| 摘要 |
<p>PURPOSE:To reduce the power consumption of an input/output circuit by providing a function to suppress the power consumption of the input/output circuit for a period when the input/output circuit has no signal access to other circuits. CONSTITUTION:A power control signal generating circuit 2 detects previously whether the input/output circuits 3 - 6 have the signal accesses to other semiconductor integrated circuit devices or not. If so, the circuit 2 outputs an enable signal (EN = 'H'). If not, an enable signal (EN = 'L') is outputted. Under such conditions, ENB = 'H' is satisfied with the circuit 3 as long as EN = 'L' is satisfied. Then a PMOS transistor 31 is turned off. Thus no current is supplied to the input/output circuits from a 1st power supply 7, and no power is consumed. In such constitution, the power consumption of the input/output circuit can be reduced.</p> |
