| 摘要 |
PURPOSE:To prevent a memory from being allocated wastefully while making a memory error check possible covering the entire area of the writable memory, by controlling a check-bit generating and error detecting circuit via a memory address register, address comparing circuit, etc. CONSTITUTION:Read-only memory ROM2 and writable memory 3 are addressed consecutively and microprocessor 1 reads set program 2 in ROM2 to control data transfer between input-output port 11 and memory 3. Memory address register 4 is previously stored with address information corresponding to the address boundary between memories 2 and 3 through processor 1 and when the contents of system address bus 8 shows the address of memory 3, register 4 and comparing circuit 5 apply an access signal to check-bit generating and error detecting circuit 6 to make a memory error check covering the entire area of memory 3. This constitution never wastes both memories in allocation. |
