| 摘要 |
PURPOSE:To perform the test of a microprocessor without using an expensive large-scale LIS tester by using a program counter which produces by itself an instruction to be supplied to an instruction register and a switch means for input instruction. CONSTITUTION:When the transfer gates 45a-45N of a switch circuit 4 are opened, the instructions given from external instruction terminals 5a-5N are supplied to an instruction register 2 and decoded by an instruction decoder 3. Thus a control signal C is delivered. Then the NOT gate 42 of a circuit 4 is opened together with transfer gates 46a-46N. Thus the value sent from a program counter 1 is supplied to the register 2 and then decoded by the decoder 3. Then the signal C is delivered. Under such conditions, all instructions can be loaded to the register 2. Thus the quality of a microprocessor to be tested can be decided with the comparison of output between a nondefective microprocessor and the microprocessor to be tested. |
