| 摘要 |
PURPOSE:To set a plurality of test modes by one input terminal and to eliminate variations in input/output electric characteristics of test mode input terminal by supplying a serial signal corresponding to each test mode to the input terminal of a semiconductor integrated circuit. CONSTITUTION:A serial signal for designating a test mode is input to a mode terminal 7 in a semiconductor integrated circuit device having a plurality of test modes. A shift register 3 for serial-to-parallel converting a signal is connected with the terminal 7 to perform shifting according to a system clock 5. When a counter 2 gives a set value and a control signal 12 is generated, the register 3 stops shifting, converts a serial signal input from the terminal 7 to a parallel signal, and outputs it. A decoder 4 decodes a parallel signal from the register 3 by a control signal 13 from the counter 2, and generates various types of test mode set signals 14. Thus, a microcomputer is set to a predetermined test mode to be tested.
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