Quad-data-rate-IV SRAMs offer highest Random Transaction Rate

April 01, 2014 // By Graham Prophet
Intended for next-generation networking equipment, Cypress’ 144-Mbit and 72-Mbit SRAMs deliver up to 2,132 million transactions per second, enabling 100-400 Gigabit line cards for routers and switches

Cypress Semiconductor has the first Quad Data Rate IV (QDR-IV) SRAM with the Random Transaction Rate (RTR) required for 100-400 Gigabit line cards in next-generation switches and routers. Cypress says its QDR-IV SRAM is the highest performance, standardised networking memory solution.

RTR, the number of fully random memory accesses per second, is the critical memory performance metric for increased line card and switching rates. The bottleneck for reaching increased line card rates is the processing of look-up tables, statistics and state counters stored in memory, as well as scheduling functions. QDR-IV devices deliver the RTR required to support these functions, enabling higher bandwidth and higher quality video streams.

Altera’s Argy Krikelis, strategic marketing architect, comments, “Working closely with Cypress has enabled Altera to support customers in architecting systems that will use Cypress QDR-IV memories together with Altera’s Arria 10 FPGAs and SoCs to meet next-generation system requirements.”

At Xilinx, Dave Myron, senior director of FPGA product management and marketing, adds, “Xilinx UltraScale FPGA devices were architected to support high-performance memory devices such as Cypress’s QDR-IV SRAM and deliver the flexibility required in high-bandwidth applications.”

Cypress’s QDR-IV SRAM is capable of operating in burst-of-two or banked burst-of-two modes, which deliver the fastest clock speeds and highest RTR of all QDR SRAMs. The banked burst-of-two operating mode operates at a maximum frequency of 1,066 MHz with an RTR of 2,132 million transactions per second (MT/sec), while the standard burst-of-two operating mode can achieve a maximum frequency of 667 MHz and an RTR of 1,334 MT/sec. Both of these operating modes represent a significant improvement over the previous generation of QDR SRAM (450 MHz frequency, 900 MT/sec RTR).

QDR-IV was developed in the QDR consortium, whose members jointly define SRAM standards to enable multiple sources and supply stability.

Cypress; www.cypress.com/sync_SRAMs