Microcomputer with processor bus having smaller width than memory bus

摘要

A microcomputer comprises a processor, a memory and a buffer including a selector for changing a bus width, wherein a processor bus has a smaller width than that of a memory bus. The microcomputer further comprises a bus interface unit which has a selector for changing the bus width, and is used for inputting/outputting signals from/to the outside, and an external bus for connecting the bus interface unit and the outside, wherein the bus interface unit is connected to the memory via the memory bus, and the external bus has a smaller width than that of the memory bus. Still further the memory includes a plurality of memory regions, and the processor is disposed in a space of the memory regions.