| 摘要 |
PURPOSE:To attain a low power for a flip-flop by interrupting a current supply of scan-in/out at the system operation not requiring the scan-in/out function. CONSTITUTION:In applying a level 1 to a terminal TEST MODE of the flip-flop at the system operation not requiring the scan-in/out, the level 1 is applied to a transistor Q4 so as to turn it off, and a Q3 is turned off at the same time, a current of Q1a, Q1b, Q1c and Q2 is cut off and no power is consumed. The low power for the FF is attained by cutting off the current supply of the scan-in/out, i.e., OR/NOR 3, 4 so as to inactivate the unnecessary function without losing the operation of the FF at the system operation not requiring the scan-in/out. |
