| 摘要 |
PURPOSE:To shorten the test time by performing simultaneously a test of the function module of the microcomputer, in the one-chip microcomputer loaded with plural same function modules. CONSTITUTION:This microcomputer is provided with a detecting circuit consisting of read-out buffers 3a, 3b having the same output resistance and a detection buffer 53 whose threshold voltage is less than 1/2 of a power supply voltage V, a detection buffer 54 whose threshold voltage exceeds V/2, and an EX-OR gate 55, and constituted so as to decide whether the function module is defective or not by detecting whether the potential of an internal bus 24 is V/2 or not. |
