| 摘要 |
An electronic device uses a pseudo-SRAM (14) having a self-refreshing function, as a memory, and a refresh timing signal having a predetermined period is supplied to the pseudo-SRAM in the operation state of the electronic device. When no key operation is performed with a keyboard (17) for a predetermined period of time, the electronic device switches a mode into an idle mode to stop supply of an operation clock to a CPU (11) and to stop supply of the timing signal to the pseudo-SRAM. When the supply of the timing signal to the pseudo-SRAM is stopped, the pseudo-SRAM operates the self-refreshing function for holding data with low power consumption. When a key operation is detected in the idle mode, a refresh timing signal having a high frequency is supplied to the pseudo-SRAM for a predetermined period of time. Thereafter, the supply of a clock to the CPU is restarted, and the state of the electronic device is returned to a normal operation state. <IMAGE> |
