WFI doesn't reduce power

zarozaro · ‎2006-06-05

Posted on June 05, 2006 at 13:57

zarozaro · ‎2006-05-12

Posted on May 12, 2006 at 16:22

Hi,

I'm trying (unsuccessfuly) to use WFI mode to reduce power consumption between interrupts. Program execution stops when I clear WFI bit in RCCU_SMR register, but current remains the same. Once interrupt is detected program execution resumes.

I tried it with 2 eval boards - IAR (STR712FR2) and Hitex (STR710FZ2).

zarozaro · ‎2006-05-15

Posted on May 15, 2006 at 12:03

Hi,

I'm powering the board from external power supply and measuring the total current drawn from the board, so it includes LEDs, RS232 and CAN drivers.

I tried several MCLK/FCLK/PCLK combinations, here are some of the results:

MCLK FCLK PCLK mA

32 32 32 80

32 16 16 71

16 16 16 58

16 8 8 54

8 8 8 47

Application I'm running is very similar with AN2100 application note ''STR71x power management''.

I cannot get any current reduction with WFI mode (RCCU->SMR &=0xFE;), eventhough processor stops program execution until detects interrupt.

Thanks.

zarozaro · ‎2006-06-05

Posted on June 05, 2006 at 13:57

Hello,

Does anybody have better luck reducing current consumption in WFI mode?

Thanks.