Linux是有低功耗模式的（Low Power Mode）,emcraft的STM32F7也实现了这个功能，它支持suspend to RAM模式。也就是电脑上常说的挂起到内存。
在STM32F750开发板上可以通过命令行使系统挂起，使用SW3 button唤醒系统（wake up）。
1. 系统正常启动，测量5V输入端电流，大约210mA
wake up pin.png (702.38 KB, 下载次数: 0) 下载附件 2019-4-2 20:49 上传

1. dwc2 50000000.usb: suspending usb gadget g_serial
   
2. dwc2 50000000.usb: s3c_hsotg_ep_disable: called for ep0
   
3. dwc2 50000000.usb: s3c_hsotg_ep_disable: called for ep0
   
4. PM: suspend of devices complete after 5.553 msecs
   
5. PM: late suspend of devices complete after 4.632 msecs
   
6. PM: noirq suspend of devices complete after 2.482 msecs
   
7. PM: noirq resume of devices complete after 1.748 msecs
   
8. PM: early resume of devices complete after 2.316 msecs
   
9. dwc2 50000000.usb: resuming usb gadget g_serial
   
10. PM: resume of devices complete after 111.242 msecs
    
11. Restarting tasks ... done.
    
12. / #

复制代码此时系统电流重新回到210mA左右。