The BCM3348 combines an RF receiver with an advanced QAM

and S-CDMA demodular, an advanced QAM transmitter, a

complete DOCSIS 2.0 Media Access Controller (MAC), a

200-MHz MIPS32™ communication processor, a 16-bit,

100-MHz SDRAM interface, 10/100 Ethernet MAC with

integrated transceiver and MII Interface, and a medium-speed

USB 2.0 controller with integrated transceiver.

The QAM receiver directly samples a tuner output with a 11-bit

A/D converter and input ACG amplifier. The receiver digitally

resamples and demodulates the signal with recovered clock and

carrier timing, filters and equalizes the data and passes soft

decisions to an ITU-T J.83 Annex A/B/C compatible decoder.

The

receiver

supports

variable

symbol

rate

4/16/32/64/128/256/512/1024-QAM FEC decoding. The final

received data stream is delivered in a serial MPEG-2 transport

format. All gain, clock, and carrier, acquisition and tracking

loops are integrated in the QAM receiver.

The upstream transmitter takes burst or continuous data, provides

FEC encoding and pre-equalization for DOCSIS applications,

filters and applies 2/4/8/16/64/128/256-QAM or S-CDMA,

modulation to the data stream, amplifies the signal through the

integrated upstream power amplifier and provides a direct

0–65 MHz analog output.

The BCM3348 Media Access Controller (MAC) includes all

features required for full DOCSIS 1.0, 1.1 and 2.0 compliance,

including full support for baseline privacy (BPI+) encryption and

decryption. Single-user support includes 4 SIDS in downstream,

4 DA perfect-match filters, a 256-entry CAM for

multicast/unicast hash filter, and 4 independent upstream queues

for simultaneous support of QoS and BE traffic. To enhance

operational support, the BCM3348 MAC provides extended

network management MIB/diagnostic features, as well as

immediate UCC (on-the-fly) using independent resets for

downstream and upstream and both individual queue reset/flush

for upstream queues. The BCM3348 uses advanced PROPANE

techniques to provide packet acceleration to significantly

improve upstream channel utilization.

With the incorporation of an upstream power amplifier, the

BCM3348 allows a complete cable modem to be assembled with

a minimal set of external components. When used with the

silicon tuner, the BCM3348 offers the lowest-price solution for a

high performance, single-user DOCSIS 2.0 cable modem.

BCM3348

OVER VIEW

100-MHz ISB

Ethernet

MAC

USB

MAC

EBI/PCMCIA

Expansion

Module

16-bit

SDRAM

Interface

Transmission

Convergence

Module

Silicon

Tuner

Coaxial

cable

DiPlexer

USB

10/100

Ethernet

Isolation

64-MB

100-MHz

8-MB

FLASH

SDRAM

DOCSIS 2.0

MAC

Module

Peripheral

Logic

200-MHz

MIPS32 Core

with MMU

8/8-KB

I/D Cache

Advanced

Modulator

QPSK-256-QAM

Advanced

Demodulator

16

–1024-QAM

Power

Amplifier

Filter

Ethernet

Transceiver

BCM3348

Isolation

SPI

I/F

Serial

FLASH

(optional)

®

Phone: 949-450-8700

FAX: 949-450-8710

Email: info@broadcom.com

Web: www.broadcom.com

are trademarks of Broadcom Corporation and/or its subsidiaries in the United States and

certain other countries. All other trademarks are the property of their respective owners.

BROADCOM CORPORATION

16215 Alton Parkway, P.O. Box 57013

Irvine, California 92619-7013

© 2002 by BROADCOM CORPORATION. All rights reserved.

3348-PB02-403-R 11.26.02