topic Re: VLLSx on Coldefile+ in ColdFire/68K Microcontrollers and Processors

VLLSx on Coldefile+

nz_developer — Thu, 27 Sep 2012 08:23:32 GMT

Trying to get a coldfire+ into VLLS3 mode but when I measure the current it is not dropping (3uA according to datasheet. I am at several mA.)

Any Ideas? I call the Sleep function to put into low power mode

void deepsleep (void)

{

/* Set the SLEEPDEEP bit to enable deep sleep mode (STOP) */

asm ( stop #0x2000; );

}

void Sleep(void){

u8 dummyread;

SetAlarm(10); // wake up in 10 seconds

SetLLWU(); // setup wakeup events

SMC_PMPROT = SMC_PMPROT_AVLLS_MASK;

SMC_PMCTRL &= ~SMC_PMCTRL_STOPM_MASK ;

SMC_PMCTRL |= SMC_PMCTRL_STOPM(0x4) ;

dummyread = SMC_PMCTRL_STOPM(0x4);

SMC_VLLSCTRL = BIT2;

/*wait for write to complete to SMC before stopping core */

dummyread = SMC_VLLSCTRL;

dummyread = SMC_PMCTRL;

deepsleep();

}

Re: VLLSx on Coldefile+

Nouchi — Thu, 27 Sep 2012 08:34:55 GMT

Hello,

You have to take care about unused pins, they must be configured as output, or tied to vdd, because floating pin may draw current.

Emmanuel

Re: VLLSx on Coldefile+

nz_developer — Thu, 27 Sep 2012 08:44:43 GMT

Hi Thanks,

Can I just set to output low? some of my pins need to be low while in Sleep mode.

Thanks again

Re: VLLSx on Coldefile+

Nouchi — Thu, 27 Sep 2012 08:54:12 GMT

Yes but, if you have some pull-up on it, it will drawn current, so you have to take to disable internals pull-up and remove external if needed.

Re: VLLSx on Coldefile+

nz_developer — Fri, 28 Sep 2012 01:58:18 GMT

Tried lots of port configeration settings including disabling all ports etc. Got the current down to 360uA about 100x what I should be getting from the datasheet. Not too easy to solve, I will request support from Freescale through distributor.

Re: VLLSx on Coldefile+

Nouchi — Fri, 28 Sep 2012 06:55:30 GMT

You have maybe something still powered or clocked.

When you begin to play with micro amps, you have to hunt for leaks.

Re: VLLSx on Coldefile+

nz_developer — Thu, 11 Oct 2012 20:17:52 GMT

Found the problem, it was a register to enable stop mode had not been set right. Used Processor expert to setup and that solved it. Got 3uA draw and wake on timer or one of my 3 buttons, very nice.