| 摘要 |
PROBLEM TO BE SOLVED: To surely complete memory check by both CPU in a short time in a microcomputer (2-CPU microcomputer) provided with two CPUs. SOLUTION: In the microcomputer wherein each CPU 1, 2 is independent of shared RAM and ROM respectively and can access, when each CPU 1, 2 establishes a memory check performance condition, a RAM check for inspecting whether data can be correctly written/read on each address of RAM or not is performed on the whole area of RAM, the data stored to the whole area of ROM are read successively to perform the ROM check inspecting whether the data in ROM is normal or not, CPU 1 performs the ROM check after performing the RAM check, and CPU 2 performs the RAM check after performing the ROM check. Thus, even when either CPU is made not a wait state, simultaneous access can be prevented to the same address of RAM. |
