| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce the power consumption in a standby state in an electronic apparatus driven by a battery power source. <P>SOLUTION: A system LSI2 includes a standby control circuit 21, a main circuit 22 having a CPU, and an eDRAM 23. Each circuit block receives a power via independent power source lines L21, L22 and L23. The circuit 21 is always supplied with the power. The circuit 22 turns off a power source at a standby time. The power is supplied to the eDRAM 23 only when the eDRAM 23 is used. The supply of the power to each circuit block is performed by the circuit 21 and a power source control circuit 3. When a task to be processed by the CPU is eliminated, the CPU is set to a standby state from a normal operation state. When an operating input is generated from an operating unit 7 or an input is generated at an external input 8, the circuit 21 performs a process necessary for wake-up, and the power is supplied to the circuit 22. <P>COPYRIGHT: (C)2004,JPO</p> |
