When enter low power mode,what's the difference between wfi,and wfi sev wfi

RE: When enter low power mode,what's the difference between wfi,and wfi sev wfi

Simonr — Tue, 14 May 2019 11:29:10 GMT

Sure you can set the __SEV after __WFI, but I don't think that will do what you want. Please see this post for an accurate explanation on WFE and SEV. And sorry, as my explanation was not correct.

For the record, if __WFI by itself is sufficient for your application, I think it will be okay to stick with that.

Best regards,

Simon

RE: When enter low power mode,what's the difference between wfi,and wfi sev wfi

Pupil — Tue, 14 May 2019 09:10:01 GMT

Thanks Simon !

when using wait for event function,the mcu consumes too much power than __WFI.

Why didn't clear the internal event register consumes more power?

Is there any other way to clear it?

Can I move the __SEV function to the start of application,so after interrupt wake the application,clear the register first,

after doing the work,then go to __WFI.

Or like that:

__WFI;              //Wait for interrupt
__SEV;              //Interrupt ocurred ,clear the regirster

//...                 //go to process application

RE: When enter low power mode,what's the difference between wfi,and wfi sev wfi

Simonr — Mon, 13 May 2019 08:25:03 GMT

What happens is that the __SEV function clears the internal event register, which includes the timer you set, and is why the timer is not waking the application as you want. Not clearing the event register however, will consume more power than just going to sleep will. Also, the __WFI function is short for wait for interrupt, which means the application will sleep until an interrupt event occurs. You could use the __WFE function instead which wakes up on any event.

Best regards,

Simon