In many applications, Random Access Memory (RAM) is required for various types of temporary memory storage. While virtually all microcontrollers contain some RAM, external serial SRAM represents a simple way to add additional memory to an application. Microchip’s 2 new device families, the 23 x 640 and 23 x 256, can add 8kB or 32kB of external RAM to an application. The parts use a standard SPI interface that requires only 4 I/O pins and are available in 8-DIP, 8-SOIC, and 8-TSSOP packages.