INTEL LXP730

LXP730
Multi-Rate DSL Framer
Datasheet
The LXP730 is a multi-purpose Digital Subscriber Line (DSL) framer which complements the
Level One SK70725/21 Enhanced MDSL Data Pump (EMDP) to provide seamless transport of
data and voice signals over one or more DSL datapaths.
Applications
The LXP730 in combination with the EMDP
chipset is optimized for use as a framer or I/O
interface device for the following applications:
■ Digital Pair Gain Systems
■ Ethernet Modems
■
■
■
■
T1/E1 Fractional Transport Systems
Videoconferencing Systems
Simultaneous Data - Voice Transport
Systems
Wireless Base Station Access Systems
Product Features
The LXP730 provides the basic functions
required of a DSL framer:
■ Synchronization of external data streams to
the DSL line
■ Multiplexing and demultiplexing of
independent data streams for voice and data
■ Loopback of payload data at the DSL
interface
■ Creation, insertion, and recovery of the
MDSL Overhead (MOH) structure,
performance monitoring, and message
transport required in a DSL system with a
capacity of up to 32 kbps
■
■
■
■
Supports two input/output data streams
simultaneously
— Slave mode: external clock determines
the rate at which data will be transferred
to and from the framer
— Master mode: clock derived from
received DSL clock or external
oscillator
Single part architecture allows one chip to
be used economically in both central and
remote locations
Supports systems with point-to-point
architectures
Alternate Hardware Control mode (HWC)
for operation without an external
microprocessor
As of January 15, 2001, this document replaces the Level One document
LXP730 Multi-Rate DSL Framer Datasheet.
Order Number: 249266-001
January 2001
Information in this document is provided in connection with Intel® products. No license, express or implied, by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Intel’s Terms and Conditions of Sale for such products, Intel assumes no liability
whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or warranties relating to
fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Intel products are not
intended for use in medical, life saving, or life sustaining applications.
Intel may make changes to specifications and product descriptions at any time, without notice.
Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for
future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.
The LXP730 may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current
characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
Copies of documents which have an ordering number and are referenced in this document, or other Intel literature may be obtained by calling 1-800548-4725 or by visiting Intel’s website at http://www.intel.com.
Copyright © Intel Corporation, 2001
*Third-party brands and names are the property of their respective owners.
Datasheet
Multi-Rate DSL Framer — LXP730
Contents
1.0
Pin Assignments and Signal Descriptions ....................................................10
2.0
Functional Description...........................................................................................14
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
2.13
2.14
2.15
3.0
LXP730 Nx64 Framer..........................................................................................14
Time Slot Interchange (TSI) ................................................................................14
PCM-Bus Interface ..............................................................................................15
Codec Interface ...................................................................................................16
T1/E1 Interface....................................................................................................17
Asynchronous Data Port Interface (ADPI)...........................................................17
Overhead Interface..............................................................................................18
2.7.1 Overhead Serial I/O (OSIO) ...................................................................18
2.7.2 MDSL Overhead Μιχροπροχεσσορ Interface.........................................18
MDSL Interface ...................................................................................................19
All Digital PLL (ADPLL) .......................................................................................20
2.9.1 ADPLL Performance: The Selection of Kloop ........................................20
2.9.2 ADPLL Center Frequency: The computation of CFREQ ........................21
Clock Generation and Distribution.......................................................................21
Modes of Operation.............................................................................................22
2.11.1 Microprocessor Control (MPC) Mode.....................................................22
2.11.2 Hardware Control (HWC) Mode .............................................................23
MDSL Overhead Definition..................................................................................23
2.12.1 Predefined Overhead .............................................................................24
2.12.2 Z bits.......................................................................................................24
MDSL Frame Format...........................................................................................25
Startup Operation ................................................................................................26
Activation State Machine.....................................................................................27
Application Information .........................................................................................28
3.1
Typical Applications.............................................................................................28
3.1.1 IOM Interface Circuitry ...........................................................................29
3.1.2 Handling TIP/RING Reversal in Early Version of SK70725 ...................30
3.1.3 DSL System Loopbacks .........................................................................31
3.1.4 Using Multiple Devices on an Interrupt Line...........................................32
4.0
Test Specifications ..................................................................................................33
5.0
Register Definitions.................................................................................................47
5.1
5.2
Datasheet
Number MDSL Channels Register ......................................................................48
MDSL Channel Configuration Registers (18 bytes) ............................................49
5.2.1 Channel 1 ...............................................................................................49
5.2.2 Channel 2 ...............................................................................................49
5.2.3 Channel 3 ...............................................................................................49
5.2.4 Channel 4 ...............................................................................................50
5.2.5 Channel 5 ...............................................................................................50
5.2.6 Channel 6 ...............................................................................................50
5.2.7 Channel 7 ...............................................................................................51
5.2.8 Channel 8 ...............................................................................................51
3
LXP730 — Multi-Rate DSL Framer
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
5.11
5.12
5.13
4
5.2.9 Channel 9............................................................................................... 51
5.2.10 Channel 10............................................................................................. 52
5.2.11 Channel 11............................................................................................. 52
5.2.12 Channel 12............................................................................................. 52
5.2.13 Channel 13............................................................................................. 53
5.2.14 Channel 14............................................................................................. 53
5.2.15 Channel 15............................................................................................. 53
5.2.16 Channel 16............................................................................................. 54
5.2.17 Channel 17............................................................................................. 54
5.2.18 Channel 18............................................................................................. 54
Reserved Registers (3 bytes).............................................................................. 55
Wander Reduction Register ................................................................................ 55
FIFO/Miscellaneous Control Register ................................................................. 55
Slip Buffer Lower Threshold Register ................................................................. 56
Slip Buffer Upper Threshold Register ................................................................. 57
Version Register.................................................................................................. 57
Internal Clock Control Registers (4 bytes) .......................................................... 57
5.9.1 ADPLL Control 1 .................................................................................... 57
5.9.2 ADPLL Control 2 .................................................................................... 58
5.9.3 ADPLL Control 3 .................................................................................... 58
5.9.4 MCLK Divide .......................................................................................... 58
Programmable Idle Code Byte ............................................................................ 58
PCM Configuration Registers.............................................................................. 59
5.11.1 PCM1 Configuration ............................................................................... 59
5.11.2 PCM2 Configuration ............................................................................... 59
Codec Configuration Register ............................................................................. 60
Overhead Registers (25 bytes) ........................................................................... 60
5.13.1 Miscellaneous Control ............................................................................ 60
5.13.2 Overhead Configuration ......................................................................... 61
5.13.3 CRC Error Counter................................................................................. 61
5.13.4 FEBE Error Counter ............................................................................... 62
5.13.5 CRC - FEBE - LOS Status ..................................................................... 62
5.13.6 MX Overhead Bits 1 - 8.......................................................................... 62
5.13.7 MX Overhead Bits 9 - 16 ........................................................................ 63
5.13.8 MX Overhead Bits 17 - 24 ...................................................................... 63
5.13.9 MX Overhead Bits 25 - 32 ...................................................................... 63
5.13.10 MX Z Bits 1 - 8 ....................................................................................... 64
5.13.11 MX Z Bits 9 - 16 ..................................................................................... 64
5.13.12 MX Z Bits 17 - 24 ................................................................................... 64
5.13.13 MX Z Bits 25 - 32 ................................................................................... 65
5.13.14 MX Z Bits 33 - 40 ................................................................................... 65
5.13.15 MX Z Bits 41 - 48 ................................................................................... 65
5.13.16 DX Overhead Bits 1 - 8 .......................................................................... 65
5.13.17 DX Overhead Bits 9 - 16 ........................................................................ 66
5.13.18 DX Overhead Bits 17 - 24 ...................................................................... 66
5.13.19 DX Overhead Bits 25 - 32 ...................................................................... 66
5.13.20 DX Z Bits 1 - 8........................................................................................ 67
5.13.21 DX Z Bits 9 - 16 ...................................................................................... 67
5.13.22 DX Z Bits 17 - 24 .................................................................................... 67
5.13.23 DX Z Bits 25 - 32 .................................................................................... 68
Datasheet
Multi-Rate DSL Framer — LXP730
5.14
5.15
6.0
5.13.24 DX Z Bits 33 - 40 ....................................................................................68
5.13.25 DX Z Bits 41 - 48 ....................................................................................68
Reserved Registers (2 bytes)..............................................................................68
Interrupt Registers (2 bytes)................................................................................69
5.15.1 Interrupt Enables ....................................................................................69
5.15.2 Interrupt Status.......................................................................................69
Mechanical Specifications....................................................................................70
Figures
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
Datasheet
LXP730 Block Diagram ......................................................................................... 9
LXP730 Pin Assignments....................................................................................10
Clock Generation and Distribution.......................................................................22
Frame Format for N=12.......................................................................................26
Activation State Machine.....................................................................................27
High Performance Voice/Data Transport ............................................................28
Pair Gain Transport .............................................................................................29
T1/E1 Fractional Transport..................................................................................29
IOM Adaption Circuitry ........................................................................................30
Multiple Interrupt Line Circuit...............................................................................32
Generic PCM Interface Timing ............................................................................34
PCM Timing, 1X Clock ........................................................................................35
PCM Timing, 2X Clock ........................................................................................36
Codec Interface Timing .......................................................................................37
Asynchronous Port Timing ..................................................................................38
OSIO Timing........................................................................................................39
MDSL Interface Input Timing...............................................................................40
MDSL Interface Output Timing............................................................................40
E1/T1 Input Timing ..............................................................................................41
E1/T1 Output Timing ...........................................................................................41
Microprocessor Write Cycle - Motorola Mode .....................................................42
Microprocessor Read Cycle - Motorola Mode .....................................................43
Microprocessor Write Cycle - Intel Mode ............................................................44
Microprocessor Read Cycle - Intel Mode ............................................................45
Reset Timing .......................................................................................................45
64 - Pin LQFP Package Specification .................................................................70
5
LXP730 — Multi-Rate DSL Framer
Tables
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
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
6
LXP730 Pin Descriptions .................................................................................... 11
Common Transport & Line Rates........................................................................ 19
Kloop Values ....................................................................................................... 20
Typical ADPLL Register Settings, MCLK = 16.384MHz...................................... 22
Pin settings for HWC DSL Line Rates................................................................. 23
MDSL Frame Sync Word (FSW) Patterns .......................................................... 25
MDSL Frame Format .......................................................................................... 25
Absolute Maximum Ratings ................................................................................ 33
Recommended Operating Conditions ................................................................. 33
I/O Electrical Characteristics ............................................................................... 33
Generic PCM Bus Interface Timing Specifications (See Figure 11).................... 34
Codec Interface Timing Specifications (See Figure 14) ...................................... 37
Asynchronous Port Timing Specifications (See Figure 15) ................................. 38
OSIO Timing Specifications (See Figure 16) ...................................................... 39
MDSL Interface Input Timing Specifications (See Figure 17) ............................. 40
MDSL Interface Output Timing Specifications (See Figure 18) .......................... 40
E1/T1 Input Timing Specifications (See Figure 19)............................................. 41
E1/T1 Output Timing Specifications (See Figure 20) .......................................... 42
Microprocessor Write Cycle Specifications—Motorola Mode (See Figure 21).... 42
Microprocessor Read Cycle Specifications - Motorola Mode (See Figure 22).... 43
Microprocessor Write Cycle Specifications—Intel Mode (See Figure 23)........... 44
Microprocessor Read Cycle Specifications—Intel Mode (See Figure 24) .......... 45
MCLK Frequency and Tolerance Specification................................................... 45
Reset Timing Specifications (See Figure 25) ...................................................... 46
LXP730 Register Summary................................................................................. 47
Number MDSL Channels .................................................................................... 49
Timeslot to Channel 1 ......................................................................................... 49
Timeslot to Channel 2 ......................................................................................... 49
Timeslot to Channel 3 ......................................................................................... 50
Timeslot to Channel 4 ......................................................................................... 50
Timeslot to Channel 5 ......................................................................................... 50
Timeslot to Channel 6 ......................................................................................... 51
Timeslot to Channel 7 ......................................................................................... 51
Timeslot to Channel 8 ......................................................................................... 51
Timeslot to Channel 9 ......................................................................................... 52
Timeslot to Channel 10 ....................................................................................... 52
Timeslot to Channel 11 ....................................................................................... 52
Timeslot to Channel 12 ....................................................................................... 53
Timeslot to Channel 13 ....................................................................................... 53
Timeslot to Channel 14 ....................................................................................... 53
Timeslot to Channel 15 ....................................................................................... 54
Timeslot to Channel 16 ....................................................................................... 54
Timeslot to Channel 17 ....................................................................................... 54
Timeslot to Channel 18 ....................................................................................... 55
Reserved Registers............................................................................................. 55
Wander Reduction Register ................................................................................ 55
FIFO/Miscellaneous Control Register ................................................................. 56
Slip Buffer Lower Threshold................................................................................ 56
Slip Buffer Upper Threshold................................................................................ 57
Datasheet
Multi-Rate DSL Framer — LXP730
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
Datasheet
Version ................................................................................................................57
ADPLL Control 1 .................................................................................................57
ADPLL Control 2 .................................................................................................58
PROG Divide.......................................................................................................58
Programmable Idle Code Byte ............................................................................59
PCM 1 Configuration Bits ....................................................................................59
PCM 2 Configuration Bits ....................................................................................60
Codec Configuration............................................................................................60
Miscellaneous Control .........................................................................................60
Overhead Configuration ......................................................................................61
CRC Error Counter..............................................................................................62
FEBE Error Counter ............................................................................................62
CRC - FEBE Status.............................................................................................62
MX Overhead Bits 1 - 8 .......................................................................................63
MX Overhead Bits 9 - 16 .....................................................................................63
MX Overhead Bits 17 - 24 ...................................................................................63
MX Overhead Bits 25 - 32 ...................................................................................64
MX Z Bits 1 - 8.....................................................................................................64
MX Z Bits 9 - 16...................................................................................................64
MX Z Bits 17 - 24.................................................................................................64
MX Z Bits 25 - 32.................................................................................................65
MX Z Bits 33 - 40.................................................................................................65
MX Z Bits 41 - 48.................................................................................................65
DX Overhead Bits 1 - 8 .......................................................................................66
DX Overhead Bits 9 - 16 .....................................................................................66
DX Overhead Bits 17 - 24 ...................................................................................66
DX Overhead Bits 25 - 32 ...................................................................................67
DX Z Bits 1 - 8 .....................................................................................................67
DX Z Bits 9 - 16 ...................................................................................................67
DX Z Bits 17 - 24 .................................................................................................67
DX Z Bits 25 - 32 .................................................................................................68
DX Z Bits 33 - 40 .................................................................................................68
DX Z Bits 41 - 48 .................................................................................................68
Reserved Registers.............................................................................................68
Interrupt Enables .................................................................................................69
Interrupt Status....................................................................................................69
7
LXP730 — Multi-Rate DSL Framer
Revision History
Revision
8
Date
Description
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 1. LXP730 Block Diagram
PCM-Bus
Interface
Slip
Buffer
Time Slot
Interchange
(TSI)
Codec
Interface
Shared
Datasheet
Registers
Microprocessor
Interface
MOH MX
Stuff
DX Elastic
Store
Async
Data Port
Interface
(ADPI)
Overhead
Serial I/O
(OSIO)
Interface
MX Elastic
Store
Recovered Clock All Digital PLL
(ADPLL)
MDSL
Interface
MOH DX
Receive
Framer
Clock Generation and Distribution
9
LXP730 — Multi-Rate DSL Framer
1.0
Pin Assignments and Signal Descriptions
Figure 2. LXP730 Pin Assignments
Part #
LOT #
FPO #
LXP730LE XX
XXXXXX
XXXXXXXX
Rev #
Package Topside Markings
Marking
Part #
Unique identifier for this product family.
Rev #
Identifies the particular silicon “stepping” — refer to the specification update for additional stepping
information.
Lot #
Identifies the batch.
FPO #
10
Definition
Identifies the Finish Process Order.
Datasheet
Multi-Rate DSL Framer — LXP730
Table 1.
LXP730 Pin Descriptions
Pin
Symbol
Type1
1, 9, 16,
33, 48
VCC
_
Power Supply.
10, 17,
32, 49,
64
GND
_
Ground.
28
DATA0/
CRC_ERROR
DI/O, DO
DATA0. MPC mode/CRC_ERROR. flag HWC mode, indicates an error was detected
in the previous frame.
29
DATA1/FEBE
DI/O, DO
DATA1. MPC mode/FEBE. flag HWC mode, indicates the other side of the DSL link
encountered a CRC error.
30
DATA2/
LINK_ACTIVE
DI/O, DO
DATA2. MPC mode/LINK_ACTIVE. HWC mode, indicates that the DSL link is active
and ready to transport data.
31
DATA3/RUNSTOP
DI/O, DI
DATA3. MPC mode/RUN-STOP. HWC mode, set to low to activate the DSL link,
edge triggered input.
34
DATA4/
FRMSYNC15
DI/O, DO
DATA4. MPC mode /FRMSYNC15. HWC mode, Frame Sync Pulse, channel 15.
35
DATA5/
FRMSYNC16
DI/O, DO
DATA5. MPC mode /FRMSYNC16. HWC mode. Frame Sync Pulse, channel 16.
36
DATA6/
FRMSYNC17
DI/O, DO
DATA6. MPC mode /FRMSYNC17. HWC mode. Frame Sync Pulse, channel 17.
37
DATA7/
FRMSYNC18
DI/O, DO
DATA7. MPC mode /FRMSYNC18. HWC mode. Frame Sync Pulse, channel 17.
22
ADDR0/
FRMSYNC13
DI, DO
ADDR0. MPC mode/FRMSYNC13. HWC mode. Frame Sync Pulse, channel 13,
output.
23
ADDR1/N1
DI
ADDR1. MPC mode/N1. DSL rate select, HWC mode.
24
ADDR2/N2
DI
ADDR2. MPC mode/N2. DSL rate select, HWC mode.
25
ADDR3/N3
DI
ADDR3. MPC mode/N3. DSL rate select, HWC mode.
26
ADDR4/N4
DI
ADDR4. MPC mode/N4. DSL rate select, HWC mode.
27
ADDR5/
FRMSYNC14
DI, DO
57
MOTEL/HWC
DI
MOTEL/HWC. Set high for Motorola mode, set low for Intel mode, Micro Processor
Control (MPC) mode, input /HWC. pull high for HWC mode, input.
39
R/W(WR)/HWC
select
DI
R/W(WR). R/W for Motorola interface, WR for Intel interface /HWC select, set low for
HWC mode.
40
(RD)/HWC select
DI
(RD). Unused for Motorola interface, RD for Intel interface /HWC select, set low for
HWC mode.
38
CS /HWC select
DI
CS. Chip select, HWC select, set low for HWC mode.
41
ALE/HTU_SEL
DI
ALE. Address latch enable for Intel interface, MPC mode, input /HTU_SEL. HTUC/
HTUR select, High for HTUC, Low for HTUR, HWC mode, input.
Description
ADDR5. MPC mode/FRMSYNC14. Frame Sync Pulse, channel 14, output, HWC
mode.
1. AI = Analog Input; AO = Analog Output; DI = Digital Input; DO = Digital Output; NC = No Clamp. Pad will not clamp input in
the absence of power; PU = Input contains pull-up; PD = Input contains pull-down; I/O = Input/Output; OD = Open Drain
Output;
TO = Tri-State Output.
Datasheet
11
LXP730 — Multi-Rate DSL Framer
Table 1.
LXP730 Pin Descriptions (Continued)
Pin
Symbol
Type1
42
INT
DO
INT. Interrupt output. Programmed by setting bits in the INT_EN register.
56
RESET
DI
RESET. Active low input. All registers revert to their default values.
8
MCLK
DI
MCLK. Master Clock.
4
CDATI
DI
CDATI. Codec Data In.
3
CDATO
TO
CDATO. Codec Data Out, Tri-state.
2
CCLK/TCLKO
TO
CCLK. Codec Clock, Nominal 2.048 MHz, tri-state. /TCLKO. Transport Clock for T1/
E1: 1.544 MHz or 2.048 MHz clock derived from line rate.
5
FRMSYNC1/
FRMOUT
DO
FRMSYNC1. Frame Sync Pulse, channel 1, output. /FRMOUT. Frame Out, for T1/E1
application, output.
6
FRMSYNC2
DO
FRMSYNC2. Frame Sync Pulse, channel 2, output.
7
FRMSYNC3
DO
FRMSYNC3. Frame Sync Pulse, channel 3, output.
62
FRMSYNC4
DO
FRMSYNC4. Frame Sync Pulse, channel 4, output.
61
FRMSYNC5
DO
FRMSYNC5. Frame Sync Pulse, channel 5, output.
60
FRMSYNC6
DO
FRMSYNC6. Frame Sync Pulse, channel 6, output.
59
FRMSYNC7/
SDOCK
DO
FRMSYNC7. Frame Sync Pulse, channel 7, output. /SDOCK. Serial Data Out Clock,
ADPI serial mode, output.
58
FRMSYNC8/ SDO
DO
FRMSYNC8. Frame Sync Pulse, channel 8, output. /SDO. Serial Data Out, ADPI
serial mode, output.
55
FRMSYNC9
SDICK
DO
FRMSYNC9. Frame Sync Pulse, channel 9, output. /SDICK. Serial Data In Clock,
ADPI serial mode, output.
54
FRMSYNC10/ SDI
DO, DI
FRMSYNC10. Frame Sync Pulse, channel 10, output. /SDI. Serial Data In, ADPI
serial mode, input.
53
FRMSYNC11
DO
FRMSYNC11. Frame Sync Pulse, channel 11, output.
52
FRMSYNC12/
PDOE
DO
FRMSYNC12. Frame Sync Pulse, channel 12, output. /PDOE. PCM Data Output
Enable, control for external PCM interface buffer, output. Enabled by bit-3 of Register
23h.
51
GAP_CLK
DO
GAP_CLK. Gapped Clock, N x 64 kHz recovered from DSL for optional external
ADPLL, output. Output is high when option not selected.
63
TEST1
DI
TEST1. Factory Test Pin 1, input; should be tied to GND.
11
TEST2
DI
TEST2. Factory Test Pin 2, input; should be tied to VCC.
21
OSDICK
DO
OSDCKI. Overhead Serial Data In Clock, output.
20
OSDI
PU
OSDI. Overhead Serial Data In, input.
19
OSDOCK
DO
OSDOCK. Overhead Serial Data Out Clock, output.
18
OSDO
DO
OSDO. Overhead Serial Data Out, output.
Description
1. AI = Analog Input; AO = Analog Output; DI = Digital Input; DO = Digital Output; NC = No Clamp. Pad will not clamp input in
the absence of power; PU = Input contains pull-up; PD = Input contains pull-down; I/O = Input/Output; OD = Open Drain
Output;
TO = Tri-State Output.
12
Datasheet
Multi-Rate DSL Framer — LXP730
Table 1.
LXP730 Pin Descriptions (Continued)
Pin
Symbol
Type1
44
OSOF
DO
OSOF. Overhead Serial Output Flag, output. Indicates the first bit of OSIO output
frame.
50
OSIF
DO
OSIF. Overhead Serial Input Flag, output. Indicates the first bit of OSIO input frame.
45
TDATA
DO
TDATA. Transmit Data, output. Connect to SK70725.
47
RDATA
DI
RDATA. Receive Data, input. Connect to SK70725.
46
QUATCLK
DI
QUATCLK. Quaternary alignment Clock, input. Connect to SK70725.
43
BITCLK
DI
BITCLK. Bit Clock, input. Connect to SK70725.
13
PFRM / FRMIN /
Z0
DI,DO,DI
PFRM. PCM frame pulse: input for PCM slave, output for PCM master. Alignment
signal for the first time slot for both PDI and PDO. /FRMIN. Frame In, for T1/E1
application, input. /Zo. Bit zero of the 3-bit word used to specify the number of Z bits
in the Hardware mode, input.
12
PDI / T1E1I / Z1
PU,DI,
DI
PDI. PCM Data In, input. /T1E1I. T1 or E1 Input data, input. /Z1. Bit one of the 3-bit
word used to specify the number of Z bits in the Hardware mode, input.
15
PDO / T1E1O / Z2
TO,TO,DI
PDO. PCM Data Out, tri-stateable output. /T1E1O. T1 or E1 Output data, tristateable output. /Z2. Bit two of the 3-bit word used to specify the number of Z bits in
the Hardware mode, input.
14
PCLK/TCLKI
DI/O
Description
PCLK. PCM clock: input for PCM slave, output for PCM master. /TCLKI. Transport
Clock In, for T1/E1 application, 1.544MHZ - T1, 2.048MHz - E1, input.
1. AI = Analog Input; AO = Analog Output; DI = Digital Input; DO = Digital Output; NC = No Clamp. Pad will not clamp input in
the absence of power; PU = Input contains pull-up; PD = Input contains pull-down; I/O = Input/Output; OD = Open Drain
Output;
TO = Tri-State Output.
Datasheet
13
LXP730 — Multi-Rate DSL Framer
2.0
Functional Description
2.1
LXP730 Nx64 Framer
The LXP730 is designed to multiplex/demultiplex two payload sources to/from a DSL stream, and
add/recover overhead data for link control. Several popular interfaces are provided to support a
variety of applications.
The two major categories of payload supported are synchronous (i.e. voice-frequency data - PCM)
and asynchronous (i.e. digital data - Packet/Cell). The LXP730 supports Nx64 kbps channels in the
DSL with N = 4 to 18. The LXP730 consists of the following functional blocks as shown on page
1:
•
•
•
•
•
•
•
•
•
•
Time Slot Interchange (TSI)
PCM-Bus Interface
Codec Interface
T1/E1 Interface
Asynchronous Data Port Interface (ADPI)
Microprocessor Interface
Overhead Serial I/O (OSIO) Interface
SK70725/SK70721 (MDSL) Interface
All Digital PLL (ADPLL)
Clock Generation and Distribution
The terms Local and Remote are used in this document to designate the two ends of a DSL link.
The Local is usually the master in that it initiates the link startup and can control the actions and
configuration of the Remote. There are several equivalent nomenclatures in the Telecom industry.
Some of these are, respectively: CO and CPE, or HTU-C and HTU-R, or LTU and NTU.
The following is a description of the LXP730 functional blocks.
2.2
Time Slot Interchange (TSI)
The Time Slot Interchange (TSI) is the central module of the LXP730 Nx64 framer. The TSI maps
payload to the available DSL N-channels for transport across the loop.
The TSI uses register settings to select time slots to map into the N MDSL channels. The total
number of available payload channels is N and is set by the N_MDSL register (00h), with selected
valid values from 4 to 18. Each of the 18 Nx registers (01h -012h) is used to select the payload
source, and if applicable, the PCM time slot assigned to the register’s corresponding MDSL
channel.
In the MX direction (from the TSI to the MDSL Interface), the TSI multiplexes the payload sources
into the MX elastic store (MX ES). The payload and overhead are multiplexed into the DSL stream
for loop transport.
14
Datasheet
Multi-Rate DSL Framer — LXP730
In the DX direction (from the MSDL Interface to the TSI), the TSI reads from the DX elastic store
(DX ES) and demultiplexes the loop data into its payload data sources.
Synchronous payload sources are typically 8-bit serial time slots, cascaded together with each
source repeating every 125 µsec (i.e. 8 kHz). A framing pulse, separate from the data signal,
signifies the start of a frame. A 2.048 Mbps data stream has 32 time slot sources, while a 1.544
Mbps data stream has 24 time slot sources plus one extra bit for framing.
When the PCM or codec interfaces are running, the framing pulses are used by the TSI to initialize
operation to the MX ES. The MX ES and DX ES have triple buffering schemes that prevent the
loss of data. The PCM/codec interfaces typically produce high speed data bursts while the MDSL
interface runs at a slower though irregular rate.
Asynchronous data is typically a sequence of bytes which have no explicit timing relationship
between them. Asynchronous Data Port Interface (ADPI) bytes may be inserted into payload slots
that are not carrying PCM data. ADPI bytes are inserted into the DSL stream in the order they are
received from the interface.
Channel blocking on a MDSL channel is achieved by setting the CH_CFG bits in the Nx register to
01. The transported value for that MDSL channel will be the one stored in the IDLE register.
The TSI uses the MCLK clock to synchronize to the various interfaces. The MCLK frequency must
be at least three times the highest interface clock frequency for the TSI to function properly. There
are other considerations to select the operating frequency of MCLK when using the internal
ADPLL.
2.3
PCM-Bus Interface
The LXP730 provides a generic interface for common PCM-bus configurations and can either be
master or slave to these PCM busses. Some of the key features that allow flexibility are:
• Clock at 1x or 2x the data rate
• Programmable number of bytes per frame; 8, 16, 32, 64
• Programmable clock and frame pulse polarities
These features allow interfacing to standard PCM styles such as: ST, IOM, IOM2 (see Figure 9 for
circuit) and CHI. The data rates can range from 256 kbps to 4096 kbps. The clock rates can range
from 256 kHz to 8196 kHz.
The range of permissible PCM time slots are 0 to 31 for a 2.048 Mbps backplane and 0 to 63 for a
4.096 Mbps backplane for a total number of time slots up to the maximum number N. PCM time
slots must be assigned in ascending order to MDSL channels. The value set in the TS-bits in the Nx
registers select the PCM timeslot to go into the xth MDSL channel.
There is a limitation of the disparity allowed between the PCM clock and the BIT_CLK. For N = 4,
the PCM bit rate cannot exceed 2 Mbps. To use a 4 Mbps PCM interface the NMDSL setting must
be at least 6 channels.
On these busses, the input and output data streams are synchronized to the same clock. A slip
buffer is present on the receive side to accommodate the differences in the PCM clock frequencies
of the two ends of the MDSL line.
Datasheet
15
LXP730 — Multi-Rate DSL Framer
The slip buffer is two frame lengths long. The buffer will empty if the PCM clock is reading data
out of the slip buffer faster than the TSI is writing into it. When the last bit for the frame has been
read and there is not another byte from the next frame to clock out, the read pointer is set back to
the beginning of the current frame and repeated. The other slip situation occurs when the TSI is
writing data faster than the PCM is clocking it out. When the write pointer gets close to the read
pointer that hasn’t finished a frame, then the read pointer is allowed to finish the current frame and
then is advanced to skip the next frame.
The slip buffer may be bypassed by setting the SBBP bit, (bit 0, in the PCM_CFG1, register). Slip
occurrences are detected and signalled in the Interrupt Status register.
Normally the LXP730 PCM bus is configured as a slave in the Local unit, while the Remote
LXP730 PCM bus can be either configured as slave or master off the PCM bus. When the Remote
LXP730 is in PCM slave mode, the slip buffers accommodate the differences in the two PCM
clocks. When the Remote LXP730 is in PCM master mode, the PCM clock and frame pulse are
derived from the receive DSL clock using the internal ADPLL to provide loop timing to prevent
the slip action from occurring.
The PCM bus timeslot assignments to the DSL channels may be altered while the DSL link is
active. The Nx registers can be changed without interfering with other Nx registers and the effect
of their settings.
The PDO pin is tri-stated except during programmed time slots.
The PFRM pulse defines the start of a PCM frame. The number of PCM time slots per frame is
variable from 4 to 64. This is programmed by setting the six MAXPCHN bits in, the PCM_CFG2
register, with the value n-1 number time slots.
PCM selection for a MDSL channel is accomplished by setting the CH_CFG bits in the Nx register
to ‘10’ (binary).
2.4
Codec Interface
The LXP730 primarily supports the COMBO codec I style devices. The LXP730 codec interface is
programmable to allow the use of other codec type devices that require a positive frame pulse. The
LXP730 provides a separate set of pins for this interface allowing simultaneous operation with a
PCM bus with the following characteristics:
• Short frame positive sync pulse
• Clock at 1x or 2x the data rate
• Programmable number of bytes per frame in MPC; 8, 16, 32, 64
The data rates can range from 256 kbps to 4096 kbps. The clock rates can range from 256 kHz to
8196 kHz. Under HWC mode, the number of bytes per frame is limited to 32.
The input and output data from the TSI are connected to the codec CDATI and CDATO pins for the
appropriate time slot. The CDATO pin is tri-stated except during programmed time slots. Only
twelve (12) codecs are supported in the MPC mode.
The LXP730 is always the master on the codec bus. The LXP730 can be configured to derive the
clock and frame pulse from either MCLK (in codec Master mode) or from the DSL clock using the
internal ADPLL (in codec Slave mode). One LXP730 of the DSL link must be in the Master codec
mode and the other in the Slave codec mode.
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Datasheet
Multi-Rate DSL Framer — LXP730
The LXP730 generates the codec clock and the framing pulses for eighteen (18) codecs from the
selected reference. Selecting codec timeslot 0 in an Nx register corresponds to FRMSYNC1, 1 to
FRMSYNC2, etc. In HWC mode, the FRMSYNC pins are automatically assigned with the
programming of the Nx pins. The number of codec time slots per frame is variable from 4 to 64.
This is programmed by setting the six MAXCCHN bits in the COD_CFG register (22h) with the
value n-1 number time slots.
Codec selection for a MDSL channel is accomplished by setting the CH_CFG bits in the Nx
register to ‘00’ (binary).
2.5
T1/E1 Interface
The LXP730 supports T1/E1 framer interfaces by using a hybrid of the PCM and codec interfaces
to transport pleisiochronous data.
The PCM interface is used in its slave mode to connect a T1/E1 framer and its TxData (T1E1O),
RxData (T1E1I), RxCLK (TCLKI) and FramePulseOut (FRMIN). The slip buffer must be in the
bypass mode.
The codec interface is used in its slave mode to derive the FramePulseIn (FRMOUT) and TxCLK
(TCLKO) to the T1/E1 framer. The derived T1/E1 FRMOUT tracks the MDSL frame rate from the
DSL, and in cases where framing is lost, the DX tracking circuits slowly reacquire to prevent a
drastic change in the output frame frequency.
The PCM and codec sections must each be configured through registers to handle the T1/E1
pleisiochronous data.
For T1, only N=12 or fractional T1 is supported. In T1, the only workable value for the
PCM_CFG2 register is 98h. The MX T1 F-bits must be part of the data stream coming from the
external T1 framer. The 12 unused DX T1 time slots are filled with the value programmed in the
IDLE register if the TFI bit (bit 0) is set to 0.
Key features of the T1E1 interface are:
• Framer interfaces: DS2141and DS2143
• Data rates: 1544 and 2048 kbps
• Clock rates: 1544 and 2048 kHz
2.6
Asynchronous Data Port Interface (ADPI)
The LXP730 supports a serial method for the Asynchronous Data Port Interface (ADPI). The ADPI
is available only in the MPC operating mode. MDSL channels are programmed for ADPI by
setting the CH_CFG bits to ‘11’ (binary) in the desired Nx register. The operation of the ADPI is
mutually exclusive with the LXP730 codec frame sync pins (FRMSYNC7-10).
The serial ADPI mode provides separate pins for data in, data out, clock-in and clock-out. This is
compatible with the bit operation protocol (BOP) for HDLC devices. The LXP730 controls both of
the clocks, and therefore, the data flow. The LXP730 moves the bits in and out in 8-bit groups. The
maximum clock rate for the bit-to-bit transfer is set by the SAPCLKDIV bits in the FIFO_MISC
register. This allows the clocks to run at MCLK ÷ 2 or slower. The groups of clock pulses will be
gapped due to the availability of bit positions in the DSL data stream.
Datasheet
17
LXP730 — Multi-Rate DSL Framer
2.7
Overhead Interface
The LXP730 provides two options for the interface to insert and receive overhead data for the link:
via an external serial interface or through the microprocessor register interface. The data can either
be user defined or partially predefined as described in “MDSL Overhead Definition” on page 23.
The overhead channel is used for signalling, status flags, loopback control, and diagnostic
messaging between the Local and Remote ends of a MDSL link. The LXP730 provides the
transparent channel for the overhead data and does not interpret the protocol operation.
The F-bits in the fractional T1 mode are not part of the overhead.
2.7.1
Overhead Serial I/O (OSIO)
The OSIO interface is the default overhead access for both the MPC and HWC operational modes.
The serial interface provides six separate pins for data in (OSDI), data out (OSDO), clock-in
(OSDICK) clock-out (OSDOCK), start flag in (OSIF), and start flag out (OSOF). The use of the
first four pins is compatible with the bit operation protocol (BOP) for HDLC devices. The two flag
pins (OSIF and OSOF) provide indications of the start of a MDSL frame and may used with
custom overhead handling devices. The flag signals are coincident with the first overhead bit in the
MDSL frame.
The LXP730 controls both of the clocks, and thus, the data flow. The clocks will be gapped due to
the availability of bit positions in the DSL data stream. The OSIO may be disabled in the MPC
mode by setting the Par/Ser bit in the OVRHD_SEL register (24h). OSIF and OSOF will continue
to operate.
The defined bits (except the indc_r bit) go to the microprocessor interface registers. The undefined
bits (plus the indc_r bit) go to the OSIO interface. This allows a separate transport for HDLC
devices while maintaining DSL performance monitoring.
2.7.2
MDSL Overhead Microprocessor Interface
The MDSL overhead microprocessor interface mode uses internal registers to provide the access to
insert and receive overhead data for the link. The Par/Ser bit must be set to access the contents of
the overhead and Z bit registers. Interrupts may be used to synchronize the contents with the
MDSL link. The data can either be user defined or partially predefined as described in “MDSL
Overhead Definition” on page 23. Microprocessor writes to defined bits have no effect, with the
exception of the indc_r bit.
The registers for the OH and Z bits are double buffered for both the MX and DX sections. When
the OHMX bit is set in the INT_STAT, 3Fh, register, the values in the user assessable MX registers
are latched into an internal set of registers, and then serially shift throughout the frame. The user
has a nominal 6 ms to update the MX registers before they are latched again for transport.
Likewise, the DX registers hold their values until the OHDX bit is set, then the overhead data from
the latest frame is available. The user again has a nominal 6 ms to read the DX data before it is over
written.
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Datasheet
Multi-Rate DSL Framer — LXP730
2.8
MDSL Interface
Each LXP730 device works directly with one SK70725/21 data pump chip set. The SK70725/21
chip set must be in Mode 0 to work with the LXP730. Refer to the SK70725/21 data sheet for
details.
The LXP730 provides TDATA to the data pump and accepts QUATCLK, BITCLK and RDATA
signals from the data pump. The framer supports line data rates from 272 kbps to 1168 kbps. Table
2 shows some of the common even-numbered transport, nominal line rates and the number of bits
per frame. Odd numbered N values may also be used.
The first value in the Bits/Frame column is the number of bits in an unstuffed frame, and the
second value is with stuffing. MDSL Frame periods are a nominal 6 ms regardless of the nominal
line rate.
Table 2.
Common Transport & Line Rates
Data Rate
(kbps)
Nominal Line
Rate (kbps)
64 kbps Channels
(N)
Bits/Frame
256
272
4
1630/1634
384
400
6
2398/2402
512
528
8
3166/3170
640
656
10
3934/3938
768
784
12
4702/4706
1152
1168
18
7006/7010
The line rate is calculated as N x 64 kbps + 16 kbps, where N is the number of 64 kbps channels to
be transported. The 16 kbps is the total overhead provided by the MDSL transport system.
The 16 kbps holds true as long there is one Z bit per block as described in “MDSL Frame Format”
on page 25. The LXP730 supports up to eight Z bits per block, but when greater than one, the
overhead rate increases. This causes the line rate to increase accordingly. The equation to calculate
the DSL line rate is as follows:
Line rate (kbps) = 8[Z + 1 + (N x 8)]
The LXP730 will scramble payload data, but pass the sync word in the clear. In the Local mode, the
LXP730 uses the following scrambling polynomial:
x-23 + x-5 + 1,
In the Remote mode the scrambling polynomial is:
x-23 + x-18 + 1.
In transparent mode, the LXP730 uses the quat alignment signal (QUATCLK) from the data pump
to align the sign and magnitude bits in both the transmit and receive directions.
The overhead bits are described in “MDSL Overhead Definition” on page 23.
Before routing the data to the descrambler, the LXP730 will invert the sign bits of the received data
stream, if the detected frame sync word has inverted sign bits.
Datasheet
19
LXP730 — Multi-Rate DSL Framer
The MDSL interface provides loopback of TDATA, bypassing the external RDATA. Loopback is
activated by setting the DSL_LB bit in the OVRHD_CFG register (24h). This routes the 64 kbps
channels and MDSL Overhead (MOH) from the MX section to the DX section. When using an
external loopback configuration, such as FELB in the SK70725, it is necessary to switch the DX
de-scrambling polynomial to the MX polynomial. The descrambling polynomial is inverted by
setting the REMOTE_LB bit of the FIFO_MISC register (17h). The BITCLK and QUATCLK
control the transfer of data from the MX to the DX section.
2.9
All Digital PLL (ADPLL)
The LXP730 ADPLL is necessary for clock recovery and to control output jitter and wander
produced in the DSL environment.
The ADPLL uses MCLK to drive the NCO circuitry, while the reference frequency comes from the
received DSL frame rate that has a nominal 6 ms period.
2.9.1
ADPLL Performance: The Selection of Kloop
The performance of the ADPLL is user programmable via a register. As shown in Table 3, the 5-bit
value, Kloop, in PLLCTL3 register controls the lock time and the bandwidth of the ADPLL. The
lock time is the amount of time required for the ADPLL to acquire and synchronize to the input
MDSL signal. The bandwidth of the ADPLL determines the jitter rejection characteristics of the
ADPLL. The bandwidth and lock time are inversely related: BW = 3/Tlock.
Table 3.
Kloop Values
Register Bits
Kloop_Value
00000
PLL freeze
00001
20
00010
2-1
00011
2-2
00100
2-3
...
...
11111
2-30
Kloop is a 5 bit control field found in register PLLCTL3 (address 1D hex, 29 dec). The register bits
are used to select a constant (Kloop_Value) that controls the loop bandwidth.
The Bandwidth of the loop filter is determined from the selected Kloop_Value and the frequency of
MCLK. Loop bandwidth (BW) is calculated as follows:
BW (3db) = Kloop_Value × MCLK × 3.89e-5 Hz
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Datasheet
Multi-Rate DSL Framer — LXP730
2.9.2
ADPLL Center Frequency: The computation of CFREQ
The center frequency of the ADPLL is set by an 18-bit unsigned fractional number, CFREQ(17:0).
This value is programmed in PLLCTL1, PLLCTL2, and PLLCTL3. CFREQ(17:0) is the ratio of
the Numerically Controlled Oscillator (NCO) and MCLK, and is shown below. The 218 is the
normalizing factor to express it in integer notation. It must then be converted to hexadecimal to
load into the CFREQ register.
The output of the NCO is divided by 2 before being provided to the clock multiplex circuitry and
the optional PROG_DIV block. This must be taken into account when deciding upon the frequency
for the NCO.
The NCO/MCLK ratio should be set to a value greater than or equal to 0.5 but less than 0.98. This
ensures that there will be the maximum number of bits of accuracy for the NCO to generate the
frequency. The ratio of 0.5 normalized with 218 is 131072 or in hexadecimal, 20000h. This is the
smallest recommended value.
Equation 1. Calculation of CFREQ
18
( NCOFREQ × 2 )
CFREQ = ROUND -----------------------------------------------MCLK
Table 4 list values for: CFREQ(17:0), Programmable Divider, and NCO frequency for a MCLK of
16.384MHz in several configurations.
2.10
Clock Generation and Distribution
The LXP730 has a flexible clock generation circuit as shown in Figure 3. The clocks for the PCM
and codec interfaces can be an independent external input, a division of MCLK, a division of the
ADPLL output, or the ADPLL output as selected by the PCM Configuration 1 register
(PCM_CFG1) and the Codec Configuration register (COD_CFG).
The PCM port is considered to be in slave mode when its clock source is the external pin. The PCM
frame pulse is also sourced from its external PFRM pin when the clock is configured as such. The
PCM port is in master mode for the other three settings. The PCM frame pulse is derived from the
internal PCLK and driven out on the PFRM pin.
The codec port initially has the CCLK pin tristated until it is configured as an output by setting the
CCLK_OE bit in the MISC_CTL register. It is never an input. The external source for the codec
clock is the PCLK pin. This allows simultaneous use of the PCM and codec interfaces with the
PCM bus providing the clock and allowing MCLK to be some other frequency that may not be
suitable to divide down for the codecs.
The ADPI clock is not derived from the circuit shown in Figure 3, but rather comes from the TSI
module. The TSI keeps track of opportunities to transmit bytes into the DSL frame and creates a
burst of eight pulses to clock a byte of data to insert in the MX direction. The TSI unloads data
from the DX DSL direction and also creates a burst of eight pulses to clock a byte of data to the
external device connected to the ADPI interface.
Datasheet
21
LXP730 — Multi-Rate DSL Framer
The burst frequency of the ADPI clocks is derived from MCLK and can be adjusted by the
SAPCLKDIV (bits 6 & 7, in register 17h, FIFO_MISC).
Table 4.
Typical ADPLL Register Settings, MCLK = 16.384MHz
PCMCLK
Output
(MHz)
#B PCM
#B DSL
NCO Frequency
(MHz)
PROG_
DIV
NCOFREQ/
MCLK
CFREQ(17:0)
1.544
24
12
PCMCLK × 8
4
0.754
0x30400
2.048
32
18
PCMCLK × 4
2
0.5
0x20000
1.152
18
18
PCMCLK × 8
4
0.5625
0x24000
0.896
14
14
PCMCLK × 16
8
0.875
0x38000
0.768
12
12
PCMCLK × 16
8
0.75
0x30000
0.256
4
4
PCMCLK × 32
16
0.5
0x20000
Figure 3. Clock Generation and Distribution
MCLK (pin 8)
NCO
÷2
Divider
Clock
Select
Programmable Divider
(1E: 7 - 0)
PCM
Clock
Select
PCM Port (20: 6 - 5)
Codec
Clock
Select
Codec Port (22: 7 - 6)
PCLK (pin 14)
2.11
Modes of Operation
2.11.1
Microprocessor Control (MPC) Mode
The Microprocessor Control (MPC) mode provides access for a microprocessor to configure and
control the operation of the framer. The LXP730 provides an 8-bit data bus for the purpose of
reading and writing internal registers. The registers are used to configure framer settings, to read
and write the MDSL Overhead bits and to configure interrupts and other run-time operational
functions.
The microprocessor access circuits support both MOTEL (MOTorola/IntEL) microprocessor
interfaces. A chip select signal activates the interface between the device and the microprocessor.
In the Motorola mode, the LXP730 supports the R/W and CS signals. The Motorola signal DS is
not used in this mode. In the Intel mode, the LXP730 supports the CS, ALE, WR and RD signals.
In the Intel mode, the data pins conform to the Intel style Address/Data (AD) functionality. The
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Datasheet
Multi-Rate DSL Framer — LXP730
address is presented to the AD pins and internally latched with ALE, then the data is either read
from or written to the device. ALE may be held high for non-multiplexed address and data
operation in the Intel mode for use of the WR and RD signals.
One interrupt pin is provided. Registers are provided for enabling/disabling the interrupts and
monitoring the status of the interrupt signals.
In the MPC mode, both the PCM and Codec/Data Port interfaces may be used simultaneously. The
assignment of the 64 kbps timeslots from the interfaces to the DSL is controlled by the TSI (Time
Slot Interchange) block. This feature allows data from two different sources to be transported over
the DSL.
2.11.2
Hardware Control (HWC) Mode
This mode provides an operational method to run only the codec and OSIO interface without a
microprocessor. Pins are provided to select the number (N) of 64 kbps channels to be transported.
The following Error/Status flags output pins are provided: LINK_ACTIVE, CRC_ERR and FEBE.
RESET, HTUC/HUTR and RUN-STOP control signals (input pins) are provided.
These pins are shared with the microprocessor mode pins. The HWC mode is selected by pulling
the WR, RD, CS and ALE pins Low and the MOTEL pin High.
Only the codec and OSIO interfaces are accessible in the HWC mode. The first N codec frame sync
pins are active in sequence from 1 to N. As shown in Table 5, pins N1 through N4 are used to select
the quantity of codecs supported and to select the proper MDSL frame format. The N0 pin is not
used since N is always an even number in the HWC mode. The codec interface runs only at the
2.048 MHz 1x clock in the HWC mode.
Table 5.
Pin settings for HWC DSL Line Rates
Number of
MDSL Channels
2.12
Pin
N4
N3
N2
N1
4
0
0
0
1
6
0
0
1
0
8
0
0
1
1
10
0
1
0
0
12
0
1
0
1
18
1
0
0
0
MDSL Overhead Definition
The MDSL overhead bits do not carry any payload values but are used for exchanging messaging
and signalling information between the two ends of the DSL link. The overhead bits are divided
into two categories; OH and Z bits.
The OH bits are defined in both the ETSI ERT/ETS-152 and ANSI T1E1.4/94-006 standards.
These usually have specific definitions. In the LXP730, the OH bits may be partially defined,
according to the standards, or totally user definable which is referred to as transparent mode.
The LXP730 supports DSL OH bits in four modes:
Datasheet
23
LXP730 — Multi-Rate DSL Framer
•
•
•
•
Transparent and register accessible.
Transparent and OSIO accessible.
Partially Predefined and register accessible.
Partially Predefined and OSIO accessible.
The reset default overhead mode is number 4. The modes are selected by setting bits 7 and 6 of
register 24h, OVRHD_CFG.
In the HWC mode some of the pre-defined bits’ status is routed to external status pins, i.e.
CRC_ERROR, FEBE, LINK_ACTIVE.
2.12.1
Predefined Overhead
Pre-defined bit-fields support: frame sync word, stuff-bits, los, CRC-6, febe, indc_r, f bits and user
defined overhead bits. In this mode the user may write to the corresponding bits in the MXOH
registers, but the LXP730 will ignore them and insert the predefined bits into the bit stream.
The frame sync word (FSW) bit pattern consists of the following 14 bits in order from left to right:
(10101000001000), this generates the +3 +3 +3 -3 -3 +3 -3 quat valued sync waveform on the
MDSL. Other valid sync patterns are the time-reversed, sign bit inverted, and the time reversed
sign bit inverted patterns shown in Table 6. The generation and detection of the FSW is automatic.
Detection of a frame that has an inverted sign bit causes the MDSL block to invert the sign bits of
the data stream before it is sent to the descrambler.
Stuff-bits are normally either four (4) bits or zero (0) bits immediately before the sync word of the
next frame. The stuffing decision circuit is located in the MDSL Interface block. A special mode
fixes the stuff bits at two per frame for applications that require fixed timing such as connections
from a wireless base station to its remote sites. This is controlled by bit 0 in register 17h,
FIFO_MISC.
The los bit is used to notify the other side of the DSL of a loss of source from the PCM bus.
CRC-6 bits are calculated at the transmitter for each frame and sent during the following frame. At
the receiver the CRC-6 is calculated on the received frame, stored and then compared with the
CRC-6 value received in the following frame. Sync word bits, stuff bits and CRC-6 bits are the
CRC-6 calculation.
The febe bit is set in the MX side to the other MDSL unit when a CRC-6 error detected is in the DX
side.
The indc_r bit is set in the MX side to notify the other MDSL unit that it is ready to receive
transport data.
2.12.2
Z bits
The first three Z bits in an MDSL frame are reserved for loop ID for multi-loop DSL systems by
the ETSI standard. All other Z bits are user defined. One common use is to send the time slot
configuration from the Local unit to the Remote unit.
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Datasheet
Multi-Rate DSL Framer — LXP730
The Z bits may either accessed through the registers or the OSIO interface. This is controlled by the
Z_CTL bit in register 23h, MISC_CTL. When OH and Z bits both go through the OSIO, they go in
order as listed in the frame structure in Table 7. For example: if transparent OH and Z bits all go
through the OSIO, then the order for an MDSL frame is 2 OH bits, 12 Z bits, 10 OH bits, 12 Z bits,
10 OH bits, 12 Z bits, 10 OH bits, 12 Z bits. Switching to OH predefined, the corresponding
predefined OH bits would not appear at the OSIO and there would be a gap at those time locations.
In HWC mode all the Z bits and the user definable OH bits go through the OSIO.
When the LXP730 is in fractional T1 mode, Z bits are part of the payload and not accessible,
otherwise they are accessible in the Z bit registers.
2.13
MDSL Frame Format
The LXP730 has a transport frame format that adjusts automatically with the N setting. The overall
structure remains constant while adjusting the number of time slots within the payload blocks.
Table 7 and Figure 4 shows the overall frame format.
Table 6.
Table 7.
MDSL Frame Sync Word (FSW) Patterns
Type Pattern
Bits
Quat Value
Normal
10101000001000
+3 +3 +3 -3 -3 +3 -3
Time-reversed
00100000101010
-3 +3 -3 -3 +3 +3 +3
Inverted-Sign-Bit
00000010100010
-3 -3 -3 +3 +3 -3 +3
Inverted-Sign-Time-Reversed
10001010000000
+3 -3 +3 +3 -3 -3 -3
MDSL Frame Format
Description
Number of Bits
Sync Word
14
MOH
2
B1-B12
[Z + (N × 8)] × 12
MOH
10
B13-B24
[Z + (N × 8)] × 12
MOH
10
B25-B36
[Z + (N × 8)] × 12
MOH
10
B37-B48
[Z + (N × 8)] × 12
Stuff
0 or 4, typ avg 2
The frame is made up of a sync word, followed by alternating sets of MDSL Overhead bits and
groups of data blocks. The final element of each frame is a section set aside for stuffing, used to
synchronize payload with DSL framing where required.
Datasheet
25
LXP730 — Multi-Rate DSL Framer
Each data block contains [Z + (N × 8)] bits. The blocks are transmitted in groups of 12. In T1 mode
Z=1 and the 12 Z-bits per block group are reserved for framing/signalling and are referred to as fbits. In all other modes they are user accessible overhead bits known as Z-bits. The frame structure
matches the 784 kbps structure adopted by T1E1 and ETSI. For N=18 and Z=1, the frame format
follows that of an 1168 kbps HDSL system compliant with ETSI standards.
2.14
Startup Operation
This description applies to the MPC mode for the LXP730. Typically the user sets most of the
desired register values and then sets the RUN bit in register 24h, OVRHD_CFG. At this point the
MX side of the framer is sending data to TDATA and the DX side is looking for the FSW. The next
step requires clearing of INT_STAT register by writing OxFF to it. It must be ensured that the
SK70725/21 chipset is in either Master or Slave mode as needed. The SK70725/21 chipset needs to
be reset and the ACTIVATE bit toggled in the SK70725/21 chipsets. The main control register has
to be toggled. In Master mode, the SK70725/21 will start the activation sequence with the Slave
responding. In a few seconds the data pumps will have set their filter and echo coefficients and
switch to transparent transport mode.
There is an additional setup to consider when the LXP730 is in PCM slave mode and N=18. If
there is no clock running, then there is a halt condition when 18 PCM time slots are selected. The
work around is to temporarily set the last two of the Nx registers to codec configuration, then set
the RUN bit. Once that is done then change the Nx registers back to the desired PCM
configuration.
Figure 4. Frame Format for N=12
MDSL Frame (784k):
14
SYNCH
2
1164
OH
BLKS 1 - 12
10
1164
OH
10
BLKS 13 - 24
1164
OH
10
BLKS 25 - 36
OH
1164
0/4
BLKS 37 - 48
STUFF
6 msec
MDSL Block (784k):
8
Z TS0
8
8
8
8
8
8
8
8
8
8
8
TS1
TS2
TS3
TS4
TS5
TS6
TS7
TS8
TS9
T10
T11
The DX side of the LXP730 will go to ACTIVE upon receipt of two successive MDSL frames.
When this first occurs, the ACTIVE bit in INT_STAT is set, but will stay reset once it is cleared
until the framer goes to inactive and back to active again. The ACTIVE bit is edge triggered. The
DSLACTIVE bit in CRC_FEBE_ST is level triggered or ‘sticky’.
Once the DSL is active, no support is required to keep it operating. At this point there are basically
two tasks to perform: 1) monitor for error conditions, 2) use the overhead to pass messages/
signalling between the Local and Remote units.
26
Datasheet
Multi-Rate DSL Framer — LXP730
Most of registers/bits can be changed while the RUN bit is set with the following exceptions:
• N_MDSL register
• TX8KSSEL bit in 17h
The MX and DX FIFOs (MXFIFORXT & DXFIFORXT) should be reset whenever the PCM or
codec clocks are changed while the framer is in the RUN mode. This will cause an interruption in
the payload, but the DSL link will stay up.
2.15
Activation State Machine
The LXP730 framer has an ANSI T1E1.4/94-006 compatible activation state machine. The
operation of the state machine is shown in Figure 5.
Figure 5. Activation State Machine
No
Sync
Sync &
RUN/
STOP =
RUN
Initial
"Out-of-Sync"
State 0
ACTIVE = 0
LOS = 1
Sync
1
No
Sync
Sync
(COFA = 0)
Sync with No
Change Of
Frame
Alignment
No
Sync
Sync
In
Sync
State 2
ACTIVE = 1
No
Sync
Out
of Sync
State 8
ACTIVE = 0
LOS = 0
No
Sync
Sync with Change
Of Frame
Alignment
Datasheet
Sync
7
No
Sync
Sync
9
5
6
No
Sync
10 COFA = 1
No
Sync
4
No
Sync
No
Sync
3
No
Sync
Sync
COFA = 1
27
LXP730 — Multi-Rate DSL Framer
3.0
Application Information
3.1
Typical Applications
This section shows some block diagrams to serve as example applications. Connections to the
LXP730 as shown emphasize those relevant for the application. Detailed connections to the
processor are not shown.
Figure 6 demonstrates how the LXP730 can simultaneously handle voice from a PCM circuit and
packet-type data from an HDLC style device.
Figure 7 is an example of the HWC mode. The codecs’ digital interfaces connect directly to the
LXP730. An external device is needed to handle signalling information for each voice line
supported. In this case the Z bits could be used to carry the signalling information such as off-hook
status from the CPE and ringing signal from the CO. An FPGA or a fast dedicated processor could
handle these tasks.
Figure 6. High Performance Voice/Data Transport
2.048/4.096 Mbps
PCM Highway
PDI
PDO
PCLK
PFRM
HDLC
4
µP - Router
TDATA
RDATA
PCM
LXP730
Framer
QUATCLK
BIT_CK
SK70725/21
Data Pump
ADPI
Microprocessor Bus
Packet/Cell
Data
LAN
Transceiver
LXT905
Nx64 kbps
Channels
28
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 7. Pair Gain Transport
2.048 Mbps
PCM Highway
TDATA
RDATA
QUATCLK
BITCLK
CDATI
CDATO
CCLK
SK70725/21
Data Pump
ACTIVE
Combo
Codec
FRM1
LXP730
Framer
SIO
Signalling Control
Indicators
Combo
Codec
FRMn
64 kbps Voiceband
Channels
Figure 8 shows a more traditional DSL application to carry phone traffic over a longer distance on
a single copper pair. The LXP730 supports the pleisiochronous nature of T1/E1 traffic.
3.1.1
IOM Interface Circuitry
The LXP730 uses a frame pulse in the second cycle of the two clocks per data bit timing. This is
directly compatible with the ST electrical interface. The IOM interfaces use the first clock cycle for
the frame pulse. The circuit in Figure 9 shows how to adapt the LXP730 to the IOM bus. Note that
even though the circuit is the same for the PCM master or slave modes, there is a difference in the
connections to the LXP730 and the IOM device.
Figure 8. T1/E1 Fractional Transport
TDATA
RDATA
PFRM
PDATI
PCLK
T1/E1 Framer
QUATCLK
BITCLK
FRM1
PDO
CCLK
SK70725/21
Data Pump
LXP730
Framer
Microprocessor
Datasheet
29
LXP730 — Multi-Rate DSL Framer
Figure 9. IOM Adaption Circuitry
LXP730 PCM Master
PCM_FS_POS = 1
PFRM
PCLK
Master PCM
FRAME
PCLK
3.1.2
D
Q
1/2
74HC74
D
Q
PFRM Delayed
1/2
74HC74
LXP730 PCM Slave
PCM_FS_POS = 0
D
Q
1/2
74HC74
D
Q
PFRM
1/2
74HC74
Handling TIP/RING Reversal in Early Version of SK70725
The early version of the SK70725 data pump device has an error in the Master (CO) mode. The
QUAT_CLK is not aligned correctly with the RDATA for the sign and magnitude bits. When there
is no TIP/RING reversal, the LXP730 is able to correctly parse the data bits. However, when TIP/
RING reversal has occurred the LXP730 detects that the sign bit is inverted by detecting the
inverted Frame Sync Word (FSW) pattern. The LXP730 then uses the QUAT_CLK to determine
which bit to invert. The sign bit is already inverted and the LXP730 inverts the magnitude bit.
This problem does not occur in the Slave (CPE) mode of the SK70725. The SK70725 has the
ability to invert the received data pulses inside itself. This is done by setting bit 7 of the register
WR2. The following procedure takes advantage of how the LXP730 reacts during the error
condition and the ability to invert the data stream from the SK70725. The procedure uses one of
the Z-bit bytes after frame sync has been achieved to determine if there is a tip-ring reversal at the
LTU. DXZ2 and MXZ2 are good choices and are used only at the start up time. The TIP/RING
reversal indicator in the SK70725 does not have any meaning in mode 0, as the transparent mode
needed to work with LXP730. This procedure can be left in the code for the future SK70725
revision. The procedure also shows how to handle BELB from the CPE end.
TIP/RING Reversal Procedure:
1. Start.
2. Initialize the LXP730s for required configuration.
3. Activate the SK70725s.
4. Send the test pattern MXZ2 from the NTU side. MXZ2 = AAh.
5. If DXZ2 = AAh is received on LTU TIP/RING lines are straight and system is ready for
transmission. Go to step 7.
30
Datasheet
Multi-Rate DSL Framer — LXP730
6. Otherwise if DXZ2 = 55h, set B7 to 1 in register WR2 of SK70725 (Address 02, data 80h). Set
bit B0 to 0 in register 24h of LXP730 to stop it and then set this bit back to 1 to re-start. The
framer needs to be restarted to recognize the new sync word. TIP/RING lines are reversed and
corrected for in the SK70725, and the system is ready for transmission.
7. Normal operation.
For BELB (Back End Loop Back) on the NTU side:
8. Send message to NTU side to set the SK70725 in BELB (set bit B6 to 1 in register WR0 of
SK70725 on the NTU side).
9. If the TIP/RING was detected to be straight then set B4 to 1 in register 17h in LTU LXP730
(Address 57h, data 10h) and go to step 11. BELB is completed and the system is ready for
transmission.
10. If the TIP/RING reversal was detected and corrected on the LTU side, then set B7 to 0 in
register WR2 of LTU SK70725. Set B4 to 1 in register 17 in LXP730 (Address 57h, data 10h).
Set bit B0 to 0 in register 24 of LXP730 to stop it and then set this bit back to 1 to re-start.
BELB is completed and the system is ready for transmission.
11. When BELB testing is done, reset B4 to 1 in register 17h in LTU LXP730 and send the
command to NTU to undo BELB. Before NTU shuts off BELB all received payload and
overhead data will be scrambled with the wrong polynomial and the value in DXZ2 will jump.
At the LTU wait until there are two consecutive frames where DXZ2 = 55h or AAh.
12. Go to step 4.
3.1.3
DSL System Loopbacks
Data loopbacks in telecom systems are primarily used for system diagnostics. These tests are
usually either BER (Bit Error Rate), or to determine which part of the system is malfunctioning.
In DSL systems the loopback points are usually controlled by the CO (Central Office) end. Line
cards may have one or more DSL loops, and the processor on the board sets the loopback
operation; typically on command from the central control point in the switching system.
The loopback in the linecard demonstrates that the data can successfully be moved from the input
at the MX section through the DX section to receive side of the payload. Typically this is done
with the data pump Front End Loop Back (FELB). This transmits the data onto the wire pair, but
the receive signal from the wire pair is ignored. Instead, the DSL receiver is fed the signal from the
transmitter via an internal multiplexer.
The framer also has a loop back that ignores data from the data pump. This is useful in isolating the
data pump as the source of a malfunction such as when the line has been hit by lightning.
A back end loopback (BELB) is used to test the wire pair and the remote data pump. Here the
RDATA from the data pump is passed to the framer so it can still receive commands from the CO,
such as to turn off the BELB.
A payload loopback at the remote line card will check out the framer and give a more complete
evaluation of the DSL system.
The CO and the CPE each use a different scrambling polynomial in their transmitted data. Each
side expects to receive a different scrambling setting than the one they transmit. When the framer
is in loopback it knows to switch its receive scrambler to match the transmitter. When the local
Datasheet
31
LXP730 — Multi-Rate DSL Framer
FELB is on, the framer does not know by itself that its receive scrambler has to be switched.
Switching is accomplished in the LXP730 by setting the REMOTE_LB bit in register 17h. This
also needs to be done when the remote BELB is in operation.
When the remote CPE end switches off the BELB the CO end will not correctly interpret the data
until the REMOTE_LB is turned off. However it will still recognize the FSW because it is not
scrambled.
3.1.4
Using Multiple Devices on an Interrupt Line
The LXP730 INT pin is an output pin and therefore requires a circuit, as shown in Figure 10, to
operate with additional devices that share the same interrupt line to the microprocessor. Each
LXP730 that is tied to the shared interrupt line will need its own isolating diode.
Figure 10. Multiple Interrupt Line Circuit
+5V
LXP730
Interrupt
Line Pull-up
INT
1N4148 or
equivalent
µP
INT
LXP730
INT
1N4148 or
equivalent
To other
device
interrupt pins
32
Datasheet
Multi-Rate DSL Framer — LXP730
4.0
Test Specifications
Note:
Table 8.
Table 8 through Table 23 and Figure 11 through Figure 24 represent the performance specifications
of the LXP730 and are guaranteed by test except, where noted, by design. The minimum and
maximum values listed in Table 10 through Table 23 are guaranteed over the recommended
operating conditions specified in Table 9.
Absolute Maximum Ratings
Parameter
Symbol
Min
Max
Unit
Supply voltage
VCC
-0.3
6
V
Storage temperature
TST
-65
+150
ºC
Caution: Exceeding these values may cause permanent damage.
Functional operation under these conditions is not implied.
Exposure to maximum rating conditions for extended periods may affect device reliability.
Table 9.
Recommended Operating Conditions
Sym
Min
Typ1
Max
Unit
Recommended supply voltage
VCC
4.5
5.0
5.5
V
Recommended operating temperature
TOP
-40
25
+85
°C
Power dissipation
PD
-
0.3
0.6
W
Parameter
1. Typical figures are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
Table 10. I/O Electrical Characteristics
Parameter
Sym
Min
Typ1
Max
Unit
Test Conditions
Input Low voltage
VIL
–
–
0.3xVCC
V
CMOS inputs
Input High voltage
VIH
0.7xVCC
–
–
V
CMOS inputs
Output Low voltage
VOL
–
–
0.4
V
IOL = 4 mA
Output High voltage
VOH
0.7xVCC
–
–
V
IOH = -4 mA
Input Low current
IIL
-10
–
–
µA
VIN = Gnd, VCC = 5.5V
Input High current
IIH
–
–
10
µA
VIN = VCC, VCC = 5.5V
tR, tF
–
5
–
ns
CLOAD = 30 pF
CIN
–
12
–
pF
Output rise/fall time
Capacitance, any input pin
1. Typical values are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
Datasheet
33
LXP730 — Multi-Rate DSL Framer
Figure 11. Generic PCM Interface Timing
tCP1
PCLK1
tCH1
tCP2
tCL1
PCLK2
tCL2
tDO
tCH2
PDO
tSU
PDI
tHT
tFPW
PFRM
tFHT
tFSU
NOTES:
PCLK1 = 1x clock, PCLK2 = 2x clock.
Clock sampling edges and frame pulse polarity are programmable.
Table 11. Generic PCM Bus Interface Timing Specifications (See Figure 11)
Parameter
PCLK period
Sym
Min
Typ1
Max
Unit
tCP1
tCP2
122
–
3906
ns
40
–
60
%
PCLK duty cycle input
PCLK duty cycle output
(MCLK)
50
PCLK duty cycle output
(ADPLL)
See Note 2
PDO delay time
PDI setup time
PDI hold time
PFRM setup time
PFRM hold time
PFRM pulse width
tDO
tSU
tHT
tFSU
tFHT
tFPW
%
–
–
80
ns
20
–
–
ns
10
–
–
ns
20
–
–
ns
–
–
10
1
Test Conditions
ns
tcp
1. Typical values are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
2. UI Jitter = PCLK frequency ÷ MCLK frequency.
34
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 12. PCM Timing, 1X Clock
Clocks are shown with arrow
indicating sampling edge for data
FE=0, FS_POS=0
DCE=0
DATA
2
1
0
7
6
5
2
1
0
7
6
5
2
1
0
7
6
5
2
1
0
7
6
5
FE=0, FS_POS=1
FE=1, FS_POS=0
DCE=1
DATA
FE=1, FS_POS=1
FE=1, FS_POS=0
DCE=0
DATA
FE=1, FS_POS=1
FE=0, FS_POS=0
DCE=1
DATA
FE=0, FS_POS=1
Datasheet
35
LXP730 — Multi-Rate DSL Framer
Figure 13. PCM Timing, 2X Clock
Clocks are shown with arrow
indicating sampling edge for data
FE=0, FS_POS=0
DCE=0
DATA
3
2
1
0
7
3
2
1
0
7
FE=0, FS_POS=1
FE=1, FS_POS=0
DCE=1
DATA
FE=1, FS_POS=1
FE=1, FS_POS=0
DCE=0
DATA
3
2
1
0
7
3
2
1
0
7
FE=1, FS_POS=1
FE=0, FS_POS=0
DCE=1
DATA
FE=0, FS_POS=1
36
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 14. Codec Interface Timing
CDATO
tDO
CCLK
1
2
3
4
5
tCH
6
tDO
7
8
9
tCL
tCP
tSU
FRAMESYNCk
tHT
CDATI
Table 12. Codec Interface Timing Specifications (See Figure 14)
Sym
Min
Typ1
Max
Unit
Output delay time of CDATO,
FRAMESYNCk
tDO
–
–
40
ns
Codec clock period
tCP
122
488
3906
ns
Parameter
CCLK duty cycle output (MCLK)
50
CCLK duty cycle output (ADPLL)
See Note 2
Test Conditions
Referenced from rising edge of
CCLK
%
CDATI setup
tSU
20
–
–
ns
Referenced from the falling edge of
CCLK
CDATI hold time
tHT
50
–
–
ns
Referenced from the falling edge of
CCLK
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. UI Jitter = PCLK frequency ÷ MCLK frequency.
Datasheet
37
LXP730 — Multi-Rate DSL Framer
Figure 15. Asynchronous Port Timing
Arrows on clocks indicate
sampling edge
OSIF
tBYTE_SPACE
tD1
SDICK
Waveforms assume ADPI
programmed for first two
MDSL channels
tPER
SDICK
tSU
SDI
tHT
OSOF
tBYTE_SPACE
tD2
SDOCK
tPER
SDOCK
tD
SDO
Table 13. Asynchronous Port Timing Specifications (See Figure 15)
Parameter
Time to next adjacent byte
Clock period
Delay to first transmit byte
Sym
Min
Typ1
Max
Unit
tBYTE_SPACE
-
8 x BIT_CLK-1
-
seconds
-
seconds
-
seconds
-
seconds
tPER
tD1
-
-1
MCLK x SAPCLKDIV
140 x BIT_CLK
-1
-1
Delay to first receive byte
tD2
-
Set-up time
tSU
20
-
ns
Hold time
tHT
10
-
ns
Output delay
tD
-
-
11 x BIT_CLK
40
ns
1. Typical figures are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
38
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 16. OSIO Timing
TDATA Frame
1 2 3
11
14 15 16
OSIF
OSDICK
tSU
OSDI
tHT
BIT_CLK
RDATA Frame
33
OSOF
OSDOCK
tD
NOTE:
1. OSDICK and OSDOCK are shown for OH transparent setting, and both OH and Z bits tr
2. Data waveforms exagerated with respect to clock to show timing details more clearly.
Table 14. OSIO Timing Specifications (See Figure 16)
Sym
Min
Typ1
Max
Unit
Set-up time
tSU
-
-
20
ns
Hold time
tHT
10
-
-
-
Output delay
tD
-
-
80
ns
Parameter
1. Typical figures are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
Datasheet
39
LXP730 — Multi-Rate DSL Framer
Figure 17. MDSL Interface Input Timing
BITCLK
RDATA
tSU
QUATCLK
tHT
Sign bit
Magnitude bit
Table 15. MDSL Interface Input Timing Specifications (See Figure 17)
Parameter
Sym
Min
Typ1
Max
Unit
Test Conditions
tSU
tHT
30
–
–
ns
Referenced from falling edge of BITCLK
10
–
–
ns
Referenced from falling edge of BITCLK
Setup time of RDATA
Hold time of RDATA
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Figure 18. MDSL Interface Output Timing
BITCLK
Sign bit
TDATA
Magnitude bit
tD
QUATCLK
Table 16. MDSL Interface Output Timing Specifications (See Figure 18)
Parameter
Output delay time of TDATA
Sym
Min
Typ1
Max
Unit
Test Conditions
tD
–
–
100
ns
Referenced from rising edge of BITCLK
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
40
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 19. E1/T1 Input Timing
tR
tPW
tPWL
TCLKI
tPWH
tF
T1E1I, FRMIN
tSU
tHT
Table 17. E1/T1 Input Timing Specifications (See Figure 19)
Sym
Min
Typ1
Max
Unit
30
–
–
ns
Referenced from falling edge of PCLK
Hold time of T1E1I, FRMIN
tSU
tHT
10
–
–
ns
Referenced from falling edge of PCLK
E1, T1 clock period
tPW
–
488,
647
–
ns
TCLKI pulse width low
tPWL
tPWH
50
–
–
ns
50
–
–
ns
Parameter
Setup time of T1E1I, FRMIN
TCLKI pulse width high
Test Conditions
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Figure 20. E1/T1 Output Timing
tPW
tPWH
tPWL
TCLK0
tF
tR
T1E10,
FRMOUT
tD
Datasheet
41
LXP730 — Multi-Rate DSL Framer
Table 18. E1/T1 Output Timing Specifications (See Figure 20)
Sym
Min
Typ1
Max
Unit
Output delay time of T1E10,
FRMOUT
tD
–
–
100
ns
E1, T1 nominal clock period
tPW
–
488,
647
–
ns
tPWL
tPWH
50
–
–
ns
50
–
–
ns
Parameter
TCLK0 pulse width Low
TCLK0 pulse width High
Test Conditions
Referenced from rising edge of CCLK
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Figure 21. Microprocessor Write Cycle - Motorola Mode
tASU
Address (A<0:5>)
tDSU
D<0:7>
tDHT
CS
tCPW
tDHW
R/W
Table 19. Microprocessor Write Cycle Specifications—Motorola Mode (See Figure 21)
Parameter
Address setup time to CS
D<0:7> setup time to CS
Data-In hold time from CS
Allowable CS width
Write hold time
Sym
Min
Typ1
Max
Unit
tASU
tDSU
tDHT
tCPW
tDHW
20
–
–
ns
0
–
–
ns
10
–
–
ns
4/MCLK
–
–
s
20
Test Conditions
ns
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
42
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 22. Microprocessor Read Cycle - Motorola Mode
Address (A<0:5>)
R/W
CS
t1
t2
D<0:7>
Table 20. Microprocessor Read Cycle Specifications - Motorola Mode (See Figure 22)
Sym
Min
Typ1
Max
Unit
D<0:7> valid after CS
t1
–
-
4/MCLK
s
D<0:7> keep valid after CS
negation
t2
–
–
10
ns
Parameter
Test Conditions
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Datasheet
43
LXP730 — Multi-Rate DSL Framer
Figure 23. Microprocessor Write Cycle - Intel Mode
tCPW
CS
tWPW
WR
tASU
tWSU
tDHT
AD<0:7>
tAPW
ALE
Table 21. Microprocessor Write Cycle Specifications—Intel Mode (See Figure 23)
Sym
Min
Typ1
Max
Unit
tASU
30
–
–
ns
Address latch enable pulse
width
tAPW
30
D<0:7> setup time
tWSU
30
–
–
ns
Referenced from rising edge of CS or
WR
D<0:7> hold time
tDHT
10
–
–
ns
Referenced from rising edge of CS or
WR
CS width
tCPW
tWPW
4/MCLK
–
–
s
4/MCLK
–
–
s
Parameter
Address setup time
WR width
Test Conditions
Referenced from falling edge of ALE
ns
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
44
Datasheet
Multi-Rate DSL Framer — LXP730
Figure 24. Microprocessor Read Cycle - Intel Mode
CS
tCPW
RD
tRPW
tASU
tDHT
AD<0:7>
tAPW
tDO
ALE
Table 22. Microprocessor Read Cycle Specifications—Intel Mode (See Figure 24)
Sym
Min
Typ1
Max
Unit
tASU
30
–
–
ns
Address latch enable pulse
width
tAPW
30
–
–
ns
D<0:7> valid after CS, RD
assertion
tDO
–
–
60
ns
Referenced from the falling edge of RD
and CS
D<0:7> keep valid after CS,
RD negation
tDHT
–
10
20
ns
Referenced from rising edge of CS or
RD
Allowed width of CS
tCPW
tRPW
4/MCLK
–
–
s
4/MCLK
–
–
s
Parameter
Address setup time
Allowed width of RD
Test Conditions
Referenced from falling edge of ALE
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Table 23. MCLK Frequency and Tolerance Specification
Sym
Min
Typ1
Max
Unit
MCLK frequency
Fmclk
–
–
24.832
MHz
MCLK duty cycle
MDC
40
–
60
%
Parameter
Test Conditions
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Figure 25. Reset Timing
tRESET
RESET
Datasheet
45
LXP730 — Multi-Rate DSL Framer
Table 24. Reset Timing Specifications (See Figure 25)
Parameter
Reset Time
46
Sym
Min
Typ
Max
tRESET
3
-
-
Unit
Clock periods of slowest externally applied clock
Datasheet
Multi-Rate DSL Framer — LXP730
5.0
Register Definitions
Table 25. LXP730 Register Summary
Datasheet
Hex Address
Decimal
Address
Symbol
Type
00
0
N_MDSL
R/W
Number of nx64 channels
01
1
N1
R/W
MDSL channel 1 configuration
02
2
N2
R/W
MDSL channel 2 configuration
03
3
N3
R/W
MDSL channel 3 configuration
04
4
N4
R/W
MDSL channel 4 configuration
05
5
N5
R/W
MDSL channel 5 configuration
06
6
N6
R/W
MDSL channel 6 configuration
07
7
N7
R/W
MDSL channel 7 configuration
08
8
N8
R/W
MDSL channel 8 configuration
09
9
N9
R/W
MDSL channel 9 configuration
0A
10
N10
R/W
MDSL channel 10 configuration
0B
11
N11
R/W
MDSL channel 11 configuration
0C
12
N12
R/W
MDSL channel 12 configuration
0D
13
N13
R/W
MDSL channel 13 configuration
0E
14
N14
R/W
MDSL channel 14 configuration
0F
15
N15
R/W
MDSL channel 15 configuration
10
16
N16
R/W
MDSL channel 16 configuration
11
17
N17
R/W
MDSL channel 17 configuration
12
18
N18
R/W
MDSL channel 18 configuration
13
19
RSVR1
-
Reserved for future use
14
20
RSVR2
-
Reserved for future use
15
21
RSVR3
-
Reserved for future use
16
22
WANDER
R/W
Wander Reduction Register
17
23
FIFO_MISC
R/W
Fifo/Miscellaneous Control Register
Description
18
24
SLIP_THDL
R/W
Slip Buffer Threshold Low Level
19
25
SLIP_THDH
R/W
Slip Buffer Threshold High Level
1A
26
VERSION
R
1B
27
PLLCTL1
R/W
ADPLL Control 1
1C
28
PLLCTL2
R/W
ADPLL Control 2
1D
29
PLLCTL3
R/W
ADPLL Control 3
1E
30
PROG_DIV
R/W
MCLK Divide for PCM/codec blocks
1F
31
IDLE
R/W
Idle code for blocked PCM and MDSL slots
20
32
PCM1_CFG
R/W
PCM 1 configurations
21
33
PCM2_CFG
R/W
PCM 2 configuration
Version of the LXP730
47
LXP730 — Multi-Rate DSL Framer
Table 25. LXP730 Register Summary (Continued)
5.1
Hex Address
Decimal
Address
Symbol
Type
22
34
COD_CFG
R/W
23
35
MISC_CTL
R/W
Miscellaneous Control
24
36
OVRHD_CFG
R/W
Overhead mode
25
37
CRC_ERR_CNT
R/W
CRC error counter
26
38
FEBE_ERR_CNT
R/W
FEBE error counter
27
39
CRC_FEBE_ST
R/W
CRC and FEBE status
28
40
MXOH1
R/W
Mux Overhead Bits 1 - 8
29
41
MXOH2
R/W
Mux Overhead Bits 9 - 16
2A
42
MXOH3
R/W
Mux Overhead Bits 17 - 24
Description
Codec Configuration
2B
43
MXOH4
R/W
Mux Overhead Bits 25 - 32
2C
44
MXZ1
R/W
Mux Z Bits 1 - 8
2D
45
MXZ2
R/W
Mux Z Bits 9 - 16
2E
46
MXZ3
R/W
Mux Z Bits 17 - 24
2F
47
MXZ4
R/W
Mux Z Bits 25 - 32
30
48
MXZ5
R/W
Mux Z Bits 33 - 40
31
49
MXZ6
R/W
Mux Z Bits 41 - 48
32
50
DXOH1
R
Demux Overhead Bits 1 - 8
33
51
DXOH2
R
Demux Overhead Bits 9 - 16
34
52
DXOH3
R
Demux Overhead Bits 17 - 24
35
53
DXOH4
R
Demux Overhead Bits 25 - 32
36
54
DXZ1
R
Demux Z Bits 1 - 8
37
55
DXZ2
R
Demux Z Bits 9 - 16
38
56
DXZ3
R
Demux Z Bits 17 - 24
39
57
DXZ4
R
Demux Z Bits 25 - 32
3A
58
DXZ5
R
Demux Z Bits 33 - 40
3B
59
DXZ6
R
Demux Z Bits 41 - 48
3C
60
RSVR4
-
Reserved for future use
3D
61
RSVR5
-
Reserved for future use
3E
62
INT_EN
R/W
Interrupt enables
3F
63
INT_STATUS
R/W
Interrupt status flags
Number MDSL Channels Register
Address: 00
Abbreviation: N_MDSL
Read/Write
48
Datasheet
Multi-Rate DSL Framer — LXP730
Table 26. Number MDSL Channels
Bit
Name
Default
Description
<7:5>
Z_NUM
0
Number of Z bits in a group, valid values 0 - 7, Number of Z bits =
Z_NUM + 1. For T1/E1, only Z_NUM = 0 is valid
<4:0>
Number<4:0>
3
Number of MDSL channels, valid values: 3 - 17, Number of DSL
channels = Number + 1.
5.2
MDSL Channel Configuration Registers (18 bytes)
5.2.1
Channel 1
Address: 01
Abbreviation: N1
Read/Write
Table 27. Timeslot to Channel 1
5.2.2
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 2
Address: 02
Abbreviation: N2
Read/Write
Table 28. Timeslot to Channel 2
5.2.3
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 3
Address: 03
Abbreviation: N3
Read/Write
Datasheet
49
LXP730 — Multi-Rate DSL Framer
Table 29. Timeslot to Channel 3
5.2.4
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 4
Address: 04
Abbreviation: N4
Read/Write
Table 30. Timeslot to Channel 4
5.2.5
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 5
Address: 05
Abbreviation: N5
Read/Write
Table 31. Timeslot to Channel 5
5.2.6
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 6
Address: 06
Abbreviation: N6
Read/Write
50
Datasheet
Multi-Rate DSL Framer — LXP730
Table 32. Timeslot to Channel 6
5.2.7
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 7
Address: 07
Abbreviation: N7
Read/Write
Table 33. Timeslot to Channel 7
5.2.8
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 8
Address: 08
Abbreviation: N8
Read/Write
Table 34. Timeslot to Channel 8
5.2.9
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 9
Address: 09
Abbreviation: N9
Read/Write
Datasheet
51
LXP730 — Multi-Rate DSL Framer
Table 35. Timeslot to Channel 9
5.2.10
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 10
Address: 0A
Abbreviation: N10
Read/Write
Table 36. Timeslot to Channel 10
5.2.11
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 11
Address: 0B
Abbreviation: N11
Read/Write
Table 37. Timeslot to Channel 11
5.2.12
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 12
Address: 0C
Abbreviation: N12
Read/Write
52
Datasheet
Multi-Rate DSL Framer — LXP730
Table 38. Timeslot to Channel 12
5.2.13
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 13
Address: 0D
Abbreviation: N13
Read/Write
Table 39. Timeslot to Channel 13
5.2.14
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 14
Address: 0E
Abbreviation: N14
Read/Write
Table 40. Timeslot to Channel 14
5.2.15
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 15
Address: 0F
Abbreviation: N15
Read/Write
Datasheet
53
LXP730 — Multi-Rate DSL Framer
Table 41. Timeslot to Channel 15
5.2.16
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 16
Address: 10
Abbreviation: N16
Read/Write
Table 42. Timeslot to Channel 16
5.2.17
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 17
Address: 11
Abbreviation: N17
Read/Write
Table 43. Timeslot to Channel 17
5.2.18
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Channel 18
Address: 12
Abbreviation: N18
Read/Write
54
Datasheet
Multi-Rate DSL Framer — LXP730
Table 44. Timeslot to Channel 18
5.3
Bit
Name
Default
Description
<7,6>
CH_CFG
0
Channel configuration: 00 codec, 01 Idle code, 10 PCM, 11 Async
data
<5:0>
TS
0
PCM timeslot, valid values 0 - 63.
Reserved Registers (3 bytes)
Addresses: 13 - 15
Abbreviation: RSVR1-3
Table 45. Reserved Registers
5.4
Bit
Name
Default
<7:0>
RSRV1-3
-
Description
Not valid for read or write.
Wander Reduction Register
Addresses: 16
Abbreviation: WANDER
Read/Write
Table 46. Wander Reduction Register
5.5
Bit
Name
Default
Description
<7:0>
W_ENABLE
0
0 = disable wander reduction circuit; 24h = enable wander reduction
circuit.
FIFO/Miscellaneous Control Register
Addresses: 17
Abbreviation: FIFO_MISC
Read/Write
Datasheet
55
LXP730 — Multi-Rate DSL Framer
Table 47. FIFO/Miscellaneous Control Register
5.6
Bit
Name
Default
Description
<7:6>
SAPCLKDIV
00b
Async serial port clock select, 0 = MCLK/2, 1 = MCLK/4, 2 = MCLK/
8,
3 = MCLK/16.
5
TX8KSSEL
0
Transmit 8 KHz reference sync select control. 0 = TX reference
sync selected from PCM interface, 1 = TX reference sync selected
from codec interface.
4
REMOTE_LB
0
Remote Loopback select. Controls the scrambling polynomial for
remote loopback. 0 = normal operation, 1 = remote loopback.
3
PDOE_SEL
0
PCM data output enable select. Default value of 0 causes pin to be
FRMSYNC12 for codec operation. Set to 1 to create the output
enable signal PDOE for PCM usage. PDOE goes high for
programmed PCM time slots in the Nx registers.
2
DXFIFORXT
0
DX FIFO reset control. The DX elastic store FIFO is reset on a 0 to a
1 transition. The 0 or 1 state must be active for a minimum of 3
BITCLK periods.
1
MXFIFORXT
0
MX FIFO reset control. The MX elastic store FIFO is reset on a 0 to
a 1 transition. The 0 or 1 state must be active for a minimum of 3
BITCLK periods.
0
FIX2BSTUF
0
Fixed 2-bit stuffing mode enable; 0 = disable, 1 = enable.
Slip Buffer Lower Threshold Register
Address: 18
Abbreviation: SLP_THDL
Read/Write
Table 48. Slip Buffer Lower Threshold
56
Bit
Name
Default
Description
<7>
SLP_L_EN
0
0 = Use default, 1 = Enable and use Bits <6:0> for the Lower
Threshold. Must be set when Stopped (Run/Stop = 0).
<6:0>
SLP_LWR
0
MPC Mode: Lower Threshold of PCM Receive Slip Buffer (Default
31-N). HWC Mode: Not Used.
Datasheet
Multi-Rate DSL Framer — LXP730
5.7
Slip Buffer Upper Threshold Register
Address: 19
Abbreviation: SLP_THDH
Read/Write
Table 49. Slip Buffer Upper Threshold
5.8
Bit
Name
Default
Description
<7>
SLP_U_EN
0
0 = Use default, 1 = Enable and use Bits <6:0> for the Upper
Threshold. Must be set when Stopped (Run/Stop = 0).
<6:0>
SLP_UPR
0
MPC Mode: Upper Threshold of PCM Receive Slip Buffer (Default
32+N). HWC Mode: Not Used.
Version Register
Address: 1A
Abbreviation: VERSION
Read only
Table 50. Version
Bit
Name
Default
<7:0>
VER
0
Description
Version of Device.
5.9
Internal Clock Control Registers (4 bytes)
5.9.1
ADPLL Control 1
Address: 1B
Abbreviation: PLLCTL1
Read/Write
Table 51. ADPLL Control 1
Datasheet
Bit
Name
Default
<7:0>
CFREQ(17:1
0)
40
Description
Center Frequency of the ADPLL.
57
LXP730 — Multi-Rate DSL Framer
5.9.2
ADPLL Control 2
Address: 1C
Abbreviation: PLLCTL2
Read/Write
Table 52. ADPLL Control 2
5.9.3
Bit
Name
Default
<7:0>
CFREQ(9:2)
0
Description
Center Frequency of the DPPL.
ADPLL Control 3
Address: 1D
Abbreviation: PLLCTL3
Read/Write
5.9.4
Bit
Name
Default
Description
<7:6>
CFREQ(1:0)
0
Center Frequency of the DPPL.
<5>
AUTO_RST
0
1 = the ADPLL automatically resets the RX FIFO after lock. 0 = No
Reset.
<4:0>
KLOOP(4:0)
9
ADPLL Loop Filter Gain Setting.
MCLK Divide
Address: 1E
Abbreviation: PROG_DIV
Read/Write
Table 53. PROG Divide
5.10
Bit
Name
Default
<7:0>
PROG_DIV
07
Description
PROG Divide, pre-scaler for PCM and codec Interfaces,
PrescaleOut = MCLK/(MCLK_DIV + 1).
Programmable Idle Code Byte
Address: 1F
Abbreviation: IDLE
Read/Write
58
Datasheet
Multi-Rate DSL Framer — LXP730
Table 54. Programmable Idle Code Byte
Bit
Name
Default
<7:0>
IDLE <7:0>
FFh
Description
Programmable idle code. This 8 bit code contains the bit used for
channel blocking.
5.11
PCM Configuration Registers
5.11.1
PCM1 Configuration
Address: 20
Abbreviation: PCM_CFG1
Read/Write
Table 55. PCM 1 Configuration Bits
Bit
Name
Default
7
PCLKMODE
0
Description
Set to ‘0’ for 1x clock, set to ‘1’ for 2x clock.
PCM Clock Mux
5.11.2
00
01
10
11
External Pin, PCLK pin-14 (PCM Slave)
Internal ADPLL (PCM Master)
MCLK divided by PROG_DIV register
ADPLL output divided by PROG_DIV register
<6:5>
PCLKMUX
10b
4
DCE
0
Data clock edge, 0 = sample input data on falling edge - output data
on rising edge, 1 = sample input on rising edge - output data on
falling edge.
3
FINV
0
Frame Sync Pulse polarity, 0 = Active low, 1 = Active high.
2
FE
0
Frame Clock Edge, 0 = sample frame sync on falling edge - output
on rising edge, 1 = sample frame sync on rising edge - output on
falling edge.
1
SBBP
1
Slip buffer ByPass, 0 = Slip buffer active, 1 = Slip buffer bypassed.
0
TFI
0
Tri-state for IDLE code, 0 = pass IDLE to PCM, 1 = Tri-state PCM for
IDLE.
PCM2 Configuration
Address: 21
Abbreviation: PCM_CFG2
Read/Write
Datasheet
59
LXP730 — Multi-Rate DSL Framer
Table 56. PCM 2 Configuration Bits
5.12
Bit
Name
Default
Description
7
T1E1/PCM
0
T1E1 - PCM selection, 0 = PCM mode, 1 = T1E1 mode.
6
T1E1
1
T1/E1 selection, 0 = T1 frame mode, 1 = E1 frame mode.
<5:0>
MAXPCHN
1Fh
Max Number of PCM Channels, values 0 - 63, MAXPCHN + 1 = n
PCM channels between PCM sync pulses.
Codec Configuration Register
Address: 22
Abbreviation: COD_CFG
Read/Write
Table 57. Codec Configuration
Bit
Name
Default
Description
Codec Clock Mux
00
<7:6>
<0:5>
CCLKMUX
MAXCCHN
10b
1Fh
External Pin, PCLK pin-14
01
Internal ADPLL
10
MCLK divided by PROG_DIV register
11
ADPLL output divided by PROG_DIV register
Max Number of codec channels, values 0 - 31, MAXCCHN + 1 = n
codec channels between codec sync pulses.
5.13
Overhead Registers (25 bytes)
5.13.1
Miscellaneous Control
Address: 23
Abbreviation: MISC_CTL
Read/Write
Table 58. Miscellaneous Control
Bit
Name
Default
Description
LOS Select, for outgoing MX direction
00 set LOS based on PCLK
<7:6>
LOS_SEL
00b
01 set LOS based on codec clock
10 disable LOS; set ‘1’ to LOSD on TX DSL frame
11 enable LOS, for testing; set ‘0’ to LOSD on TX DSL frame
5
60
CCLKMODE
0
Set to ‘0’ for 1x clock, set to ‘1’ for 2x clock.
Datasheet
Multi-Rate DSL Framer — LXP730
Table 58. Miscellaneous Control (Continued)
5.13.2
Bit
Name
Default
Description
4
GAP_CLK
0
Gapped DSL Clock Out Select, Enable output for gapped receive
DSL clock. 0 = output always high, 1 = Gapped clock out.
3
Z_CTL
0
Z bit Mux control, 1 = Z bits to registers (Z_NUM = 0 only), 0 = Z bits
to OSIO.
2
ASPSEL
0
ADPI serial port select enable. 0 = disabled, 1 = enabled. Enabling
the ADPI disables codec frame syncs 7, 8, 9, and 10.
1
CCLK_OE
0
Codec Clock Output Enable. 0 = disabled, 1 = enabled.
0
PCM_FS_PO
S
1
PCM Frame Sync Position: 0 = first bit of the frame, 1= last bit of the
frame.
Overhead Configuration
Address: 24
Abbreviation: OVRHD_CFG
Read/Write
Table 59. Overhead Configuration
5.13.3
Bit
Name
Default
Description
7
Par/Ser
0
Overhead Data Mode: set to ‘0’ for external pins, ‘1’ for internal
register.
6
Trans/PreDef
0
‘1’ for transparent mode, ‘0’ for limited pre-defined mode.
5
CRC_CNT
0
CRC-6 error counter mode: ‘0’ for reset when read, ‘1’ for modulo
count.
4
FEBE_CNT
0
FEBE error counter mode: ‘0’ for reset when read, ‘1’ for modulo
count.
3
L/R
0
Local/Remote Mode, ‘0’ for Remote, ‘1’ for Local, selects scrambling
polynomial.
2
SRC_EN
0
Scrambler Enable, ‘0’ enabled, ‘1’ disabled.
1
DSL_LB
0
DSL Interface Loop Back, ‘0’ disabled, ‘1’ enabled.
0
RUN/STOP
0
0 = Set MDSL framer state machine to Deactivated state, 1 = Set
MDSL framer state machine to Activation state.
CRC Error Counter
Address: 25
Abbreviation: CRC_ERR_CNT
Read/Write
Datasheet
61
LXP730 — Multi-Rate DSL Framer
Table 60. CRC Error Counter
Bit
<7:0>
5.13.4
Name
CRC_ERR_
CNT <7:0>
Default
Description
CRC error counter, mode set by CRC mode bit in OVRHD_CFG
register.
0
FEBE Error Counter
Address: 26
Abbreviation: FEBE_ERR_CNT
Read/Write
Table 61. FEBE Error Counter
5.13.5
Bit
Name
Default
<7:0>
FEBE_ERR_
CNT <7:0>
0
Description
FEBE error counter, mode set by FEBE mode bit in OVRHD_CFG
register.
CRC - FEBE - LOS Status
Address: 27
Abbreviation: CRC_FEBE_ST
Read/Write
Table 62. CRC - FEBE Status
5.13.6
Bit
Name
Default
Description
7
CRC_OVR
0
‘1’ when CRC error counter overflowed in reset mode. Must write ‘1’
to reset.
6
FEBE_OVR
0
‘1’ when FEBE error counter overflowed in reset mode. Must write ‘1’
to reset.
5
CRCERRINJ
0
CRC Error Injection; when this bit is set to ‘1’ a CRC will be injected,
then the LXP730 will clear this bit after 1 DSL frame.
4
MX_LOS
0
<3:1>
n/a
000b
0
DSLACTIVE
0
‘1’ when LOS occurs, affected by LOS_SEL in MISC_CTL.
Reserved.
DSL link active status -- reports current status.
MX Overhead Bits 1 - 8
Address: 28
Abbreviation: MXOH1
Read/Write
62
Datasheet
Multi-Rate DSL Framer — LXP730
Table 63. MX Overhead Bits 1 - 8
5.13.7
Bit
Name
Default
Description
7
mx8/crc2
0
Transparent mode/ Pre defined mode.
6
mx7/crc1
0
Transparent mode/ Pre defined mode.
<5:2>
mx<6:3>
00b
1
mx2/febe
0
Transparent mode/ Pre defined mode.
0
mx1/los
0
Transparent mode/ Pre defined mode.
User definable.
MX Overhead Bits 9 - 16
Address: 29
Abbreviation: MXOH2
Read/Write
Table 64. MX Overhead Bits 9 - 16
5.13.8
Bit
Name
Default
<7:0>
mx<16:9>
0
Description
User definable.
MX Overhead Bits 17 - 24
Address: 2A
Abbreviation: MXOH3
Read/Write
Table 65. MX Overhead Bits 17 - 24
5.13.9
Bit
Name
Default
Description
<7:2>
mx<24:19>
0
User definable.
1
mx18/crc4
0
Transparent mode/ Pre defined mode.
0
mx17/crc3
0
Transparent mode/ Pre defined mode.
MX Overhead Bits 25 - 32
Address: 2B
Abbreviation: MXOH4
Read/Write
Datasheet
63
LXP730 — Multi-Rate DSL Framer
Table 66. MX Overhead Bits 25 - 32
5.13.10
Bit
Name
Default
<7:6>
mx<32,31>
00b
5
mx30/indcr
0
Transparent mode/ Pre defined mode.
4
mx29
0
User definable.
3
mx28/crc6
0
Transparent mode/ Pre defined mode.
2
mx27/crc5
0
<0:1>
mx<25,26>
00b
Description
User definable.
Transparent mode/ Pre defined mode.
User definable.
MX Z Bits 1 - 8
Address: 2C
Abbreviation: MXZ1
Read/Write
Table 67. MX Z Bits 1 - 8
5.13.11
Bit
Name
Default
<7:0>
mxz<8:1>
0
Description
User definable when not in T1 mode.
MX Z Bits 9 - 16
Address: 2D
Abbreviation: MXZ2
Read/Write
Table 68. MX Z Bits 9 - 16
5.13.12
Bit
Name
Default
<7:0>
mxz<16:9>
0
Description
User definable when not in T1 mode.
MX Z Bits 17 - 24
Address: 2E
Abbreviation: MXZ3
Read/Write
Table 69. MX Z Bits 17 - 24
64
Bit
Name
Default
<7:0>
mxz<17:24>
0
Description
User definable when not in T1 mode.
Datasheet
Multi-Rate DSL Framer — LXP730
5.13.13
MX Z Bits 25 - 32
Address: 2F
Abbreviation: MXZ4
Read/Write
Table 70. MX Z Bits 25 - 32
5.13.14
Bit
Name
Default
<7:0>
mxz<32:25>
0
Description
User definable when not in T1 mode.
MX Z Bits 33 - 40
Address: 30
Abbreviation: MXZ5
Read/Write
Table 71. MX Z Bits 33 - 40
5.13.15
Bit
Name
Default
<7:0>
mxz<40:33>
0
Description
User definable when not in T1 mode.
MX Z Bits 41 - 48
Address: 31
Abbreviation: MXZ6
Read/Write
Table 72. MX Z Bits 41 - 48
5.13.16
Bit
Name
Default
<7:0>
mxz<48:41>
0
Description
User definable when not in T1 mode.
DX Overhead Bits 1 - 8
Address: 32
Abbreviation: DXOH1
Read/Write
Datasheet
65
LXP730 — Multi-Rate DSL Framer
Table 73. DX Overhead Bits 1 - 8
5.13.17
Bit
Name
Default
Description
7
dx8/crc2
0
Transparent mode/ Pre defined mode.
6
dx7/crc1
0
Transparent mode/ Pre defined mode.
<5:2>
dx<6:3>
0000b
1
dx2/febe
0
Transparent mode/ Pre defined mode.
0
dx1/los
0
Transparent mode/ Pre defined mode.
User definable.
DX Overhead Bits 9 - 16
Address: 33
Abbreviation: DXOH2
Read/Write
Table 74. DX Overhead Bits 9 - 16
5.13.18
Bit
Name
Default
<7:0>
dx<16:9>
0
Description
User definable.
DX Overhead Bits 17 - 24
Address: 34
Abbreviation: DXOH3
Read/Write
Table 75. DX Overhead Bits 17 - 24
5.13.19
Bit
Name
Default
Description
<7:2>
dx<24:19>
0
User definable.
1
dx18/crc4
0
Transparent mode/ Pre defined mode.
0
dx17/crc3
0
Transparent mode/ Pre defined mode.
DX Overhead Bits 25 - 32
Address: 35
Abbreviation: DXOH4
Read/Write
66
Datasheet
Multi-Rate DSL Framer — LXP730
Table 76. DX Overhead Bits 25 - 32
5.13.20
Bit
Name
Default
<7:6>
dx<32,31>
00b
5
dx30/indcr
0
Transparent mode/ Pre defined mode.
4
dx29
0
User definable.
3
dx28/crc6
0
Transparent mode/ Pre defined mode.
2
dx27/crc5
0
<0:1>
dx<25,26>
00b
Description
User definable.
Transparent mode/ Pre defined mode.
User definable.
DX Z Bits 1 - 8
Address: 36
Abbreviation: DXZ1
Read/Write
Table 77. DX Z Bits 1 - 8
5.13.21
Bit
Name
Default
<7:0>
dxz<8:1>
0
Description
User definable when not in T1 mode.
DX Z Bits 9 - 16
Address: 37
Abbreviation: DXZ2
Read/Write
Table 78. DX Z Bits 9 - 16
5.13.22
Bit
Name
Default
<7:0>
dxz<16:9>
0
Description
User definable when not in T1 mode.
DX Z Bits 17 - 24
Address: 38
Abbreviation: DXZ3
Read/Write
Table 79. DX Z Bits 17 - 24
Datasheet
Bit
Name
Default
<7:0>
dxz<17:24>
0
Description
User definable when not in T1 mode.
67
LXP730 — Multi-Rate DSL Framer
5.13.23
DX Z Bits 25 - 32
Address: 39
Abbreviation: DXZ4
Read/Write
Table 80. DX Z Bits 25 - 32
5.13.24
Bit
Name
Default
<7:0>
dxz<32:25>
0
Description
User definable when not in T1 mode.
DX Z Bits 33 - 40
Address: 3A
Abbreviation: DXZ5
Read/Write
Table 81. DX Z Bits 33 - 40
5.13.25
Bit
Name
Default
<7:0>
dxz<40:33>
0
Description
User definable when not in T1 mode.
DX Z Bits 41 - 48
Address: 3B
Abbreviation: DXZ6
Read/Write
Table 82. DX Z Bits 41 - 48
5.14
Bit
Name
Default
<7:0>
dxz<48:41>
0
Description
User definable when not in T1 mode.
Reserved Registers (2 bytes)
Addresses: 3C and 3D
Abbreviation: RSVR4 and 5
Table 83. Reserved Registers
68
Bit
Name
Default
<7:0>
RSRV4,5
-
Description
Not valid for read or write.
Datasheet
Multi-Rate DSL Framer — LXP730
5.15
Interrupt Registers (2 bytes)
5.15.1
Interrupt Enables
Address: 3E
Abbreviation: INT_EN
Read/Write
Table 84. Interrupt Enables
5.15.2
Bit
Name
Default
Description
7
LOS_EN
0
Loss of source interrupt enable (set to ‘1’ to enable).
6
CRC_FEBE_E
N
0
CRC - FEBE interrupt enable.
5
INDCR_EN
0
indcr interrupt enable.
4
SLIP_DET_ EN
0
Slip detect interrupt enable.
3
OHMX_EN
0
Overhead MX interrupt enable.
2
OHDX_EN
0
Overhead DX interrupt enable.
1
ACTIVE_EN
0
ACTIVE interrupt enable.
0
COFA_EN
0
COFA interrupt enable.
Interrupt Status
Address: 3F
Abbreviation: INT_STAT
Read/Write
Table 85. Interrupt Status
Datasheet
Bit
Name
Default
Description
7
LOS
0
loss of source interrupt, set to ‘1’ when los is received in dx1/los.
6
CRC_FEBE
0
CRC - FEBE interrupt, set to ‘1’ when 1.) CRC error is detected in
DX, or 2.) febe is received in dx2/febe.
5
INDCR
0
indcr interrupt, set to ‘1’ when indcr is received in dx30/indcr.
4
SLIP_DET
0
Slip detect interrupt, set to ‘1’ when slip occurs in slip buffer.
3
OHMX
0
Overhead MX interrupt, set to ‘1’ when MX frame has started
allowing 6ms to write MX registers before start of next frame.
2
OHDX
0
Overhead DX interrupt, set to ‘1’ when DX frame has ended allowing
6ms to read DX registers before end of next frame.
1
ACTIVE
0
ACTIVE interrupt, set to ‘1’ when MDSL link is up.
0
COFA
0
COFA interrupt, set to ‘1’ when change of frame position occurs.
69
LXP730 — Multi-Rate DSL Framer
6.0
Mechanical Specifications
Figure 26. 64 - Pin LQFP Package Specification
Part Number LXP730LE
• 64-pin Low Profile Quad Flat Pack
• Extended Temperature Range (-40 to +85° C)
D
e
D1
for sides with even
number of pins
/2
e
E1
for sides with odd
number of pins
E
θ3
L1
A2
A
θ
A1
θ3
L
B
Inches
Millimeters
Dim
Min
A
Min
Max
.063
–
1.60
A1
.002
.006
0.05
0.15
A2
.053
.057
1.35
1.45
b
.007
.011
0.17
0.27
1
12.00 BSC
D1
1
0.394 BSC
10.00 BSC1
E
0.472 BSC1
12.00 BSC1
E1
1
0.394 BSC
10.00 BSC1
e
0.020 BSC1
0.50 BSC1
D
L
0.472 BSC
0.018
0.030
0.45
0.039 REF
L1
70
Max
1
0.75
1.00 REF
q3
11°
13°
11°
13°
q
0°
7°
0°
7°
Datasheet