The MSM65X227 is a high-performance, 8-bit microcontroller that employs OKI original CPU core, the nX-8/50. The MSM65X227 includes a minimum instruction execution time of 667 ns (@6 MHz) that enables high-speed processing. It has 60K-byte program memory space, internal 4K bytes of EEPROM (general memory space), 1K-byte data memory (384 bytes for local memory space and 640 bytes for general memory space), a timer, a serial port and an A/D converter. The MSM65X227, which has no internal program ROM, is provided with the special time-division data/address bus that can be connected to an extrernal program ROM.