These are single-chip microcomputers designed with high-performance CMOS silicon gate technology, including the internal flash memory. These microcomputers support the 7900 Series instruction set, which are enhanced and expanded instruction set and are upper-compatible with the 7700/7751 Series instruction set. The CPU of these microcomputers is a 16-bit parallel processor that can also be switched to perform 8-bit parallel processing. Also, the bus interface unit of these microcomputers enhances the memory access efficiency to execute instructions fast. Therefore, these microcomputers are suitable for office, business, and industrial equipment controller that require high-speed processing of large data. For the internal flash memory, single-power-supply programming and erasure, using a PROM programmer or the control by the central processing unit (CPU), is supported. Also, each of these microcomputers has the memory area dedicated for storing a certain software which controls programming and erasure (reprogramming control software). Therefore, on these microcomputers, the program can easily be changed even after they are mounted on the board.