ST70135A

 COMPLETE CHIP SET FOR ADSL CPE MODEM
COMPLIANCE WITH ANSI T1.413 ISSUE 1 & ISSUE 2
COMPLIANCE WITH G.992.1 (FULL RATE) & G.992.2 (G. LITE)
IMPLEMENTS DISCRETE MULTITONE
    (DMT) MODULATION AND DEMODULATION ON CPE SIDE
DATA RATES UP TO 8Mbps DOWNSTREAM AND TO 1Mbps UPSTREAM WITH 32Kbps GRANULARITY
BUILT-IN ATM TRANSPORT
SUPPORT ADAPTIVE RATE MODE IN 32Mbps INCREMENTS
255/128 CARRIERS WITH 4.3125KHz SPACING
DEDICATEDSOFTWARE DRIVERAVAILABLE
PROCESSOR INDEPENDENT C++ SOURCE COMPILATION
FREQUENCY DIVISION MULTIPLEXING
    (FDM) FOR HIGH ROBUSTNESS IN PRESENCE OF CROSSTALK
REED-SOLOMON FORWARD ERROR CORRECTION
TRELLIS CODER AND DECODER
PROGRAMMABLE SIMULTANEOUS SUPPORT OF INTERLEAVED AND NON-INTERLEAVED CHANNELS
    (DUAL LATENCY)
FULL, REDUCED AND MINIMAL ATM OVERHEAD FRAMING MODES
BIT STREAM MODE CAPABLITY FOR STM TRANSPORT
DIRECT CONNECTION TO ATM SYSTEMS VIA UTOPIA INTERFACE (LEVEL 1 OR 2)
MICROCONTROLLER INTERFACE WITH 16 BITS MULTIPLEXED ADDRESS/DATA BUS
LOW POWER TECHNOLOGY: 1.3w TOTAL
SINGLE 3.3V POWER SUPPLY
0 TO +70°C OPERATING TEMPERATURE RANGE

The ADSL modem ST70135A set with ATM interface provides all the active functions required to build a complete ATM-based ADSL modem from line interface to ATM UTOPIA bus. The chip set employs Discrete MultiTone modulation as specified in ANSI T1.413.

The ST70135A set operates at CPE end of the loop (ATU-R mode). Reed-Solomon forward error correction plus Trellis coding with or without interleaving in internal interleaving RAM provides maximum noise immunity (see Figure 3).

Interleaving is optional and can be used simultaneously on a slow channel (e.g., for data or control info) while a fast channel (e.g., video) operates without interleaving. ST70135As include rate adaptation capabilities during show time.

In transmit direction the chip set allows to select an attenuation of the signal in case of short loops or large echo (politeness). In receive direction the chip set can optionally control an external multiplexer to select an external attenuation of the signal in case of short loops, and provide a 2-bit output external gain control.