| 摘要 |
PROBLEM TO BE SOLVED: To enable stable test at the actual operating frequency by controlling, during the test of semiconductor device, power source noise and power source voltage drop due to heavy current in the test mode for operating a test circuit. SOLUTION: As the external terminal of a semiconductor device, an external terminal 153 is provided in order to switch the function thereof from the functions as a signal terminal, as well as signal terminal and power source terminal, for inputting and outputting signals to and from an internal circuit 157 in the ordinary mode in accordance with the value of the mode signal 154 and as a power source terminal for supplying electrical power to the internal circuit 157 in the test mode. The function switchable external terminal 153 is connected to the power source 156 of the internal circuit via a path switch 155 so that these are not conductive in the ordinary mode, while conductive in the test mode. The output path 158 of the internal circuit connected to the function switchable external terminal 153 is controlled to the high impedance state in the test mode. COPYRIGHT: (C)2006,JPO&NCIPI
|
