APEX devices offer integrated content-addressable memory (CAM) to accelerate applications requiring fast searches of databases, lists, and patterns. With CAM, input data is compared against a list of stored entries in a single clock cycle, significantly reducing search time when compared to random-access memory (RAM). By eliminating on-chip/off-chip and board delays, the APEX integrated CAM provides greatly enhanced system performance over discrete CAM. As seen in the table below, the advanced APEX process technology enables a CAM access time that is four to five times faster than discrete CAM.
| Comparison of Discrete CAM & APEX CAM | ||
| Feature | Discrete CAM | APEX CAM |
|---|---|---|
| Access time | 20 ns | 4 ns |
| System performance | Multi-device solution 28.2 ns |
Single-device solution 4.9 ns |
APEX CAM Provides Configuration Flexibility
The embedded system block (ESB) is the heart of the APEX device architecture. One APEX ESB can be configured to a 32-word x 32-bit CAM, and multiple ESBs can be cascaded together to implement wider and deeper CAMs. As shown in Figure 1, the APEX CAM architecture provides great flexibility because the designer can create a wide range of CAM depths or widths.
Figure 1. APEX CAM Configurations Meet Market Demands
CAM Applications
The APEX CAM is ideally suited to high-level pattern matching and data searching operations. Its superior performance has led the communications industry, for example, to use APEX CAM in many applications, including:
- 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, bridge, and routers
The APEX integrated CAM provides significant system performance enhancements and allows for more efficient resource utilization in system design. With their programmable CAM configuration flexibility, APEX devices provide a true programmable solution to meet the market demand for CAM.
Related Links
- CAM Comparison: APEX 20KE vs. Virtex-E Devices
- Faster Search Applications Using APEX 20KE CAM
- TB 56 (Using APEX 20KE CAM for Fast Search Application)s (PDF - 113 Kb)
- TB 61 (CAM Comparison: APEX 20KE vs. Virtex-E Devices) (PDF - 122 Kb)
- AN 119 (Implementing High-Speed Searching Functions with APEX CAM) (PDF - 224 Kb)
