| 摘要 |
PURPOSE:To simplify both the circuit constitution and a diagnosis program and to assure the display of the result of diagnosis, by allotting a display storage region over plural RAMs. CONSTITUTION:An ROM24 stores a program by which a CPU21 controls a device 22 to be controlled and the arithmetic processing is given to the signal supplied from the device 22. A diagnosis program of each block is stored in a diagnosis ROM26. A multiplexer 18 connects selectively RAM16 and 28 to a bus 10 or a display control circuit 20 in response to the control signal given from the circuit 20. A display RAM region covers the RAM16 and 28 consecutively. In case the CPU12 uses the CPURAM region and the display RAM region of the RAM16 and 28, the multiplexer 18 connects the RAM16 and 28 to a main bus 10. |
