Offering higher memory density, reduced power consumption and enhanced functional safety for next-generation automotive and data-intensive systems, the company presented the development at the International Solid-State Circuits Conference (ISSCC 2026) in San Francisco.

The rapid growth of 5G, cloud computing and edge processing has driven demand for larger and more flexible TCAM configurations, such as 256-bit × 4,096-entry arrays. Traditional scaling methods rely on hard macros, which increase the number of banks and repeaters, enlarge peripheral circuitry, complicate timing closure and raise search power. Automotive systems add further requirements, including higher safety coverage to meet standards such as ISO 26262.

Renesas’s new approach combines finely grained hard macros - offered with search key widths from 8 to 64 bits and entry depths from 32 to 128 entries - with an automated soft-macro generator. Together, they can be configured into larger blocks on a single chip while maintaining efficiency. The company said the design achieves a memory density of 5.27 Mb/mm², which it described as an industry-leading figure.

Each hard macro integrates an all-mismatch detection circuit and uses a two-stage pipelined search system. Depending on the first-stage result, the second stage can be halted to avoid unnecessary energy use.

In configurations ranging from 64 to 256 bits at 512 entries, Renesas reports energy reductions of:

Up to 71.1% with column-wise pipelined search for key widths above 64 bits Up to 65.3% with row-wise pipelined search for keys at or below 64 bits In a 256-bit × 512-entry design, search energy reaches 0.167 fJ/bit, supported by a 1.7 GHz search clock enabled through distributed timing load. Renesas states that the resulting figure-of-merit - defined by density multiplied by speed and divided by energy - reaches 53.8, surpassing previous implementations.

Because TCAM bitcells storing the same address sit physically adjacent, soft errors can create double-bit faults that conventional SECDED error-correction code cannot repair. Renesas said it has introduced two measures to mitigate this:

Splitting odd and even data buses for both user data and ECC parity to increase the physical separation of memory cells, reducing the likelihood of uncorrectable double-bit errors.

A dedicated SRAM for ECC parity, with an address decoder separate from the TCAM array, improving detection when incorrect addresses are accessed during write operations.

These changes are intended to raise safety coverage levels required for automotive electronics while also supporting industrial and consumer systems where fast data exchange between sensors and processors is essential.

Renesas said it plans to continue advancing memory architectures focused on high capacity, low power and strong reliability as demand for high-performance TCAM accelerates across automotive and communications markets.

By: DocMemory
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