Applications

STV0498

2/4

CD00152563

1

Applications

The STV0498 kit, when accompanied with a back-end decoder, provides a complete

low-cost solution for interactive cable set-top boxes.

The STV0498 has been designed to work as a kit with an analog front-end companion chip,

the STV0130. This analog chip does the analog-digital conversion for the QAM signal input

and the digital-analog conversion for the DOCSIS return path whilst the STV0498 does the

digital operations.

The STV0498 performs downstream and upstream operations for video and data. Three

high-performance QAM/FEC modules demodulate and correct the cable signals to be sent

either to a stream merger for video application or to the DOCSIS media access controller

(MAC) for data flow. The forward error correction (FEC) blocks support the ITU-T J83 Annex

A, B and C specification. The demodulators support square constellation from the QPSK

used in legacy out-of-band (SCTE-55 parts 1 and 2) to QAM 256 and non-square

constellation such as QAM 32 and QAM 128. The Japanese transport stream multiplex

(TSMF) is also supported.

The merged video stream is compatible with Multi-Stream CableCARD. This stream is then

sent to a standard video decoder. Up to three video channels can be received

simultaneously.

The DOCSIS subsystem is fully compatible with the DOCSIS 2.0 specification and supports

downstream channel bonding, compatible with the DOCSIS 3.0 specification, bringing the

data rate up to 120 Mbit/s. Up to 16 QOS channels can be supported simultaneously. The

STV0130 analog block provides direct connection to the upstream power amplifier. All

DOCSIS operations are controlled by a high performance CPU running the OS21 operating

system.

Integrated peripheral blocks (the Ethernet and USB interfaces, for example) provide

low-cost connections between the DOCSIS modem and the host computer. MPX is a

primary connection mode between the STV0498 and ST decoder chips.

Several modes of operations are available, from a stand-alone mode to a fully embedded

solution with the back-end device.

Figure 1.

Typical application

STB71xx

Flash

PGA

Diplex

filter

LMI

EMI

MII

SDRAM / DDR

STB Host

RESET

HDD

YPbPr

SDRAM / DDR

IR

USB

SPDIF

HDMI

Y/C

CVBS

Audio L/R

MII

Local

memory

STLC1502

VoIP

engine

SLIC/

CODEC

PHY

RJ45

RJ11

USB 2.0

PIO

TS

TS

TS

TS

SATA

FMI/EMPI

STV0498

USB MAC

and PHY

LMI

ADC1

ADC2

ADC3

STV0130

Down-

stream

interface

Up-

stream

interface

SPI

control

interface

DAC

L/R audio

CVBS

S-video

HDMI

YPbPr

S/PDIF

USB 2.0

IR

Silicon

tuner

Silicon

tuner

Silicon

tuner