ST70235A Datasheet, PDF (1/28 Pages) STMicroelectronics – ASCOTTM DMT TRANSCEIVER

ST70235A
ASCOT^TM DMT TRANSCEIVER
PRELIMINARY DATA
s DMT MODEM FOR CPE ADSL,
COMPATIBLE WITH THE FOLLOWING
STANDARDS:
- ANSI T1.413 ISSUE 2
- ITU-T G.992.1 (G.DMT)
- ITU-T G.992.2 (G.LITE)
s SUPPORTS EITHER ATM (UTOPIA LEVEL
1 & 2) OR BITSTREAM INTERFACE
s 16 BIT MULTIPLEXED MICROPROCESSOR
INTERFACE (LITTLE AND BIG ENDIAN
COMPATIBILITY)
s ANALOG FRONT END MANAGEMENT
s DUAL LATENCY PATHS: FAST AND
INTERLEAVED
s ATM’S PHY LAYER: CELL PROCESSING
(CELL DELINEATION, CELL INSERTION,
HEC)
s ADSL’S OVERHEAD MANAGEMENT
s REED SOLOMON ENCODE/DECODE
s TRELLIS ENCODE/DECODE (VITERBI)
s DMT MAPPING / DEMAPPING OVER 256
CARRIERS
s FINE (2PPM) TIMING RECOVER USING
ROTOR AND ADAPTATIVE FREQUENCY
DOMAIN EQUALIZING
s TIME DOMAIN EQUALIZATION
s FRONT END DIGITAL FILTERS
s 0.25µm HCMOS7 TECHNOLOGY
s 144 PIN TQFP
s POWER CONSUMPTION: 0.4 WATT
APPLICATIONS
Routers at SOHO, stand-alone modems, PC
modems.
GENERAL DESCRIPTION
The ST70235A is the DMT modem and ATM
framer of the STMicroelectronics ASCOT™
chipset. When coupled with ST70134 analog
front-end and an external controller running
dedicated firmware, the product fulfills ANSI
T1.413 "Issue 2" DMT ADSL specification. The
chip supports UTOPIA level 1 and UTOPIA level 2
interface.
The ST70235A can be split up into two different
sections. The physical one performs the
DMT modulation, demodulation, Reed-Solomon
encoding, bit interleaving and 4D trellis coding.
The ATM section embodies framing functions for
the generic and ATM Transmission Convergence
(TC) layers. The generic TC consists of data
scrambling and Reed Solomon error corrections,
with and without interleaving.
The ST70235A is controlled and programmed
by an external controller (ADSL Transceiver Con-
troller, ATC) that sets the programmable coeffi-
cients. The firmware controls the initialization
phase and carries out the consequent adaptation
operations.
TQFP144 Full Plastic
(20 x 20 x 1.40 mm)
ORDER CODE: ST70235A
October 2001
This is advance information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
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