Skip to main content
Visitor II
July 26, 2005
Question

flash power off question

  • July 26, 2005
  • 2 replies
  • 769 views
Posted on July 26, 2005 at 10:54

flash power off question

    This topic has been closed for replies.

    2 replies

    ben2Author
    Visitor II
    July 20, 2005
    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

    Visitor II
    July 26, 2005
    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