摘要 |
A radio transmit-receive unit can perform the communication processing stably without being affected by high frequency noise with the system activation of a computer unit, whereby if a communication processing request from the radio transmit-receive unit occurs, the computer unit sets the system state of a sub-CPU being activated to a rest state, a counter starts clocking the signal receive time of the radio transmit-receive unit when the system state of the sub-CPU is in a rest state, and a latch circuit holds electric field strength information of carrier received by the radio transmit-receive unit upon the termination of clocking by the counter. And the computer unit switches the system state of the sub-CPU being at rest to an active state, based on the end state of clocking by the counter, to restart the activation of the computer unit. <IMAGE> |