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DS21Q55 Quad T1/E1/J1 Transceiver
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1. MAIN FEATURES
The DS21Q55 contains all the features of the previous generation of Dallas Semiconductor’s T1 and E1
transceivers plus many new features.
General
§ Programmable output clocks for fractional T1, E1,
H0, and H12 applications
§ Interleaving PCM bus operation
§ 8-bit parallel control port, multiplexed or
nonmultiplexed, Intel or Motorola
§ IEEE 1149.1 JTAG-Boundary Scan
§ 3.3V supply with 5V tolerant inputs and outputs
§ Pin compatible with DS21Qx5y family of products
§ Signaling System 7 Support
§ RAI-CI, AIS-CI support
§ 27mm 1.27 pitch BGA package
§ 3.3V supply with 5V tolerant inputs and outputs
§ Evaluation kits
§ IEEE 1149.1 JTAG boundary scan
§ Driver source code available from the factory
Line Interface
§ Requires only a 2.048MHz master clock for both
E1 and T1 operation with the option to use
1.544MHz for T1 operation
§ Fully software configurable
§ Short-haul and long-haul applications
§ Automatic receive sensitivity adjustments
§ Receive sensitivity ranges include 0 to 43dB or 0 to
12dB for E1 applications and 0 to 13dB or 0 to
36dB for T1 applications
§ Receive level indication in 2.5dB steps from
-42.5dB to -2.5dB
§ Internal receive termination option for 75, 100,
and 120 lines
§ Internal transmit termination option for 75, 100,
and 120 lines
§ Monitor application gain settings of 20dB, 26dB,
and 32dB
§ G.703 receive synchronization-signal mode
§ Flexible transmit waveform generation
§ T1 DSX-1 line build-outs
§ T1 CSU line build-outs of -7.5dB, -15dB, and
-22.5dB
§ E1 waveforms include G.703 waveshapes for
both 75 coax and 120 twisted cables
§ AIS generation independent of loopbacks
§ Alternating ones and zeros generation
§ Square-wave output
§ Open-drain output option
§ NRZ format option
§ Transmitter power-down
§ Transmitter 50mA short-circuit limiter with
current-limit-exceeded indication
§ Transmit open-circuit-detected indication
§ Line interface function can be completely
decoupled from the framer/formatter
Clock Synthesizer
§ Output frequencies include 2.048MHz, 4.096MHz,
8.192MHz, and 16.384MHz
§ Derived from recovered receive clock
Jitter Attenuator
§ 32-bit or 128-bit crystal-less jitter attenuator
§ Requires only a 2.048MHz master clock for both
E1 and T1 operation with the option to use
1.544MHz for T1 operation
§ Can be placed in either the receive or transmit path
or disabled
§ Limit trip indication
Framer/Formatter
§ Fully independent transmit and receive
functionality
§ Full receive and transmit path transparency
§ T1 framing formats include D4 (SLC-96) and ESF
§ Detailed alarm and status reporting with optional
interrupt support
§ Large path and line error counters for:
–
T1: BPV, CV, CRC6, and framing bit errors
–
E1: BPV, CV, CRC4, E-bit, and frame
alignment errors
§ Timed or manual update modes
§ DS1 idle code generation on a per-channel basis in
both transmit and receive paths
–
User-defined
–
Digital milliwatt
§ ANSI T1.403-1998 Support
§ RAI-CI detection and generation
§ AIS-CI detection and generation
§ E1ETS 300 011 RAI generation
§ G.965 V5.2 link detect
§ Ability to monitor one DS0 channel in both the
transmit and receive paths
§ In-band repeating pattern generators and detectors
–
Three independent generators and detectors
–
Patterns from 1 to 8 bits or 16 bits in length
§ RCL, RLOS, RRA, and RAIS alarms interrupt on
change-of-state
§ Flexible signaling support