The FUJITSU FR family of single-chip microcontrollers using a 32-bit high-performance RISC CPU, with a variety of built-in I/O resources and bus control mechanisms for built-in control applications requiring high-capability, high-speed CPU processing. External bus access is assumed in order to support the expanded address space accessible by the 32-bit CPU, and a 1K bytes cache memory plus large RAM are provided for high-speed execution of CPU instructions.