| 摘要 |
A test system of this invention is capable of distinguishing interface circuit trouble from keyboard trouble. For diagnosis, an inhibit signal is generated to supply a test clock signal to an output shift register and an input shift register of the interface circuit instead of a clock signal generated from the keyboard, and test data are loaded into the output shift register. If the test data are transferred from the output shift register to the input shift register correctly, it is detected that the interface circuit does not have trouble. |
