BCM3138 FEATURES
BCM3138
Dual Adv. TDMA
Receiver
BCM3138
BCM3138
5-65 MHz Upstream
Routing/
Classification
Engine
Ethernet
System
CPU
Memory
PCI Bus
BCM3212
Advanced
CMTS MAC
Downstream
SDRAM
(PHS,
output
queues)
BCM3034
Advanced QAM
Modulator
LPFPA
WAN
44 MHz IF
Cable Modem Termination System (CMTS) Block Diagram
•Presents a high-performance, integrated solution for
upstream demodulation in cable over data, video and
telephony applications.
•Two independent burst receivers per package enable
high-density equipment designs, reducing equipment
floor space requirements.
•Based on DOCSIS/EuroDOCSIS standards for use in
Cable Modem Termination Systems (CMTS).
•Seamless integration with BCM3212 Advanced CMTS
Media Access Controller (MAC).
•Applies to digital CATV reverse-channel receiver.
•High bps/Hz modulation enables advanced digital
services over narrow RF channels.
•Includes flexible analog front end options.
•Use of on-board ADCs minimizes external
components.
•Direct sampling option via external 12-bit ADC
minimizes RF components.
•On-board equalizer enables operation of digital
services under challenging plant conditions.
•On-chip FFT enables spectrum analysis and
management of the entire upstream channel.
•Small footprint enables high-density equipment.
•Deploys advanced functions in harsh environments.
• Distributed CMTS in Hybrid Fiber Coaxial Fiber Node
SUMMARY OF BENEFITS
DUAL UNIVERSAL ADVANCED TDMA PHY-LAYER BURST RECEIVER
•The BCM3138 is a universal headend advanced TDMA
physical layer QPSK/QAM burst receiver
•DOCSIS/EuroDOCSIS-based, IEEE 802.14, DAVIC
and DVB compliant
•Programmable demodulation including BPSK, QPSK,
8, 16, 32, 64, 128 and 256 QAM formats
•Variable symbol rates from 160 Kbaud to 5.12 Mbaud
providing 320 Kbps to 40 Mbps operation
•Powerful Reed Solomon FEC decoder with byte
deinterleave options for impulse/burst noise mitigation
•Burst acquisition as fast as 16 preamble symbols
•On-board 10-bit analog-to-digital converters for each
channel
•Direct sampling option for DOCSIS and EuroDOCSIS
via 12-bit digital input operating at 160 MHz with
LVDS or TTL level interface options
•Powerful on-board equalizer provides ingress and
adjacent channel overlap protection
•Integrated Fast Fourier Transform (FFT) processor
with variable FFT sizes and programmable window
options
•I2C or SPI-compatible microcontroller interface
•JTAG test interface
•208-pin PQFP package
•Operates over industrial temperature range (-40 to +85
degrees C)
PRODUCT
Brief
BCM3138
The BCM3138 QAMLink®Universal QPSK/QAM burst
receiver is a highly integrated solution that significantly
decreases the board space and cost of demodulators in digital
cable modem head-ends applications. The BCM3138 provides
two independent cable network receivers that accept QPSK and
m-QAM burst data in frequency-agile, time-division multiple
access (TDMA) schemes. Advanced features in the BCM3138
include an analog front end (AFE), a QAM demodulator, a
generalized equalizer and an enhanced Reed Solomon (RS) FEC
decoder with dynamic deinterleaving.
The AFE provides coarse gain setting and A-to-D conversion
(ADC) on either an IF input or baseband I/Q inputs. When the
internal ADC is bypassed, the on-chip digital mix er translates the
desired signal at RF to true DC where the I and Q samples pass
through variable decimators and matched raised-cosine filters.
The BCM3138 incorporates unique word detections of
programmable length and pattern in the burst preamble for signal
acquisition as fast as 16 symbols. An adaptive equalizer and
ingress canceller characterizes the RF channel response, cancels
ingress noise and remov es inter-symbol interference (ISI) caused
by micro-reflections in the channel. The FEC decoder consists
of a programmable de-randomizer, a programmable RS decoder
with T values programmable up to 16 and a byte deinterleaver
with burst-by-burst reconfiguration capability.
The BCM3138 delivers the recovered data stream and accepts
receiver control inputs through a receive interface linked to a
DOCSIS MAC chip such as the BCM3212. The BCM3138
prepends ranging and data information to each received code
word and packet for processing by the BCM3212. The
BCM3138 can be configured through either an SPI or I2C-
compatible serial interface.
The BCM3138 is a highly integrated, mixed-signal and cost-
effecti v e de vice providing a worldwide solution for b urst recei ver
applications. The dual receiver design of the BCM3138 is
packaged in a 208-pin PQFP, enabling a significant increase
upstream channel density for head-end based CMTS equipment.
The BCM3138, combined with the BCM3034 QAMLink®
Universal Modulator and the BCM3212 Advanced QAMLink®
CMTS MAC, provides a complete solution for advanced cable
headend equipment.
BCM3138 OVERVIEW
DAP/N
A_IP/N
FFT STRT
FFT CLK
FFT DATA
FFTDV
DBP/N
B_IP/N
CKIP/N
24
2
2
2
24
JTAG
FFT
Processor DDFS
AFE
(ADC
and
MUX)
Digital
Complex
Mixer
I
Q
Variable
Decimator
Variable
Decimator
Matched
Filter
Matched
Filter
Ranging
Block Preamble
Process Tracking
Loops
De-
scrambler RS
Decoder
QAM
Burst
Demodulation
Adaptive
Equalization
and
Ingress
Cancellation
Deinterleaver
FEC Interface
and FIFOs
MAC/
PHY
Interface
Ch-A
4
13
6
6
2445
MAC/PHY
Interface
Ch-B
Micro InterfacePLL & Clock Generation Bypass/
Probe
Exit Control
Receive Channel B
RACLK
RASOBN
RADV
RADATA[3:0]
RADATAP
MSCLKA
MAPCLKA
MAPDVAN
MAPDATA
INTAN
EXCTLA[5:0]
EXCTLB[5:0]
TPA/B[11:0]TM[3:0]SDASCL
SCK MOSI MISOSPI
I2C
ADDR[6:2]ADDR1ADDR0
SS
RESETXTALOXTALIPLLBYPTDOTDITMSTCK
Phone: 949-450-8700
FAX: 949-450-8710
Email: info@broadcom.com
Web: www.broadcom.com
Broadcom®, the pulse logo®, QAMLink®and Connecting EverythingTM 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.
3138-PB02-R-4.19.02
