The ON Semiconductor serial SRAM family includes several integrated memory devices including this 1 Mb serially accessed Static Random Access Memory, internally organized as 128 K words by 8 bits. The devices are designed and fabricated using ON Semiconductor’s advanced CMOS technology to provide both high-speed performance and low power. The devices operate with a single chip select (CS) input and use a simple Serial Peripheral Interface (SPI) protocol. In SPI mode, a single data-in (SI) and data-out (SO) line is used along with the clock (SCK) to access data within the device. In DUAL mode, two multiplexed data-in/data-out (SIO0-SIO1) lines are used and in QUAD mode, four multiplexed data-in/data-out (SIO0-SIO3) lines are used with the clock to access the memory. The devices can operate over a wide temperature range of −40°C to +85°C and are available in a 8-lead TSSOP package.