| 摘要 |
PURPOSE:To use always the same input information without depending upon an ambient function for the test input information of a central control function part by separating the central processing function part and an ambient function part and testing independently respective parts when a microcomputer is tested. CONSTITUTION:The second test input 6 is a test input signal to test an ambient function part and supplied to the second test circuit 7. The second internal test signal 8, which is the output of the second test circuit 7, releases the control line to link a central processing function part 4 and an ambient function and the linking of the central processing function part 4 and a data bus, and the control is entrusted to the internal test signal 8. Consequently, by operating the second test input 6, an ambient function part 9 can be freely controlled, the ambient function action can be performed and the output of the ambient function part 9 is derived to the external terminal as the second test result 10. Namely, in a microcomputer 11, the central processing function part 4 and the ambient function part 9 are completely separated and the test can be executed respectively independently at the time of the test mode. |
