8-bit Microcontrollers中的主题 Current problem MC9S08QE16 in Stop3.

Current problem MC9S08QE16 in Stop3.

Braulio_Cespede — Tue, 02 Dec 2014 19:18:45 GMT

Hello Everyone.

Recently I was assigned a project. But to achieve that project, I need to make the MC9S08QE16 go below to 4uA with a extern RTC.
Currently I was able to achieve 25-22~uA with RTC and 8-7.5~uA without RTC.

I had read a lot in the forum but I cannot make it go below.

I will attach some picture and the code.

Processor Expert Components:

Processor Expert CPU config:

RTC config:

Note:

LVD module is disable in Stop mode.
All unused I/O pins were set as Output and default value 0;
ADC module is disable.

Thanks for advance.

Original Attachment has been moved to: Source-Code.txt.zip

Re: Current problem MC9S08QE16 in Stop3.

tonyp — Tue, 02 Dec 2014 20:00:58 GMT

I don't know if you're already doing these but, if not, you could try:

* Turn off the various unused peripherals (like, for example, the SCI). Turn it off means, in most cases, writing the default reset values to the related registers.

* Turn off all clocks to the various peripherals (that you don't need).

Order matters so you should first turn off, say, the SCI, and then remove its clock.

[Note: It's been a really long time I had to do this but I think that shutting off just the clock (say, to the SCI) did not reduce consumption as much as first turning the SCI off, and then its clock. I could be mistaken about the exact details, because it was many years ago, but there was some little quirk like this that took me a while to figure out, and it alone dropped consumption to acceptable levels.]

Hope it helps!

Re: Current problem MC9S08QE16 in Stop3.

Braulio_Cespede — Tue, 02 Dec 2014 20:57:39 GMT

Thanks for answer.

I've already did it and not just the SCI.

look:

ACMP1SC=0x00;

ACMP2SC=0x00;

IICC1=0x00;

IICC2=0x00;

SCI1C2=0x00;

SCI2C2=0x00;

TPM1SC = 0x00;

TPM2SC = 0x00;

TPM3SC = 0x00;

Re: Current problem MC9S08QE16 in Stop3.

tonyp — Tue, 02 Dec 2014 21:40:40 GMT

Fine, but I don't see any references to the SCGC1 and SCGC2 registers to turn off the peripheral clocks.

Re: Current problem MC9S08QE16 in Stop3.

Braulio_Cespede — Wed, 03 Dec 2014 14:18:23 GMT

Thank you for answer again.

I've set the SCGC1 and SCGC2, but apparently It doesn't do anything different from before.

/*SCGC1: TPM3=0,TPM2=0,TPM1=0,ADC=0,??,IIC=0,SCI2=0,SCI1=0*/

SCGC1 = 0x00;

/*SCGC2: DBG=0,FLS=0,IRQ=0,KBI=0,ACMP=0,RTC=1, ??,SPI=0 */

SCGC2 = 0x04;

Note: SCGC2 = 0x04, because if I disable the RTC the current consumption goes up to 6 mA.

Right now with this set and the RTC clock enable it's consumption is 24-30~uA in stop3.

Do you any other suggestion?

Thank again.