With the rapid expansion of 5G and cloud and edge computing, network traffic continues to increase, driving demand for large and diverse TCAM configurations, such as 256 bits × 4,096 entries. Conventional scaling, based solely on hard macros, increases the peripheral area due to a greater number of banks and repeaters, complicates timing closure, and increases power consumption during lookups. Furthermore, automotive applications require greater security coverage to comply with standards such as ISO 26262. Renesas addresses these challenges with the following innovations:
1. Integrated Hard and Soft Macro Approach for Flexible Configuration.
The new TCAM hard macros are supported by a memory compiler with fine granularity: search key widths from 8 to 64 bits and entry depths from 32 to 128. Larger configurations (e.g., 256 bits × 4,096 entries) are achieved by combining these macros with automatic soft macro generation, creating a single configurable macro that covers multiple use cases on a single chip. This enables an industry-leading memory density of 5.27 Mb/mm².
2. Detection of total non-match and segmented search at the macro level
Each macro integrates a total mismatch detection circuit and performs a two-stage segmented search. Depending on the result of the first stage, the second stage can either continue or stop to avoid unnecessary power consumption.
In 64–256 bit × 512 entry configurations, this approach reduces search power consumption by up to:
71.1% with column-segmented search
and 65.3% with row-segmented search
. In a 256 bit × 512 entry configuration, the design achieves a power consumption of 0.167 fJ/bit and a search frequency of 1.7 GHz. The TCAM performance index reaches 53.8, surpassing previous results.
3. Enhanced Functional Safety for Automotive Applications:
Because TCAM cells for the same address are physically close, double errors cannot be corrected with conventional ECC. Renesas introduces:
Even/odd data bus splitting to physically separate data and
dedicated SRAM parity for ECC parity with independent decoding.
These techniques significantly improve the safety coverage required in automotive applications.
Thanks to its flexibility, energy efficiency, and high reliability, this TCAM is ideal not only for automotive applications but also for industrial and consumer applications. Renesas will continue to advance high-capacity, low-power, and high-reliability memory architectures.
