These 256K Byte cache modules offer dual asynchronous 32K x 32 banks of memory. There is a 16K x 8 tag memory for main memory cacheability up to 64 Megabytes. The MCM32N865 and MCM32P865 include a 16K x 1 common I/O dirty bit for writeback cache capability. The modules are designed to support common 486 chipsets which utilize chip enable (CEx) byte control and bank write enable (CWEx ). The MCM32N864 and MCM32N865 operate at 5 V while the MCM32P864 and MCM32P865 operate at 3.3 V power. PD pins are provided for cache size identification at system startup