| 摘要 |
PURPOSE:To test an internal circuit entirely by converting the internal loop back test function of a self-diagnosing function in an intermediate controller to the control function of an external interface. CONSTITUTION:In a loop back test circuit, first and second selection circuits 13 and 14 which select a signal with respect to the control function of the external interface are added. And on a write register 102' being used for an external test similarly as a loop back test, the control signal of operating sequence for an external device is set as a test pattern via the external interface 101. Then, its response pattern is set at a read register 103' being used for the external test, and an MPU 11 reads it, then, executes the check of the action. |
