Data Sheet
D8953BDSB
March 30, 1999
RS8953B/8953SPB
HDSL Channel Unit
The RS8953B is a High-Bit-Rate Digital Subscriber Line (HDSL) channel unit designed
to perform data, clock, and format conversions necessary to construct a Pulse Code
Multiplexed (PCM) channel from one, two, or three HDSL channels. The PCM channel
consists of transmit and receive data, clock and frame sync signals configured for
standard T1 (1544 kbps), standard E1 (2048 kbps), or custom (Nx64 kbps) formats.
The PCM channel connects directly to a Bt8370 T1/E1 Controller or similar T1/E1 device.
Connection to other network/subscriber physical layer devices is supported by the
custom PCM frame format. Three identical HDSL channel interfaces consist of serial
data and clock connected to a Bt8970 HDSL Transceiver or similar 2B1Q bit pump
device. The RS8953SPB contains one HDSL channel interface.
Control and status registers are accessed via the Microprocessor Unit (MPU)
interface. One common register group configures the PCM interface formatter,
Pseudo-Random Bit Sequence (PRBS) generator, Bit Error Rate (BER) meter, timeslot
router, Digital Phase Lock Loop (DPLL) clock recovery, and PCM Loopbacks (LB). Three
groups of HDSL channel registers configure the elastic store FIFOs, overhead MUXes,
receive framers, payload mappers, and HDSL loopbacks. Status registers monitor
received overhead, DPLL, FIFO, and framer operations, including CRC and FEBE error
counts.
The RS8953B adheres to Bellcore TA-NWT-001210 and FA-NWT-001211 and the
latest ETSI RTR/TM-03036 standards. C-language software for all standard T1/E1
configuration and startup procedures is implemented on Conexant's HDSL Evaluation
Module (Bt8973EVM) and is available under a no-fee license agreement. RS8953B
software can also be developed for non-standard HDSL applications or to interoperate
with existing HDSL equipment.
Functional Block Diagram
Distinguishing Features
Supports All HDSL Bit Rates
2 pair T1 standard (784 kbps)
2 pair E1 standard (1168 kbps)
3 pair E1 standard (784 kbps)
1/2/3 pair custom (Nx64 kbps,
N=2-36)
T1/E1 Primary Rate (PCM) Channel
Connects to Conexant E1/T1
Framers
Framed or unframed mode
Sync/Async payload mapping
Clock recovery/jitter attenuation
PRBS/fixed test patterns
BER measurement
HDSL Channels
Connects to Conexant ZipWire
Transceivers
Three independent serial channels
Central, remote, or repeater
Overhead (HOH) management
Programmable path delays
Error performance monitoring
Software controlled EOC and IND
Auxiliary payload/Z-bit data link
Master loop ID and interchange
Auto tip/ring reversal
Programmable Data Routing
PCM timeslots HDSL payload
Drop/Insert HDSL payload
Auxiliary HDSL payload
PRBS/Fixed PCM or HDSL
PCM and HDSL loopbacks
Intel
or Motorola
MPU interface
CMOS technology, 3.3 V operation
68-pin PLCC or 80-pin PQFP
Applications
Full, Fractional or Multipoint T1/E1
Single and Multichannel Repeaters
Voice Pair Gain Systems
Wireless LAN/PBX
PCS, Cellular Base Station
Fiber Access/Distribution
Loop Carrier, Remote Switches
Subscriber Line Modem
MPU
Registers
DPLL
Receive
Framer
Payload
Mapper
Elastic
Store
Stuff
2B1Q
Decoder
LB
Mapper
HOH Mux
2B1Q
Encoder
Elastic
Store
LB
PRBS
BER
PCM
F
o
r
m
at
ter
Ti
m
e
slot Router
HDSL
Channels
1, 2, 3
Drop
Insert
PCM
Channel
Microprocessor
PLL Filter
D8953BDSB
Conexant
Information provided by Conexant Systems, Inc. (Conexant) is believed to be accurate and reliable. However, no responsibility is
assumed by Conexant for its use, nor any infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent rights of Conexant other than for circuitry embodied in Conexant
products. Conexant reserves the right to change circuitry at any time without notice. This document is subject to change without
notice.
Conexant and "What's Next in Communications Technologies" are trademarks of Conexant Systems, Inc.
Product names or services listed in this publication are for identification purposes only, and may be trademarks or registered
trademarks of their respective companies. All other marks mentioned herein are the property of their respective holders.
1999 Conexant Systems, Inc.
Printed in U.S.A.
All Rights Reserved
Reader Response: To improve the quality of our publications, we welcome your feedback. Please send comments or
suggestions via e-mail to
Conexant Reader Response@conexant.com
. Sorry, we can't answer your technical
questions at this address. Please contact your local Conexant
sales office
or local field applications engineer if you
have technical questions.
Ordering Information
Order Number
Package
Number of
HDSL Channels
Operating Temperature Range
RS8953BEPF
80Pin Plastic Quad Flat Pack (PQFP)
3
40C to +85C
RS8953BEPJ
68Pin Plastic Leaded Chip Carrier (PLCC)
3
40C to +85C
RS8953SPB EPF
80Pin Plastic Quad Flat Pack (PQFP)
1
40C to +85C
RS8953SPB EPJ
68Pin Plastic Leaded Chip Carrier (PLCC)
1
40C to +85C
N8953BDSB
Conexant
iii
Table of Contents
List of Figures
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
List of Tables
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
1.0
HDSL Systems
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1
HTU Applications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1.1
Repeaters
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.1.2
Fractional Transport
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.1.3
Switching Systems
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.1.4
Loop Carrier/Pair Gain
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.1.5
Point-to-Multipoint
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1.1.6
Subscriber Modem
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
1.2
System Interfaces
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
2.0
Pin Descriptions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1
Pin Assignments
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.2
Signal Definitions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
3.0
Circuit Descriptions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1
MPU Interface
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1.1
Address/Data Bus
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.1.2
Bus Controls
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.1.3
Interrupt Request
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.1.4
Hardware Reset
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.2
PCM Channel
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.2.1
PCM Transmit
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.2.1.1
Transmit Synchronization
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.2.1.2
Transmit Routing Table
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.2.1.3
PRBS Generator
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.2.1.4
Drop/Insert Channel
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
3.2.1.5
TFIFO Water Levels
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
3.2.2
PCM Receive
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Table of Contents
RS8953B/8953SPB
HDSL Channel Unit
iv
Conexant
N8953BDSB
3.2.2.1
Receive Synchronization
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
3.2.2.2
Receive Combination Table
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
3.2.2.3
BER Meter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
3.2.2.4
RFIFO Water Level
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
3.3
Clock Recovery DPLL
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
3.4
Loopbacks
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
3.5
HDSL Channel
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
3.5.1
HDSL Transmit
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
3.5.1.1
Transmit Payload Mapper
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
3.5.1.2
HOH Multiplexer
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
3.5.1.3
CRC Calculation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.5.1.4
Scrambler
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.5.1.5
STUFF Generator
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.5.1.6
2B1Q Encoder
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
3.5.1.7
HDSL Auxiliary Transmit
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
3.5.2
HDSL Receive
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
3.5.2.1
2B1Q Decoder
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
3.5.2.2
HDSL Receive Framer
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
3.5.2.3
Descrambler
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
3.5.2.4
CRC Checking
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
3.5.2.5
HOH Demux
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
3.5.2.6
Receive Payload Mapper
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
3.5.2.7
HDSL Auxiliary Receive
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
3.6
PRA Function
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
3.6.1
Transferring Data from HDSL to RSER
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
3.6.2
Definitions of Detection Algorithms
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
3.6.3
Inserting Data Transferred from HDSL to RSER
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
3.6.4
Transferring Data from TSER to HDSL
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
3.6.5
Inserting Data Transferred from TSER to HDSL
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36
4.0
Registers
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
4.1
Address Map
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
4.2
HDSL Transmit
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
RS8953B/8953SPB
Table of Contents
HDSL Channel Unit
N8953BDSB
Conexant
v
0x00--Transmit Embedded Operations Channel (TEOC_LO)
. . . . . . . . . . . . . . . . . . . . . 5-10
0x01--Transmit Embedded Operations Channel (TEOC_HI)
. . . . . . . . . . . . . . . . . . . . . . 5-10
0x02--Transmit Indicator Bits (TIND_LO)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
0x03--Transmit Indicator Bits (TIND_HI)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
0x04--Transmit Z-Bits (TZBIT_1)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
0xDF--Transmit Z-Bits (TZBIT_2)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
0xE0--Transmit Z-Bits (TZBIT_3)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
0xE1--Transmit Z-Bits (TZBIT_4)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
0xE2--Transmit Z-Bits (TZBIT_5)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
0xE3--Transmit Z-Bits (TZBIT_6)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
0x05--Transmit FIFO Water Level (TFIFO_WL)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
0x06--Transmit Command Register 1 (TCMD_1)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
0x07--Transmit Command Register 2 (TCMD_2)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
4.3
Transmit Payload Mapper
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
0x08--Transmit Payload Map (TMAP_1)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
0x09--Transmit Payload Map (TMAP_2)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
0x0A--Transmit Payload Map (TMAP_3)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
0x0B--Transmit Payload Map (TMAP_4)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
0x0C--Transmit Payload Map (TMAP_5)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
0x0F--Transmit Payload Map (TMAP_6)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
0x10--Transmit Payload Map (TMAP_7)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
0x11--Transmit Payload Map (TMAP_8)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
0x12--Transmit Payload Map (TMAP_9)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
0x0D--Transmit FIFO Reset (TFIFO_RST)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
0x0E--Scrambler Reset (SCR_RST)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
4.4
HDSL Receive
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
0x60--Receive Command Register 1 (RCMD_1)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
0x61--Receive Command Register 2 (RCMD_2)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
0x62--Receive Elastic Store FIFO Reset (RFIFO_RST)
. . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
0x63--Receive Framer Synchronization Reset (SYNC_RST)
. . . . . . . . . . . . . . . . . . . . . 5-21
4.5
Receive Payload Mapper
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
0x64--Receive Payload Map (RMAP_1)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
0x65--Receive Payload Map (RMAP_2)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
0x66--Receive Payload Map (RMAP_3)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
0x69--Receive Payload Map (RMAP_4)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
0x6A--Receive Payload Map (RMAP_5)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
0x6B--Receive Payload Map (RMAP_6)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
0x67--Error Count Reset (ERR_RST)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
0x68--Receive Signaling Location (RSIG_LOC)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
4.6
PCM Formatter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
0xC0--TSER Frame Bit Location (TFRAME_LOC_LO)
. . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
0xC1--TSER Frame Bit Location (TFRAME_LOC_HI)
. . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
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ZIP