DISK DRIVE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a technology to increase processing speed in a microcomputer by efficiently using a built-in RAM. SOLUTION: A first means to save storage information of a RAM built-in the microcomputer in a cache memory 21 based on command issuance from a host system 26, a second means to develop a program stored in an external program memory of the microcomputer in the RAM and a third means to execute the developed program are formed by the microcomputer 23. A free space of the RAM is expanded by saving the storage information of the RAM in the cache memory and program development from the program memory to the RAM is made possible. In addition, the processing speed is increased by instruction fetch from the built-in RAM to which high speed access is possible.