Introduction - Dallas Semiconductor DS21354L Manual

3 INTRODUCTION

The DS21354/554 is a superset version of the popular DS2153 and DS2154 SCTs offering the new
features listed below. All of the original features of the DS2153 and DS2154 have been retained and
software created for the original devices is transferable into the DS21354/554.
New Features in the DS21354 and DS21554
FEATURE
HDLC controller with 64-byte buffers for Sa bits or DS0s or sub DS0s
Interleaving PCM bus operation
IEEE 1149.1 JTAG-Boundary Scan Architecture
3.3V (DS21354 only) supply
Line Interface Support for the G.703 2.048 Synchronization Interface
Customer Disconnect Indication (...101010...) Generator
Open Drain Line Driver Option
New Features in the DS2154 (also in the DS21354 and DS21554)
FEATURE
Option for non–multiplexed bus operation
Crystal–less jitter attenuation
Additional hardware signaling capability including:
Receive signaling reinsertion to a backplane multiframe sync
Availability of signaling in a separate PCM data stream
Signaling freezing Interrupt generated on change of signaling data
Improved receive sensitivity: 0 dB to –43 dB
Per–channel code insertion in both transmit and receive paths
Expanded access to Sa and Si bits
RCL, RLOS, RRA, and RAIS alarms now interrupt on change of state
8.192 MHz clock synthesizer
Per–channel loopback
Addition of hardware pins to indicate carrier loss and signaling freeze
Line interface function can be completely decoupled from the framer/formatter to
allow:
Interface to optical, HDSL, and other NRZ interfaces
"tap" the transmit and receive bipolar data streams for monitoring purposes
Be able to corrupt data and insert framing errors, CRC errors, etc.
Transmit and receive elastic stores now have independent backplane clocks
Ability to monitor one DS0 channel in both the transmit and receive paths
Access to the data streams in between the framer/formatter and the elastic stores
AIS generation in the line interface that is independent of loopbacks
Transmit current limiter to meet the 50 mA short circuit requirement
Option to extend carrier loss criteria to a 1 ms period as per ETS 300 233
Automatic RAI generation to ETS 300 011 specifications
7 of 117
DS21354 & DS21554
SECTION
15
18
17
2 and 3
16
6
16
SECTION
1 and 2
12
7
12
8
11
4
1
8
1
1
1
6
1
1 and 3
12
3
3