The ISSI IS6MC256K is a secondary cache module designed for use with Intel Pentium CPUbased systems. This ISSI synchronous cache module uses IS61C632 32K x 32 pipelined synchronous burst static RAMs which are mounted on a multilayer board. In addition, this module uses a single 5V 8-bit wide CMOS SRAM for the tag. On-board logic, 3.3V data RAM, and a 5V tag RAM provide an exact interface between the module and the PC chipset. Five PD (presence detect) input pins allow the system to determine the particular cache configuration.