Mitsubishi Offers 133 MHz, 1-Mbit SRAM for Level-2 PC Cache Memory Applications; Speed-Enhanced, Low-Power Synchronous Pipeline Burst Device Allows Designers to Boost System Performance

Business Wire, Oct 15, 1996

SUNNYVALE, Calif.--(BUSINESS WIRE)--Oct. 15, 1996--The Electronic Device Group of Mitsubishi Electronics America, Inc., today announced the North American availability of a speed-enhanced, 1-Mbit synchronous pipeline burst SRAM that provides a high-speed, Level-2, cache solution for Pentium and PowerPC microprocessor-based personal computer (PC) systems.

The device is targeted for PC cache applications that require the cache-memory bus to operate at up to 133 MHz. The device is also available in COAST 3.1-compliant modules that operate at 66 MHz. In addition to PC systems, the SRAM provides a cache memory solution for ISDN, office network switch, router, telecom and datacom applications that require access times as fast as 5 ns.

The 1-Mbit synchronous SRAM device, the M5M5V1132A, has a 32-Kword by 32-bit organization and integrates a 2-bit burst counter, as well as input and output registers on a single monolithic circuit. The device is manufactured in Mitsubishi's 0.4-um SuperCMOS process technology, which combines the best characteristics of bipolar and CMOS technology to enable high-frequency, low-power ICs, such as this 1-Mbit SRAM device, to fit in small die sizes.

"This speed-enhanced device allows designers to run the cache-memory bus at clock rates much faster than 66 MHz, which until now has been the ceiling for Level-2 cache," said Narayan Purohit, Mitsubishi Electronics' product manager for SRAMs, Flash memories and PC cards. "As a result, PC, telecom and office networking applications will be able to offer greatly improved performance."

Key Features

The M5M5V1132A incorporates the following key design features:

--A burst mode control pin allows designers to choose either an interleaved burst for Pentium applications or a linear burst for PowerPC applications;

--A snooze mode feature turns off Level-2 cache when it is not in use, extending battery life for portable applications while maintaining data integrity;

--Synchronous circuitry provides designers with a precise cycle control that is triggered by a positive-edge clock transition;

--An on-chip, self-timed write operation eliminates complex signal generation characteristics associated with off-chip write operations;

--A flow-through mode offers designers a 2-1-1-1 burst sequence.

Supports Level-2 Cache Applications for High-Speed Cpus

Designers can implement the M5M5V1132A synchronous SRAM as either single-or dual-banked cache memory for systems that require a bus clock frequency of up to 133 MHz. For example, designers can configure a 256-Kbyte single bank with two devices or configure a 512-Kbyte dual bank with four devices. The SRAM is LVTTL compatible and available in the following access times: 5.0 ns at 133 MHz and 117 MHz, and 5.5 ns at 100 MHz.

Designed For Low Voltage And Low Power Consumption

The M5M5V1132A features single, 3.3V power supply operation as well as 3.3V and 2.5V I/O supply operation. It also offers low power consumption, typically dissipating from 660 mW (at 100 MHz) to 792 mW (at 133 MHz). It consumes only 3.3 mW in stand-by and snooze mode.

Available As Both An Ic And Coast 3.1-Compliant Cache Modules

This speed-enhanced, 1-Mbit synchronous pipeline burst SRAM device is available in both discrete and COAST 3.1-compliant module form. The 133-MHz device is available as a 1-Mbit IC with the product number M5M5V1132A. The device is also available as 66-MHz cache modules that have been designed to meet the COAST 3.1 specification developed by Intel Corporation. The 512-Kbyte module has the product number MH64S64TR3N, and the a 256-Kbyte module has the product number MH32S64TR3N.

Compact Footprint And 100-Pin Standard Package And Module Sizes

The 1-Mbit M5M5V1132A IC fits within a 14.0 mm by 20.0 mm footprint, has a pin pitch of 0.65 mm and is available in 100-pin TQFP packages. The 512-Kbyte MH64S64TR3N and the 256-Kbyte MH32S64TR3N devices are contained in standard 100-pin SIMM modules.

Availability and Pricing

The 1-Mbit M5M5V1132A discrete device is available now in volume production. The 133-MHz version of the IC will sell for $16.50 each in 1,000-unit quantities. The 512-Kbyte MH64S64TR3N and 256-Kbyte MH32S64TR3N cache modules are currently available in volume production.

About COAST

The COAST (Cache-On-A-STick) flexible cache solution, developed by Intel Corporation, is a de facto industry standard for cache memory modules used with Pentium processors. The COAST solution allows one system board to accommodate 256-Kbyte and 512-Kbyte asynchronous and pipeline burst modules. As a result, the COAST solution allows one system board to support caches spanning a wide range of price and performance points.

About Mitsubishi Electric and Mitsubishi Electronics America

Mitsubishi Electric Corporation is one of the leaders in providing high-speed and low-power SRAM products in small package sizes, and is known throughout the industry as a market-driven memory supplier to its OEM customer base. Mitsubishi markets its SRAM products in North America through the Electronic Device Group, a wholly owned subsidiary of Mitsubishi Electronics America, Inc.