| 摘要 |
PURPOSE:To apply a test pattern in common to many ICs and to attain a burn-in action by supplying clocks until the state of a prescaler of a microcomputer can fetch an instruction. CONSTITUTION:A rest switch 10 turned on to clear a counter 3 and to reset monostable multivibrator 2. Thus the CLK of a clock terminal 9 is applied to the Extal of a CUT1 through NAND gates 5 and 6. When an F/F of a prescaler of the DUT1 can fetch an instruction, a terminal E(IRU) of the DUT changes to H from L. Then an input is supplied to the input B of the multivibrator 2. The output Q of the multivibrator 2 is changed to H from L, and NAND gates 4 and 5 are kept closed. Thus the supply of clocks is stopped to the DUT, and the F/F of the prescaler is put under a waiting mode in an instruction fetch enable state. |
