| 摘要 |
PURPOSE:To add a fault diagnostic function and to improve the reliability by providing a test information memory, a bus control line and a diagnostic information line in the inside of a microprocessor. CONSTITUTION:The inside of the microprocessor 14 is provided with the test information memory 8, the bus controller 11 and the diagnostic information transmission line 7. Further, an internal control signal line 9 of a CPU-core 1b, a controller signal line 5, an internal address data bus 10 and an address data bus 4 are coupled directly by a bus buffer 12 at normal operation. The line 7 is connected to the bus controller 11 via the internal control signal line 9 and the internal address data bus 10b at diagnosis. The CPU-core 1b reads test information by the internal address data bus 10 and the internal control signal line 9 to control the bus controller 11 according to the information. |
