| 摘要 |
PROBLEM TO BE SOLVED: To provide an I/O extension device group and an I/O extension device capable of synchronizing the states of a plurality of I/O extension devices without interposing a CPU.SOLUTION: An I/O extension device 30 in charge of an input function is configured to, when the value of an input signal to an input control register 32 changes, determine whether or not the power supply state of the device is made transit from a sleep state to a normal state by a restoration condition determination part 34 on the basis of the change, and to, when the determination is affirmative, output a state notification signal indicating the state of a transition destination to a second I/O extension device 50. The second I/O extension device 50 in charge of an output function is configured to, when the state of the transition destination is notified by the state notification signal, automatically rewrite the value of an output control register 53 to a value corresponding to the state of the transition destination, and to change the value of the output signal. For example, an output signal for power supply control is changed to turn on a power supply of a peripheral device, and then to turn on a power supply of a CPU such that state shift to the normal state is achieved. |
