Re: [Contiki-developers] Tmote sky low-power modes

[Bjorn G. <bg...@si...>]

On Fri, 3 Oct 2008 15:40:07 +0100
"Jonathan Lewis" <jo...@cs...> wrote:

Moi,

> Thanks for the tip about putting the M25P80 chip into "Deep Power-down (DP)"
> mode. I'll investigate. However, if anyone knows off the top of their head
> how to do this I would much appreciate them posting it here.

This is untested code that may serve as a starting point:

int
xmem_deep_power_down(void)
{
  spl_t s;

  wait_ready();

  s = splhigh();
  SPI_FLASH_ENABLE();

  spi_tx(SPI_FLASH_INS_DP);
  
  SPI_FLASH_DISABLE();
  splx(s);

  return xxx;
}

#define M25P80_SIGNATURE 0x13

int
xmem_release_from_deep_power_down(void)
{
  unsigned char signature;
  spl_t s;

  s = splhigh();
  SPI_FLASH_ENABLE();

  spi_tx(SPI_FLASH_INS_RES);
  spi_tx(0);			/* Three dummy bytes */
  spi_tx(0);			/* Three dummy bytes */
  spi_tx(0);			/* Three dummy bytes */

  FASTSPI_CLEAR_RX();
  FASTSPI_RX(signature);

  SPI_FLASH_DISABLE();
  splx(s);

  if (signature == M25P80_SIGNATURE)
    return 0;			/* Success */
  else
    return -1;			/* Fail */
}

Cheers,
/b


--
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Bjorn Gronvall (Björn Grönvall)                    /_______________/|
Swedish Institute of Computer Science              |               ||
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