| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To save power consumption at the time of a standby mode. <P>SOLUTION: When an event is generated in the standby mode, data corresponding to the event are set to a shadow register 35. The register 35 is operated by a low-speed local clock, and the contents of the register 35 are copied through a selector 37 to a bus IF register 31. The bus IF register 31 is connected through a system LSI bus to a main circuit and read / write are performed in synchronism with a high-speed clock s3. When the state change of the bus IF register 31 is generated, interruption is reported to a CPU. In a normal mode, setting is executed to a data bus IF register 31 corresponding to the state change of the event without interposing the shadow register 35. In the standby mode, since the power source of the main circuit is turned off and the supply of the clock s3 to the bus IF register is stopped, the power consumption is reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
