| 摘要 |
PURPOSE:To decide a RAM to be functioning normally when an address to be confirmed is sequentially added by one and when it exceeds an address of a RAM3 by writing/reading data in accordance with each address of the RAM and simultaneously detecting whether or not data of other addresses are destructed. CONSTITUTION:When the indication is given for inspecting a start of write/read of a RAM3, a micro processor 1 reads a program out of a ROM2 to start checking the RAM3. First of all, a specific data, for instance, a hexadecimal 55H is written in all the addresses of the RAM3. After that, an address to be confirmed is specified for trial reading of the data. When the read-out data is not 55H, the RAM3 is decided to be abnormal. Whereas the read-out data is 55H, another specific data, for instance, a hexadeciman AAH is written in the same address. The data is read by specifying the address to which the AAH is written. When the read-out data is AAH, all the addresses are sequentially specified for data reading. When the entire read-out data is 55H as it is, an address is added by one, and if is exceeds the address of the RAM3, the RAM is decided to be normal. |
