Renesas Technology Introduces Ternary Content Addressable Memory (TCAM) Family Designed for Multi-Layer Packet Processing

TCAM is a type of memory in which each memory cell can store three data states: 0, 1, and X (“Don’t Care”). It is suitable for applications such as networking equipment because it achieves deterministic, high-speed searches by using simultaneous parallel operation to compare data strings input from an external device with data strings stored in the memory and outputting the matches. As the use of networks, typified by the Internet, has spread widely in recent years, attention has focused on TCAMs as a key device for increasing the speed of packet forwarding (packet data transfers) by networking equipment by enabling high-speed lookup of destinations, etc., for large volumes of information during packet data transfers.

Renesas Technology has tremendous expertise in designing custom TCAM products for selected tier one customers built up over many years. Building on the sophisticated technology (including CAM cells, search circuits, ultra-low power, and yield boost circuits exclusive to Renesas Technology) and experience built up over that time, the company now plans to release a line of general-purpose standard TCAM products to support the high growth rate of multi-layer packet processing in networking applications.

The features of the R8A20410BG are summarized below.

(1) Industry-leading, high-speed, low power data packet search

Renesas Technology’s patented CAM cells and search circuits have a proven track record and deliver high-speed search capability combined with ultra-low -power consumption. For example, at a clock frequency of 360 MHz, the search processing performance is 360 MSPS/Table, the highest level in the industry today. This makes it possible to design communications equipment offering superior performance.

(2) Flexible search conditions to accommodate a broad range of applications

Flexible search conditions allow the search bit length to be set to 40L/H, 80, 160, 320, 480, or 640 bits. In addition, functions such as four parallel independent search engines significantly increase lookup performance and provide support for a wide range of network applications.

(3) Interoperability with Xelerated’s HX family of NPUs

The Renesas R8A20410BG TCAM is designed to seamlessly interwork with NPUs. The TCAM will be fully interoperable with Xelerated’s HX family of high performance Network Processors.

Renesas is increasing the number of NPUs, which the R8A20410BG interoperates with, to provide a wide range of packet processing.

Product Background

Recent years have seen a notable expansion in the use of networks such as the Internet and Ethernet LANs. In the field of communications equipment such as networking components, there is strong demand for high-speed and highly reliable packet data transfer capabilities. This demand is expected to increase in the further in future.

One key device in achieving high-speed data transfer is the TCAM, which enables rapid lookup of data destinations, etc., and demand is growing for TCAM products with larger capacities and faster search speeds. However, CAM cells generally have a large surface area. This means that increasing the memory capacity to boost the amount of data that can be processed results in a larger chip size and higher power consumption.

In response to the growingmarket demand, Renesas Technology has used patented technology in TCAM cells, search circuits, etc., which was developed for custom TCAM products for tier one customers, to overcome problems related to achieving larger capacity and faster speeds while retaining low power consumption. The company now plans to release the Renesas Standard TCAM Series of general-purpose TCAM products that support flexible search conditions for a variety of networking equipment applications. The 20 Mbit R8A20410BG is the first product in the series.