CAM Accelerates Fast Searches
Content-addressable memory (CAM), a
memory technology developed from random
access memory (RAM), accelerates applica-
tions requiring fast searches of databases,
lists, and patterns. CAM simultaneously
compares input data against an entire list of
pre-stored entries in a single clock cycle,
which provides an extremely significant
reduction in search time when compared to
RAM.
APEX Devices: The Only PLDs with CAM
Altera’s APEX™ devices, the only
programmable logic devices (PLDs) to offer
integrated CAM, have up to one million
gates (2.67 million system gates) and allow
for complete System-on-a-Programmable-
Chip™ integration. Designers can use the
APEX CAM to simplify applications that
require the searching of lists and tables of
data. The APEX integrated CAM provides
significant system performance enhance-
ments and allows for more efficient resource
utilization in the system design.
CAM Available in Each APEX Embedded
System Block
The embedded system block (ESB) is at the
heart of the Altera® APEX architecture. One
APEX ESB can be configured to be a
32-word x 32-bit CAM, and multiple ESBs
can be cascaded together to implement
wider and deeper CAMs. The APEX CAM
architecture provides great flexibility
because the designer can create a wide
range of CAM depths or widths.
APEX CAM Applications
■Ethernet address look-up
■Internet protocol filtering
■Data compression
■Pattern recognition
■Cache tags
■Fast look-up for routing tables
■High-bandwidth packet
searches for data switches,
firewalls, bridges, and routers
APEX CAM Architecture
■32-word x 32-bit CAM in
each ESB
■Programmable width and
depth expansion
■Faster access time (4 ns)
than discrete CAM
■ESBs can be cascaded for
wider and deeper CAMs
APEX Integrated
Content
Addressable
Memory (CAM)
Greatly Accelerates
Applications Requiring List
and Data Searches
¨
Address
Match Flag
CAM
Data
APEX Integrated CAM
Altera APEX Devices: The Only Programmable Logic Devices with CAM
Maximum
System Gates
Typical Gates
Logic Elements
ESBs
Maximum
CAM Bits
263K
53K - 106K
4,160
26
26,624
404K
82K - 163K
6,400
40
40,960
526K
106K -211K
8,320
52
53,248
728K
147K - 293K
11,520
72
73,728
1,052K
213K - 423K
16,640
104
106,496
1,537K
311K - 618K
24,320
152
155,648
2,670K
541K - 1,073K
42,240
264
270,336
EP20K100E EP20K160E EP20K200E EP20K300E EP20K400E EP20K600E EP20K1000E
APEX Device Densities and ESB Resources
Altera Offices
Corporate Headquarters
Altera Corporation
101 Innovation Drive
San Jose, CA 95134
Telephone: (408) 544 7000
http://www.altera.com
Altera European Headquarters
Altera U.K. Limited
Holmers Farm Way
High Wycombe
Buckinghamshire
HP12 4XF
United Kingdom
Telephone: (44) 1 494 602 000
Altera Japan, Limited
Shinjuku Mitsui Building 36F
1-1, Nishi-Shinjuku, 2 Chome
Shinjuku-ku, Tokyo 163-0436
Japan
Telephone: (81) 3 3340 9480
http://www.altera.com/japan
Altera International, Limited
Suite 908-920, Tower 1
Metroplaza
223 Hing Fong Road
Kwai Fong, New Territories
Hong Kong
Telephone: (852) 2487 2030
¨
Copyright © 1999 Altera Corporation. Altera, APEX, APEX 20K, APEX 20KE, System-on-a-Programmable-Chip, The Altera Advantage, and specific
device designations are trademarks and/or service marks of Altera Corporation in the United States of America and other countries. Other brands or
products are trademarks of their respective holders. The specifications herein are subject to change without notice. All rights reserved.
M-SS-APEXCAM-01
CAM Applications
The superior performance
advantages of CAM have
attracted much attention from
the communications industry.
The CAM architecture is ideally
suited for high-level pattern matching and
data searching operations. Because APEX
devices provide the superior performance of
a single-chip solution as well as greatly
enhanced size and configuration flexibility,
the APEX CAM provides significant
advantages over discrete CAMs.
Advantages of APEX Integrated CAM
By eliminating on-/off-chip and PCB board
delays, the APEX integrated CAM provides
greatly enhanced system performance over
discrete CAM. The advanced APEX process
technology also enables a 4x to 5x faster
CAM access time than discrete CAMs. With
the programmable CAM configuration
flexibility, APEX devices provide a true
programmable solution to meet the market
demand for CAM.
Contact Altera Today!
To determine which APEX device will work
best for you, contact your local Altera sales
representative or visit the Altera web site at
http://www.altera.com/apex.
APEX Provides Flexible CAM Configurations to Meet Market Demands
CAM Depth
CAM Width
256 x 64 512 x 64
1,024 x 128
2,048 x 64
4,096 x 64
8,192 x 80
16,384 x 64
Discrete CAM (Fixed Sizes)
APEX 20KE CAM Coverage
Flexible configuration up to 264 Kbits
Small CAM Applications
•Switch address mapping
•Packet header identification
•Pattern recognition
•IP filter
•Cache tag
Medium CAM Applications
•MAC address look-up in two-layer bridges and switches
•Address translation or protocol conversion in gateways
•Layer 3 longest match address look-up for Ipv4, DECNET, and AppleTalk
•VPI/VCI translation in ATM switches
Large CAM Applications
•ARP cache in network server
•Layer 2/4 flow recognition for fair bandwidth sharing
•Layer 3 address caching of switch of IPv6
Access Time
System Performance
20 ns
Multi-chip solution
28.2 ns
Discrete CAM
4 ns
Single-chip solution
4.9 ns
APEX CAM
APEX Integrated CAM Provides Superior Performance
