| 摘要 |
PURPOSE:To make it possible to set up a test state without requiring a test mode setting terminal by controlling the waveform of power supply voltage to be impressed to an integrated circuit and detecting the specific waveform by the integrated circuit. CONSTITUTION:This semiconductor integrated circuit is constituted of a power supply terminal 1 for the integrated circuit, a test signal generating circuit 2, a pulse detecting circuit 3 for detecting a pulse superposed to power supply voltage and converting the pulse into a logical level, and a counter 4 for counting up the pulse converted into the logical level. Namely the circuit 2 consisting of the circuit 3 and the counter 4 is connected to the post stage of the terminal 1, the number of pulses superposed on the power supply voltage, and when the count value becomes a prescribed value, a test signal is generated to set up the integrating circuit to a test mode. Thereby, the test mode can be set up without additionally connecting an exclusive terminal for setting up the test mode in the integrated circuit. |
