flash power off question

ben2 · ‎2005-07-26

Posted on July 26, 2005 at 10:54

ben2 · ‎2005-07-20

Posted on July 20, 2005 at 11:40

I am powering of the internal flash by setting

FLASHR->CR0 |= 0x8000; // set bit PWD

And then going into LPWFI mode

The datasheet is not very clear about turning the internal flash back on again.

Does this happen automatically ? It would appear to be doing this, but I would just like to make sure. I currently only have the interrupt vectors in Ram and have no delay and it seems to power up ok.

The core is only running at 32Khz which will make the cycle time ~32us which is longer than the 20us suggested delay before accessing Flash.

Does anyone know if the flash is automatically powered back on?

many thanks Ben

olivier239955_stm1_st · ‎2005-07-26

Posted on July 26, 2005 at 10:54

Yes the internal flash automatically powers back on following a wakeup event (interrupt, wakeup, system reset).

As you stated the fact that you resume operation from the 32KHz clock, you don't need to insert an extra delay of 20us corresponding to the flash initialisation time.

Oliver