| 摘要 |
PURPOSE:To execute exactly disconnection control of a power source by cutting a low-order power source only in case when all high-order devices are in a state that the power source is cut, when a power source cutting indication is outputted from some high-order device. CONSTITUTION:A power source control device 2 is interposed between a central processing unit 1 being a high-order device, and a peripheral device 3 being a low-order device, and turn-on and turn-off of a power source to the peripheral device 3 are controlled by an indication from the central processing unit 1. When cutting the power source, power source cut state signals OFS1, OFS2 from each central processing unit 1 become an AND signal OFS3 through an AND gate 11, and also power source cutting signals OFF1, OFF2 are inputted to a pulse generating circuit 17 through AND gates 14, 15 and an OR gate 16 together with the OFS3. In this way, when the OFF1 or the OFF2 is turned on, the power source of the peripheral device 3 is cut by a power source control part 10 only in case when both the OFS1 and the OFS2 are turned on. |
