Dallas DS2153Q E1 single-chip transceiver Datasheet

DS2153Q
E1 Single-Chip Transceiver
www.dalsemi.com
ELASTIC
STORES
FRAMER
LONG & SHORT
HAUL LINE
INTERFACE
40
41
42
43
1
2
3
44
39
35
12
34
13
33
14
32
15
31
16
30
17
29
28
36
11
27
37
10
26
9
25
38
24
8
23
7
22
ALE
WR
RLINK
RLCLK
DVSS
RCLK
RCHCLK
RSER
RSYNC
RLOS/LOTC
SYSCLK
4
ACTUAL SIZE OF 44-PIN PLCC
21
DALLAS
DS2153Q
E1 SCT
20
CS
RD
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
TCHCLK
PARALLEL CONTROL
PORT
5
6
FUNCTIONAL BLOCKS
19
Complete E1(CEPT) PCM-30/ISDN-PRI
transceiver functionality
Onboard line interface for clock/data recovery
and waveshaping
32-bit or 128-bit jitter attenuator
Generates line build-outs for both 120-ohm
and 75-ohm lines
Frames to FAS, CAS, and CRC4 formats
Dual onboard two-frame elastic store slip
buffers that can connect to backplanes up to
8.192 MHz
8-bit parallel control port that can be used on
either multiplexed or non-multiplexed buses
Extracts and inserts CAS signaling
Detects and generates Remote and AIS alarms
Programmable output clocks for Fractional
E1, H0, and H12 applications
Fully independent transmit and receive
functionality
Full access to both Si and Sa bits
Three separate loopbacks for testing
Large counters for bipolar and code
violations, CRC4 code word errors, FAS
errors, and E bits
Pin-compatible with DS2151Q T1 SingleChip Transceiver
5V supply; low power CMOS
Industrial grade version (-40°C to +85°C)
available (DS2153QN)
TSER
TCLK
DVDD
TSYNC
TLINK
TLCLK
TCHBLK
TRING
TVDD
TVSS
TTIP
RCHBLK
ACLKI
BTS
RTIP
RRING
RVDD
RVSS
XTAL1
XTAL2
INT1
INT2
PIN ASSIGNMENT
18
FEATURES
DESCRIPTION
The DS2153Q T1 Single-Chip Transceiver (SCT) contains all of the necessary functions for connection
to E1 lines. The onboard clock/data recovery circuitry coverts the AMI/HDB3 E1 waveforms to a NRZ
serial stream. The DS2153 automatically adjusts to E1 22 AWG (0.6 mm) twisted-pair cables from 0 to
1.5 km. The device can generate the necessary G.703 waveshapes for both 75-ohm and 120-ohm cables.
The onboard jitter attenuator (selectable to either 32 bits or 128 bits) can be placed in either the transmit
or receive data paths. The framer locates the frame and multiframe boundaries and monitors the data
stream for alarms. It is also used for extracting and inserting signaling data, Si, and Sa-bit information.
The device contains a set of 71 8-bit internal registers which the user can access to control the operation
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070299
DS2153Q
of the unit. Quick access via the parallel control port allows a single micro to handle many E1 lines. The
device fully meets all of the latest E1 specifications, including ITU G.703, G.704, G.706, G.823, and
I.431 as well as ETSI 300 011, 300 233, TBR 12 and TBR 13.
TABLE OF CONTENTS
1. Introduction
2. Parallel Control Port
3. Control and Test Registers
4. Status and Information Registers
5. Error Count Registers
6. Sa Data Link Control and Operation
7. Signaling Operation
8. Transmit Idle Registers
9. Clock Blocking Registers
10. Elastic Store Operation
11. Additional (Sa) and International (Si) Bit Operation
12. Line Interface Control Function
13. Timing Diagrams, Synchronization Flowchart, and Transmit flow Diagram
14. DC and AC Characteristics
1.0 INTRODUCTION
The analog AMI waveform off of the E1 line is transformer coupled into the RRING and RTIP pins of
the DS2153Q. The device recovers clock and data from the analog signal and passes it through the jitter
attenuation mux to the receive side framer where the digital serial stream is analyzed to locate the framing
pattern. If needed, the receive side elastic store can be enabled in order to absorb the phase and frequency
differences between the recovered E1 data stream and an asynchronous backplane clock which is
provided at the SYSCLK input.
The transmit side of the DS2153Q is totally independent from the receive side in both the clock
requirements and characteristics. The transmit formatter will provide the necessary data overhead for E1
transmission. Once the data stream has been prepared for transmission, it is sent via the jitter attenuation
mux to the waveshaping and line driver functions. The DS2153Q will drive the E1 line from the TTIP
and TRING pins via a coupling transformer.
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DS2153Q
Reader’s Note
This data sheet assumes a particular nomenclature of the E1 operating environment. There are 32 8-bit
timeslots in E1 systems which are numbered 0 to 31. Timeslot 0 is transmitted first and received first.
These 32 timeslots are also referred to as channels with a numbering scheme of 1 to 32. Timeslot 0 is
identical to channel 1, timeslot 1 is identical to channel 2, and so on. Each timeslot (or channel) is made
up of 8 bits which 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. Throughout this data sheet, the following abbreviations will be used:
FAS
CAS
MF
Si
CRC4
CCS
Sa
E-bit
Frame Alignment Signal
Channel Associated Signaling
Multiframe
International Bits
Cyclical Redundancy Check
Common Channel Signaling
Additional bits
CRC4 Error bits
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DS2153Q
DS2153Q BLOCK DIAGRAM Figure 1-1
4 of 52
DS2153Q
PIN DESCRIPTION Table 1-1
PIN
SYMBOL
TYPE
DESCRIPTION
1
2
3
4
AD4
AD5
AD6
AD7
I/O
5
RD (DS)
I
Read Input (Data Strobe).
6
CS
I
Chip Select. Must be low to read or write the port.
7
ALE(AS)
I
Address Latch Enable (Address Strobe). A positive going edge
serves to demultiplex the bus.
8
WR (R/ W )
I
Write Input (Read/Write).
9
RLINK
O
Receive Link Data. Outputs the full receive data stream including
the Sa bits. See Section 13 for timing details.
10
RLCLK
O
Receive Link Clock. 4 kHz to 20 kHz demand clock for the RLINK
output; controlled by RCR2. See Section 13 for timing details.
11
DVSS
-
Digital Signal Ground. 0.0 volts. Should be tied to local ground
plane.
12
RCLK
O
Receive Clock. Recovered 2.048 MHz clock.
13
RCHCLK
O
Receive Channel Clock. 256 kHz clock which pulses high during
the LSB of each channel. Useful for parallel to serial conversion of
channel data. See Section 13 for timing details.
14
RSER
O
Receive Serial Data. Received NRZ serial data, updated on rising
edges of RCLK or SYSCLK.
15
RSYNC
I/O
Receive Sync. An extracted pulse, one RCLK wide, is output at this
pin which identifies either frame (RCR1.6=0) or multiframe
boundaries (RCR1.6=1). If the elastic store is enabled via the
RCR2.1, then this pin can be enabled to be an input via RCR1.5 at
which a frame boundary pulse is applied. See Section 13 for timing
details.
16
RLOS/LOTC
O
Receive Loss of Sync/Loss of Transmit Clock. A dual function
output. If TCR2.0=0, will toggle high when the synchronizer is
searching for the E1 frame and multiframe; if TCR2.0=1, will toggle
high if the TCLK pin has not toggled for 5 µs.
17
SYSCLK
I
System Clock. 1.544 MHz or 2.048 MHz clock. Only used when
the elastic store functions are enabled via RCR2.1. Should be tied
low in applications that do not use the elastic store. If tied high for at
least 100 µs, will force all output pins (including the parallel port) to
3-state.
Address/Data Bus. An 8-bit multiplexed address/data bus.
5 of 52
DS2153Q
PIN
SYMBOL
TYPE
DESCRIPTION
18
RCHBLK
O
Receive Channel Block. A user-programmable output that can be
forced high or low during any of the 32 E1 channels. Useful for
blocking clocks to a serial UART or LAPD controller in
applications where not all E1 channels are used, such as Fractional
E1, 384 kbps service (H0), 1920 kbps (H12), or ISDN-PRI. Also
useful for locating individual channels in drop-and-insert
applications. See Section 13 for timing details.
19
ACLKI
I
Alternate Clock Input. Upon a receive carrier loss, the clock
applied at this pin (normally 2.048 MHz) will be routed to the
RCLK pin. If no clock is routed to this pin, then it should be tied to
DVSS VIA A 1 kΩ resistor.
20
BTS
I
Bus Type Select. 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 parenthesis ().
21
22
RTIP
RRING
-
Receive Tip and Ring. Analog inputs for clock recovery circuitry;
connects to a 1:1 transformer (see Section 12 for details).
23
RVDD
-
Receive Analog Positive Supply. 5.0 volts. Should be tied to
DVDD and TVDD pins.
24
RVSS
-
Receive Signal Ground. 0.0 volts. Should be tied to local ground
plane.
25
26
XTAL1
XTAL2
-
Crystal Connections. A pullable 8.192 MHz crystal must be
applied to these pins. See Section 12 for crystal specifications.
27
INT1
O
Receive Alarm Interrupt 1. Flags host controller during alarm
conditions defined in Status Register 1. Active low, open drain
output.
28
INT2
O
Receive Alarm Interrupt 2. Flags host controller during conditions
defined in Status Register 2. Active low, open drain output.
29
TTIP
-
Transmit Tip. Analog line driver output; connects to a step-up
transformer (see Section 12 for details).
30
TVSS
-
Transmit Signal Ground. 0.0 volts. Should be tied to local ground
plane.
31
TVDD
-
Transmit Analog Positive Supply. 5.0 volts. Should be tied to
DVDD and RVDD pins.
32
TRING
-
Transmit Ring. Analog line driver outputs; connects to a step-up
transformer (see Section 12 for details).
6 of 52
DS2153Q
PIN
SYMBOL
TYPE
DESCRIPTION
33
TCHBLK
O
Transmit Channel Block. A user-programmable output that can be
forced high or low during any of the 32 E1 channels. Useful for
blocking clocks to a serial UART or LAPD controller in
applications where not all E1 channels are used, such as Fractional
E1, 384 kbps service (H0), 1920 kbps (H12), or ISDN-PRI. Also
useful for locating individual channels in drop-and-insert
applications. See Section 13 for timing details.
34
TLCLK
O
Transmit Link Clock. 4 kHz to 20 kHz demand clock for the
TLINK input; controlled by TCR2. See Section 13 for timing
details.
35
TLINK
I
Transmit Link Data. If enabled, this pin will be sampled on the
falling edge of TCLK to insert the Sa bits See Section 13 for timing
details.
36
TSYNC
I/O
Transmit Sync. A pulse at this pin will establish either frame or
multiframe boundaries for the DS2153Q. Via TCR1.1, the DS2153Q
can be programmed to output either a frame or multiframe pulse at
this pin. See Section 13 for timing details.
37
DVDD
-
Digital Positive Supply. 5.0 volts. Should be tied to RVDD and
TVDD pins.
38
TCLK
I
Transmit Clock. 2.048 MHz primary clock. Needed for proper
operation of the parallel control port.
39
TSER
I
Transmit Serial Data. Transmit NRZ serial data, sampled on the
falling edge of TCLK.
40
TCHCLK
O
Transmit Channel Clock. 256 kHz clock which pulses high during
the LSB of each channel. Useful for parallel to serial conversion of
channel data. See Section 13 for timing details.
41
42
43
44
AD0
AD1
AD2
AD3
I/O
Address/Data Bus. A 8-bit multiplexed address/data bus.
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DS2153Q
DS2153Q REGISTER MAP
ADDRESS R/W
REGISTER NAME
ADDRESS
R/W
REGISTER NAME
00
R
BPV or Code Violation
Count 1
20
R/W Transmit Align Frame
01
R
BPV or Code Violation
Count 2
21
R/W Transmit Non-Align Frame
02
R
CRC4 Count 1/FAS Error
Count 1
22
R/W Transmit Channel Blocking 1
03
R
CRC4 Error Count 2
23
R/W Transmit Channel Blocking 2
04
R
E-Bit Count 1/FAS Error
Count 2
24
R/W Transmit Channel Blocking 3
05
R
E-Bit Count 2
25
R/W Transmit Channel Blocking 4
06
R
Status 1
26
R/W Transmit Idle 1
07
R
Status 2
27
R/W Transmit Idle 2
08
R/W Receive Information
28
R/W Transmit Idle 3
10
R/W Receive Control 1
29
R/W Transmit Idle 4
11
R/W Receive Control 2
2A
R/W Transmit Idle Definition
12
R/W Transmit Control 1
2B
R/W Receive Channel Blocking 1
13
R/W Transmit Control 2
2C
R/W Receive Channel Blocking 2
14
R/W Common Control 1
2E
R/W Receive Channel Blocking 3
15
R/W Test 1
2E
R/W Receive Channel Blocking 4
16
R/W Interrupt Mask 1
2F
17
R/W Interrupt Mask 2
18
R/W Line Interface Control
19
R/W Test 2
1A
R/W Common Control 2
1B
R/W Common Control 3
1E
R
Synchronizer Status
1F
R
Receive Non-Align Frame
8 of 52
R
Receive Align Frame
DS2153Q
ADDRESS R/W
REGISTER NAME
ADDRESS
R/W
REGISTER NAME
30
R
Receive Signaling 1
40
R/W Transmit Signaling 1
31
R
Receive Signaling 2
41
R/W Transmit Signaling 2
32
R
Receive Signaling 3
42
R/W Transmit Signaling 3
33
R
Receive Signaling 4
43
R/W Transmit Signaling 4
34
R
Receive Signaling 5
44
R/W Transmit Signaling 5
35
R
Receive Signaling 6
45
R/W Transmit Signaling 6
36
R
Receive Signaling 7
46
R/W Transmit Signaling 7
37
R
Receive Signaling 8
47
R/W Transmit Signaling 8
38
R
Receive Signaling 9
48
R/W Transmit Signaling 9
39
R
Receive Signaling 10
49
R/W Transmit Signaling 10
3A
R
Receive Signaling 11
4A
R/W Transmit Signaling 11
3B
R
Receive Signaling 12
4B
R/W Transmit Signaling 12
3C
R
Receive Signaling 13
4C
R/W Transmit Signaling 13
3D
R
Receive Signaling 14
4D
R/W Transmit Signaling 14
3E
R
Receive Signaling 15
4E
R/W Transmit Signaling 15
3F
R
Receive Signaling 16
4F
R/W Transmit Signaling 16
Note: the Test Registers 1 and 2 are used only by the factory; these registers must be cleared (set to all 0s)
on power-up initialization to insure proper operation.
2.0 PARALLEL PORT
The DS2153Q is controlled via a multiplexed bidirectional address/data bus by an external
microcontroller or microprocessor. The DS2153Q can operate with either Intel or Motorola bus timing
configurations. If the BTS pin is tied low, Intel timing will be selected; if tied high, Motorola timing will
be selected. All Motorola bus signals are listed in parenthesis (). See the timing diagrams in the AC
Electrical Characteristics for more details. The multiplexed bus on the DS2153Q saves pins because the
address information and data information share the same signal paths. The addresses are presented to the
pins in the first portion of the bus cycle and data will be transferred on the pins during second portion of
the bus cycle. Addresses must be valid prior to the falling edge of ALE(AS), at which time the DS2153Q
latches the address from the AD0 to AD7 pins. Valid write data must be present and held stable during
the later portion of the DS WR pulses. In a read cycle, the DS2153Q outputs a byte of data during the
latter portion of the DS or RD pulses. The read cycle is terminated and the bus returns to a high
impedance state as RD transitions high in Intel timing or as DS transitions low in Motorola timing.
3.0 CONTROL AND TEST REGISTERS
The operation of the DS2153Q is configured via a set of seven registers. Typically, the control registers
are only accessed when the system is first powered up. Once the DS2153Q has been initialized, the
control registers will only need to be accessed when there is a change in the system configuration. There
are two Receive Control Register (RCR1 and RCR2), two Transmit Control Registers (TCR1 and TCR2),
and three Common Control Registers (CCR1, CCR2 and CCR3). Each of the seven registers are
described in this section.
The Test Registers at addresses 15 and 19 hex are used by the factory in testing the DS2153Q. On powerup, the Test Registers should be set to 00 hex in order for the DS2153Q to operate properly.
9 of 52
DS2153Q
RCR1: RECEIVE CONTROL REGISTER 1 (Address=10 Hex)
(MSB)
RSMF
RSM
RSIO
-
-
FRC
SYNCE
(LSB)
RESYNC
SYMBOL
POSITION
NAME AND DESCRIPTION
RSMF
RCR1.7
RSYNC Multiframe Function. Only used if the RSYNC pin is
programmed in the multiframe mode (RCR1.6=1).
0=RSYNC outputs CAS multiframe boundaries
1=RSYNC outputs CRC4 multiframe boundaries
RSM
RCR1.6
RSYNC Mode Select.
0=frame mode (see the timing in Section 13)
1=multiframe mode (see the timing in Section 13)
RSIO
RCR1.5
RSYNC I/O Select.
0=RSYNC is an output (depends on RCR1.6)
1=RSYNC is an input (only valid if elastic store enabled) (note:
this bit must be set to 0 when RCR2.1=0)
-
RCR1.4
Not Assigned. Should be set to 0 when written.
-
RCR1.3
Not Assigned. Should be set to 0 when written.
FRC
RCR1.2
Frame Resync Criteria.
0=resync if FAS received in error 3 consecutive times
1=resync if FAS or bit 2 of non-FAS is received in error 3
consecutive times
SYNCE
RCR1.1
Sync Enable.
0=auto resync enabled
1=auto resync disabled
RESYNC
RCR1.0
Resync. When toggled from low to high, a resync is initiated.
Must be cleared and set again for a subsequent resync.
SYNC/RESYNC CRITERIA Table 3-1
FRAME OR
MULTIFRAME
LEVEL
FAS
SYNC CRITERIA
RESYNC CRITERIA
ITU
SPEC.
FAS present in frames N and N + 2, and Three consecutive incorrect FAS G.706
FAS not present in frame N + 1.
received.
4.1.1
4.1.2
Alternate (RCR1.2=1) the above
criteria is met or three consecutive
incorrect bit 2 of non-FAS received.
CRC4
Two valid MF alignment words found 915 or more CRC4 code words out G.706
within 8 ms.
of 1000 received in error.
4.2
4.3.2
CAS
Valid MF alignment word found and Two consecutive MF alignment
previous time slot 16 contains code words received in error.
other than all 0s.
10 of 52
G.732
5.2
DS2153Q
RCR2: RECEIVE CONTROL REGISTER 2 (Address=11 Hex)
(MSB)
Sa8S
Sa7S
Sa6S
Sa5S
Sa4S
RSCLKM
RESE
(LSB)
-
SYMBOL
POSITION
NAME AND DESCRIPTION
Sa8S
RCR2.7
Sa8 Bit Select. Set to 1 to report the Sa8 bit at the RLINK pin;
set to 0 to not report the Sa8 bit.
Sa7S
RCR2.6
Sa7 Bit Select. Set to 1to report the Sa7 bit at the RLINK pin;
set to 0 to not report the Sa7 bit.
Sa6S
RCR2.5
Sa6 Bit Select. Set to 1 to report the Sa6 bit at the RLINK pin;
set to 0 to not report the Sa6 bit.
Sa5S
RCR2.4
Sa5 Bit Select. Set to 1 to report the Sa5 bit at the RLINK pin;
set to 0 to not report the Sa5 bit.
Sa4S
RCR2.3
Sa4 Bit Select. Set to 1 to report the Sa4 bit at the RLINK pin;
set to 0 to not report the Sa4 bit.
RSCLKM
RCR2.2
Receive Side SYSCLK Mode Select.
0=if SYSCLK is 1.544 MHz
1=if SYSCLK is 2.048 MHz
RESE
RCR2.1
Receive Side Elastic Store Enable.
0=elastic store is bypassed
1=elastic store is enabled
-
RCR2.0
Not Assigned. Should be set to 0 when written.
11 of 52
DS2153Q
TCR1: TRANSMIT CONTROL REGISTER 1 (Address=12 Hex)
(MSB)
-
TFPT
T16S
TUA1
TSiS
TSA1
TSM
(LSB)
TSIO
SYMBOL
POSITION
NAME AND DESCRIPTION
-
TCR1.7
Not Assigned. Should be set to 0 when written to.
TFPT
TCR1.6
Transmit Timeslot 0 Pass Through.
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
T16S
TCR1.5
Transmit Timeslot 16 Data Select.
0=sample timeslot 16 at TSER pin
1=source timeslot 16 from TS1 to TS16 registers
TUA1
TCR1.4
Transmit Unframed All 1s.
0=transmit data normally
1=transmit an unframed all 1’s code at TPOS and TNEG
TSiS
TCR1.3
Transmit International Bit Select.
0=sample Si bits at TSER pin
1=source Si bits from TAF and TNAF registers (in this mode,
TCR1.6 must be set to 0)
TSA1
TCR1.2
Transmit Signaling All 1s.
0=normal operation
1=force timeslot 16 in every frame to all 1s
TSM
TCR1.1
TSYNC Mode Select.
0=frame mode (see the timing in Section 13)
1=CAS and CRC4 multiframe mode (see the timing in Section
13)
TSIO
TCR1.0
TSYNC I/O Select.
0=TSYNC is an input
1=TSYNC is an output
Note: See Figure 13-9 for more details about how the Transmit Control Registers affect the operation of
the DS2153Q.
12 of 52
DS2153Q
TCR2: TRANSMIT CONTROL REGISTER 2 (Address=13 Hex)
(MSB)
Sa8S
Sa7S
Sa6S
Sa5S
Sa4S
-
AEBE
(LSB)
P16F
SYMBOL
POSITION
NAME AND DESCRIPTION
Sa8S
TCR2.7
Sa8 Bit Select. Set to 1 to source the Sa8 bit from the TLINK
pin; set to 0 to not source the Sa8 bit.
Sa7S
TCR2.6
Sa7 Bit Select. Set to 1 to source the Sa7 bit from the TLINK
pin; set to 0 to not source the Sa7 bit.
Sa6S
TCR2.5
Sa6 Bit Select. Set to 1 to source the Sa6 bit from the TLINK
pin; set to 0 to not source the Sa6 bit.
Sa5S
TCR2.4
Sa5 Bit Select. Set to 1 to source the Sa5 bit from the TLINK
pin; set to 0 to not source the Sa5 bit.
Sa4S
TCR2.3
Sa4 Bit Select. Set to 1 to source the Sa4 bit from the TLINK
pin; set to 0 to not source the Sa4 bit.
-
TCR2.2
Not Assigned. Should be set to 0 when written.
AEBE
TCR2.1
Automatic E-Bit Enable.
0=E-bits not automatically set in the transmit direction
1=E-bits automatically set in the transmit direction
P16F
TCR2.0
Function of Pin 16.
0=Receive Loss of Sync (RLOS)
1=Loss of Transmit Clock (LOTC)
13 of 52
DS2153Q
CCR1: COMMON CONTROL REGISTER 1 (Address=14 Hex)
(MSB)
FLB
THDB3
TG802
TCRC4
RSM
RHDB3
RG802
(LSB)
RCRC4
SYMBOL
POSITION
NAME AND DESCRIPTION
FLB
CCR1.7
Framer Loopback.
0=loopback disabled
1=loopback enabled
THDB3
CCR1.6
Transmit HDB3 Enable.
0=HDB3 disabled
1=HDB3 enabled
TG802
CCR1.5
Transmit G.802 Enable. See Section 13 for details.
0=do not force TCHBLK high during bit 1 of timeslot 26
1=force TCHBLK high during bit 1 of timeslot 26
TCRC4
CCR1.4
Transmit CRC4 Enable.
0=CRC4 disabled
1=CRC4 enabled
RSM
CCR1.3
Receive Signaling Mode Select.
0=CAS signaling mode
1=CCS signaling mode
RHDB3
CCR1.2
Receive HDB3 Enable.
0=HDB3 disabled
1=HDB3 enabled
RG802
CCR1.1
Receive G.802 Enable. See Section 13 for details.
0=do not force RCHBLK high during bit 1 of timeslot 26
1=force RCHBLK high during bit 1 of timeslot 26
RCRC4
CCR1.0
Receive CRC4 Enable.
0=CRC4 disabled
1=CRC4 enabled
FRAMER LOOPBACK
When CCR1.7 is set to a 1, the DS2153Q will enter a Framer LoopBack (FLB) mode. This loopback is
useful in testing and debugging applications. In FLB, the DS2153Q will loop data from the transmit side
back to the receive side. When FLB is enabled, the following will occur:
1. data will be transmitted as normal at TTIP and TRING
2. data off the E1 line at RTIP and RRING will be ignored
3. the RCLK output will be replaced with the TCLK input.
14 of 52
DS2153Q
CCR2: COMMON CONTROL REGISTER 2 (Address=1A Hex)
(MSB)
ECUS
VCRFS
AAIS
ARA
RSERC
LOTCMC
RLB
(LSB)
LLB
SYMBOL
POSITION
NAME AND DESCRIPTION
ECUS
CCR2.7
Error Counter Update Select.
0=update error counters once a second
1=update error counters every 62.5 ms (500 frames)
VCRFS
CCR2.6
VCR Function Select.
0=count BiPolar Violations (BPVs)
1=count Code Violations (CVs)
AAIS
CCR2.5
Automatic AIS Generation.
0=disabled
1=enabled
ARA
CCR2.4
Automatic Remote Alarm Generation.
0=disabled
1=enabled
RSERC
CCR2.3
RSER Control.
0=allow RSER to output data as received under all conditions
1=force RSER to 1 under loss of frame alignment conditions
LOTCMC
CCR2.2
Loss of Transmit Clock Mux Control. Determines whether the
transmit side formatter should switch to the ever present RCLK
if the TCLK should fail to transition (see Figure 1.1).
0=do not switch to RCLK if TCLK stops
1=switch to RCLK if TCLK stops
RLB
CCR2.1
Remote Loopback.
0=loopback disabled
1=loopback enabled
LLB
CCR2.0
Local Loopback.
0=loopback disabled
1=loopback enabled
REMOTE LOOPBACK
When CCR2.1 is set to a 1, the DS2153Q will be forced into Remote LoopBack (RLB). In this loopback,
data recovered off of the E1 line from the RTIP and RRING pins will be transmitted back onto the E1 line
(with any BPV’s that might have occurred intact) via the TTIP and TRING pins. Data will continue to
pass through the receive side of the DS2153Q as it would normally and the data at the TSER pin will be
ignored. Data in this loopback will pass through the jitter attenuator. Please see Figure 1.1 for more
details.
15 of 52
DS2153Q
LOCAL LOOPBACK
When CCR2.0 is set to a 1, the DS2153Q will be forced into Local LoopBack (LLB). In this loopback,
data will continue to be transmitted as normal through the transmit side of the SCT. Data being received
at RTIP and RRING will be replaced with the data being transmitted. Data in this loopback will pass
through the jitter attenuator. Please see Figure 1.1 for more details.
AUTOMATIC ALARM GENERATION
When either CCR2.4 or CCR2.5 is set to 1, the DS2153Q monitors the receive side to determine if any of
the following conditions are present: loss of receive frame synchronization, AIS alarm (all 1s) reception,
or loss of receive carrier (or signal). If any one (or more) of the above conditions is present, then the
DS2151Q will either force an AIS alarm (if CCR2.5=1) or a Remote Alarm (CCR2.4=1) to be transmitted
via the TTIP and TRING pins. It is an illegal state to have both CCR2.4 and CCR2.5 set to 1 at the same
time.
CCR3: COMMON CONTROL REGISTER 3 (Address=1B Hex)
(MSB)
TESE
TCBFS
TIRFS
ESR
LIRST
-
TSCLKM
(LSB)
-
SYMBOL
POSITION
NAME AND DESCRIPTION
TESE
CCR3.7
Transmit Elastic Store Enable.
0 = elastic store is disabled
1 = elastic store is enabled
TCBFS
CCR3.6
Transmit Channel Blocking Registers (TCBR) Function
Select.
0=TCBRs define the operation of the TCHBLK output pin
1=TCBRs define which signaling bits are to be inserted
TIRFS
CCR3.5
Transmit Idle Registers (TIR) Function Select.
0=TIRs define in which channels to insert idle code
1=TIRs define in which channels to insert data from RSER
ESR
CCR3.4
Elastic Stores Reset. Setting this bit from a 1 to a 0 will force
the elastic stores to a known depth. Should be toggled after
SYSCLK has been applied and is stable. Must be set and cleared
again for a subsequent reset. Do not leave this bit set high.
LIRST
CCR3.3
Line Interface Reset. Setting this bit from a 0 to a 1 will initiate
an internal reset that affects the slicer, AGC, clock recovery state
machine, and jitter attenuator. Normally this bit is only toggled
on power-up. Must be cleared and set again for a subsequent
reset.
-
CCR3.2
Not Assigned. Should be set to 0 when written.
TSCLKM
CCR3.1
Transmit Backplane Clock Select. Must be set like RCR2.2.
0 = 1.544 MHz
1 = 2.048 MHz
-
CCR3.0
Not Assigned. Should be set to 0 when written.
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DS2153Q
POWER-UP SEQUENCE
On power-up, after the supplies are stable, the DS2153Q should be configured for operation by writing to
all of the internal registers (this includes the Test Registers) since the contents of the internal registers
cannot be predicted on power-up. Next, the LIRST bit should be toggled from 0 to 1 to reset the line
interface circuitry (it will take the DS2153Q about 40 ms to recover from the LIRST bit being toggled).
Finally, after the SYSCLK input is stable, the ESR bit should be toggled from a 0 to a 1 and back to 0
(this step can be skipped if the elastic store is not being used).
4.0 STATUS AND INFORMATION REGISTERS
There is a set of four registers that contain information on the current real time status of the DS2153Q,
Status Register 1 (SR1), Status Register 2 (SR2), Receive Information Register (RIR), and Synchronizer
Status Register (SSR). When a particular event has occurred (or is occurring), the appropriate bit in one
of these four registers will be set to a 1. All of the bits in these registers operate in a latched fashion
(except for the SSR). This means that if an event occurs and a bit is set to a 1 in any of the registers, it
will remain set until the user reads that bit. The bit will be cleared when it is read and it will not be set
again until the event has occurred again or if the alarm is still present.
The user will always precede a read of the SR1, SR2, and RIR registers with a write. The byte written to
the register will inform the DS2153Q which bits the user wishes to read and have cleared. The user will
write a byte to one of these three registers, with a 1 in the bit positions he or she wishes to read and a 0 in
the bit positions he or she does not wish to obtain the latest information on. When a 1 is written to a bit
location, the read register will be updated with current value and it will be cleared. When a 0 is written to
a bit position, the read register will not be updated and the previous value will be held. A write to the
status and information registers will be immediately followed by a read of the same register. The read
result should be logically AND’ed with the mask byte that was just written and this value should be
written back into the same register to insure that bit does indeed clear. This second write step is necessary
because the alarms and events in the status registers occur asynchronously in respect to their access via
the parallel port. This write-read-write 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 DS2153Q with higher-order software languages.
The SSR register operates differently than the other three. It is a read-only register and it reports the status
of the synchronizer in real time. This register is not latched and it is not necessary to precede a read of
this register with a write.
The SR1 and SR2 registers have the unique ability to initiate a hardware interrupt via the INT1 and INT2
pins respectively. Each of the alarms and events in the SR1 and SR2 can be either masked or unmasked
from the interrupt pins via the Interrupt Mask Register 1 (IMR1) and Interrupt Mask Register 2 (IMR2)
respectively.
17 of 52
DS2153Q
RIR: RECEIVE INFORMATION REGISTER (Address=08 Hex)
(MSB)
TESF
TESE
JALT
RESF
RESE
CRCRC
FASRC
(LSB)
CASRC
SYMBOL
POSITION
NAME AND DESCRIPTION
TESF
RIR.7
Transmit Elastic Store Full. Set when the elastic store fills and
a frame is deleted.
TESE
RIR.6
Transmit Elastic Store Empty. Set when the elastic store
empties and a frame is repeated.
JALT
RIR.5
Jitter Attenuator Limit Trip. Set when the jitter attenuator
FIFO reaches to within 4-bits of its limit; useful for debugging
jitter attenuation operation.
RESF
RIR.4
Elastic Store Full. Set when the elastic store buffer fills and a
frame is deleted.
RESE
RIR.3
Elastic Store Empty. Set when the elastic store buffer empties
and a frame is repeated.
CRCRC
RIR.2
CRC Resync Criteria Met. Set when 915/1000 code words are
received in error.
FASRC
RIR.1
FAS Resync Criteria Met. Set when three consecutive FAS
words are received in error.
CASRC
RIR.0
CAS Resync Criteria Met. Set when two consecutive CAS MF
alignment words are received in error.
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DS2153Q
SSR: SYNCHRONIZER STATUS REGISTER (Address=1E Hex)
(MSB)
CSC5
CSC4
CSC3
CSC2
CSC0
FASSA
CASSA
(LSB)
CRC4SA
SYMBOL
POSITION
NAME AND DESCRIPTION
CSC5
SSR.7
CRC4 Sync Counter Bit 5. MSB of the 6-bit counter.
CSC4
SSR.6
CRC4 Sync Counter Bit 4.
CSC3
SSR.5
CRC4 Sync Counter Bit 3.
CSC2
SSR.4
CRC4 Sync Counter Bit 2.
CSC0
SSR.3
CRC4 Sync Counter Bit 0. LSB of the 6-bit counter. The next
to LSB bit is not accessible. This bit will toggle each time the
CRC4 MF search times out at 8 ms.
FASSA
SSR.2
FAS Sync Active. Set while the synchronizer is searching for
alignment at the FAS level.
CASSA
SSR.1
CAS MF Sync Active. Set while the synchronizer is searching
for the CAS MF alignment word.
CRC4SA
SSR.0
CRC4 MF Sync Active. Set while the synchronizer is searching
for the CRC4 MF alignment word.
CRC4 SYNC COUNTER
The CRC4 Sync Counter increments each time the 8 ms CRC4 multiframe search times out. The counter
is cleared when the DS2153Q has successfully obtained synchronization at the CRC4 level. The counter
can also be cleared by disabling the CRC4 mode (CCR1.0=0). This counter is useful for determining the
amount of time the DS2153Q has been searching for synchronization at the CRC4 level. Annex B of
CCITT G.706 suggests that if synchronization at the CRC4 level cannot be obtained within 400 ms, then
the search should be abandoned and proper action taken. The CRC4 Sync Counter will rollover.
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DS2153Q
SR1: STATUS REGISTER 1 (Address=06 Hex)
(MSB)
RSA1
RDMA
RSA0
RSLIP
RUA1
RRA
RCL
(LSB)
RLOS
SYMBOL
POSITION
NAME AND DESCRIPTION
RSA1
SR1.7
Receive Signaling All 1s. Set when the contents of timeslot 16
contains less than three 0s over 16 consecutive frames. This
alarm is not disabled in the CCS signaling mode.
RDMA
SR1.6
Receive Distant MF Alarm. Set when bit 6 of timeslot 16 in
frame 0 has been set for two consecutive multiframes. This
alarm is not disabled in the CCS signaling mode.
RSA0
SR1.5
Receive Signaling All 0s. Set when over a full MF, timeslot 16
contains all 0s.
RSLIP
SR1.4
Receive Elastic Store Slip Occurrence. Set when the elastic
store has either repeated or deleted a frame of data.
RUA1
SR1.3
Receive Unframed All 1s. Set when an unframed all 1s code is
received at RTIP and RRING.
RRA
SR1.2
Receive Remote Alarm. Set when a remote alarm is received at
RTIP and RRING.
RCL
SR1.1
Receive Carrier Loss. Set when 255 consecutive 0s have been
detected at RTIP and RRING.
RLOS
SR1.0
Receive Loss of Sync. Set when the device is not synchronized
to the receive E1 stream.
ALARM CRITERIA Table 4-1
ALARM
SET CRITERIA
CLEAR CRITERIA
CCITT
SPEC.
RSA1
(receive signaling
all 1s)
over 16 consecutive frames (one full over 16 consecutive frames (one G.732
MF) timeslot 16 contains less than three full MF) timeslot 16 contains three 4.2
0s
or more 0s
RSA0
(receive signaling
all 0s)
over 16 consecutive frames (one full over 16 consecutive frames (one G.732
full MF) timeslot 16 contains at 5.2
MF) timeslot 16 contains all 0s
least a single 1
RDMA
(receive distant
multiframe alarm)
bit 6 in timeslot 16 of frame 0 set to 1 for
two consecutive MF
RUA1
(receive unframed
all 1s)
less than three 0s in two frames (512 more than two 0s in two frames O.162
bits)
(512 bits)
1.6.1.2
20 of 52
bit 6 in timeslot 16 of frame 0 set to O.162
0 for a two consecutive MF
2.1.5
DS2153Q
RRA
(receive remote
alarm)
bit 3 of non-align frame set to 1 for three bit 3 of non-align frame set to 0 for O.162
consecutive occasions
three consecutive occasions
2.1.4
RCL
(receive carrier
loss)
255 consecutive 0s received
in 255-bit times, at least 32 1s are G.775
received
SR2: STATUS REGISTER 2 (Address=07 Hex)
(MSB)
RMF
RAF
TMF
SEC
TAF
LOTC
RCMF
(LSB)
TSLIP
SYMBOL
POSITION
NAME AND DESCRIPTION
RMF
SR2.7
Receive CAS Multiframe. Set every 2 ms (regardless if CAS
signaling is enabled or not) on receive multiframe boundaries.
Used to alert the host that signaling data is available.
RAF
SR2.6
Receive Align Frame. Set every 250 ms at the beginning of
align frames. Used to alert the host that Si and Sa bits are
available in the RAF and RNAF registers.
TMF
SR2.5
Transmit Multiframe. Set every 2 µs (regardless if CRC4 is
enabled) on transmit multiframe boundaries. Used to alert the
host that signaling data needs to be updated.
SEC
SR2.4
1-Second Timer. Set on increments of 1 second based on
RCLK. If CCR2.7=1, then this bit will be set every 62.5 ms
instead of once a second.
TAF
SR2.3
Transmit Align Frame. Set every 250 µs at the beginning of
align frames. Used to alert the host that the TAF and TNAF
registers need to be updated.
LOTC
SR2.2
Loss of Transmit Clock. Set when the TCLK pin has not
transitioned for one channel time (or 3.9 µs). Will force pin 16
high if enabled via TCR2.0. Based on RCLK.
RCMF
SR2.1
Receive CRC4 Multiframe. Set on CRC4 multiframe
boundaries; will continue to be set every 2 ms on an arbitrary
boundary if CRC4 is disabled.
TSLIP
SR2.0
Transmit Elastic Store Slip. Set when the elastic store has
either repeated or deleted a frame of data.
21 of 52
DS2153Q
IMR1: INTERRUPT MASK REGISTER1 (Address=16 Hex)
(MSB)
RSA1
RDMA
RSA0
RSLIP
RUA1
RRA
SYMBOL
POSITION
NAME AND DESCRIPTION
RSA1
IMR1.7
Receive Signaling All 1s.
0=interrupt masked
1=interrupt enabled
RDMA
IMR1.6
Receive Distant MF Alarm.
0=interrupt masked
1=interrupt enabled
RSA0
IMR1.5
Receive Signaling All 0s.
0=interrupt masked
1=interrupt enabled
RSLIP
IMR1.4
Receive Elastic Store Slip Occurrence.
0=interrupt masked
1=interrupt enabled
RUA1
IMR1.3
Receive Unframed All 1s.
0=interrupt masked
1=interrupt enabled
RRA
IMR1.2
Receive Remote Alarm.
0=interrupt masked
1=interrupt enabled
RCL
IMR1.1
Receive Carrier Loss.
0=interrupt masked
1=interrupt enabled
RLOS
IMR1.0
Receive Loss of Sync.
0=interrupt masked
1=interrupt enabled
22 of 52
RCL
(LSB)
RLOS
DS2153Q
IMR2: INTERRUPT MASK REGISTER 2 (Address=17 Hex)
(MSB)
RMF
RAF
TMF
SEC
TAF
LOTC
SYMBOL
POSITION
RMF
IMR2.7
Receive CAS Multiframe.
0=interrupt masked
1=interrupt enabled
RAF
IMR2.6
Receive Align Frame.
0=interrupt masked
1=interrupt enabled
TMF
IMR2.5
Transmit Multiframe.
0=interrupt masked
1=interrupt enabled
SEC
IMR2.4
1-Second Timer.
0=interrupt masked
1=interrupt enabled
TAF
IMR2.3
Transmit Align Frame.
0=interrupt masked
1=interrupt enabled
LOTC
IMR2.2
Loss Of Transmit Clock.
0=interrupt masked
1=interrupt enabled
RCMF
IMR2.1
Receive CRC4 Multiframe.
0=interrupt masked
1=interrupt enabled
TSLIP
IMR2.0
Transmit Side Elastic Store Slip.
0 = interrupt masked
1 = interrupt enabled
RCMF
(LSB)
TSLIP
NAME AND DESCRIPTION
5.0 ERROR COUNT REGISTERS
There are a set of four counters in the DS2153Q that record bipolar or code violations, errors in the CRC4
SMF code words, E bits as reported by the far end, and word errors in the FAS. Each of these four
counters are automatically updated on either 1-second boundaries (CCR2.7=0) or every 62.5 ms
(CCR2.7=1) as determined by the timer in Status Register 2 (SR2.4). Hence, these registers contain
performance data from either the previous second or the previous 62.5 ms. The user can use the interrupt
from the timer to determine when to read these registers. The user has a full second (or 62.5 ms) to read
the counters before the data is lost.
5.1 BPV or Code Violation Counter
Violation Count Register 1 (VCR1) is the most significant word and VCR2 is the least significant word of
a 16-bit counter that records either BiPolar Violations (BPVs) or Code Violations (CVs). If CCR2.6=0,
23 of 52
DS2153Q
then the VCR counts bipolar violations. Bipolar violations are defined as consecutive marks of the same
polarity. In this mode, if the HDB3 mode is set for the receive side via CCR1.2, then HDB3 code words
are not counted as BPVs. If CCR2.6=1, then the VCR counts code violations as defined in CCITT O.161.
Code violations are defined as consecutive bipolar violations of the same polarity. In most applications,
the DS2153Q 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 will not rollover. The bit error rate on an E1 line would have to be
greater than 10**-2 before the VCR would saturate.
VCR1: UPPER BIPOLAR VIOLATION COUNT REGISTER 1 (Address=00 Hex)
VCR2: LOWER BIPOLAR VIOLATION COUNT REGISTER 2 (Address=01 Hex)
(MSB)
V15
V14
V13
V12
V11
V10
V9
(LSB)
V8
V6
V5
V4
V3
V2
V1
V0
V7
SYMBOL
POSITION
V15
VCR1.7
MSB of the 16-bit bipolar or code violation count
V0
VCR2.0
LSB of the 16-bit bipolar or code violation count
VCR1
VCR2
NAME AND DESCRIPTION
5.2 CRC4 Error Counter
CRC4 Count Register 1 (CRCCR1) is the most significant word and CRCCR2 is the least significant
word of a 10-bit counter that records word errors in the Cyclic Redundancy Check 4 (CRC4). Since the
maximum CRC4 count in a 1-second period is 1000, this counter cannot saturate. The counter is disabled
during loss of sync at either the FAS or CRC4 level; it will continue to count if loss of multiframe sync
occurs at the CAS level.
CRCCR1: CRC4 COUNT REGISTER 1 (Address=02 Hex)
CRCCR2: CRC4 COUNT REGISTER 2 (Address=03 Hex)
(MSB)
(note 1)
(note 1)
(note 1)
(note 1)
(note 1)
(note 1)
CRC9
(LSB)
CRC8
CRCCR1
CRC7
CRC6
CRC5
CRC4
CRC3
CRC2
CRC1
CRC0
SYMBOL
POSITION
NAME AND DESCRIPTION
CRC9
CRCCR1.1
MSB of the 10-bit CRC4 error count
CRC0
CRCCR2.0
LSB of the 10-bit CRC4 error count
CRCCR2
NOTES:
1. The upper 6 bits of CRCCR1 at address 02 are the most significant bits of the 12-bit FAS error
counter.
5.3 E-Bit Counter
E-bit Count Register 1 (EBCR1) is the most significant word and EBCR2 is the least significant word of
a 10-bit counter that records Far End Block Errors (FEBE) as reported in the first bit of frames 13 and 15
24 of 52
DS2153Q
on E1 lines running with CRC4 multiframe. These count registers will increment once each time the
received E-bit is set to 0. Since the maximum E-bit count in a 1-second period is 1000, this counter
cannot saturate. The counter is disabled during loss of sync at either the FAS or CRC4 level; it will
continue to count if loss of multiframe sync occurs at the CAS level.
EBCR1: E-BIT COUNT REGISTER 1 (Address=04 Hex)
EBCR2: E-BIT COUNT REGISTER 2 (Address=05 Hex)
(MSB)
(note 1)
(note 1)
(note 1)
(note 1)
(note 1)
(note 1)
EB7
EB6
EB5
EB4
EB3
EB2
SYMBOL
POSITION
NAME AND DESCRIPTION
EB9
EBCR1.1
MSB of the 10-bit E-Bit count
EB0
EBCR2.0
LSB of the 10-bit E-Bit count
EB9
(LSB)
EB8
EBCR1
EB1
EB0
EBCR2
NOTES:
1. The upper 6 bits of EBCR1 at address 04 are the least significant bits of the 12-bit FAS error counter.
5.4 FAS Bit Error Counter
FAS Count Register 1 (FASCR1) is the most significant word and FASCR2 is the least significant word
of a 12-bit counter that records word errors in the Frame Alignment Signal in timeslot 0. This counter is
disabled during loss of synchronization conditions, (RLOS = 1). Since the maximum FAS word error
count in a 1-second period is 4000, this counter cannot saturate.
FASCR1: FAS BIT COUNT REGISTER 1 (Address=02 Hex)
FASCR2: FAS BIT COUNT REGISTER 2 (Address=04 Hex)
(MSB)
FAS11
FAS10
FAS9
FAS8
FAS7
FAS6
FAS5
FAS4
FAS3
FAS2
FAS1
FAS0
(note 2)
(LSB)
(note 2)
FASCR1
(note 1)
(note 1)
FASCR2
SYMBOL
POSITION
NAME AND DESCRIPTION
FAS11
FASCR1.7
MSB of the 12-bit FAS error count
FAS0
FASCR2.2
LSB of the 12-bit FAS error count
NOTES:
1. The lower 2 bits of FASCR1 at address 02 are the most significant bits of the 10-bit CRC4 error
counter.
2. The lower 2 bits of FASCR2 at address 04 are the most significant bits of the 10-bit E-Bit counter.
6.0 Sa DATA LINK CONTROL AND OPERATION
The DS2153Q provides for access to the proposed E1 performance monitor data link in the Sa bit
positions. The device allows access to the Sa bits either via a set of two internal registers (RNAF and
TNAF) or via two external pins (RLINK and TLINK).
25 of 52
DS2153Q
On the receive side, the Sa bits are always reported in the internal RNAF register (see Section 11 for more
details). All five Sa bits are always output at the RLINK pin. See Section 13 for detailed timing. Via
RCR2, 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.
On the transmit side, the individual Sa bits can be either sourced from the internal TNAF register
(TCR1.6=0) or from the external TLINK pin. Via TCR2, the DS2153Q can be programmed to source any
combination of the additional bits from the TLINK pin. If the user wishes to pass the Sa bits through the
DS2153Q without them being altered, then the device should be set up to source all five Sa bits via the
TLINK pin and the TLINK pin should be tied to the TSER pin. Please see the timing diagrams and the
transmit data flow diagram in Section 13 for examples.
7.0 SIGNALING OPERATION
The Channel Associated Signaling (CAS) bits embedded in the E1 stream can be extracted from the
receive stream and inserted into the transmit stream by the DS2153Q. Each of the 30 channels has four
signaling bits (A/B/C/D) associated with it. The numbers in parenthesis () are the channel associated with
a particular signaling bit. The channel numbers have been assigned as described in the ITU documents.
For example, channel 1 is associated with timeslot 1 and channel 30 is associated with timeslot 31. There
is a set of 16 registers for the receive side (RS1 to RS16) and 16 registers on the transmit side (TS1 to
TS16). The signaling registers are detailed below.
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DS2153Q
RS1 TO RS16: RECEIVE SIGNALING REGISTERS (Address=30 to 3F Hex)
(MSB)
0
(LSB)
X
RS1 (30)
0
0
0
X
Y
X
A(1)
B(1)
C(1)
D(1)
A(16)
B(16)
C(16)
D(16)
RS2 (31)
A(2)
B(2)
C(2)
D(2)
A(17)
B(17)
C(17)
D(17)
RS3 (32)
A(3)
B(3)
C(3)
D(3)
A(18)
B(18)
C(18)
D(18)
RS4 (33)
A(4)
B(4)
C(4)
D(4)
A(19)
B(19)
C(19)
D(19)
RS5 (34)
A(5)
B(5)
C(5)
D(5)
A(20)
B(20)
C(20)
D(20)
RS6 (35)
A(6)
B(6)
C(6)
D(6)
A(21)
B(21)
C(21)
D(21)
RS7 (33)
A(7)
B(7)
C(7)
D(7)
A(22)
B(22)
C(22)
D(22)
RS8 (37)
A(8)
B(8)
C(8)
D(8)
A(23)
B(23)
C(23)
D(23)
RS9 (38)
A(9)
B(9)
C(9)
D(9)
A(24)
B(24)
C(24)
D(24)
RS10 (39)
A(10)
B(10)
C(10)
D(10)
A(25)
B(25)
C(25)
D(25)
RS11 (3A)
A(11)
B(11)
C(11)
D(11)
A(26)
B(26)
C(26)
D(26)
RS12 (3B)
A(12)
B(12)
C(12)
D(12)
A(27)
B(27)
C(27)
D(27)
RS13 (3C)
A(13)
B(13)
C(13)
D(13)
A(28)
B(28)
C(28)
D(28)
RS14 (3D)
A(14)
B(14)
C(14)
D(14)
A(29)
B(29)
C(29)
D(29)
RS15 (3E)
A(15)
B(15)
C(15)
D(15)
A(30)
B(30)
C(30)
D(30)
RS16 (3F)
SYMBOL
POSITION
NAME AND DESCRIPTION
X
RS1.0/1/3
Y
RS1.2
Remote Alarm Bit (integrated and reported in SR1.6)
A(1)
RS2.7
Signaling Bit A for Channel 1
D(30)
RS16.0
Signaling Bit D for Channel 30
Spare Bits
Each Receive Signaling Register (RS1 to RS16) reports the incoming signaling from two timeslots. The
bits in the Receive Signaling Registers are updated on multiframe boundaries so the user can utilize the
Receive Multiframe Interrupt in the Receive Status Register 2 (SR2.7) to know when to retrieve the
signaling bits. The user has a full 2 ms to retrieve the signaling bits before the data is lost. The RS
registers are updated under all conditions. Their validity should be qualified by checking for
synchronization at the CAS level. In CCS signaling mode, RS1 to RS16 can also be used to extract
signaling information. Via the SR2.7 bit, the user will be informed when the signaling registers have been
loaded with data. The user has 2 ms to retrieve the data before it is lost.
27 of 52
DS2153Q
TS1 TO TS16: TRANSMIT SIGNALING REGISTERS (Address=40 to 4F Hex)
(MSB)
0
(LSB)
X
TS1 (40)
0
0
0
X
Y
X
A(1)
B(1)
C(1)
D(1)
A(31)
B(16)
C(16)
D(16)
TS2 (41)
A(2)
B(2)
C(2)
D(2)
A(32)
B(17)
C(17)
D(17)
TS3 (42)
A(3)
B(3)
C(3)
D(3)
A(33)
B(18)
C(18)
D(18)
TS4 (43)
A(4)
B(4)
C(4)
D(4)
A(34)
B(19)
C(19)
D(19)
TS5 (44)
A(5)
B(5)
C(5)
D(5)
A(35)
B(20)
C(20)
D(20)
TS6 (45)
A(6)
B(6)
C(6)
D(6)
A(36)
B(21)
C(21)
D(21)
TS7 (43)
A(7)
B(7)
C(7)
D(7)
A(37)
B(22)
C(22)
D(22)
TS8 (47)
A(8)
B(8)
C(8)
D(8)
A(38)
B(23)
C(23)
D(23)
TS9 (48)
A(9)
B(9)
C(9)
D(9)
A(39)
B(24)
C(24)
D(24)
TS10 (49)
A(10)
B(10)
C(10)
D(10)
A(40)
B(25)
C(25)
D(25)
TS11 (4A)
A(11)
B(11)
C(11)
D(11)
A(41)
B(26)
C(26)
D(26)
TS12 (4B)
A(12)
B(12)
C(12)
D(12)
A(42)
B(27)
C(27)
D(27)
TS13 (4C)
A(13)
B(13)
C(13)
D(13)
A(43)
B(28)
C(28)
D(28)
TS14 (4D)
A(14)
B(14)
C(14)
D(14)
A(44)
B(29)
C(29)
D(29)
TS15 (43)
A(15)
B(15)
C(15)
D(15)
A(45)
B(30)
C(30)
D(30)
TS16 (4F)
SYMBOL
POSITION
NAME AND DESCRIPTION
X
TS1.0/1/3
Y
TS1.2
Remote Alarm Bit
A(1)
TS2.7
Signaling Bit A for Channel 1
D(30)
TS16.0
Signaling Bit D for Channel 30
Spare Bits
Each Transmit Signaling Register (TS1 to TS16) contains the CAS bits for two timeslots that will be
inserted into the outgoing stream if enabled to do so via TCR1.5. On multiframe boundaries, the
DS2153Q will load the values present in the Transmit Signaling Register into an outgoing signaling shift
register that is internal to the device. The user can utilize the Transmit Multiframe bit in Status Register 2
(SR2.5) to know when to update the signaling bits. The bit will be set every 2 ms and the user has 2 ms to
update the TSRs before the old data will be retransmitted.
The TS1 register is special because it contains the CAS multiframe alignment word in its upper nibble.
The upper nibble must always be set to 0000, or else the terminal at the far end will lose multiframe
synchronization. If the user wishes to transmit a multiframe alarm to the far end, then the TS1.2 bit
should be set to a 1. If no alarm is to be transmitted, then the TS1.2 bit should be cleared. The three
remaining bits in TS1 are the spare bits. If they are not used, they should be set to 1. In CCS signaling
mode, TS1 to TS16 can also be used to insert signaling information. Via the SR2.5 bit, the user will be
informed when the signaling registers need to be loaded with data. The user has 2 ms to load the data
before the old data will be retransmitted. Via the CCR3.6 bit, the user has the option to use the Transmit
Channel Blocking Registers (TCBRs) to determine on a channel by channel basis which signaling bits are
28 of 52
DS2153Q
to be inserted via the TSRs (the corresponding bit in the TCBRs=1) and which are to be sourced from the
TSER pin (the corresponding bit in the TCBRs=0). See the Transmit Data Flow diagram in Section 13 for
more details.
8.0 TRANSMIT IDLE REGISTERS
There is a set of five registers in the DS2153Q that can be used to custom tailor the data that is to be
transmitted onto the E1 line, on a channel by channel basis. Each of the 32 E1 channels can be forced to
have a user defined idle code inserted into them.
TIR1/TIR2/TIR3/TIR4: TRANSMIT IDLE REGISTERS (Address=26 to 29 Hex)
(MSB)
CH8
CH2
(LSB)
CH1
CH7
CH6
CH5
CH4
CH3
TIR1 (26)
CH16
CH15
CH14
CH13
CH12
CH11
CH10
CH9
TIR2 (27)
CH24
CH23
CH22
CH21
CH20
CH19
CH18
CH17
TIR3 (28)
CH32
CH31
CH30
CH29
CH28
CH27
CH26
CH25
TIR4 (29)
SYMBOL
POSITION
NAME AND DESCRIPTION
CH32
TIR4.7
Transmit Idle Registers.
0=do not insert the Idle Code into this channel
CH1
TIR1.0
1=insert the Idle Code into this channel
NOTE:
If CCR3.5=1, then a 0 in the TIRs implies that channel data is to be sourced from TSER and a 1 implies
that channel data is to be sourced from the RSER pin.
TIDR: TRANSMIT IDLE DEFINITION REGISTER (Address=2A Hex)
(MSB)
TIDR7
TIDR6
TIDR5
TIDR4
TIDR3
SYMBOL
POSITION
TIDR7
TIDR.7
MSB of the Idle Code
TIDR0
TIDR.0
LSB of the Idle Code
TIDR2
TIDR1
(LSB)
TIDR0
NAME AND DESCRIPTION
Each of the bit positions in the Transmit Idle Registers (TIR1/TIR2/TIR3/TIR4) represent a timeslot in
the outgoing frame. When these bits are set to a 1, the corresponding channel will transmit the Idle Code
contained in the Transmit Idle Definition Register (TIDR). In the TIDR, the MSB is transmitted first. Via
the CCR3.5 bit, the user has the option to use the TIRs to determine on a channel by channel basis, if data
from the RSER pin should be substituted for data from the TSER pin. In this mode, if the corresponding
bit in the TIRs is set to 1, then data will be sourced from the RSER pin. If the corresponding bit in the
TIRs is set to 0, then data for that channel will sourced from the TSER pin. See the Transmit Data Flow
diagram in Section 13 for more details.
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DS2153Q
9.0 CLOCK BLOCKING REGISTERS
The Receive Channel Blocking Registers (RCBR1/RCBR2/RCBR3/RCBR4) and the Transmit Channel
Blocking Registers (TCBR1/TCBR2/TCBR3/TCBR4) control the RCHBLK and TCHBLK pins
respectively. The RCHBLK and TCHCLK 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
TCHCLK pins will be held high during the entire corresponding channel time. See the timing in Section
13 for an example. The TCBRs have an alternate mode of use. Via the CCR3.6 bit, the user has the option
to use the TCBRs to determine on a channel by channel basis, which signaling bits are to be inserted via
the TSRs (the corresponding bit in the TCBRs=1) and which are to be sourced from the TSER pin (the
corresponding bit in the TCBR=0). See the Transmit Data Flow diagram in Section 13 for more details.
RCBR1/RCBR2/RCBR3/RCBR4:
RECEIVE CHANNEL BLOCKING REGISTERS (Address=2B to 2E Hex)
(MSB)
CH8
CH2
(LSB)
CH1
CH7
CH6
CH5
CH4
CH3
RCBR1 (2B)
CH16
CH15
CH14
CH13
CH12
CH11
CH10
CH9
RCBR2 (2C)
CH24
CH23
CH22
CH21
CH20
CH19
CH18
CH17
RCBR3 (2D)
CH32
CH31
CH30
CH29
CH28
CH27
CH26
CH25
RCBR4 (2E)
SYMBOL
POSITION
NAME AND DESCRIPTION
CH32
RCBR4.7
Receive Channel Blocking Registers.
0=force the RCHBLK pin to remain low during this channel
time
CH1
RCBR1.0
1=force the RCHBLK pin high during this channel time
TCBR1/TCBR2/TCBR3/TCBR4:
TRANSMIT CHANNEL BLOCKING REGISTERS (Address=22 to 25 Hex)
(MSB)
CH8
CH2
(LSB)
CH1
CH7
CH6
CH5
CH4
CH3
TCBR1 (22)
CH16
CH15
CH14
CH13
CH12
CH11
CH10
CH9
TCBR2 (23)
CH24
CH23
CH22
CH21
CH20
CH19
CH18
CH17
TCBR3 (24)
CH32
CH31
CH30
CH29
CH28
CH27
CH26
CH25
TCBR4 (25)
SYMBOL
POSITION
NAME AND DESCRIPTION
CH32
TCBR4.7
Transmit Channel Blocking Registers.
0=force the TCHBLK pin to remain low during this channel
time
CH1
TCBR1.0
1=force the TCHBLK pin high during this channel time
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DS2153Q
NOTE:
If CCR3.6=1, then a 0 in the TCBRs implies that signaling data is to be sourced from TSER and a 1
implies that signaling data for that channel is to be sourced from the Transmit Signaling (TS) registers.
See definition below.
TCBR1/TCBR2/TCBR3/TCBR4: DEFINITION WHEN CCR3.6 = 1
(MSB)
CH20
CH17*
(LSB)
CH1*
CH4
CH19
CH3
CH18
CH2
TCBR1
CH24
CH8
CH23
CH7
CH22
CH6
CH21
CH5
TCBR2
CH28
CH12
CH27
CH11
CH26
CH10
CH25
CH9
TCBR3
CH32
CH16
CH31
CH15
CH30
CH14
CH29
CH13
TCBR4
* = CH1 and CH17 should be set to 1 to allow the internal TS1 register to create the CAS Multiframe
Alignment Word and Spare/Remote Alarm bits.
10.0 ELASTIC STORE OPERATION
The DS2153Q has an onboard two-frame (512 bits) elastic store. This elastic store can be enabled via
RCR2.1. If the elastic store is enabled (RCR2.1=1), then the user must provide either a 1.544 MHz
(RCR2.2=0) or 2.048 MHz (RCR2.2=1) clock at the SYSCLK pin. If the elastic store is enabled, then the
user has the option of either providing a frame sync at the RSYNC pin (RCR1.5=1) or having the
RSYNC pin provide a pulse on frame or multiframe boundaries (RCR1.5=0). If the user wishes to obtain
pulses at the frame boundary, then RCR1.6 must be set to 0, and if the user wishes to have pulses occur at
the multiframe boundary, then RCR1.6 must be set to 1. If the user selects to apply a 1.544 MHz clock to
the SYSCLK pin, then every fourth channel will be deleted and the F-bit position inserted (forced to 1).
Hence channels 1, 5, 9, 13, 17, 21, 25, and 29 (timeslots 0, 4, 8, 12, 16, 20, 24, and 28) will be deleted.
Also, in 1.544 MHz applications, the RCHBLK output will not be active in channels 25 through 32 (or in
other words, RCBR4 is not active). See Section 13 for more details. If the 512-bit elastic buffer either
fills or empties, a controlled slip will occur. If the buffer empties, then a full frame of data (256 bits) will
be repeated at RSER and the SR1.4 and RIR.3 bits will be set to a 1. If the buffer fills, then a full frame of
data will be deleted and the SR1.4 and RIR.4 bits will be set to a 1.
11.0 ADDITIONAL (Sa) AND INTERNATIONAL (Si) BIT OPERATION
The DS2153Q provides for access to both the Additional (Sa) and International (Si) bits. On the receive
side, the RAF and RNAF registers will always report the data as it received in the Additional and
International bit locations. The RAF and RNAF registers are updated with the setting of the Receive
Align Frame bit in Status Register 2 (SR2.6). The host can use the SR2.6 bit to know when to read the
RAF and RNAF registers. It has 250 µs 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 2 (SR2.3). The host can use the SR2.3 bit to know when to update the
TAF and TNAF registers. It has 250 µs to update the data or else the old data will be retransmitted. Data
in the Si bit position will be overwritten if either the DS2153Q is programmed: (1) to source the Si bits
from the TSER pin, (2) in the CRC4 mode, or (3) have automatic E-bit insertion enabled. Data in the Sa
bit position will be overwritten if any of the TCR2.3 to TCR2.7 bits are set to 1. Please see the register
descriptions for TCR1 and TCR2 and the Transmit Data Flow diagram in Section 13 for more details.
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DS2153Q
RAF: RECEIVE ALIGN FRAME REGISTER (Address=2F Hex)
(MSB)
Si
0
0
1
1
SYMBOL
POSITION
Si
RAF.7
International Bit.
0
RAF.6
Frame Alignment Signal Bit.
0
RAF.5
Frame Alignment Signal Bit.
1
RAF.4
Frame Alignment Signal Bit.
1
RAF.3
Frame Alignment Signal Bit.
0
RAF.2
Frame Alignment Signal Bit.
1
RAF.1
Frame Alignment Signal Bit.
1
RAF.0
Frame Alignment Signal Bit.
0
1
(LSB)
1
NAME AND DESCRIPTION
RNAF: RECEIVE NON-ALIGN FRAME REGISTER (Address=1F Hex)
(MSB)
Si
1
A
Sa4
Sa5
Sa6
SYMBOL
POSITION
NAME AND DESCRIPTION
Si
RNAF.7
International Bit.
1
RNAF.6
Frame Non-Alignment Signal Bit.
A
RNAF.5
Remote Alarm.
Sa4
RNAF.4
Additional Bit 4.
Sa5
RNAF.3
Additional Bit 5.
Sa6
RNAF.2
Additional Bit 6.
Sa7
RNAF.1
Additional Bit 7.
Sa8
RNAF.0
Additional Bit 8.
32 of 52
Sa7
(LSB)
Sa8
DS2153Q
TAF: TRANSMIT ALIGN FRAME REGISTER (Address=20 Hex)
(MSB)
Si
0
0
1
1
SYMBOL
POSITION
Si
TAF.7
International Bit.
0
TAF.6
Frame Alignment Signal Bit.
0
TAF.5
Frame Alignment Signal Bit.
1
TAF.4
Frame Alignment Signal Bit.
1
TAF.3
Frame Alignment Signal Bit.
0
TAF.2
Frame Alignment Signal Bit.
1
TAF.1
Frame Alignment Signal Bit.
1
TAF.0
Frame Alignment Signal Bit.
0
1
(LSB)
1
NAME AND DESCRIPTION
TNAF: TRANSMIT NON-ALIGN FRAME REGISTER (Address=21 Hex)
(MSB)
Si
1
A
Sa4
Sa5
Sa6
SYMBOL
POSITION
Si
TNAF.7
International Bit.
1
TNAF.6
Frame Non-Alignment Signal Bit.
A
TNAF.5
Remote Alarm.
Sa4
TNAF.4
Additional Bit 4.
Sa5
TNAF.3
Additional Bit 5.
Sa6
TNAF.2
Additional Bit 6.
Sa7
TNAF.1
Additional Bit 7.
Sa8
TNAF.0
Additional Bit 8.
Sa7
(LSB)
Sa8
NAME AND DESCRIPTION
12.0 LINE INTERFACE FUNCTIONS
The line interface function in the DS2153Q contains three sections: (1) the receiver which handles clock
and data recovery, (2) the transmitter which waveshapes and drives the E1 line, and (3) the jitter
attenuator. Each of these three sections is controlled by the Line Interface Control Register (LICR), which
is described below.
33 of 52
DS2153Q
LICR: LINE INTERFACE CONTROL REGISTER (Address=18 Hex)
(MSB)
L2
L1
L0
EGL
JAS
JABDS
DJA
(LSB)
TPD
LICR
SYMBOL
POSITION
NAME AND DESCRIPTION
LB2
LICR.7
Line Build Out Bit 2. Transmit waveshape setting; see Table
12.2.
LB1
LICR.6
Line Build Out Bit 1. Transmit waveshape setting; see Table
12.2.
LB0
LICR.5
Line Build Out Bit 0. Transmit waveshape setting; see Table
12.2.
EGL
LICR.4
Receive Equalizer Gain Limit.
0 = -12 dB
1 = -30 dB
JAS
LICR.3
Jitter Attenuator Select.
0=place the jitter attenuator on the receive side
1=place the jitter attenuator on the transmit side
JABDS
LICR.2
Jitter Attenuator Buffer Depth Select .
0=128 bits
1=32 bits (use for delay sensitive applications)
DJA
LICR.1
Disable Jitter Attenuator.
0=jitter attenuator enabled
1=jitter attenuator disabled
TPD
LICR.0
Transmit Power Down.
0=normal transmitter operation
1=powers down the transmitter and 3-states the TTIP and
TRING pins
12.1 Receive Clock and Data Recovery
The DS2153Q contains a digital clock recovery system. See the DS2153Q Block Diagram in Section 1
and Figure 12.1 for more details. The DS2153Q couples to the receive E1 shielded twisted pair or COAX
via a 1:1 transformer. See Table 12.3 for transformer details. The DS2153Q automatically adjusts to the
E1 signal being received at the RTIP and RRING pins and can handle E1 twisted pair cables of 0.6 mm
(22 AWG) from 0 to 1.5 KM in length. The crystal attached at the XTAL1 and XTAL2 pins is multiplied
by 4 via an internal PLL and fed to the clock recovery system. The clock recovery system uses both edges
of the clock from the PLL circuit to form a 32 times oversampler which is used to recover the clock and
data. This oversampling technique offers outstanding jitter tolerance (see Figure 12.2).
Normally, the clock that is output at the RCLK pin is the recovered clock from the E1 AMI/HDB3
waveform presented at the RTIP and RRING inputs. When no AMI signal is present at RTIP and RRING,
a Receive Carrier Loss (RCL) condition will occur and the RCLK can be sourced from either the ACLKI
34 of 52
DS2153Q
pin or from the crystal attached to the XTAL1 and XTAL2 pins. The DS2153Q will sense the ACLKI pin
to determine if a clock is present. If no clock is applied to the ACLKI pin, then it should be tied to RVSS
to prevent the device from falsely sensing a clock. See Table 12.1. If the jitter attenuator is either placed
in the transmit path or is disabled, the RCLK output can exhibit short high cycles of the clock. This is due
to the highly oversampled digital clock recovery circuitry. If the jitter attenuator is placed in the receive
path (as is the case in most applications), the jitter attenuator restores the RCLK to being close to 50%
duty cycle. Please see the Receive AC Timing Characteristics in Section 14 for more details.
SOURCE OF RCLK UPON RCL Table 12-1
ACLKI PRESENT?
RECEIVE SIDE JITTER
ATTENUATOR
TRANSMIT SIDE JITTER
ATTENUATOR
yes
ACLKI via the jitter attenuator
ACLKI
no
centered crystal
TCLK via the jitter attenuator
12.2 Transmit Waveshaping and Line Driving
The DS2153Q uses a set of laser-trimmed delay lines along with a precision Digital-to-Analog Converter
(DAC) to create the waveforms that are transmitted onto the E1 line. The waveforms created by the
DS2153Q meet the ITU specifications. See Figure 12.3. The user will select which waveform is to be
generated by properly programming the L2/L1/L0 bits in the Line Interface Control Register (LICR). The
DS2153Q can set up in a number of various configurations depending on the application. See Table 12.2
and Figure 12.1.
LINE BUILD OUT SELECT IN LICR Table 12-2
L2
0
L1
0
L0
0
0
0
1
0
1
0
APPLICATION
75-ohm normal
TRANSFORMER
1:1.15 step-up
RETURN LOSS
NM
Rt
0 ohms
120-ohm normal
1:1.15 step-up
NM
0 ohms
0
75-ohm normal with
protection resistors
1:1.15 step-up
NM
8.2
ohms
1
1
120-ohm normal with
protection resistors
1:1.15 step-up
NM
8.2
ohms
1
0
0
75-ohm with high return loss
1:1.15 step-up
21 dB
27 ohms
1
1
0
75-ohm with high return loss
1:1.36 step-up
21 dB
18 ohms
1:1.36 step-up
21 dB
27 ohms
1
0
0
120-ohm with high return loss
NM=Not Meaningful
Due to the nature of the design of the transmitter in the DS2153Q, very little jitter (less then 0.00 5UIpp
broadband from 10 Hz to 100 kHz) is added to the jitter present on TCLK. Also, the waveforms that they
create are independent of the duty cycle of TCLK. The transmitter in the DS2153Q couples to the E1
transmit shielded twisted pair or COAX via a 1:1.15 or 1:1.36 step up transformer as shown in Figure
12.1. In order for the devices to create the proper waveforms, this transformer used must meet the
specifications listed in Table 12.3.
35 of 52
DS2153Q
TRANSFORMER SPECIFICATIONS Table 12-3
SPECIFICATION
RECOMMENDED VALUE
Turns Ratio
1:1 (receive) and 1:1.15 or 1:1.36 (transmit) ±5%
Primary Inductance
600 µH minimum
Leakage Inductance
1.0 µH maximum
Interwinding Capacitance
60 pF maximum
DC Resistance
1.2 ohms maximum
12.3 Jitter Attenuator
The DS2153Q contains an onboard jitter attenuator that can be set to a depth of either 32 or 128 bits via
the JABDS bit in the Line Interface Control Register (LICR). 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 12.4. The jitter attenuator can be placed in
either the receive path or the transmit path by appropriately setting or clearing the JAS bit in the LICR.
Also, the jitter attenuator can be disabled (in effect, removed) by setting the DJA bit in the LICR. In order
for the jitter attenuator to operate properly, a crystal with the specifications listed in Table 12.4 below
must be connected to the XTAL1 and XTAL2 pins.
The jitter attenuator divides the clock provided by the 8.192 MHz crystal at the XTAL1 and XTAL2 pins
to create an output clock that contains very little jitter. Onboard circuitry will pull the crystal (by
switching in or out load capacitance) to keep it long-term averaged to the same frequency as the incoming
E1 signal. If the incoming jitter exceeds either 120 UIpp (buffer depth is 128 bits) or 28 UIpp (buffer
depth is 32 bits), then the DS2153Q will divide the attached crystal by either 3.5 or 4.5 instead of the
normal 4 to keep the buffer from overflowing. When the device divides by either 3.5 or 4.5, it also sets
the Jitter Attenuator Limit Trip (JALT) bit in the Receive Information Register (RIR.5).
CRYSTAL SPECIFICATIONS GUIDELINES Table 12-4
PARAMETER
SPECIFICATION
Parallel Resonant Frequency
8.192 MHz
Mode
Fundamental
Load Capacitance
18 pF to 20 pF (18.5 pF nominal)
Tolerance
±50 ppm
Pullability
CL=10 pF, delta frequency=+175 to +250 ppm
CL=45 pF, delta frequency=-175 to -250 ppm
Effective Series Resistance
30 ohms maximum
Crystal Cut
AT
36 of 52
DS2153Q
DS2153Q EXTERNAL ANALOG CONNECTIONS Figure 12-1
NOTES:
1. All resistor values are ±1%.
2. The Rt resistors are used to increase the transmitter return loss or to protect the device from overvoltage.
3. The Rr resistors are used to terminate the receive E1 line.
4. For 75-ohm termination, Rr=37.5 ohms/for 12- ohm termination Rr=60 ohms.
5. See the separate Application Note for details on how to construct a protected interface.
DS2153Q JITTER TOLERANCE Figure 12-2
37 of 52
DS2153Q
DS2153Q TRANSMIT WAVEFORM TEMPLATE Figure 12-3
DS2153Q JITTER ATTENUATION Figure 12-4
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DS2153Q
13.0 TIMING DIAGRAMS/SYNCHRONIZATION FLOWCHART/TRANSMIT
DATA FLOW DIAGRAM
RECEIVE SIDE TIMING Figure 13-1
NOTES:
1. RSYNC in the frame mode (RCR1.6=0).
2. RSYNC in the multiframe mode (RCR1.6=1).
3. RLCLK is programmed to output just the Sa4 bit.
4. RLINK will always output all five Sa bits as well as the rest of the receive data stream.
5. This diagram assumes the CAS MF begins with the FAS word.
RECEIVE SIDE BOUNDARY TIMING
(WITH ELASTIC STORES DISABLED) Figure 13-2
NOTES:
1. RCHBLK is programmed to block channel 2.
2. RLINK is programmed to output the Sa4 bits.
3. RLINK is programmed to output the SA4 and SA8 bits.
4. RLINK is programmed to output the Sa5 and Sa7 bits.
5. Shown is a non-align frame boundary.
39 of 52
DS2153Q
1.544 MHz BOUNDARY TIMING
WITH ELASTIC STORE(S) ENABLED Figure 13-3
NOTES:
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 1).
2. RSYNC is in the output mode (RCR1.5=0).
3. RSYNC is in the input mode (RCR1.5=1).
4. RCHBLK is programmed to block channel 24.
2.048 MHz BOUNDARY TIMING
WITH ELASTIC STORE(S) ENABLED Figure 13-4
NOTES:
1. RSYNC is in the output mode (RCR1.5=0).
2. RSYNC is in the input mode (RCR1.5=1).
3. RCHBLK is programmed to block channel 1.
40 of 52
DS2153Q
TRANSMIT SIDE TIMING Figure 13-5
NOTES:
1. TSYNC in the frame mode (TCR1.1=0).
2. TSYNC in the multiframe mode (TCR1.1=1).
3. TLINK is programmed to source only the Sa4 bit.
4. This diagram assembles both the CAS MF and the CRC4 begin with the align frame.
TRANSMIT SIDE BOUNDARY TIMING Figure 13-6
NOTES:
1. TSYNC is in the input mode (TCR1.0=0).
2. TSYNC is in the output mode (TCR1.0=1).
3. TCHBLK is programmed to block channel 2.
4. TLINK is programmed to source the Sa4 bits.
5. TLINK is programmed to source the Sa7 and Sa8 bits.
6. Shown is a non-align frame boundary.
7. See Figures 13.3 and 13.4 for details on timing with the transmit side elastic store enabled.
41 of 52
DS2153Q
G.802 TIMING Figure 13-7
NOTE:
1. RCHBLK or TCHBLK is programmed to pulse high during timeslots 1 to 15, 17 to 25, and during bit
1 of timeslot 26.
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DS2153Q
DS2153Q SYNCHRONIZATION FLOWCHART Figure 13-8
43 of 52
DS2153Q
DS2153Q TRANSMIT DATA FLOW Figure 13-9
NOTE:
1. TCLK must be tied to RCLK (or SYSCLK if the elastic store is enabled) and TSYNC must be tied to
RSYNC for data to be properly sourced from RSER.
44 of 52
DS2153Q
ABSOLUTE MAXIMUM RATINGS*
Voltage on Any Pin Relative to Ground
Operating Temperature
Storage Temperature
Soldering Temperature
*
-1.0V to +7.0V
0°C to 70°C (-40°C to +85°C for DS2153QN)
-55°C to +125°C
260°C for 10 seconds
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.
RECOMMENDED DC
OPERATION CONDITIONS
(0°C to 70°C)
(-40°C to +85°C for DS2153QN)
PARAMETER
Logic 1
SYMBOL
VIH
MIN
2.0
Logic 0
VIL
Supply for DS2153Q
Supply for DS2153QN
TYP
MAX
VDD+0.3
UNITS
V
-0.3
+0.8
V
VDD
4.75
5.25
V
1
VDD
4.80
5.25
V
1
CAPACITANCE
(tA=25°C)
PARAMETER
Input Capacitance
SYMBOL
CIN
Output Capacitance
DC
CHARACTERISTICS
NOTES
MIN
COUT
TYP
5
MAX
7
UNITS
pF
NOTES
pF
(0°C to 70°C; VDD=5V ± 5%)
(-40°C to +85°C; VDD=5V +5%/-4% for DS2153QN)
PARAMETER
Supply Current @ 5V
SYMBOL
IDD
MIN
Input Leakage
IIL
-1.0
Output Leakage
ILO
Output Current (2.4V)
IOH
-1.0
mA
Output Current (0.4V)
IOL
+4.0
mA
NOTES:
1. Applies to RVDD, TVDD, and DVDD.
2. TCLK=2.048 MHz.
3. 0.0V < VIN < VDD.
4. Applies to INT1 and INT2 when 3-stated.
45 of 52
TYP
60
MAX
UNITS
mA
NOTES
2
+1.0
µA
3
1.0
µA
4
DS2153Q
AC CHARACTERISTICS (0°C to 70°C; VDD=5V ± 5%)
PARALLEL PORT
(-40°C to +85°C; VDD=5V +5%/-4% for DS2153QN)
PARAMETER
Cycle Time
SYMBOL
tCYC
MIN
250
Pulse Width, DS Low or RD High
PWEL
150
ns
Pulse Width, DS High or RD Low
PWEH
100
ns
Input Rise/Fall Time
tR, tF
R/ W Hold Time
tRWH
10
ns
R/ W Setup Time Before DS High
tRWS
50
ns
tCS
20
ns
CS Hold Time
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
20
ns
Muxed Address Hold Time
tAHL
10
ns
Delay Time DS, WR or RD to AS or
ALE Rise
tASD
25
ns
PWASH
40
ns
tASED
20
ns
tDDR
20
tDSW
80
CS Setup Time Before DS, WR or RD
TYP
MAX
30
UNITS
ns
ns
active
Pulse Width AS or ALE High
Delay Time, AS or ALE to DS, WR or
50
ns
RD
Output Data Delay Time from DS or
100
ns
RD
Data Setup Time
46 of 52
ns
NOTES
DS2153Q
INTEL READ BUS AC TIMING Figure 14-1
INTEL WRITE BUS AC TIMING Figure 14-2
MOTOROLA BUS AC TIMING Figure 14-3
47 of 52
DS2153Q
AC CHARACTERISTICS (0°C to 70°C; VDD=5V ± 5%)
RECEIVE SIDE
(-40°C to +85°C; VDD =5V +5%/-4% for DS2153QN)
PARAMETER
ACLKI/RCLK Period
SYMBOL
tCP
MIN
TYP
488
RCLK Pulse Width
tCH
tCL
180
180
RCLK Pulse Width
tCH
tCL
90
200
SYSCLK Period
tSP
tSP
SYSCLK Pulse Width
tSH
tSL
50
50
RSYNC Set Up to SYSCLK Falling
tSU
25
RSYNC Pulse Width
tPW
50
SYSCLK Rise/Fall Times
tR, tF
25
ns
Delay RCLK or SYSCLK to RSER Valid
tDD
70
ns
Delay RCLK or SYSCLK to RCHCLK
tD1
50
ns
Delay RCLK or SYSCLK to RCHBLK
tD2
50
ns
Delay RCLK or SYSCLK to RSYNC
tD3
50
ns
Delay RCLK to RLCLK
tD4
50
ns
Delay RCLK to RLINK Valid
tD5
50
ns
NOTES:
1. Jitter attenuator enabled in the receive side path.
2. Jitter attenuator disabled or enabled in the transmit path.
3. SYSCLK=1.544 MHz.
4. SYSCLK=2.048 MHz.
48 of 52
MAX
UNITS
ns
NOTES
244
244
ns
ns
1
244
244
ns
ns
2
648
488
ns
ns
3
4
ns
tSH-5
ns
ns
DS2153Q
RECEIVE SIDE AC TIMING Figure 14-4
NOTES:
1. RSYNC is in the output mode (RCR1.5=0).
2. RSYNC is in the input mode (RCR1.5=1).
3. RLCLK and RLINK only have a timing relationship to RCLK; no timing relationship between
RLCLK/RLINK and RSYNC is implied.
4. RCLK can exhibit a short high time if the jitter attenuator is either disabled or in the transmit path.
49 of 52
DS2153Q
AC CHARACTERISTICS (0°C to 70°C; VDD=5V ± 5%)
TRANSMIT SIDE
(-40°C to +85°C; VDD=5V +5%/-4% for DS2153QN)
PARAMETER
TCLK Period
SYMBOL
tP
MIN
TCLK Pulse Width
tCH
tCL
75
75
ns
ns
TSER, TLINK Set Up to TCLK Falling
tSU
25
ns
1
TSER, TLINK Hold from TCLK Falling
tHD
25
ns
1
TSYNC Setup to TCLK Falling
tHD
25
TSYNC Pulse Width
tPW
25
TCLK Rise/Fall Times
TYP
488
MAX
tCH-5
UNITS
ns
NOTES
ns
ns
tR, tF
25
ns
Delay TCLK to TCHCLK
tD1
50
ns
Delay TCLK to TCHBLK
tD2
50
ns
Delay TCLK to TSYNC
tD3
50
ns
Delay TCLK to TLCLK
tD4
50
ns
NOTES:
1. If the transmit side elastic store is enabled, then TSER is sampled on the falling edge of SYSCLK and
the parameters tSU and tHD still apply.
50 of 52
DS2153Q
TRANSMIT SIDE AC TIMING Figure 14-5
NOTES:
1. TSYNC is in the output mode (TCR1.0=1).
2. TSYNC is in the input mode (TCR1.0=0).
3. No timing relationship between TSYNC and TLCLK/TLINK is implied.
4. TSER is sampled on the falling edge of SYSCLK if the transmit side elastic store is enabled.
51 of 52
DS2153Q
DS2153Q E1 SINGLE-CHIP TRANSCEIVER 44-PIN PLCC
NOTE 1: PIN 1 IDENTIFIER TO BE LOCATED IN ZONE INDICATED.
INCHES
DIM
MIN
MAX
A
0.165
0.180
A1
0.090
0.120
A2
0.020
-
B
0.026
0.033
B1
0.013
0.021
C
0.009
0.012
CH1
0.042
0.048
D
0.685
0.695
D1
0.650
0.656
D2
0.590
0.630
E
0.685
0.695
E1
0.650
0.656
E2
0.590
0.630
e1
N
0.050 BSC
44
-
52 of 52