Register
51h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
2
—
0
1
—
0
0
—
0
Bits 0 to 7/The host should always write 0x00 to this register when latching the PMON counter.
This register is provided for latching in the 16-bit transmit assigned cell-count value of a port into the common
transmit assigned cell-counter latch register. For reading the transmit assigned cell-count value, software writes
into this register and then reads from transmit-assigned cell-counter MSB and LSB registers. A write into this
register clears the transmit-assigned cell-count value.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TACC15
0
U_TACC1
UTOPIA Transmit-Assigned Cell-Count Register 1
52h
6
TACC14
0
5
TACC13
0
4
TACC12
0
3
TACC11
0
2
TACC10
0
1
TACC9
0
0
TACC8
0
Bits 0 to 7/Transmit-Assigned Cell Count (TACC9 to TACC15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TACC7
0
U_TACC2
UTOPIA Transmit-Assigned Cell-Count Register 2
53h
6
TACC6
0
5
TACC5
0
4
TACC4
0
3
TACC3
0
2
TACC2
0
1
TACC1
0
0
TACC0
0
Bits 0 to 7/Transmit-Assigned Cell Count (TACC0 to TACC7)
Transmit-assigned cell-count value reflects the number of ATM layer cells transmitted since last latching. For
reading the 16-bit transmit-assigned cell count for a port, software has to write into the transmit PMON-counter
latch-enable register for the port before reading these registers. Reading from these registers without writing into
the latch-enable register returns the old value that was latched and not the current MSB value.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TIUP7
0
U_TIUPB
UTOPIA Transmit Idle/Unassigned Payload Byte Register
54h
6
TIUP6
1
5
TIUP5
1
4
TIUP4
0
3
TIUP3
1
2
TIUP2
0
1
TIUP1
1
0
TIUP0
0
Bits 0 to 7/Transmit Idle/Unassigned Payload (TIUP0 to TIUP7). Holds the payload byte to be carried in octets
of idle/unassigned cells, transmitted towards line for cell rate decoupling.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
HOFFP4
0
U_THEPR
UTOPIA Transmit HEC Error-Insertion Pattern Register
55h
6
HOFFP3
0
5
HOFFP2
1
4
HOFFP1
0
3
HOFFP0
1
2
HONP2
0
1
HONP1
0
0
HONP0
1
Bits 0 to 2/HEC On Period (HONP0 to HONP2). Holds the number of cells in which incorrect HEC is sent if
HEC error insertion is enabled.
Bits 3 to 7/HEC Off Period (HOFFP0 to HOFFP4). Holds the number of cells in which correct HEC is sent if
HEC error insertion is enabled.
If HEC error insertion in the transmit control register is enabled for a port, then for the HEC off period cells are
transmitted to the port with correct HEC. For the HEC on period, cells are sent with incorrect HEC. This cycle
repeats until HEC error insertion is disabled. Note that HEC error is introduced in all transmitted cells based on the
transmit HEC error-insertion pattern register, if the HEC error-insertion bit in the transmit control register is
enabled irrespective of whether the HEC insertion bit in the transmit control register is enabled or disabled.
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DS2156
Register Name:
Register Description:
Register Address:
U_TCR1
UTOPIA Transmit Control Register 1
56h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
TPSE
0
3
TCRDS
0
2
TCAE
1
1
THEIE
0
0
THIE
1
Bit 0/Transmit HEC-Insertion Enable (THIE)
0 = HEC byte as received from ATM layer is transparently passed
1 = proper HEC value is computed and inserted in the HEC byte of the cell
Bit 1/Transmit HEC Error-Insertion Enable (THEIE)
0 = HEC error insertion disabled
1 = HEC errors introduced in the transmitted cells as specified by transmit HEC error-insertion pattern
register
Bit 2/Transmit COSET-Addition Enable (TCAE)
0 = no COSET addition
1 = COSET (0x55) addition to the calculated HEC
Note that if HEC insertion is disabled, then the HEC byte is transmitted transparently (this bit does not
impact ATM layer cells). However, the HEC byte of idle/unassigned cells used for cell-rate decoupling
includes COSET addition as long as the TCAE bit is enabled.
Bit 3/Transmit Cell-Rate Decoupling Selection (TCRDS)
0 = idle cell
1 = unassigned cell
Bit 4/Transmit Payload-Scrambling Enable (TPSE)
0 = disabling scrambling
1 = enabling scrambling
Bits 5 to 7/Unassigned, must be set to 0 for proper operation
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DS2156
Register Name:
Register Description:
Register Address:
U_TCR2
UTOPIA Transmit Control Register 2
57h
Bit #
Name
Default
6
—
0
7
—
0
5
FDC1
0
4
FDC0
0
3
TCES
0
2
—
0
1
TPLIM
0
0
—
0
Bits 0, 2, 6, 7/Unassigned, must be set to 0 for proper operation
Bit 1/Transmit Physical-Layer Interface Mode (TPLIM)
0 = clock + data + frame-pulse indication combination
1 = gapped clock + data combination
Bit 3/Transmit Clear E1 Selection (TCES). When this bit is set = 0, TS16 and TS0 are automatically gapped out.
This is only meaningful when U_TCR2.1 is set = 0. E1TCR1.7 must be set = 1 if TCES = 1.
0 = TS16 and TS0 gapped out
1 = TS16 and TS0 not gapped out
Bits 4, 5/Transmit FIFO Depth Configuration Bits (FDC1, FDC0)
FDC1
0
0
1
1
FDC0
0
1
0
1
Cell Depth
4
3
2
Reserved
Register Name:
Register Description:
Register Address:
U_RCFR
UTOPIA Receive Configuration Register
60h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
Bit 0/Receive Port Configuration (RPC)
0 = T1 mode
1 = E1 mode
Bit 1/Receive UTOPIA Polling Mode (RUPM)
0 = multiplexed with 1CLAV mode
1 = direct status
Bits 2 to 7/Unassigned, should be set to 0 for proper operation
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2
—
0
1
RUPM
0
0
RPC
0
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RLIP7
0
U_RLCDIP
UTOPIA Receive LCD Integration Period Register
61h
6
RLIP6
1
5
RLIP5
1
4
RLIP4
0
3
RLIP3
0
2
RLIP2
1
1
RLIP1
1
0
RLIP0
0
Bits 0 to 7/Receive LCD Integration Period (RLIP0 to RLIP7)
This 8-bit register holds the LCD integration period value for which the out-of-cell delineation condition must
persist for declaring loss-of-cell delineation (LCD). For deasserting LCD, cell delineation should persist in the
SYNC state for the same amount of time programmed in this register. LCD state change condition can be
programmed to generate an external interrupt through U_RCR2.4. A value of 0 programmed into this register
declares LCD for every OCD condition at the resolution of the internal system clock period. The internal system
clock is 8x the line clock [16.383MHz (E1 mode) and 12.352MHz (T1 mode)].
IT = Integration Time in ms
For E1 mode, register value = IT / 1ms
For T1 mode, register value = IT / 1.326ms
For example, in E1 mode a register value of 64h (100) generates a 100ms integration time. In T1 mode, a register
value of 4Bh (75) generates a 100ms integration time.
Register Name:
Register Description:
Register Address:
U_RPCE
UTOPIA Receive PMON-Counter Enable Register
62h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
2
—
0
1
—
0
0
—
0
Bits 0 to 7/The host should always write 0x00 to this register when latching the receive PMON counter.
This register is provided for latching all receive PMON-counter values, namely the 16-bit receive assigned cellcount value, 12-bit receive uncorrectable HEC-count value, and 8-bit receive correctable HEC-count value of a port
into the common receive assigned cell-counter latch register, receive uncorrectable HEC-counter latch register, and
receive correctable HEC-count latch register, respectively. A write into this register clears the receive PMON
counters for that port.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RCHC7
0
U_RCHEC
UTOPIA Receive Correctable HEC Counter Register
63h
6
RCHC6
0
5
RCHC5
0
4
RCHC4
0
3
RCHC3
0
2
RCHC2
0
1
RCHC1
0
0
RCHC0
0
Bits 0 to 7/Receive Correctable HEC Counter (RCHC0 to RCHC7)
Note that write access to the receive PMON-counter latch-enable register latches all receive PMON-counter values
into temporary latch registers and clears the internal count values. This register holds the number of correctable
HEC-errored cells received since last latching. Note that this count corresponds to cells received when cell
delineation is in SYNC. A correctable HEC-errored cell is a cell with a single-bit error, provided single-bit HECerror correction is enabled through U_RCR1.1 and the receiver mode of operation is in correction mode.
Correctable HEC count value is unaffected if HEC-error correction is disabled.
Register Name:
Register Description:
Register Address:
U_RUHEC1
UTOPIA Receive Uncorrectable HEC Counter Register 1
64h
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
RUHC11
0
2
RUHC10
0
1
RUHC9
0
0
RUHC8
0
Bits 0 to 3/Receive Uncorrectable HEC Counter (RUHC8 to RUHC11)
Bits 4 to 7/Unused
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RUHC7
0
U_RUHEC2
UTOPIA Receive Uncorrectable HEC Counter Register 2
65h
6
RUHC6
0
5
RUHC5
0
4
RUHC4
0
3
RUHC3
0
2
RUHC2
0
1
RUHC1
0
0
RUHC0
0
Bits 0 to 7/Receive Uncorrectable HEC Counter (RUHC0 to RUHC7)
The U_RUHEC1 and U_RUHEC2 registers count the number of uncorrectable HEC-errored cells received since
last latching. Note that this count corresponds to cells received when cell delineation is in SYNC. For every SYNCto-HUNT transition of the cell delineation state machine, the “Correctable + Uncorrectable” error-count value
increases by 6 instead of 7. For every SYNC-to-HUNT transition, if HEC correction is enabled, the correctable
HEC count increases by 1 and the uncorrectable HEC count increases by 5. If HEC correction is disabled,
correctable HEC count is not affected and uncorrectable HEC count increases by 6. Note that cell delineation goes
to HUNT state upon the reception of the 7th consecutive HEC pattern. Receive PMON counters are not updated
when cell delineation is out of SYNC state. Note that write access to the receive PMON-counter latch-enable
register latches internal receive PMON-counter values and clears them once they are latched.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RACC15
0
U_RACC1
UTOPIA Receive-Assigned Cell Count Register 1
66h
6
RACC14
0
5
RACC13
0
4
RACC12
0
3
RACC11
0
2
RACC10
0
1
RACC9
0
0
RACC8
0
1
RACC1
0
0
RACC0
0
Bits0 to 7/Receive-Assigned Cell Count 8 to 15 (RACC8 to RACC15)
Register Name:
Register Description:
Register Address:
U_RACC2
UTOPIA Receive-Assigned Cell Count Register 2
67h
Bit #
Name
Default
6
RACC6
0
7
RACC7
0
5
RACC5
0
4
RACC4
0
3
RACC3
0
2
RACC2
0
Bits 0 to 7/Receive-Assigned Cell Count 0 to 7 (RACC0 to RACC7)
The U_RACC1 and U_RACC2 registers are common registers for all ports. For software convenience, any of the
eight addresses can be used to access these registers. For reading the 16-bit receive assigned cell count for a port,
software has to write into the receive PMON-counter latch-enable register for the port before reading from these
registers. Reading from these registers without writing into the latch-enable register returns the old value that was
latched and not the current value of the receive-assigned cell count of a port. The assigned cell count value reflects
the number of cells written into receive FIFO that can be read by the ATM layer since last latching. Note that
whether or not the ATM layer dequeues cells from the receive FIFO, the assigned cell counter of a port is
incremented upon the reception of a valid ATM layer cell when cell delineation is in SYNC state.
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DS2156
Register Name:
Register Description:
Register Address:
U_RSR
UTOPIA Receive Status Register
68h
Bit #
Name
Default
6
—
0
7
—
0
5
CDS1
0
4
CDS0
0
3
RMS
0
2
LCDS
1
1
LCDCSIS
0
0
FOIS
0
Bit 0/Receive FIFO Overrun Interrupt Status (FOIS). Set if the receive FIFO overruns provided RxFIFO
overrun interrupt mask bit (U_RCR2.3) is set. This bit is reset when read.
Bit 1/LCD Change-of-State Interrupt Status (LCDCSIS). Set by hardware if LCD status changes, provided that
the LCD interrupt-mask bit (U_RCR2.4) is set. The LCDS bit indicates the current status of LCD. This bit is reset
when read.
Bit 2/LCD Status (LCDS)
0 = in-cell delineation
1 = loss-of-cell delineation
Bit 3/Receiver Mode Status (RMS). This bit shows valid status only when HEC correction is enabled.
0 = correction mode
1 = detection mode
Bits 4, 5/Cell Delineation Status 0 to 1 (CDS0 to CDS1). Bit 5 indicates instantaneous OCD status.
CDS1
0
0
1
CDS0
0
1
x
Cell Delineation Status
HUNT State
PRESYNC State
SYNC State
Bits 6, 7/Unused
Once a read cycle to this register is detected, the interrupt status bits are cleared. If any of the lower two bits is set,
the external interrupt signal is asserted. If both the bits are 0 for all the ports, the external interrupt signal is deasserted.
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DS2156
Register Name:
Register Description:
Register Address:
U_RCR1
UTOPIA Receive Control Register 1
69h
Bit #
Name
Default
6
—
0
7
—
0
5
RUCFE
0
4
RICFE
0
3
RPHEC
0
2
RDE
0
1
RHECE
0
0
RCSE
1
Bit 0/Receive COSET Subtraction Enable (RCSE)
0 = DS2156 does not do COSET subtraction from the HEC byte for checking HEC
1 = DS2156 subtracts COSET polynomial (0 x 55) from the HEC byte for checking HEC
Bit 1/Receive HEC-Error Correction Enable (RHECE)
0 = single-bit HEC-error correction is disabled
1 = DS2156 corrects single-bit HEC errors based on the current state of receiver mode of operation. Singlebit error correction is done only if this bit is set and receiver mode of operation is in CORRECTION state.
Bit 2/Receive Descrambling Enable (RDE)
0 = payload descrambling is disabled
1 = payload descrambling is enabled. Payload of cells received in PRESYNC and SYNC state of cell
delineation are descrambled based on the self-synchronizing polynomial X43 + 1. Cell header is unaffected
by descrambling.
Bit 3/Receive Pass HEC-Errored Cells (RPHEC)
0 = DS2156 passes only error-free and error-corrected cells to ATM layer
1 = DS2156 passes all cells including HEC-errored cells, received when cell delineation is SYNC to ATM
layer
Bit 4/Receive Idle Cell-Filter Enable (RICFE)
0 = DS2156 does not filter idle cells
1 = DS2156 filters all idle cells received from being written into receive FIFO. The cell header of idle cell
(first five bytes) is 0x00, 0x00, 0x00, 0x01 and proper HEC byte. Cell payload is not considered for idle
cell filtering.
Bit 5/Receive Unassigned Cell-Filter Enable (RUCFE)
0 = DS2156 will NOT filter unassigned cells.
1 = DS2156 filters all unassigned cells received from being written into receive FIFO. The cell header of
unassigned cell (first five bytes) is 0x00, 0x00, 0x00, 0x00, and proper HEC byte. Cell payload is not
considered for unassigned cell filtering
Bits 6, 7/Unassigned, must be set to 0 for proper operation
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Register Name:
Register Description:
Register Address:
U_RCR2
UTOPIA Receive Control Register 2
6Ah
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
LCDIM
0
3
RFOIM
0
2
—
0
1
RPLIM
0
0
DLBE
0
Bit 0/Diagnostic Loopback Enable (DLBE)
0 = normal operation
1 = diagnostic loopback is enabled. In this loopback, the transmit data and clock is looped back onto the
receive side. Receiver uses transmit data and clock instead of receive data and clock from physical layer
(typically framer).
Bit 1/Receive Physical Layer Interface Mode (RPLIM)
0 = clock + data + frame pulse combination
1 = gapped clock + data combination
Bit 2/Bit must be set = 1 after reset for proper UTOPIA bus mode operation
Bit 3/Receive FIFO Overrun Interrupt Mask (RFOIM)
0 = DS2156 does not generate external interrupt for receive FIFO overrun events
1 = DS2156 generates external interrupt if receive FIFO overrun condition has occurred
Bit 4/LCD Interrupt Mask (LCDIM)
0 = DS2156 does not generate external interrupt for LCD state changes
1 = DS2156 generates external interrupt if LCD state has changed
Bits 5 to 7/Unassigned, must be set to 0 for proper operation
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24.8 Receive FIFO Overrun
Receive FIFO overrun condition indicates that receive FIFO has been written with four cells before ATM
layer reads the cells. The four cells that cause receive FIFO overrun conditions are intact in receive FIFO,
and subsequent cells are not written into receive FIFO until ATM layer reads a cell from receive FIFO for
the port through UTOPIA-II interface. Receive FIFO overrun condition can optionally be made to raise
external interrupt by setting receive FIFO overrun interrupt mask bit U_RCR2.3.
24.9 UTOPIA Diagnostic Loopback
Diagnostic loopback toward the ATM layer side (UTOPIA side) can be enabled through receive control
register 2, U_RCR2.0. In diagnostic loopback, data, clock, and frame-pulse indication generated by the
transmit section of the DS2156 are used instead of the corresponding signals from the physical layer
device. Receive physical interface mode should be configured with the same value as transmit physical
interface mode. Receive active-edge selection bit should be configured as the opposite edge of that used
by the transmit section of the DS2156. It is possible to use the internally generated system clock divided
by 8 in place of TCLK for this mode when enabled with U_TCR2.6.
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25. PROGRAMMABLE IN-BAND LOOP CODE GENERATION AND
DETECTION
The DS2156 has the ability to generate and detect a repeating bit pattern from one to eight bits or 16 bits
in length. This function is available only in T1 mode. To transmit a pattern, the user loads the pattern
into the transmit code-definition registers (TCD1 and TCD2) and selects the proper length of the pattern
by setting the TC0 and TC1 bits in the in-band code control (IBCC) register. When generating a 1-, 2-, 4-,
8-, or 16-bit pattern, both transmit code-definition registers must be filled with the proper code.
Generation of a 3-, 5-, 6-, and 7-bit pattern only requires TCD1 to be filled. Once this is accomplished,
the pattern is transmitted as long as the TLOOP control bit (T1CCR1.0) is enabled. Normally (unless the
transmit formatter is programmed to not insert the F-bit position) the framer overwrites the repeating
pattern once every 193 bits to send the F-bit position.
For example, to transmit the standard “loop-up” code for CSUs, which is a repeating pattern of
...10000100001... , set TCD1 = 80h, IBCC = 0, and T1CCR1.0 = 1.
The framer has three programmable pattern detectors. Typically two of the detectors are used for “loopup” and “loop-down” code detection. The user programs the codes to be detected in the receive up-code
definition (RUPCD1 and RUPCD2) registers and the receive down-code definition (RDNCD1 and
RDNCD2) registers, and the length of each pattern is selected through the IBCC register. There is a third
detector (spare) that is defined and controlled through the RSCD1/RSCD2 and RSCC registers. When
detecting a 16-bit pattern, both receive code-definition registers are used together to form a 16-bit
register. For 8-bit patterns, both receive code-definition registers are filled with the same value. Detection
of a 1-, 2-, 3-, 4-, 5-, 6-, and 7-bit pattern only requires the first receive code-definition register to be
filled. The framer detects repeating pattern codes in both framed and unframed circumstances with bit
error rates as high as 10E-2. The detectors are capable of handling both F-bit inserted and F-bit overwrite
patterns. Writing the least significant byte of the receive code-definition register resets the integration
period for that detector. The code detector has a nominal integration period of 36ms. Hence, after about
36ms of receiving a valid code, the proper status bit (LUP at SR3.5, LDN at SR3.6, and LSPARE at
SR3.7) is set to a 1. Normally codes are sent for a period of five seconds. It is recommended that the
software poll the framer every 50ms to 1000ms until five seconds has elapsed to ensure the code is
continuously present.
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Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TC1
0
IBCC
In-Band Code Control Register
B6h
6
TC0
0
5
RUP2
0
4
RUP1
0
3
RUP0
0
2
RDN2
0
Bits 0 to 2/Receive Down-Code Length Definition Bits (RDN0 to RDN2)
RDN2
0
0
0
0
1
1
1
1
RDN1
0
0
1
1
0
0
1
1
RDN0
0
1
0
1
0
1
0
1
Length Selected (bits)
1
2
3
4
5
6
7
8/16
Bits 3 to 5/Receive Up-Code Length Definition Bits (RUP0 to RUP2)
RUP2
0
0
0
0
1
1
1
1
RUP1
0
0
1
1
0
0
1
1
RUP0
0
1
0
1
0
1
0
1
Length Selected (bits)
1
2
3
4
5
6
7
8/16
Bits 6, 7/Transmit Code Length Definition Bits (TC0 to TC1)
TC1
0
0
1
1
TC0
0
1
0
1
Length Selected (bits)
5
6/3
7
16/8/4/2/1
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1
RDN1
0
0
RDN0
0
DS2156
Register Name:
Register Description:
Register Address:
TCD1
Transmit Code-Definition Register 1
B7h
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Bit 0/Transmit Code-Definition Bit 0 (C0). A don’t care if a 5-, 6-, or 7-bit length is selected.
Bit 1/Transmit Code-Definition Bit 1 (C1). A don’t care if a 5-bit or 6-bit length is selected.
Bit 2/Transmit Code-Definition Bit 2 (C2). A don’t care if a 5-bit length is selected.
Bits 3–6/Transmit Code-Definition Bits 3–6 (C3–C6)
Bit 7/Transmit Code-Definition Bit 7 (C7). First bit of the repeating pattern.
Register Name:
Register Description:
Register Address:
TCD2
Transmit Code Definition Register 2
B8h
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Least significant byte of 16 bit codes.
Bits 0–7/Transmit Code-Definition Bits 0–7 (C0–C7). A don’t care if a 5-, 6-, or 7-bit length is selected.
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Register Name:
Register Description:
Register Address:
RUPCD1
Receive Up-Code Definition Register 1
B9h
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Note: Writing this register resets the detector’s integration period.
Bit 0/Receive Up-Code Definition Bits 0 (C0). A don’t care if a 1-bit to 7-bit length is selected.
Bit 1/Receive Up-Code Definition Bit 1 (C1). A don’t care if a 1-bit to 6-bit length is selected.
Bit 2/Receive Up-Code Definition Bit 2 (C2). A don’t care if a 1-bit to 5-bit length is selected.
Bit 3/Receive Up-Code Definition Bit 3 (C3). A don’t care if a 1-bit to 4-bit length is selected.
Bit 4/Receive Up-Code Definition Bit 4 (C4). A don’t care if a 1-bit to 3-bit length is selected.
Bit 5/Receive Up-Code Definition Bit 5 (C5). A don’t care if a 1-bit or 2-bit length is selected.
Bit 6/Receive Up-Code Definition Bit 6 (C6). A don’t care if a 1-bit length is selected.
Bit 7/Receive Up-Code Definition Bit 7 (C7). First bit of the repeating pattern.
Register Name:
Register Description:
Register Address:
RUPCD2
Receive Up-Code Definition Register 2
BAh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Bits 0–7/Receive Up-Code Definition Bits 0–7 (C0–C7). A don’t care if a 1-bit to 7-bit length is selected.
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Register Name:
Register Description:
Register Address:
RDNCD1
Receive Down-Code Definition Register 1
BBh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Note: Writing this register resets the detector’s integration period.
Bit 0/Receive Down-Code Definition Bit 0 (C0). A don’t care if a 1-bit to 7-bit length is selected.
Bit 1/Receive Down-Code Definition Bit 1 (C1). A don’t care if a 1-bit to 6-bit length is selected.
Bit 2/Receive Down-Code Definition Bit 2 (C2). A don’t care if a 1-bit to 5-bit length is selected.
Bit 3/Receive Down-Code Definition Bit 3 (C3). A don’t care if a 1-bit to 4-bit length is selected.
Bit 4/Receive Down-Code Definition Bit 4 (C4). A don’t care if a 1-bit to 3-bit length is selected.
Bit 5/Receive Down-Code Definition Bit 5 (C5). A don’t care if a 1-bit or 2-bit length is selected.
Bit 6/Receive Down-Code Definition Bit 6 (C6). A don’t care if a 1-bit length is selected.
Bit 7/Receive Down-Code Definition Bit 7 (C7). First bit of the repeating pattern.
Register Name:
Register Description:
Register Address:
RDNCD2
Receive Down-Code Definition Register 2
BCh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Bits 0–7/Receive Down-Code Definition Bits 0–7 (C0–C7). A don’t care if a 1-bit to 7-bit length is selected.
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Register Name:
Register Description:
Register Address:
RSCC
In-Band Receive Spare Control Register
BDh
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
2
RSC2
0
Bits 0 to 2/Receive Spare Code Length Definition Bits (RSC0 to RSC2)
RSC2
RSC1
RSC0
Length Selected (bits)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
2
3
4
5
6
7
8/16
Bits 3 to 7/Unused, must be set to 0 for proper operation
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1
RSC1
0
0
RSC0
0
DS2156
Register Name:
Register Description:
Register Address:
RSCD1
Receive Spare-Code Definition Register 1
BEh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Note: Writing this register resets the detector’s integration period.
Bit 0/Receive Spare-Code Definition Bit 0 (C0). A don’t care if a 1-bit to 7-bit length is selected.
Bit 1/Receive Spare-Code Definition Bit 1 (C1). A don’t care if a 1-bit to 6-bit length is selected.
Bit 2/Receive Spare-Code Definition Bit 2 (C2). A don’t care if a 1-bit to 5-bit length is selected.
Bit 3/Receive Spare-Code Definition Bit 3 (C3). A don’t care if a 1-bit to 4-bit length is selected.
Bit 4/Receive Spare-Code Definition Bit 4 (C4). A don’t care if a 1-bit to 3-bit length is selected.
Bit 5/Receive Spare-Code Definition Bit 5 (C5). A don’t care if a 1-bit or 2-bit length is selected.
Bit 6/Receive Spare-Code Definition Bit 6 (C6). A don’t care if a 1-bit length is selected.
Bit 7/Receive Spare-Code Definition Bit 7 (C7). First bit of the repeating pattern.
Register Name:
Register Description:
Register Address:
RSCD2
Receive Spare Code Definition Register 2
BFh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Bits 0–7/Receive Spare-Code Definition Bits 0–7 (C0–C7). A don’t care if a 1-bit to 7-bit length is selected.
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26.
BERT FUNCTION
The BERT block can generate and detect pseudorandom and repeating bit patterns. It is used to test and
stress data communication links, and it is capable of generating and detecting the following patterns:
The pseudorandom patterns 2E7, 2E11, 2E15, and QRSS
A repetitive pattern from 1 to 32 bits in length
Alternating (16-bit) words that flip every 1 to 256 words
Daly pattern
The BERT receiver has a 32-bit bit counter and a 24-bit error counter. The BERT receiver reports three
events: a change in receive synchronizer status, a bit error being detected, and if either the bit counter or
the error counter overflows. Each of these events can be masked within the BERT function through the
BERT control register 1 (BC1). If the software detects that the BERT has reported an event, then the
software must read the BERT information register (BIR) to determine which event(s) has occurred. To
activate the BERT block, the host must configure the BERT mux through the BIC register.
26.1 Status
SR9 contains the status information on the BERT function. The host can be alerted through this register
when there is a BERT change-of-state. A major change-of-state is defined as either a change in the
receive synchronization (i.e., the BERT has gone into or out of receive synchronization), a bit error has
been detected, or an overflow has occurred in either the bit counter or the error counter. The host must
read status register 9 (SR9) to determine the change-of-state.
26.2 Mapping
The BERT function can be assigned to the network direction or backplane direction through the direction
control bit in the BIC register (BIC.1). See Figure 26-1 and Figure 26-2. The BERT also can be assigned
on a per-channel basis. The BERT transmit control selector (BTCS) and BERT receive control selector
(BRCS) bits of the per-channel pointer register (PCPR) are used to map the BERT function into time slots
of the transmit and receive data streams. In T1 mode, the user can enable mapping into the F-bit position
for the transmit and receive directions through the RFUS and TFUS bits in the BERT interface control
(BIC) register.
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DS2156
Figure 26-1. Simplified Diagram of BERT in Network Direction
TO RECEIVE
SYSTEM
BACKPLANE
INTERFACE
FROM RECEIVE
FRAMER
PER-CHANNEL AND
F-BIT (T1 MODE)
MAPPING
TO TRANSMIT
FRAMER
BERT
RECEIVER
BERT
TRANSMITTER
1
FROM TRANSMIT
SYSTEM
BACKPLANE
INTERFACE
0
Figure 26-2. Simplified Diagram of BERT in Backplane Direction
FROM RECEIVE
FRAMER
0
1
TO RECEIVE
SYSTEM
BACKPLANE
INTERFACE
PER-CHANNEL AND
F-BIT (T1 MODE)
MAPPING
BERT
RECEIVER
BERT
TRANSMITTER
FROM TRANSMIT
SYSTEM
BACKPLANE
INTERFACE
TO TRANSMIT
FRAMER
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26.3 BERT Register Descriptions
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TC
0
BC1
BERT Control Register 1
E0h
6
TINV
0
5
RINV
0
4
PS2
0
3
PS1
0
2
PS0
0
1
LC
0
0
RESYNC
0
Bit 0/Force Resynchronization (RESYNC). A low-to-high transition forces the receive BERT synchronizer to
resynchronize to the incoming data stream. This bit should be toggled from low to high whenever the host wishes
to acquire synchronization on a new pattern. Must be cleared and set again for a subsequent resynchronization.
Bit 1/Load Bit and Error Counters (LC). A low-to-high transition latches the current bit and error counts into
registers BBC1/BBC2/BBC3/BBC4 and BEC1/BEC2/BEC3 and clears the internal count. This bit should be
toggled from low to high whenever the host wishes to begin a new acquisition period. Must be cleared and set
again for subsequent loads.
Bits 2 to 4/Pattern Select Bits (PS0 to PS2)
PS2
PS1
PS0
0
0
0
0
0
1
0
1
0
0
1
1
1
1
0
0
0
1
1
1
0
1
1
1
Pattern Definition
Pseudorandom 2E7 - 1
Pseudorandom 2E11 - 1
Pseudorandom 2E15 - 1
Pseudorandom pattern QRSS. A 220 - 1 pattern with 14 consecutive zero
restrictions.
Repetitive pattern
Alternating word pattern
Modified 55 octet (Daly) pattern. The Daly pattern is a repeating 55 octet
pattern that is byte-aligned into the active DS0 time slots. The pattern is
defined in an ATIS (Alliance for Telecommunications Industry Solutions)
Committee T1 Technical Report Number 25 (November 1993).
Pseudorandom 2E9 - 1
Bit 5/Receive Invert-Data Enable (RINV)
0 = do not invert the incoming data stream
1 = invert the incoming data stream
Bit 6/Transmit Invert-Data Enable (TINV)
0 = do not invert the outgoing data stream
1 = invert the outgoing data stream
Bit 7/Transmit Pattern Load (TC). A low-to-high transition loads the pattern generator with the pattern that is to
be generated. This bit should be toggled from low to high whenever the host wishes to load a new pattern. Must be
cleared and set again for subsequent loads.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
BC2
BERT Control Register 2
E1h
7
EIB2
0
6
EIB1
0
5
EIB0
0
4
SBE
0
3
RPL3
0
2
RPL2
0
1
RPL1
0
0
RPL0
0
Bits 0 to 3/Repetitive Pattern Length Bit 3 (RPL0 to RPL3). RPL0 is the LSB and RPL3 is the MSB of a nibble
that describes how long the repetitive pattern is. The valid range is 17 (0000) to 32 (1111). These bits are ignored if
the receive BERT is programmed for a pseudorandom pattern. To create repetitive patterns fewer than 17 bits in
length, the user must set the length to an integer number of the desired length that is less than or equal to 32. For
example, to create a 6-bit pattern, the user can set the length to 18 (0001) or to 24 (0111) or to 30 (1101).
Length
(bits)
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
RPL3
RPL2
RPL1
RPL0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Bit 4/Single Bit-Error Insert (SBE). A low-to-high transition creates a single-bit error. Must be cleared and set
again for a subsequent bit error to be inserted.
Bits 5 to 7/Error Insert Bits 0 to 2 (EIB0 to EIB2). Automatically inserts bit errors at the prescribed rate into the
generated data pattern. Can be used for verifying error-detection features.
EIB2
0
0
0
0
1
1
1
1
EIB1
0
0
1
1
0
0
1
1
EIB0
0
1
0
1
0
1
0
1
Error Rate Inserted
No errors automatically inserted
10E-1
10E-2
10E-3
10E-4
10E-5
10E-6
10E-7
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
SR9
Status Register 9
26h
6
BBED
0
5
BBCO
0
4
BEC0
0
3
BRA1
0
2
BRA0
0
1
BRLOS
0
0
BSYNC
0
Bit 0/BERT in Synchronization Condition (BSYNC). Set when the incoming pattern matches for 32 consecutive
bit positions. Refer to BSYNC in the INFO2 register for a real-time version of this bit. This is a double interrupt bit
(Section 6.2).
Bit 1/BERT Receive Loss-of-Synchronization Condition (BRLOS). A latched bit that is set whenever the
receive BERT begins searching for a pattern. Once synchronization is achieved, this bit remains set until read. This
is a double interrupt bit (Section 6.2).
Bit 2/BERT Receive All-Zeros Condition (BRA0). A latched bit that is set when 32 consecutive 0s are received.
Allowed to be cleared once a 1 is received. This is a double interrupt bit (Section 6.2).
Bit 3/BERT Receive All-Ones Condition (BRA1). A latched bit that is set when 32 consecutive 1s are received.
Allowed to be cleared once a 0 is received. This is a double interrupt bit (Section 6.2).
Bit 4/BERT Error-Counter Overflow (BECO) Event (BECO). A latched bit that is set when the 24-bit BERT
error counter (BEC) overflows. Cleared when read and is not set again until another overflow occurs.
Bit 5/BERT Bit-Counter Overflow Event (BBCO). A latched bit that is set when the 32-bit BERT bit counter
(BBC) overflows. Cleared when read and is not set again until another overflow occurs.
Bit 6/BERT Bit-Error Detected (BED) Event (BBED). A latched bit that is set when a bit error is detected. The
receive BERT must be in synchronization for it to detect bit errors. Cleared when read.
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Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
IMR9
Interrupt Mask Register 9
27h
6
BBED
0
5
BBCO
0
4
BEC0
0
3
BRA1
0
2
BRA0
0
1
BRLOS
0
0
BSYNC
0
Bit 0/BERT in Synchronization Condition (BSYNC)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 1/Receive Loss-of-Synchronization Condition (BRLOS)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 2/Receive All-Zeros Condition (BRA0)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 3/Receive All-Ones Condition (BRA1)
0 = interrupt masked
1 = interrupt enabled—interrupts on rising and falling edges
Bit 4/BERT Error-Counter Overflow Event (BECO)
0 = interrupt masked
1 = interrupt enabled
Bit 5/BERT Bit-Counter Overflow Event (BBCO)
0 = interrupt masked
1 = interrupt enabled
Bit 6/Bit-Error Detected Event (BBED)
0 = interrupt masked
1 = interrupt enabled
BERT Alternating Word-Count Rate. When the BERT is programmed in the alternating word mode, the words
repeat for the count loaded into this register then flip to the other word and again repeat for the number of times
loaded into this register.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
ACNT7
0
BAWC
BERT Alternating Word-Count Rate
DBh
6
ACNT6
0
5
ACNT5
0
4
ACNT4
0
3
ACNT3
0
2
ACNT2
0
1
ACNT1
0
0
ACNT0
0
Bits 0 to 7/Alternating Word-Count Rate Bits 0 to 7 (ACNT0 to ACNT7). ACNT0 is the LSB of the 8-bit
alternating word-count rate counter.
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DS2156
26.4 BERT Repetitive Pattern Set
These registers must be properly loaded for the BERT to generate and synchronize to a repetitive pattern,
a pseudorandom pattern, alternating word pattern, or a Daly pattern. For a repetitive pattern that is fewer
than 32 bits, the pattern should be repeated so that all 32 bits are used to describe the pattern. For
example, if the pattern was the repeating 5-bit pattern …01101… (where the rightmost bit is the one sent
first and received first), then BRP1 should be loaded with ADh, BRP2 with B5h, BRP3 with D6h, and
BRP4 with 5Ah. For a pseudorandom pattern, all four registers should be loaded with all 1s (i.e., FFh).
For an alternating word pattern, one word should be placed into BRP1 and BRP2 and the other word
should be placed into BRP3 and BRP4. For example, if the DDS stress pattern “7E” is to be described,
the user would place 00h in BRP1, 00h in BRP2, 7Eh in BRP3, and 7Eh in BRP4 and the alternating
word counter would be set to 50 (decimal) to allow 100 bytes of 00h followed by 100 bytes of 7Eh to be
sent and received.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RPAT7
0
BRP1
BERT Repetitive Pattern Set Register 1
DCh
6
RPAT6
0
5
RPAT5
0
4
RPAT4
0
3
RPAT3
0
2
RPAT2
0
1
RPAT1
0
0
RPAT0
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 0 to 7 (RPAT0 to RPAT7). RPAT0 is the LSB of the 32-bit
repetitive pattern set.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RPAT15
0
BRP2
BERT Repetitive Pattern Set Register 2
DDh
6
RPAT14
0
5
RPAT13
0
4
RPAT12
0
3
RPAT11
0
2
RPAT10
0
1
RPAT9
0
0
RPAT8
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 8 to 15 (RPAT8 to RPAT15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RPAT23
0
BRP3
BERT Repetitive Pattern Set Register 3
DEh
6
RPAT22
0
5
RPAT21
0
4
RPAT20
0
3
RPAT19
0
2
RPAT18
0
1
RPAT17
0
0
RPAT16
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 16 to 23 (RPAT16 to RPAT23)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RPAT31
0
BRP4
BERT Repetitive Pattern Set Register 4
DFh
6
RPAT30
0
5
RPAT29
0
4
RPAT28
0
3
RPAT27
0
2
RPAT26
0
1
RPAT25
0
0
RPAT24
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 24 to 31 (RPAT24 to RPAT31). RPAT31 is the LSB of the 32-bit
repetitive pattern set.
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DS2156
26.5 BERT Bit Counter
Once BERT has achieved synchronization, this 32-bit counter increments for each data bit (i.e., clock)
received. Toggling the LC control bit in BC1 can clear this counter. This counter saturates when full and
sets the BBCO status bit.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
BBC7
0
BBC1
BERT Bit Count Register 1
E3h
6
BBC6
0
5
BBC5
0
4
BBC4
0
3
BBC3
0
2
BBC2
0
1
BBC1
0
0
BBC0
0
Bits 0 to 7/BERT Bit Counter Bits 0 to 7 (BBC0 to BBC7). BBC0 is the LSB of the 32-bit counter.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
BBC15
0
BBC2
BERT Bit Count Register 2
E4h
6
BBC14
0
5
BBC13
0
4
BBC12
0
3
BBC11
0
2
BBC10
0
1
BBC9
0
0
BBC8
0
2
BBC18
0
1
BBC17
0
0
BBC16
0
2
BBC26
0
1
BBC25
0
0
BBC24
0
Bits 0 to 7/BERT Bit Counter Bits 8 to 15 (BBC8 to BBC15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
BBC23
0
BBC3
BERT Bit Count Register 3
E5h
6
BBC22
0
5
BBC21
0
4
BBC20
0
3
BBC19
0
Bits 0 to 7/BERT Bit Counter Bits 16 to 23 (BBC16 to BBC23)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
BBC31
0
BBC4
BERT Bit Count Register 4
E6h
6
BBC30
0
5
BBC29
0
4
BBC28
0
3
BBC27
0
Bits 0 to 7/BERT Bit Counter Bits 24 to 31 (BBC24 to BBC31). BBC31 is the MSB of the 32-bit counter.
208 of 265
DS2156
26.6 BERT Error Counter
Once BERT has achieved synchronization, this 24-bit counter increments for each data bit received in
error. Toggling the LC control bit in BC1 can clear this counter. This counter saturates when full and sets
the BECO status bit.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
EC7
0
BEC1
BERT Error-Count Register 1
E7h
6
EC6
0
5
EC5
0
4
EC4
0
3
EC3
0
2
EC2
0
1
EC1
0
0
EC0
0
Bits 0 to 7/Error Counter Bits 0 to 7 (EC0 to EC7). EC0 is the LSB of the 24-bit counter.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
EC15
0
BEC2
BERT Error-Count Register 2
E8h
6
EC14
0
5
EC13
0
4
EC12
0
3
EC11
0
2
EC10
0
1
EC9
0
0
EC8
0
2
EC18
0
1
EC17
0
0
EC16
0
Bits 0 to 7/Error Counter Bits 8 to 15 (EC8 to EC15)
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
EC23
0
BEC3
BERT Error-Count Register 3
E9h
6
EC22
0
5
EC21
0
4
EC20
0
3
EC19
0
Bits 0 to 7/Error Counter Bits 16 to 23 (EC16 to EC23). EC0 is the MSB of the 24-bit counter.
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
BIC
BERT Interface Control Register
EAh
6
RFUS
0
5
—
0
4
TBAT
0
3
TFUS
0
2
—
0
1
BERTDIR
0
0
BERTEN
0
Bit 0/BERT Enable (BERTEN)
0 = BERT disabled
1 = BERT enabled
Bit 1/BERT Direction (BERTDIR)
0 = network
BERT transmits toward the network (TTIP and TRING) and receives from the network (RTIP and
RRING). The BERT pattern can be looped back to the receiver internally by using the framer loopback
function.
1 = system
BERT transmits toward the system backplane (RSER) and receives from the system backplane (TSER).
Bits 2, 5, 7/Unused, must be set to 0 for proper operation
Bit 3/Transmit Framed/Unframed Select (TFUS)
0 = BERT does not source data into the F-bit position (framed)
1 = BERT does source data into the F-bit position (unframed)
Bit 4/Transmit Byte-Align Toggle (TBAT). A 0-to-1 transition forces the BERT to byte align its pattern with the
transmit formatter. This bit must be transitioned in order to byte align the Daly pattern.
Bit 6/Receive Framed/Unframed Select (RFUS)
0 = BERT is not sent data from the F-bit position (framed)
1 = BERT is sent data from the F-bit position (unframed)
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DS2156
27.
PAYLOAD ERROR-INSERTION FUNCTION (T1 MODE ONLY)
An error-insertion function is available in the DS2156 and is used to create errors in the payload portion
of the T1 frame in the transmit path. This function is only available in T1 mode. Errors can be inserted
over the entire frame or the user can select which channels are to be corrupted. Errors are created by
inverting the last bit in the count sequence. For example, if the error rate 1 in 16 is selected, the 16th bit is
inverted. F-bits are excluded from the count and are never corrupted. Error rate changes occur on frame
boundaries. Error-insertion options include continuous and absolute number with both options supporting
selectable insertion rates.
Table 27-A. Transmit Error-Insertion Setup Sequence
STEP
1
2A
or
2B
ACTION
Enter desired error rate in the ERC register. Note: If ER3 through ER0 = 0, no errors
are generated even if the constant error-insertion feature is enabled.
For constant error insertion, set CE = 1 (ERC.4).
For a defined number of errors:
– Set CE = 0 (ERC.4)
– Load NOE1 and NOE2 with the number of errors to be inserted
– Toggle WNOE (ERC.7) from 0 to 1 to begin error insertion
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DS2156
Register Name:
Register Description:
Register Address:
ERC
Error-Rate Control Register
EBh
Bit #
Name
Default
6
—
0
7
WNOE
0
5
—
0
4
CE
0
3
ER3
0
2
ER2
0
1
ER1
0
0
ER0
0
Bits 0 to 3/Error-Insertion Rate Select Bits (ER0 to ER3)
ER3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
ER2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
ER1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
ER0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Error Rate
No errors inserted
1 in 16
1 in 32
1 in 64
1 in 128
1 in 256
1 in 512
1 in 1024
1 in 2048
1 in 4096
1 in 8192
1 in 16,384
1 in 32,768
1 in 65,536
1 in 131,072
1 in 262,144
Bit 4/Constant Errors (CE). When this bit is set high (and the ER0 to ER3 bits are not set to 0000), the errorinsertion logic ignores the number-of-error registers (NOE1, NOE2) and generates errors constantly at the selected
insertion rate. When CE is set to 0, the NOEx registers determine how many errors are to be inserted.
Bits 5, 6/Unused, must be set to 0 for proper operation
Bit 7/Write NOE Registers (WNOE). If the host wishes to update to the NOEx registers, this bit must be toggled
from a 0 to a 1 after the host has already loaded the prescribed error count into the NOEx registers. The toggling of
this bit causes the error count loaded into the NOEx registers to be loaded into the error-insertion circuitry on the
next clock cycle. Subsequent updates require that the WNOE bit be set to 0 and then 1 once again.
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DS2156
27.1 Number-of-Errors Registers
The number-of-error registers determine how many errors are generated. Up to 1023 errors can be
generated. The host loads the number of errors to be generated into the NOE1 and NOE2 registers. The
host can also update the number of errors to be created by first loading the prescribed value into the NOE
registers and then toggling the WNOE bit in the error-rate control registers.
Table 27-B. Error Insertion Examples
VALUE
000h
001h
002h
3FFh
WRITE
Do not create any errors
Create a single error
Create two errors
Create 1023 errors
READ
No errors left to be inserted
One error left to be inserted
Two errors left to be inserted
1023 errors left to be inserted
Register Name:
Register Description:
Register Address:
NOE1
Number-of-Errors 1
ECh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Bits 0 to 7/Number-of-Errors Counter Bits 0 to 7 (C0 to C7). Bit C0 is the LSB of the 10-bit counter.
Register Name:
Register Description:
Register Address:
NOE2
Number-of-Errors 2
EDh
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
2
—
0
1
C9
0
0
C8
0
Bits 0, 1/Number-of-Errors Counter Bits 8 to 9 (C8 to C9). Bit C9 is the MSB of the 10-bit counter.
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DS2156
27.1.1
Number-of-Errors Left Register
The host can read the NOELx registers at any time to determine how many errors are left to be inserted.
Register Name:
Register Description:
Register Address:
NOEL1
Number-of-Errors Left 1
EEh
Bit #
Name
Default
6
C6
0
7
C7
0
5
C5
0
4
C4
0
3
C3
0
2
C2
0
1
C1
0
0
C0
0
Bits 0 to 7/Number-of-Errors Left Counter Bits 0 to 7 (C0 to C7). Bit C0 is the LSB of the 10-bit counter.
Register Name:
Register Description:
Register Address:
NOEL2
Number-of-Errors Left 2
EFh
Bit #
Name
Default
6
—
0
7
—
0
5
—
0
4
—
0
3
—
0
2
—
0
1
C9
0
0
C8
0
Bits 0, 1/Number-of-Errors Left Counter Bits 8 to 9 (C8 to C9). Bit C9 is the MSB of the 10-bit counter.
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DS2156
28.
INTERLEAVED PCM BUS OPERATION (IBO)
Note: The interleaved PCM bus operation is not available when UTOPIA backplane is enabled.
In many architectures, the PCM outputs of individual framers are combined into higher speed PCM buses
to simplify transport across the system backplane. The DS2156 can be configured to allow PCM data to
be multiplexed into higher speed buses eliminating external hardware, saving board space and cost. The
DS2156 can be configured for channel or frame interleave.
The interleaved PCM bus operation (IBO) supports three bus speeds. The 4.096MHz bus speed allows
two PCM data streams to share a common bus. The 8.192MHz bus speed allows four PCM data streams
to share a common bus. The 16.384MHz bus speed allows eight PCM data streams to share a common
bus. See Figure 28-1 for an example of four transceivers sharing a common 8.192MHz PCM bus. The
receive elastic stores of each transceiver must be enabled. Through the IBO register, the user can
configure each transceiver for a specific bus position. For all IBO bus configurations, each transceiver is
assigned an exclusive position in the high-speed PCM bus. The 8kHz frame sync can be generated from
the system backplane or from the first device on the bus. All other devices on the bus must have their
frame syncs configured as inputs. Relative to this common frame sync, the devices await their turn to
drive or sample the bus according to the settings of the DA0, DA1, and DA2 bits of the IBOC register.
28.1 Channel Interleave
In channel interleave mode, data is output to the PCM data-out bus one channel at a time from each of the
connected DS2156s until all channels of frame n from each DS2156 have been placed on the bus. This
mode can be used even when the DS2156s are operating asynchronous to each other. The elastic stores
manage slip conditions (Figure 34-22).
28.2 Frame Interleave
In frame interleave mode, data is output to the PCM data-out bus one frame at a time from each of the
DS2156s. This mode is used only when all connected DS2156s are operating in a synchronous fashion
(all inbound T1 or E1 lines are synchronous) and are synchronous with the system clock (system clock
derived from T1 or E1 line). Slip conditions are not allowed in this mode (Figure 34-23).
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DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
IBOC
Interleave Bus Operation Control Register
C5h
6
IBS1
0
5
IBS0
0
4
IBOSEL
0
3
IBOEN
0
2
DA2
0
1
DA1
0
0
DA0
0
Bits 0 to 2/Device Assignment Bits (DA0 to DA2)
DA2
0
0
0
0
1
1
1
1
DA1
0
0
1
1
0
0
1
1
DA0
0
1
0
1
0
1
0
1
Device Position on Bus
1st
2nd
3rd
4th
5th
6th
7th
8th
Bit 3/Interleave Bus Operation Enable (IBOEN)
0 = IBO disabled
1 = IBO enabled
Bit 4/Interleave Bus Operation Select (IBOSEL). This bit selects channel or frame interleave mode.
0 = channel interleave
1 = frame interleave
Bits 5, 6/IBO Bus Size Bit 1 (IBS0 to IBS1). Indicates how many devices are on the bus.
IBS1
0
0
1
1
IBS0
0
1
0
1
Bus Size
Two devices on bus
Four devices on bus
Eight devices on bus
Reserved for future use
Bit 7/Unused, must be set to 0 for proper operation
216 of 265
DS2156
Figure 28-1. IBO Example
RSYSCLK
TSYSCLK
RSYSCLK
TSYSCLK
RSYNC
TSSYNC
RSYNC
TSSYNC
RSIG
TSIG
RSIG
TSIG
TSER
DS2156 #1 RSER
TSER
DS2156 #3 RSER
8.192MHz SYSTEM CLOCK IN
SYSTEM 8kHz FRAME SYNC IN
PCM SIGNALING OUT
PCM SIGNALING IN
PCM DATA IN
PCM DATA OUT
RSYSCLK
TSYSCLK
RSYSCLK
TSYSCLK
RSYNC
TSSYNC
RSYNC
TSSYNC
RSIG
TSIG
RSIG
TSIG
TSER
DS2156 #2 RSER
TSER
DS2156 #4 RSER
217 of 265
DS2156
29.
EXTENDED SYSTEM INFORMATION BUS (ESIB)
The extended system information bus (ESIB) allows up to eight DS2156s to share an 8-bit CPU bus for
reporting alarms and interrupt status as a group. With a single bus read, the host can be updated with
alarm or interrupt status from all members of the group. There are two control registers (ESIBCR1 and
ESIBCR2) and four information registers (ESIB1, ESIB2, ESIB3, and ESIB4). For example, eight
DS2156s can be grouped into an ESIB group. A single read of the ESIB1 register of any member of the
group yields the interrupt status of all eight DS2156s. Therefore, the host can determine which device or
devices are causing an interrupt without polling all eight devices. Through ESIB2, the host can gather
synchronization status on all members of the group. ESIB3 and ESIB4 can be programmed to report
various alarms on a device-by-device basis.
There are three device pins involved in forming an ESIB group: ESIBS0, ESIBS1, and ESIBRD. A 10kΩ
pullup resistor must be provided on ESIBS0, ESIBS1, and ESIBRD.
Figure 29-1. ESIB Group of Four DS2156s
VDD
10kΩ (3)
DS2156 # 1
CPU I/F
ESIB0
ESIB1
ESIBRD
DS2156 # 2
CPU I/F
ESIB0
ESIB1
ESIBRD
DS2156 # 3
CPU I/F
ESIB0
ESIB1
ESIBRD
DS2156 # 4
CPU I/F
ESIB0
ESIB1
ESIBRD
218 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
ESIBCR1
Extended System Information Bus Control Register 1
B0h
6
—
0
5
—
0
4
—
0
3
ESIBSEL2
0
2
ESIBSEL1
0
1
ESIBSEL0
0
0
ESIEN
0
Bit 0/Extended System Information Bus Enable (ESIEN)
0 = disabled
1 = enabled
Bits 1 to 3/Output Data Bus Line Select (ESIBSEL0 to ESIBSEL2). These bits tell the DS2156 what data bus
bit to output the ESIB data on when one of the ESIB information registers is accessed. Each member of the ESIB
group must have a unique bit selected.
ESIBSEL2
0
0
0
0
1
1
1
1
ESIBSEL1
0
0
1
1
0
0
1
1
ESIBSEL0
0
1
0
1
0
1
0
1
Bus Bit Driven
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
Bits 4 to 7/Unused, must be set to 0 for proper operation
219 of 265
DS2156
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
—
0
ESIBCR2
Extended System Information Bus Control Register 2
B1h
6
ESI4SEL2
0
5
ESI4SEL1
0
4
ESI4SEL0
0
3
—
0
2
ESI3SEL2
0
1
ESI3SEL1
0
0
ESI3SEL0
0
Bits 0 to 2/Address ESI3 Data Output Select (ESI3SEL0 to ESI3SEL2). These bits select what status is to be
output when the DS2156 decodes an ESI3 address during a bus read operation.
ESI3SEL2
ESI3SEL1
ESI3SEL0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Status Output
(T1 Mode)
RBL
RYEL
LUP
LDN
SIGCHG
ESSLIP
—
—
Status Output
(E1 Mode)
RUA1
RRA
RDMA
V52LNK
SIGCHG
ESSLIP
—
—
Bit 3/Unused, must be set to 0 for proper operation
Bits 4 to 6/Address ESI4 Data-Output Select (ESI4SEL0 to ESI4SEL2). These bits select what status is to be
output when the DS2156 decodes an ESI4 address during a bus read operation.
ESI4SEL2
ESI4SEL1
ESI4SEL0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Status Output
(T1 Mode)
RBL
RYEL
LUP
LDN
SIGCHG
ESSLIP
—
—
Bit 7/Unused, must be set to 0 for proper operation
220 of 265
Status Output
(E1 Mode)
RUA1
RRA
RDMA
V52LNK
SIGCHG
ESSLIP
—
—
DS2156
Register Name:
Register Description:
Register Address:
ESIB1
Extended System Information Bus Register 1
B2h
Bit #
Name
Default
6
DISn
0
7
DISn
0
5
DISn
0
4
DISn
0
3
DISn
0
2
DISn
0
1
DISn
0
0
DISn
0
Bits 0 to 7/Device Interrupt Status (DISn). Causes all devices participating in the ESIB group to output their
interrupt status on the appropriate data bus line selected by the ESIBSEL0 to ESIBSEL2 bits of the ESIBCR1
register.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
DRLOSn
0
ESIB2
Extended System Information Bus Register 2
B3h
6
DRLOSn
0
5
DRLOSn
0
4
DRLOSn
0
3
DRLOSn
0
2
DRLOSn
0
1
DRLOSn
0
0
DRLOSn
0
Bits 0 to 7/Device Receive Loss-of-Sync (DRLOSn). Causes all devices participating in the ESIB group to output
their frame synchronization status on the appropriate data bus line selected by the ESIBSEL0 to ESIBSEL2 bits of
the ESIBCR1 register.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
UST1n
0
ESIB3
Extended System Information Bus Register 3
B4h
6
UST1n
0
5
UST1n
0
4
UST1n
0
3
UST1n
0
2
UST1n
0
1
UST1n
0
0
UST1n
0
Bits 0 to 7/User-Selected Status 1 (UST1n). Causes all devices participating in the ESIB group to output status or
alarms as selected by the ESI3SEL0 to ESI3SEL2 bits in the ESIBCR2 configuration register on the appropriate
data bus line selected by the ESIBSEL0 to ESIBSEL2 bits of the ESIBCR2 register
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
UST2n
0
ESIB4
Extended System Information Bus Register 4
B5h
6
UST2n
0
5
UST2n
0
4
UST2n
0
3
UST2n
0
2
UST2n
0
1
UST2n
0
0
UST2n
0
Bits 0 to 7/User-Selected Status 2 (UST2n). Causes all devices participating in the ESIB group to output status or
alarms as selected by the ESI4SEL0 to ESI4SEL2 bits in the ESIBCR2 configuration register on the appropriate
data bus line selected by the ESIBSEL0 to ESIBSEL2 bits of the ESIBCR2 register
221 of 265
DS2156
30.
PROGRAMMABLE BACKPLANE CLOCK SYNTHESIZER
The DS2156 contains an on-chip clock synthesizer that generates a user-selectable clock output on the
BPCLK pin, referenced to the recovered receive clock (RCLK). The synthesizer uses a phase-locked loop
to generate low-jitter clocks. Common applications include generation of port and backplane system
clocks. The CCR2 register is used to enable (CCR2.0) and select (CCR2.1 and CCR2.2) the clock
frequency of the BPCLK pin.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TRPA4
0
CCR2
Common Control Register 2
71h
6
TRPA3
0
5
TRPA2
0
4
TRPA1
0
3
TRPA0
0
2
BPCS1
0
1
BPCS0
0
0
BPEN
0
Bit 0/Backplane Clock Enable (BPEN)
0 = disable BPCLK pin (pin held at logic 0)
1 = enable BPCLK pin
Bits 1, 2/Backplane Clock Selects (BPCS0, BPCS1)
BPCS1
0
0
1
1
BPCS0
0
1
0
1
BPCLK Frequency (MHz)
16.384
8.192
4.096
2.048
Bits 3 to 7/UTOPIA Port Address (TRPA0 to TRPA4). See Register Definitions in Section 24.7.
31.
FRACTIONAL T1/E1 SUPPORT
31.1 TDM Backplane Mode
The DS2156 can be programmed to output gapped clocks for selected channels in the receive and
transmit paths to simplify connections into a USART or LAPD controller in fractional T1/E1 or ISDNPRI applications. The receive and transmit paths have independent enables. Channel formats supported
include 56kbps and 64kbps. This is accomplished by assigning an alternate function to the RCHCLK and
TCHCLK pins. Setting CCR3.0 = 1 causes the RCHCLK pin to output a gapped clock as defined by the
receive fractional T1/E1 function of the PCPR register. Setting CCR3.2 = 1 causes the TCHCLK pin to
output a gapped clock as defined by the transmit fractional T1/E1 function of the PCPR register. CCR3.1
and CCR3.3 can be used to select between 64kbps and 56kbps operation. See Section 5 for details about
programming the per-channel function. In T1 mode no clock is generated at the F-bit position.
When 56kbps mode is selected, the LSB clock in the channel is omitted. Only the seven most significant
bits of the channel have clocks.
222 of 265
DS2156
31.2 UTOPIA Backplane Mode
ATM traffic can be assigned on a fractional basis. See Section 24 for UTOPIA operation.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
TMSS
0
CCR3
Common Control Register 3
72h
6
INTDIS
0
5
CTTUI
0
4
CRRUI
0
3
TDATFMT
0
2
TGPCKEN
0
1
RDATFMT
0
0
RGPCKEN
0
Bit 0/Receive Gapped-Clock Enable (RGPCKEN)
0 = RCHCLK functions normally
1 = enable gapped bit-clock output on RCHCLK
Bit 1/Receive Channel-Data Format (RDATFMT)
0 = 64kbps (data contained in all 8 bits)
1 = 56kbps (data contained in seven out of the 8 bits)
Bit 2/Transmit Gapped-Clock Enable (TGPCKEN)
0 = TCHCLK functions normally
1 = enable gapped bit-clock output on TCHCLK
Bit 3/Transmit Channel-Data Format (TDATFMT)
0 = 64kbps (data contained in all 8 bits)
1 = 56kbps (data contained in seven out of the 8 bits)
Bit 4/Connect RCLK to Receive UTOPIA Interface (CRRUI). This bit selects either a constant clock (RCLK)
or a gapped clock from the framer (programmed by the user) as its data clock.
0 = gated clock is connected to receive UTOPIA interface
1 = RCLK is connected to receive UTOPIA interface
Bit 5/Connect TCLK to Transmit UTOPIA Interface (CTTUI). This bit selects either a constant clock (TCLK)
or a gapped clock from the framer (programmed by the user) as its data clock.
0 = gated clock is connected to transmit UTOPIA interface
1 = TCLK is connected to transmit UTOPIA interface
Bit 6/Interrupt Disable (INTDIS). This bit is convenient for disabling interrupts without altering the various
interrupt mask register settings.
0 = interrupts are enabled according to the various mask register settings
1 = interrupts are disabled regardless of the mask register settings
Bit 7/Transmit Multiframe Sync Source (TMSS). Should be set = 0 only when transmit hardware signaling is
enabled.
0 = elastic store is source of multiframe sync
1 = framer or TSYNC pin is source of multiframe sync
223 of 265
DS2156
32.
USER-PROGRAMMABLE OUTPUT PINS
The DS2156 provides four user-programmable output pins. The pins are automatically cleared to 0 at
power-up or as a result of a hardware- or software-issued reset.
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
7
RLT3
0
CCR4
Common Control Register 4
73h
6
RLT2
0
5
RLT1
0
4
RLT0
0
3
UOP3
0
2
UOP2
0
Bit 0/User-Defined Output 0 (UOP0)
0 = logic 0 level at pin
1 = logic 1 level at pin
Bit 1/User-Defined Output 1 (UOP1)
0 = logic 0 level at pin
1 = logic 1 level at pin
Bit 2/User-Defined Output 2 (UOP2)
0 = logic 0 level at pin
1 = logic 1 level at pin
Bit 3/User-Defined Output 3 (UOP3)
0 = logic 0 level at pin
1 = logic 1 level at pin
Bits 4 to 7/Receive Level Threshold Bits (RLT0 to RLT3)
RLT3
RLT2
RLT1
RLT0
Receive Level (dB)
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Greater than -2.5
-2.5
-5.0
-7.5
-10.0
-12.5
-15.0
-17.5
-20.0
-22.5
-25.0
-27.5
-30.0
-32.5
-35.0
Less than -37.5
224 of 265
1
UOP1
0
0
UOP0
0
DS2156
33.
JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT
33.1 Description
The DS2156 IEEE 1149.1 design supports the standard instruction codes SAMPLE/PRELOAD,
BYPASS, and EXTEST. Optional public instructions included are HIGH-Z, CLAMP, and IDCODE
(Figure 33-1.). The DS2156 contains the following features as required by IEEE 1149.1 standard test
access port (TAP) and boundary scan architecture.
Test Access Port
TAP Controller
Instruction Register
Bypass Register
Boundary Scan Register
Device Identification Register
The DS2156 is pin-compatible with the DS2152, DS21x52 (T1) and DS2154, DS21x54 (E1) SCT
families. The JTAG feature uses pins that had no function in the DS2152 and DS2154. Details about
boundary scan architecture and the TAP are in IEEE 1149.1-1990, IEEE 1149.1a-1993, and IEEE
1149.1b-1994.
The TAP contains the necessary interface pins JTRST, JTCLK, JTMS, JTDI, and JTDO. See the pin
descriptions in Section 3 for details.
Figure 33-1. JTAG Functional Block Diagram
BOUNDARY SCAN
REGISTER
IDENTIFICATION
REGISTER
BYPASS
REGISTER
MUX
INSTRUCTION
REGISTER
SELECT
TEST ACCESS PORT
CONTROLLER
+V
10kΩ
+V
10kΩ
JTDI
OUTPUT ENABLE
+V
10kΩ
JTMS
JTCLK
JTRST
225 of 265
JTDO
DS2156
TAP Controller State Machine
The TAP controller is a finite state machine that responds to the logic level at JTMS on the rising edge of
JTCLK (Figure 33-2).
Test-Logic-Reset
Upon power-up, the TAP controller is in the Test-Logic-Reset state. The instruction register contains the
IDCODE instruction. All system logic of the device operates normally.
Run-Test-Idle
The Run-Test-Idle is used between scan operations or during specific tests. The instruction register and
test registers remain idle.
Select-DR-Scan
All test registers retain their previous state. With JTMS LOW, a rising edge of JTCLK moves the
controller into the Capture-DR state and initiates a scan sequence. JTMS HIGH during a rising edge on
JTCLK moves the controller to the Select-IR-Scan state.
Capture-DR
Data can be parallel-loaded into the test data registers selected by the current instruction. If the instruction
does not call for a parallel load or the selected register does not allow parallel loads, the test register
remains at its current value. On the rising edge of JTCLK, the controller goes to the Shift-DR state if
JTMS is LOW or it goes to the Exit1-DR state if JTMS is HIGH.
Shift-DR
The test data register selected by the current instruction is connected between JTDI and JTDO and shifts
data one stage toward its serial output on each rising edge of JTCLK. If a test register selected by the
current instruction is not placed in the serial path, it maintains its previous state.
Exit1-DR
While in this state, a rising edge on JTCLK puts the controller in the Update-DR state, which terminates
the scanning process, if JTMS is HIGH. A rising edge on JTCLK with JTMS LOW puts the controller in
the Pause-DR state.
Pause-DR
Shifting of the test registers is halted while in this state. All test registers selected by the current
instruction retain their previous state. The controller remains in this state while JTMS is LOW. A rising
edge on JTCLK with JTMS HIGH puts the controller in the Exit2-DR state.
Exit2-DR
A rising edge on JTCLK with JTMS HIGH while in this state puts the controller in the Update-DR state
and terminates the scanning process. A rising edge on JTCLK with JTMS LOW enters the Shift-DR state.
Update-DR
A falling edge on JTCLK while in the Update-DR state latches the data from the shift register path of the
test registers into the data output latches. This prevents changes at the parallel output because of changes
in the shift register.
226 of 265
DS2156
Select-IR-Scan
All test registers retain their previous state. The instruction register remains unchanged during this state.
With JTMS LOW, a rising edge on JTCLK moves the controller into the Capture-IR state and initiates a
scan sequence for the instruction register. JTMS HIGH during a rising edge on JTCLK puts the controller
back into the Test-Logic-Reset state.
Capture-IR
The Capture-IR state is used to load the shift register in the instruction register with a fixed value. This
value is loaded on the rising edge of JTCLK. If JTMS is HIGH on the rising edge of JTCLK, the
controller enters the Exit1-IR state. If JTMS is LOW on the rising edge of JTCLK, the controller enters
the Shift-IR state.
Shift-IR
In this state, the shift register in the instruction register is connected between JTDI and JTDO and shifts
data one stage for every rising edge of JTCLK toward the serial output. The parallel register and all test
registers remain at their previous states. A rising edge on JTCLK with JTMS HIGH moves the controller
to the Exit1-IR state. A rising edge on JTCLK with JTMS LOW keeps the controller in the Shift-IR state
while moving data one stage through the instruction shift register.
Exit1-IR
A rising edge on JTCLK with JTMS LOW puts the controller in the Pause-IR state. If JTMS is HIGH on
the rising edge of JTCLK, the controller enters the Update-IR state and terminates the scanning process.
Pause-IR
Shifting of the instruction shift register is halted temporarily. With JTMS HIGH, a rising edge on JTCLK
puts the controller in the Exit2-IR state. The controller remains in the Pause-IR state if JTMS is LOW
during a rising edge on JTCLK.
Exit2-IR
A rising edge on JTCLK with JTMS LOW puts the controller in the Update-IR state. The controller loops
back to Shift-IR if JTMS is HIGH during a rising edge of JTCLK in this state.
Update-IR
The instruction code shifted into the instruction shift register is latched into the parallel output on the
falling edge of JTCLK as the controller enters this state. Once latched, this instruction becomes the
current instruction. A rising edge on JTCLK with JTMS LOW puts the controller in the Run-Test-Idle
state. With JTMS HIGH, the controller enters the Select-DR-Scan state.
227 of 265
DS2156
Figure 33-2. TAP Controller State Diagram
1
Test Logic
Reset
0
0
Run Test/
Idle
1
Select
DR-Scan
1
Select
IR-Scan
0
1
0
1
Capture DR
Capture IR
0
Shift DR
0
Shift IR
0
1
Exit IR
0
Pause DR
1
0
Pause IR
0
1
0
0
1
1
Exit DR
1
Exit2 DR
1
0
Exit2 IR
1
1
Update DR
Update IR
1
1
0
0
0
33.2 Instruction Register
The instruction register contains a shift register as well as a latched parallel output and is 3 bits in length.
When the TAP controller enters the Shift-IR state, the instruction shift register is connected between JTDI
and JTDO. While in the Shift-IR state, a rising edge on JTCLK with JTMS LOW shifts the data one stage
toward the serial output at JTDO. A rising edge on JTCLK in the Exit1-IR state or the Exit2-IR state with
JTMS HIGH moves the controller to the Update-IR state. The falling edge of that same JTCLK latches
the data in the instruction shift register to the instruction parallel output. Instructions supported by the
DS2156 and its respective operational binary codes are shown in Table 16-A.
228 of 265
DS2156
Table 33-A. Instruction Codes for IEEE 1149.1 Architecture
INSTRUCTION
SAMPLE/PRELOAD
BYPASS
EXTEST
CLAMP
HIGHZ
IDCODE
SELECTED REGISTER
INSTRUCTION CODES
Boundary Scan
Bypass
Boundary Scan
Bypass
Bypass
Device Identification
010
111
000
011
100
001
SAMPLE/PRELOAD
This is a mandatory instruction for the IEEE 1149.1 specification that supports two functions. The digital
I/Os of the device can be sampled at the boundary scan register without interfering with the normal
operation of the device by using the Capture-DR state. SAMPLE/PRELOAD also allows the device to
shift data into the boundary scan register through JTDI using the Shift-DR state.
BYPASS
When the BYPASS instruction is latched into the parallel instruction register, JTDI connects to JTDO
through the 1-bit bypass test register. This allows data to pass from JTDI to JTDO without affecting the
device’s normal operation.
EXTEST
This allows testing of all interconnections to the device. When the EXTEST instruction is latched in the
instruction register, the following actions occur: Once enabled through the Update-IR state, the parallel
outputs of all digital output pins are driven. The boundary scan register is connected between JTDI and
JTDO. The Capture-DR samples all digital inputs into the boundary scan register.
CLAMP
All digital outputs of the device output data from the boundary scan parallel output while connecting the
bypass register between JTDI and JTDO. The outputs do not change during the CLAMP instruction.
HIGHZ
All digital outputs of the device are placed in a high-impedance state. The BYPASS register is connected
between JTDI and JTDO.
IDCODE
When the IDCODE instruction is latched into the parallel instruction register, the identification test
register is selected. The device identification code is loaded into the identification register on the rising
edge of JTCLK following entry into the Capture-DR state. Shift-DR can be used to shift the identification
code out serially through JTDO. During Test-Logic-Reset, the identification code is forced into the
instruction register’s parallel output. The ID code always has a 1 in the LSB position. The next 11 bits
identify the manufacturer’s JEDEC number and number of continuation bytes followed by 16 bits for the
device and 4 bits for the version (Table 33-B). Table 33-C lists the device ID codes for the SCT devices.
229 of 265
DS2156
Table 33-B. ID Code Structure
MSB
LSB
Version
Contact Factory
Device ID
JEDEC
1
4 bits
16 bits
00010100001
1
Table 33-C. Device ID Codes
PART
DS2156
DS2155
DS21354
DS21564
DS21352
DS21562
16-BIT ID
0019h
0010h
0005h
0003h
0004h
0002h
33.3 Test Registers
IEEE 1149.1 requires a minimum of two test registers, the boundary scan register and the bypass register.
An optional test register, the identification register, has been included with the DS2156 design. It is used
with the IDCODE instruction and the Test-Logic-Reset state of the TAP controller.
33.4 Boundary Scan Register
This register contains both a shift register path and a latched parallel output for all control cells and digital
I/O cells. It is n bits in length. See Table 33-D for cell bit locations and definitions.
33.5 Bypass Register
This is a single one-bit shift register used with the BYPASS, CLAMP, and HIGH-Z instructions that
provides a short path between JTDI and JTDO.
33.6 Identification Register
The identification register contains a 32-bit shift register and a 32-bit latched parallel output. This register
is selected during the IDCODE instruction and when the TAP controller is in the Test-Logic-Reset state.
See Table 33-B and Table 33-C for more information on bit usage.
230 of 265
DS2156
Table 33-D. Boundary Scan Control Bits
( ) = Alternate function when in UTOPIA backplane mode.
BIT
PIN
NAME
TYPE
3
—
1
2
RCHBLK (UR_SOC)
JTMS
O
I
2
—
BPCLK.cntl
—
1
—
—
0
—
3
4
5
6
7
BPCLK (UR_ENB)
JTCLK
JTRST
RCL
JTDI
I/O
I
I
O
I
98
—
UOP0.cntl
—
97
8
UOP0 (UT_SOC)
I/O
96
—
UOP1.cntl
—
95
94
9
10
11
UOP1 (UT_ENB)
JTDO
BTS
I/O
O
I
93
—
LIUC.cntl
—
92
91
90
89
—
—
—
—
—
—
12
13
14
15
16
17
18
19, 20, 24
21
22
LIUC (UT_CLAV)
8XCLK
TSTRST
UOP2
RTIP
RRING
RVDD
RVSS
MCLK
XTALD
I/O
O
I
O
I
I
—
—
I
O
88
—
UOP3.cntl
—
87
86
85
—
—
—
—
—
23
25
26
27, 28
29
30
31
32
UOP3 (UT_ADDR0)
INT
TUSEL
N.C.
TTIP
TVSS
TVDD
TRING
I/O
O
I
—
O
—
—
O
84
—
TCHBLK.cntl
—
83
33
TCHBLK
(UT_ADDR1)
I/O
82
—
TLCLK.cntl
—
81
80
34
35
TLCLK (UT_ADDR2)
TLINK (UT_ADDR3)
I/O
I
79
—
ESIBS0.cntl
—
78
77
36
—
ESIBS0
TSYNC.cntl
I/O
—
CONTROL BIT FUNCTION
—
—
0 = BPCLK is an input (UR_ENB)
1 = BPCLK is an output
—
—
—
—
—
0 = UOP0 is an input UT_SOC
1 = UOP0 is an output
—
0 = UOP1 is an input UT_ENB
1 = UOP1 is an output
—
—
—
0 = LIUC is an input
1 = LIUC is an output (UT_CLAV)
—
—
—
—
—
—
—
—
—
—
0 = UOP3 is an input (UT_ADDR0)
1 = UOP3 is an output
—
—
—
—
—
—
—
—
0 = TCHBLK is an input (UT_ADDR1)
1 = TCHBLK is an output
—
0 = TLCLK is an input (UT_ADDR2)
1 = TLCLK is an output
—
—
0 = ESIBS0 is an input
1 = ESIBS0 is an output
—
0 = TSYNC is an input
231 of 265
DS2156
BIT
PIN
NAME
TYPE
76
75
74
73
37
38
39
40
TSYNC
TPOSI (UT_ADDR4)
TNEGI (UT_DATA0)
TCLKI (UT_DATA1)
I/O
I
I
I
72
—
TCLKO.cntl
—
71
41
TCLKO (UT_DATA2)
I/O
70
—
TNEGO.cntl
—
69
42
TNEGO (UT_DATA3)
I/O
68
—
TPOSO.cntl
—
67
—
—
66
65
64
63
62
43
44
45
46
47
48
49
50
I/O
—
—
I
I
I
O
I
61
51
60
52
TPOSO (UT_DATA4)
DVDD
DVSS
TCLK
TSER (UT_DATA5)
TSIG (UT_DATA6)
TESO (UT_UTDO)
TDATA
TSYSCLK
(UT_DATA7)
TSSYNC (UT_CLK)
59
—
TCHCLK.cntl
—
58
53
TCHCLK (UR_CLK)
I/O
57
—
ESIBS1.cntl
—
56
55
54
55
ESIBS1
MUX
I/O
I
54
—
BUS.cntl
—
53
52
51
50
—
—
49
48
47
46
45
44
43
42
41
40
39
38
37
36
56
57
58
59
60, 80, 84
61, 81, 83
62
63
64
65
66
67
68
69
70
71
72
73
74
75
D0/AD0
D1/AD1
D2/AD2
D3/AD3
DVSS
DVDD
D4/AD4
D5/AD5
D6/AD6
D7/AD7
A0
A1
A2
A3
A4
A5
A6
ALE(AS)/A7
RD (DS)
CS
I/O
I/O
I/O
I/O
—
—
I/O
I/O
I/O
I/O
I
I
I
I
I
I
I
I
I
I
35
—
ESIBRD.cntl
—
CONTROL BIT FUNCTION
1 = TSYNC is an output
—
—
—
—
0 = TCLKO is an input (UT_DATA2)
1 = TCLKO is an output
0 = TNEGO is an input (UT_DATA3)
1 = TNEGO is an output (UT_DATA4)
0 = TPOSO is an input (UT_DATA4)
1 = TPOSO is an output
—
—
—
—
—
—
—
—
I
—
I
—
0 = TCHCLK is an input (UR_CLK)
1 = TCHCLK is an output
—
0 = ESIBS1 is an input
1 = ESIBS1 is an output
—
—
0 = D0–D7/AD0–AD7 are inputs
1 = D0–D7/AD0–AD7 are inputs
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0 = ESIBRD is an input
1 = ESIBRD is an output
232 of 265
DS2156
BIT
PIN
NAME
TYPE
CONTROL BIT FUNCTION
34
33
32
31
30
29
76
77
78
79
82
85
ESIBRD
WR (R/W)
RLINK (UR_DATA0)
RLCLK (UR_DATA1)
RCLK
RDATA
I/O
I
O
O
O
O
28
—
RPOSI.cntl
—
27
86
RPOSI (UR_DATA2)
I/O
26
—
RNEGI.cntl
—
25
87
RNEGI (UR_DATA3)
I/O
24
—
RCLKI.cntl
—
23
22
21
20
88
89
90
91
RCLKI (UR_DATA4)
RCLKO (UR_DATA5)
RNEGO (UR_DATA6)
RPOSO (UR_DATA7)
I/O
O
O
O
19
—
RCHCLK.cntl
I/O
18
92
RCHCLK
(UR_ADDR0)
I/O
17
—
RSIGF.cntl
—
16
93
RSIGF (UR_ADDR1)
I/O
15
—
RSIG.cntl
—
14
13
12
94
95
—
I/O
O
—
11
96
RSIG (UR_ADDR2)
RSER (UR_CLAV)
RMSYNC.cntl
RMSYNC
(UR_ADDR3)
0 = RSIGF is an input (UR_ADDR1)
1 = RSIGF is an output
—
0 = RSIG is an input (UR_ADDR2)
1 = RSIG is an output
—
—
0 = RMSYNC is an input (UR_ADDR3)
I/O
—
10
—
RFSYNC.cntl
—
9
97
RFSYNC (UR_ADDR4)
I/O
8
—
RSYNC.cntl
—
7
6
98
99
RSYNC
RLOS/LOTC
I/O
O
5
—
RSYSCLK.cntl
—
4
100
RSYSCLK
(UT_2CLAV)
I/O
—
—
—
—
—
—
0 = RPOSI is an input
1 = RPOSI is an output (UR_DATA2)
—
0 = RNEGI is an input
1 = RNEGI is an output (UR_DATA3)
—
0 = RCLKI is an input
1 = RCLKI is an output (UR_DATA4)
—
—
—
—
0 = RCHCLK is an input (UR_ADDR0)
1 = RCHCLK is an output
—
0 = RFSYNC is an input (UR_ADDR4)
1 = RFSYNC is an output
—
0 = RSYNC is an input
1 = RSYNC is an output
—
—
0 = RSYSCLK is an input
1 = RSYSCLK in an output (UT_2CLAV)
—
233 of 265
DS2156
34.
FUNCTIONAL TIMING DIAGRAMS
34.1 T1 Mode
Figure 34-1. Receive-Side D4 Timing
1
FRAME#
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
RFSYNC
RSYNC 1
RSYNC 2
3
RSYNC
RLCLK
4
RLINK
Note 1: RSYNC in the frame mode (IOCR1.5 = 0) and double-wide frame sync is not enabled (IOCR1.6 = 0).
Note 2: RSYNC in the frame mode (IOCR1.5 = 0) and double-wide frame sync is enabled (IOCR1.6 = 1).
Note 3: RSYNC in the multiframe mode (IOCR1.5 = 1).
Note 4: RLINK data (Fs bits) is updated one bit prior to even frames and held for two frames.
Figure 34-2. Receive-Side ESF Timing
FRAME#
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 1
1
RSYNC
RFSYNC
RSYNC
RSYNC
RLCLK
2
3
4
5
RLINK
TLCLK
6
TLINK 7
Note 1: RSYNC in frame mode (IOCR1.4 = 0) and double-wide frame sync is not enabled (IOCR1.6 = 0).
Note 2: RSYNC in frame mode (IOCR1.4 = 0) and double-wide frame sync is enabled (IOCR1.6 = 1).
Note 3: RSYNC in multiframe mode (IOCR1.4 = 1).
Note 4: ZBTSI mode disabled (T1RCR2.2 = 0).
Note 5: RLINK data (FDL bits) is updated one bit time before odd frames and held for two frames.
Note 6: ZBTSI mode is enabled (T1RCR2.2 = 1).
Note 7: RLINK data (Z bits) is updated one bit time before odd frames and held for four frames.
234 of 265
2
3
4
5
DS2156
Figure 34-3. Receive-Side Boundary Timing (with elastic store disabled)
RCLK
CHANNEL 23
RSER
CHANNEL 24
CHANNEL 1
LSB
LSB MSB
F
MSB
RSYNC
RFSYNC
RSIG
CHANNEL 23
A
B C/A D/B
CHANNEL 24
A
B C/A D/B
CHANNEL 1
A
RCHCLK
RCHBLK1
RLCLK
RLINK 2
Note 1: RCHBLK is programmed to block channel 24.
Note 2: Shown is RLINK/RLCLK in the ESF framing mode.
Figure 34-4. Receive-Side 1.544MHz Boundary Timing (with Elastic Store
Enabled)
RSYSCLK
CHANNEL 23
RSER
CHANNEL 24
CHANNEL 1
LSB
LSB MSB
F
MSB
RSYNC1
RMSYNC
2
RSYNC
RSIG
CHANNEL 23
A
B C/A D/B
CHANNEL 24
A
B C/A D/B
RCHCLK
RCHBLK
3
Note 1: RSYNC is in the output mode (IOCR1.4 = 0).
Note 2: RSYNC is in the input mode (IOCR1.4 = 1).
Note 3: RCHBLK is programmed to block channel 24.
235 of 265
CHANNEL 1
A
DS2156
Figure 34-5. Receive-Side 2.048MHz Boundary Timing (with Elastic Store
Enabled)
RSYSCLK
RSER
RSYNC
CHANNEL 31
1
CHANNEL 32
CHANNEL 1
LSB
LSB MSB
2
RMSYNC
3
RSYNC
A
RSIG
CHANNEL 31
B C/A D/B
A
CHANNEL 1
CHANNEL 32
B C/A D/B
RCHCLK
RCHBLK
4
Note 1: RSER data in channels 1, 5, 9, 13, 17, 21, 25, and 29 are forced to 1.
Note 2: RSYNC is in the output mode (IOCR1.4 = 0).
Note 3: RSYNC is in the input mode (IOCR1.4 = 1).
Note 4: RCHBLK is forced to 1 in the same channels as RSER (see Note 1).
Note 5: The F-bit position is passed through the receive-side elastic store.
Figure 34-6. Transmit-Side D4 Timing
FRAME#
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
1
TSYNC
TSSYNC
2
TSYNC
3
TSYNC
TLCLK
TLINK
4
Note 1: TSYNC in the frame mode (IOCR1.2 = 0) and double-wide frame sync is not enabled (IOCR1.1 = 0).
Note 2: TSYNC in the frame mode (IOCR1.2 = 0) and double-wide frame sync is enabled (IOCR1.1 = 1).
Note 3: TSYNC in the multiframe mode (IOCR1.2 = 1).
Note 4: TLINK data (Fs bits) is sampled during the F-bit position of even frames for insertion into the outgoing T1 stream when enabled through
T1TCR1.2.
236 of 265
DS2156
Figure 34-7. Transmit-Side ESF Timing
FRAME#
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 1
2
3
4
5
TSYNC1
TSSYNC
TSYNC
2
3
TSYNC
TLCLK
4
TLINK
TLCLK
5
TLINK
6
Note 1: TSYNC in frame mode (IOCR1.2 = 0) and double-wide frame sync is not enabled (IOCR1.3 = 0).
Note 2: TSYNC in frame mode (IOCR1.2 = 0) and double-wide frame sync is enabled (IOCR1.3 = 1).
Note 3: TSYNC in multiframe mode (IOCR1.2 = 1).
Note 4: TLINK data (FDL bits) sampled during the F-bit time of odd frame and inserted into the outgoing T1 stream if enabled through TCR1.2.
Note 5: ZBTSI mode is enabled (T1TCR2.1 = 1).
Note 6: TLINK data (Z bits) sampled during the F-bit time of frames 1, 5, 9, 13, 17, and 21 and inserted into the outgoing stream if enabled
through T1TCR1.2.
Figure 34-8. Transmit-Side Boundary Timing (with Elastic Store Disabled)
TCLK
CHANNEL 1
LSB
TSER
F
CHANNEL 2
MSB
LSB MSB
LSB MSB
TSYNC1
TSYNC2
CHANNEL 1
TSIG
D/B
A
B
CHANNEL 2
C/A
D/B
TCHCLK
TCHBLK 3
TLCLK
TLINK
4
DON'T CARE
Note 1: TSYNC is in the output mode (IOCR1.1 = 1).
Note 2: TSYNC is in the input mode (IOCR1.1 = 0).
Note 3: TCHBLK is programmed to block channel 2.
Note 4: Shown is TLINK/TLCLK in the ESF framing mode.
237 of 265
A
B
C/A
D/B
DS2156
Figure 34-9. Transmit-Side 1.544MHz Boundary Timing (with Elastic Store
Enabled)
TSYSCLK
CHANNEL 23
CHANNEL 24
LSB MSB
TSER
CHANNEL 1
LSB
F
MSB
TSSYNC
CHANNEL 23
TSIG
A
B
CHANNEL 24
C/A D/B
A
B
CHANNEL 1
C/A D/B
A
TCHCLK
TCHBLK 1
Note 1: TCHBLK is programmed to block channel 24 (if the TPCSI bit is set, then the signaling data at TSIG is ignored during channel 24).
Figure 34-10. Transmit-Side 2.048MHz Boundary Timing (with Elastic Store
Enabled)
TSYSCLK
CHANNEL 31
TSER
1
CHANNEL 32
LSB MSB
CHANNEL 1
LSB
F
4
TSSYNC
CHANNEL 31
TSIG
A
B
CHANNEL 32
C/A D/B
A
B
CHANNEL 1
C/A D/B
A
TCHCLK
TCHBLK 2,3
Note 1: TSER data in channels 1, 5, 9, 13, 17, 21, 25, and 29 is ignored.
Note 2: TCHBLK is programmed to block channel 31 (if the TPCSI bit is set, then the signaling data at TSIG will be ignored).
Note 3: TCHBLK is forced to 1 in the same channels as TSER is ignored (see Note 1).
Note 4: The F-bit position for the T1 frame is sampled and passed through the transmit-side elastic store into the MSB bit position of channel 1.
(Normally, the transmit-side formatter overwrites the F-bit position unless the formatter is programmed to pass through the F-bit
position.)
238 of 265
DS2156
34.2 E1 Mode
Figure 34-11. Receive-Side Timing
1
FRAME#
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
RFSYNC
RSYNC
1
RSYNC
2
RLCLK
RLINK
3
4
Note 1: RSYNC in frame mode (IOCR1.5 = 0).
Note 2: RSYNC in multiframe mode (IOCR1.5 = 1).
Note 3: RLCLK is programmed to output just the Sa bits.
Note 4: RLINK always outputs all five Sa bits as well as the rest of the receive data stream.
Note 5: This diagram assumes the CAS MF begins in the RAF frame.
Figure 34-12. Receive-Side Boundary Timing (with Elastic Store Disabled)
RCLK
CHANNEL 32
CHANNEL 1
RSER
LSB
Si
1
A
CHANNEL 2
Sa4 Sa5 Sa6 Sa7 Sa8 MSB
RSYNC
RFSYNC
CHANNEL 32
RSIG
A
B
CHANNEL 1
C
D
Note 4
RCHCLK
RCHBLK
1
RLCLK
RLINK
2
Sa4 Sa5 Sa6 Sa7 Sa8
Note 1: RCHBLK is programmed to block channel 1.
Note 2: RLCLK is programmed to mark the Sa4 bit in RLINK.
Note 3: Shown is a RNAF frame boundary.
Note 4: RSIG normally contains the CAS multiframe alignment nibble (0000) in channel 1.
239 of 265
CHANNEL 2
A
B
DS2156
Figure 34-13. Receive-Side Boundary Timing, RSYSCLK = 1.544MHz (Elastic
Store Enabled)
RSYSCLK
CHANNEL 23/31
1
RSER
CHANNEL 24/32
CHANNEL 1/2
LSB
LSB MSB
F
MSB
RSYNC2
RMSYNC
3
RSYNC
RCHCLK
RCHBLK
4
Note 1: Data from the E1 channels 1, 5, 9, 13, 17, 21, 25, and 29 is dropped (channel 2 from the E1 link is mapped to channel 1 of the T1 link,
etc.) and the F-bit position is added (forced to on 1).
Note 2: RSYNC in the output mode (IOCR1.4 = 0).
Note 3: RSYNC in the input mode (IOCR1.4 = 1).
Note 4: RCHBLK is programmed to block channel 24.
Figure 34-14. Receive-Side Boundary Timing, RSYSCLK = 2.048MHz (Elastic
Store Enabled)
RSYSCLK
CHANNEL 31
RSER
CHANNEL 32
LSB MSB
CHANNEL 1
LSB MSB
1
RSYNC
RMSYNC
RSYNC
2
RSIG
A
CHANNEL 31
C
B
D
A
CHANNEL 32
C
B
D
CHANNEL 1
Note 4
RCHCLK
RCHBLK
3
Note 1: RSYNC is in the output mode (IOCR1.4 = 0).
Note 2: RSYNC is in the input mode (IOCR1.4 = 1).
Note 3: RCHBLK is programmed to block channel 1.
Note 4: RSIG normally contains the CAS multiframe alignment nibble (0000) in channel 1.
240 of 265
DS2156
Figure 34-15. Receive IBO Channel Interleave Mode Timing
FRAMER #1, CHANNEL #1
RSYNC
1
RSER
F2 C32
RSIG1
F2 C32
F1 C1
F1 C1
F2 C1
F1 C2
F2 C1
F1 C2
F2 C2
F2 C2
RSER2
F3 32
F4 32
F1 C1
F2 C1
F3 C1
F4 C1
F1 C2
F2 C2
F3 C2
F4 C2
RSIG2
F3 C32
F4 C32
F1 C1
F2 C1
F3 C1
F4 C1
F1 C2
F2 C2
F3 C2
F4 C2
RSER3
RSIG3
F5
C32
F5
C32
F6
C32
F7
C32
F6
C32
F8
C32
F7
C32
F8
C32
F1
C1
F1
C1
F2
C1
F2
C1
F3
C1
F3
C1
F4
C1
F4
C1
F5
C1
F5
C1
F6
C1
F6
C1
F7
C1
F8
C1
F7
C1
F8
C1
F1
C2
F1
C2
F2
C2
F2
C2
F3
C2
F3
C2
F4
C2
F4
C2
F5
C2
F6
C2
F5
C2
F7
C2
F6
C2
F8
C2
F7
C2
F8
C2
BIT LEVEL DETAIL (4.096MHz bus configurtation)
RSYSCLK
4
RSYNC
FRAMER2, CHANNEL 32
RSER
FRAMER2, CHANNEL 32
RSIG
FRAMER2, CHANNEL 1
FRAMER 1, CHANNEL 1
LSB MSB
LSB MSB
A
B
C
FRAMER2, CHANNEL 1
FRAMER 1, CHANNEL 1
D
A
B
Note 1: 4.096MHz bus configuration.
Note 2: 8.192MHz bus configuration.
Note 3: 16.384MHz bus configuration.
Note 4: RSYNC is in the input mode (IOCR1.4 = 0).
241 of 265
C
LSB
D
A
B
C
D
DS2156
Figure 34-16. Receive IBO Frame Interleave Mode Timing
FRAMER #1, CHANNELS 1 through 32
RSYNC
1
RSER
F2
F1
F2
F1
RSIG1
F2
F1
F2
F1
RSER2
F3
RSIG2
F4
F3
RSER3
F5
RSIG3
F5
F4
F6
F7
F6
F8
F7
F1
F8
F1
F2
F2
F1
F2
F3
F4
F1
F2
F3
F4
F1
F2
F3
F4
F1
F2
F3
F4
F2
F2
F3
F3
F4
F4
F5
F5
F6
F6
F7
F8
F7
F8
F1
F1
F2
F2
F3
F3
F4
F4
F5
F6
F5
F7
F6
F8
F7
F8
BIT LEVEL DETAIL (4.096MHz bus configurtation)
RSYSCLK
4
RSYNC
FRAMER2, CHANNEL 32
RSER
FRAMER2, CHANNEL 32
RSIG
FRAMER1, CHANNEL 2
FRAMER 1, CHANNEL 1
LSB MSB
LSB MSB
A
B
C
FRAMER1, CHANNEL 2
FRAMER 1, CHANNEL 1
D
A
B
Note 1: 4.096MHz bus configuration.
Note 2: 8.192MHz bus configuration.
Note 3: 16.384MHz bus configuration.
Note 4: RSYNC is in the input mode (IOCR1.4 = 0).
242 of 265
C
LSB
D
A
B
C
D
DS2156
Figure 34-17. G.802 Timing, E1 Mode Only
TS #
31 32 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 0 1 2
RSYNC
TSYNC
RCHCLK
TCHCLK
RCHBLK
TCHBLK
RCLK / RSYSCLK
TCLK / TSYSCLK
CHANNEL 25
CHANNEL 26
LSB MSB
RSER / TSER
RCHCLK / TCHCLK
RCHBLK / TCHBLK
Note 1: RCHBLK or TCHBLK programmed to pulse high during time slots 1 through 15, 17 through 25, and bit 1 of time slot 26.
Figure 34-18. Transmit-Side Timing
FRAME#
14 15 16 1
2
3
4
5 6
7
8
9 10 11 12 13 14 15 16 1
1
TSYNC
TSSYNC
TSYNC
TLCLK
TLINK
2
3
3
Note 1: TSYNC in frame mode (IOCR1.2 = 0).
Note 2: TSYNC in multiframe mode (IOCR1.2 = 1).
Note 3: TLINK is programmed to source just the Sa4 bit.
Note 4: This diagram assumes both the CAS MF and the CRC4 MF begin with the TAF frame.
Note 5: TLINK and TLCLK are not synchronous with TSSYNC.
243 of 265
2
3
4
5
6
7
8
9 10
DS2156
Figure 34-19. Transmit-Side Boundary Timing (Elastic Store Disabled)
TCLK
CHANNEL 1
LSB
TSER
Si
1
A
CHANNEL 2
Sa4 Sa5 Sa6 Sa7 Sa8 MSB
LSB MSB
TSYNC1
TSYNC2
CHANNEL 1
TSIG
CHANNEL 2
D
A
B
C
D
TCHCLK
TCHBLK 3
TLCLK
TLINK
4
4
DON'T CARE
DON'T CARE
Note 1: TSYNC is in the output mode (IOCR1.1 = 1).
Note 2: TSYNC is in the input mode (IOCR1.1 = 0).
Note 3: TCHBLK is programmed to block channel 2.
Note 4: TLINK is programmed to source the Sa4 bit.
Note 5: The signaling data at TSIG during channel 1 is normally overwritten in the transmit formatter with the CAS MF alignment nibble (0000).
Note 6: Shown is a TNAF frame boundary.
Figure 34-20. Transmit-Side Boundary Timing, TSYSCLK = 1.544MHz
(Elastic Store Enabled)
TSYSCLK
CHANNEL 23
1
TSER
CHANNEL 24
LSB MSB
TSSYNC
TCHCLK
TCHBLK
CHANNEL 1
LSB
2
Note 1: The F-bit position in the TSER data is ignored.
Note 2: TCHBLK is programmed to block channel 24.
244 of 265
F
MSB
DS2156
Figure 34-21. Transmit-Side Boundary Timing, TSYSCLK = 2.048MHz (Elastic
Store Enabled)
TSYSCLK
CHANNEL 31
TSER
CHANNEL 32
1
CHANNEL 1
LSB MSB
LSB
F
4
TSSYNC
CHANNEL 31
TSIG
A
B
CHANNEL 32
C
D
A
TCHCLK
TCHBLK 2,3
Note 1: TCHBLK is programmed to block channel 31.
245 of 265
B
CHANNEL 1
C
D
A
DS2156
Figure 34-22. Transmit IBO Channel Interleave Mode Timing
FRAMER #1, CHANNEL #1
TSSYNC
1
TSER
F2 C32
TRSIG 1
F2 C32
F1 C1
F1 C1
F2 C1
F1 C2
F2 C2
F2 C1
F1 C2
F2 C2
TSER2
F3 32
F4 32
F1 C1
F2 C1
F3 C1
F4 C1
F1 C2
F2 C2
F3 C2
F4 C2
TSIG2
F3 C32
F4 C32
F1 C1
F2 C1
F3 C1
F4 C1
F1 C2
F2 C2
F3 C2
F4 C2
TSER3
TSIG3
F5
C32
F5
C32
F6
C32
F7
C32
F6
C32
F8
C32
F7
C32
F8
C32
F1
C1
F1
C1
F2
C1
F2
C1
F3
C1
F3
C1
F4
C1
F4
C1
F5
C1
F5
C1
F6
C1
F7
C1
F6
C1
F8
C1
F7
C1
F8
C1
F1
C2
F1
C2
F2
C2
F2
C2
F3
C2
F3
C2
F4
C2
F4
C2
F5
C2
F6
C2
F5
C2
F7
C2
F6
C2
F8
C2
F7
C2
F8
C2
BIT LEVEL DETAIL (4.096MHz bus configurtation)
TSYSCLK
4
TSYNC
FRAMER2, CHANNEL 32
TSER
FRAMER2, CHANNEL 32
TSIG
FRAMER2, CHANNEL 1
FRAMER 1, CHANNEL 1
LSB MSB
LSB MSB
A
B
C
FRAMER2, CHANNEL 1
FRAMER 1, CHANNEL 1
D
A
B
Note 1: 4.096MHz bus configuration.
Note 2: 8.192MHz bus configuration.
Note 3: 16.384MHz bus configuration.
Note 4: TSYNC is in input mode.
246 of 265
C
LSB
D
A
B
C
D
DS2156
Figure 34-23. Transmit IBO Frame Interleave Mode Timing
FRAMER #1, CHANNELS 1 through 32
TSSYNC
1
TSER
TSIG1
TSER2
F2
F1
F2
F1
F2
F1
F2
F1
F3
TSIG2
F4
F3
TSER3
F5
TSIG3
F5
F4
F6
F7
F6
F8
F7
F1
F8
F1
F2
F2
F1
F2
F3
F4
F1
F2
F3
F4
F1
F2
F3
F4
F1
F2
F3
F4
F2
F2
F3
F3
F4
F4
F5
F5
F6
F6
F7
F8
F7
F8
F1
F1
F2
F2
F3
F3
F4
F4
F5
F6
F5
F7
F6
F8
F7
F8
BIT LEVEL DETAIL (4.096MHz bus configurtation)
TSYSCLK
4
TSYNC
FRAMER2, CHANNEL 32
TSER
FRAMER2, CHANNEL 32
TSIG
FRAMER1, CHANNEL 2
FRAMER 1, CHANNEL 1
LSB MSB
LSB MSB
A
B
C
FRAMER1, CHANNEL 2
FRAMER 1, CHANNEL 1
D
A
B
Note 1: 4.096MHz bus configuration.
Note 2: 8.192MHz bus configuration.
Note 3: 16.384MHz bus configuration.
Note 4: TSYNC is in input mode.
247 of 265
C
LSB
D
A
B
C
D
DS2156
35.
OPERATING PARAMETERS
ABSOLUTE MAXIMUM RATINGS
Voltage Range on Any Pin Relative to Ground
Operating Temperature Range for DS2156L
Operating Temperature Range for DS2156LN
Storage Temperature Range
Soldering Temperature
-1.0V to +6.0V
0°C to +70°C
-40°C to +85°C
-55°C to +125°C
See IPC/JEDEC J-STD-020A
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation
sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.
THERMAL CHARACTERISTICS
PARAMETER
SYMBOL
Ambient Temperature
CONDITIONS
MIN
(Note 1)
-40°C
TYP
MAX
UNITS
+85°C
Junction Temperature
+125°C
Theta-JA (θJA) in Still Air for
100-Pin LQFP
(Note 2)
+32°C/W
THETA-JA (θJA) vs. AIRFLOW
FORCED AIR
(meters per second)
0
1
2.5
THETA-JA (θJA)
100-PIN LQFP
+32°C/W
+27°C/W
+24°C/W
RECOMMENDED DC OPERATING CONDITIONS
(TA = 0°C to +70°C for DS2156L; TA = -40°C to +85°C for DS2156LN.)
PARAMETER
Logic 1
Logic 0
Supply
SYMBOL
VIH
VIL
VDD
CONDITIONS
(Note 3)
MIN
TYP
MAX
UNITS
2.0
-0.3
3.135
3.3
5.5
+0.8
3.465
V
V
V
MIN
TYP
MAX
UNITS
CAPACITANCE
(TA = +25°C)
PARAMETER
Input Capacitance
Output Capacitance
SYMBOL
CONDITIONS
CIN
5
pF
COUT
7
pF
248 of 265
DS2156
DC CHARACTERISTICS
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS2156L; VDD = 3.3V ±5%, TA = -40°C to +85°C for DS2156LN.)
PARAMETER
SYMBOL
Supply Current
Input Leakage
Output Leakage
Output Current (2.4V)
Output Current (0.4V)
IDD
IIL
ILO
IOH
IOL
CONDITIONS
(Note 4)
(Note 5)
(Note 6)
MIN
TYP
MAX
75
-1.0
-1.0
+4.0
+1.0
1.0
UNITS
mA
µA
µA
mA
mA
Note 1: The package is mounted on a four-layer JEDEC standard test board.
Note 2: Theta-JA (θJA) is the junction to ambient thermal resistance, when the package is mounted on a four-layer JEDEC standard test board.
Note 3: Applies to RVDD, TVDD, and DVDD.
Note 4: TCLK = TCLKI = RCLKI = TSYSCLK = RSYSCLK = MCLK = 1.544MHz; outputs open-circuited.
Note 5: 0.0V < VIN < VDD
Note 6: Applied to INT when tri-stated.
249 of 265
DS2156
36.
AC TIMING PARAMETERS AND DIAGRAMS
Capacitive test loads are 40pF for bus signals, 20pF for all others.
36.1 Multiplexed Bus AC Characteristics
AC CHARACTERISTICS: MULTIPLEXED PARALLEL PORT (MUX = 1)
(Figure 36-1, Figure 36-2, and Figure 36-3)
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS2156L; VDD = 3.3V ±5%, TA = -40°C to +85°C for DS2156LN.)
PARAMETER
Cycle Time
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
tCYC
200
ns
Pulse Width, DS Low or RD High
PWEL
100
ns
Pulse Width, DS High or RD Low
PWEH
100
ns
Input Rise/Fall Times
tR, tF
R/W Hold Time
tRWH
10
ns
R/W Setup Time Before DS High
CS Setup Time Before DS, WR, or RD
Active
CS Hold Time
tRWS
50
ns
tCS
20
ns
tCH
0
ns
Read Data Hold Time
tDHR
10
Write Data Hold Time
tDHW
0
ns
Muxed Address Valid to AS or ALE Fall
tASL
15
ns
Muxed Address Hold Time
Delay Time DS, WR, or RD to AS or ALE
Rise
Pulse Width AS or ALE High
tAHL
10
ns
tASD
20
ns
PWASH
tASED
30
10
ns
ns
Output Data Delay Time from DS or RD
tDDR
20
Data Setup Time
tDSW
50
Delay Time, AS or ALE to DS, WR or RD
250 of 265
20
50
80
ns
ns
ns
ns
DS2156
Figure 36-1. Intel Bus Read Timing (BTS = 0/MUX = 1)
t CYC
ALE
WR
PW
t ASD
t ASD
RD
PWEL
t ASED
PWEH
t CH
t CS
CS
t ASL
AD0–AD7
t DHR
t DDR
t AHL
Figure 36-2. Intel Bus Write Timing (BTS = 0/MUX = 1)
t CYC
ALE
RD
WR
PW
t ASD
t ASED
t ASD
PWEL
PWEH
t CH
t CS
CS
AD0–AD7
t ASL
t DHW
t AHL
251 of 265
t DSW
DS2156
Figure 36-3. Motorola Bus Timing (BTS = 1/MUX = 1)
PWASH
AS
DS
PWEH
t ASED
t ASD
PWEL
t CYC
t RWS
t RWH
R/W
AD0–AD7
(read)
t DDR
t ASL
t AHL
t DHR
t CH
t CS
CS
AD0–AD7
(write)
t DSW
t ASL
t DHW
t AHL
252 of 265
DS2156
36.2 Nonmultiplexed Bus AC Characteristics
AC CHARACTERISTICS: NONMULTIPLEXED PARALLEL PORT (MUX = 0)
(Figure 36-4, Figure 36-5, Figure 36-6, and Figure 36-7)
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS2156L; VDD = 3.3V ±5%, TA = -40°C to +85°C; for DS2156LN.)
PARAMETER
Setup Time for A0 to A7, Valid to CS
Active
Setup Time for CS Active to Either RD,
WR, or DS Active
Delay Time from Either RD or DS Active
to Data Valid
Hold Time from Either RD, WR, or DS
Inactive to CS Inactive
Hold Time from CS Inactive to Data Bus
Tri-State
Wait Time from Either WR or DS Active
to Latch Data
Data Setup Time to Either WR or DS
Inactive
Data Hold Time from Either WR or DS
Inactive
Address Hold from Either WR or DS
Inactive
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
t1
0
ns
t2
0
ns
t3
75
ns
t4
0
t5
5
t6
75
ns
t7
10
ns
t8
10
ns
t9
10
ns
253 of 265
ns
20
ns
DS2156
Figure 36-4. Intel Bus Read Timing (BTS = 0/MUX = 0)
ADDRESS VALID
A0 to A7
D0 to D7
DATA VALID
t5
5ns (min) / 20ns (max)
WR
t1
CS
0ns (min)
0ns (min)
t2
t3
t4
0ns (min)
75ns (max)
RD
Figure 36-5. Intel Bus Write Timing (BTS = 0/MUX = 0)
ADDRESS VALID
A0 to A7
D0 to D7
t7
RD
10ns (min)
t1
CS
0ns (min)
WR
t8
10ns (min)
0ns (min)
t2
t6
75ns (min)
254 of 265
t4
0ns (min)
DS2156
Figure 36-6. Motorola Bus Read Timing (BTS = 1/MUX = 0)
A0 to A7
ADDRESS VALID
DATA VALID
D0 to D7
5ns (min) / 20ns (max)
R/W
t1
CS
0ns (min)
t5
0ns (min)
t2
t3
t4
0ns (min)
75ns (max)
DS
Figure 36-7. Motorola Bus Write Timing (BTS = 1/MUX = 0)
ADDRESS VALID
A0 to A7
D0 to D7
10ns (min)
R/W
t7 t8
t1
CS
0ns (min)
DS
10ns (min)
0ns (min)
t2
t6
75ns (min)
255 of 265
t4
0ns (min)
DS2156
36.3 Receive-Side AC Characteristics
AC CHARACTERISTICS: RECEIVE SIDE
(Figure 36-8, Figure 36-9, and Figure 36-10)
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS2156L; VDD = 3.3V ±5%, TA = -40°C to +85°C for DS2156LN.)
PARAMETER
RCLKO Period
RCLKO Pulse Width
RCLKO Pulse Width
SYMBOL
MIN
TYP
(Note 1)
200
488 (E1)
648 (T1)
0.5 tLP
0.5 tLP
tLH
(Note 1)
(Note 2)
200
150
0.5 tLP
tLL
(Note 2)
150
(Note 3)
0.5 tLP
488 (E1)
648 (T1)
0.5 tCP
0.5 tCP
648
(Note 4)
488
ns
(Note 5)
244
ns
(Note 6)
122
(Note 7)
61
0.5 tSP
0.5 tSP
tLP
tLH
tLL
RCLKI Period
tCP
RCLKI Pulse Width
tCH
tCL
RSYSCLK Period
CONDITIONS
20
20
tSP
MAX
UNITS
ns
ns
ns
ns
ns
RSYNC Setup to RSYSCLK Falling
tSH
tSL
tSU
20
20
20
RSYNC Pulse Width
tPW
50
ns
RPOSI/RNEGI Setup to RCLKI Falling
RPOSI/RNEGI Hold From RCLKI
Falling
RSYSCLK, RCLKI Rise and Fall Times
Delay RCLKO to RPOSO, RNEGO Valid
Delay RCLK to RSER, RDATA, RSIG,
RLINK Valid
Delay RCLK to RCHCLK, RSYNC,
RCHBLK, RFSYNC, RLCLK
Delay RSYSCLK to RSER, RSIG Valid
Delay RSYSCLK to RCHCLK,
RCHBLK, RMSYNC, RSYNC
tSU
20
ns
tHD
20
ns
RSYSCLK Pulse Width
ns
ns
ns
tR, tF
tDD
22
50
ns
ns
tD1
50
ns
tD2
50
ns
tD3
22
ns
tD4
22
ns
Note 1: Jitter attenuator enabled in the receive path.
Note 2: Jitter attenuator disabled or enabled in the transmit path.
Note 3: RSYSCLK = 1.544MHz
Note 4: RSYSCLK = 2.048MHz
Note 5: RSYSCLK = 4.096MHz
Note 6: RSYSCLK = 8.192MHz
Note 7: RSYSCLK = 16.384MHz
256 of 265
DS2156
Figure 36-8. Receive-Side Timing
RCLK
t D1
RSER / RDATA / RSIG
1ST FRAME BIT
t D2
RSYNC 1
t D2
RFSYNC / RMSYNC
t D2
RCHCLK
t D2
RCHBLK
t D2
RLCLK 2
t D1
RLINK (T1MODE)
4
RLINK (E1 MODE)
Sa4 to Sa8
Bit Position
Note 1: RSYNC is in the output mode.
Note 2: Shown is RLINK/RLCLK in the ESF framing mode.
Note 3: No relationship between RCHCLK and RCHBLK and other signals is implied.
Note 4: RLCLK only pulses high during Sa bit locations as defined in the E1RCR2 register.
257 of 265
DS2156
Figure 36-9. Receive-Side Timing, Elastic Store Enabled
t SL
tF
tR
RSYSCLK
t SH
t SP
t D3
SEE NOTE 3
RSER / RSIG
t D4
RCHCLK
t D4
RCHBLK
t
D4
RMSYNC
RSYNC
RSYNC
t D4
1
t HD
t SU
2
Note 1: RSYNC is in the output mode.
Note 2: RSYNC is in the input mode.
Note 3: F-bit when MSTRREG.1 = 0, MSB of TS0 when MSTREG.1 = 1.
Figure 36-10. Receive Line Interface Timing
t LL
RCLKO
t LH
t LP
t DD
RPOSO, RNEGO
tR
t CL
tF
RCLKI
t CP
t SU
RPOSI, RNEGI
t HD
258 of 265
t CH
DS2156
36.4 Transmit AC Characteristics
AC CHARACTERISTICS: TRANSMIT SIDE
(Figure 36-11, Figure 36-12, and Figure 36-13)
(VDD = 3.3V ±5%, TA = -40°C to +85°C for DS2156L; VDD = 3.3V ±5%, TA = 0°C to +70°C for DS2156LN)
PARAMETER
SYMBOL
TCLK Period
tCP
TCLK Pulse Width
tCH
tCL
TCLKI Period
tLP
TCLKI Pulse Width
tLH
tLL
CONDITIONS
MIN
20
20
20
20
(Note 8)
(Note 9)
(Note 10)
(Note 11)
(Note 12)
TYP (E1)
488 (E1)
648 (T1)
0.5 tCP
0.5 tCP
488 (E1)
648 (T1)
0.5 tLP
0.5 tLP
648
448
244
122
61
0.5 tSP
0.5 tSP
MAX
UNITS
ns
ns
ns
ns
TSYSCLK Period
tSP
TSYSCLK Pulse Width
tSP
20
20
TSYNC or TSSYNC Setup to TCLK or
TSYSCLK Falling
tSU
20
ns
TSYNC or TSSYNC Pulse Width
tPW
50
ns
tSU
20
ns
tHD
20
ns
tHD
20
ns
TSER, TSIG, TDATA, TLINK, TPOSI,
TNEGI Setup to TCLK, TSYSCLK,
TCLKI Falling
TSER, TSIG, TDATA, TLINK Hold
from TCLK or TSYSCLK Falling
TPOSI, TNEGI Hold from TCLKI
Falling
TCLK, TCLKI or TSYSCLK Rise and
Fall Times
Delay TCLKO to TPOSO, TNEGO
Valid
Delay TCLK to TESO, UT-UTDO
Valid
Delay TCLK to TCHBLK, TCHCLK,
TSYNC, TLCLK
Delay TSYSCLK to TCHCLK,
TCHBLK
ns
ns
tR, tF
25
ns
tDD
50
ns
tD1
50
ns
tD2
50
ns
tD3
22
ns
Note 8: TSYSCLK = 1.544MHz
Note 9: TSYSCLK = 2.048MHz
Note 10: TSYSCLK = 4.096MHz
Note 11: TSYSCLK = 8.192MHz
Note 12: TSYSCLK = 16.384MHz
259 of 265
DS2156
Figure 36-11. Transmit-Side Timing
t CP
t CL
tF
tR
t CH
TCLK
t D1
TESO
t SU
TSER / TSIG /
TDATA
t HD
t D2
TCHCLK
t D2
TCHBLK
t D2
TSYNC1
t HD
t SU
TSYNC2
5
TLCLK
t D2
t HD
TLINK
t SU
Note 1: TSYNC is in the output mode (IOCR1.1 = 1).
Note 2: TSYNC is in the input mode (IOCR1.1 = 0).
Note 3: TSER is sampled on the falling edge of TCLK when the transmit-side elastic store is disabled.
Note 4: TCHCLK and TCHBLK are synchronous with TCLK when the transmit-side elastic store is disabled.
Note 5: In E1 mode, TLINK is only sampled during Sa bit locations as defined in E1TCR2; no relationship between TLCLK/TLINK and TSYNC
is implied.
260 of 265
DS2156
Figure 36-12. Transmit-Side Timing, Elastic Store Enabled
t SP
t SL
tF
tR
t SH
TSYSCLK
t SU
TSER
t D3
t HD
TCHCLK
t D3
TCHBLK
t SU
t HD
TSSYNC
Note 1: TSER is only sampled on the falling edge of TSYSCLK when the transmit-side elastic store is enabled.
Note 2: TCHCLK and TCHBLK are synchronous with TSYSCLK when the transmit-side elastic store is enabled.
Figure 36-13. Transmit Line Interface Timing
TCLKO
TPOSO, TNEGO
t DD
tR
t LP
t LL
tF
TCLKI
t SU
TPOSI, TNEGI
t HD
261 of 265
t LH
DS2156
36.5 UTOPIA Transmit AC Characteristics
PARAMETER
SYMBOL
Setup Time UT-ENB, UT-SOC,
UT-ADDRx, UT-DATAx to UT-CLK
Hold Time UT-ENB, UT-SOC,
UT-ADDRx, UT-DATAx from UT-CLK
Output Delay UT-CLAV, UT-2CLAV from
UT-CLK
CONDITIONS
MIN
TYP
MAX
UNITS
tT5
10
ns
tT6
1
ns
td
UT-CLAV High-Z from UT-CLK
20
ns
25
ns
MAX
UNITS
36.6 UTOPIA Receive AC Characteristics
PARAMETER
SYMBOL
Setup Time UR-ENB, UR-ADDRx to URCLK
Hold Time UR-ENB, UR-ADDRx from URCLK
Output Delay UR-CLAV, UR-DATAx, URSOC from UR-CLK
UR-CLAV, UR-DATA, UR-SOC
High-Z from UR-CLK
CONDITIONS
MIN
TYP
tT5
10
ns
tT6
1
ns
td
Figure 36-14. UTOPIA Interface Setup and Hold Times
CLOCK
SIGNAL
tT5
INPUT SETUP TO CLOCK
tT6
INPUT HOLD FROM CLOCK
Figure 36-15. UTOPIA Interface Delay Times
CLOCK
SIGNAL
td and tz
262 of 265
20
ns
25
ns
DS2156
37.
REVISION HISTORY
REVISION
011606
110502
DESCRIPTION
Added lead-free packages to Ordering Information. Added
CSBGA package drawing to Section 38: Package
Information.
Original data sheet release.
263 of 265
DS2156
38.
PACKAGE INFORMATION
(The package drawing(s) in this data sheet may not reflect the most current specifications. The package number provided for
each package is a link to the latest package outline information.)
38.1 100-Pin LQFP (56-G5002-000)
264 of 265
DS2156
38.2 100-Ball CSBGA (56-G6008-001)
265 of 265
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No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time.
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