利用实时时钟降低嵌入式系统功耗

Saving Embedded System Power Consumption by Modifying System Real-time Clock

众所周知,当嵌入式系统进入IDLE状态,CPU可以进入到低功耗模式,系统功耗会降低。但在一般的嵌入式系统中,当系统进入IDLE状态后,即使没有其他设备中断,实时时钟中断也会不断唤醒CPU,这样就会大大增加系统的功耗。本文通过对实时时钟系统的修改,延长了实时时钟中断间隔,使CPU长时间处于低功耗模式,从而大大降低了系统功耗。

As we know,when embedded system enters IDLE state,CPU could enter low power mode to low system power consumption.However,in common embedded system,the real-time clock interrupt will wake up the CPU rapidly and periodically even there is no other devices' interrupt.That will increase system power consumption. This paper will provide a discussing of disable the real-time clock interrupt by extending the real-time clock interrupt interval when the system enter IDLE state.And this paper implements it on ARM based CPU with ECOS and verified the saving of power consumption.