AnsweredAssumed Answered

Low Power Mode Steps

Question asked by vengeful on Jan 14, 2014
Latest reply on Jan 23, 2014 by iggi



I have been trying to get the device I am currently working with into Full Stop Mode, however a few moments after it executes the instruction to go into Stop Mode, the MCU resets. AN2461 doesn't quite give an example of how to do this or the steps to follow. For example do I need to disable the watchdog, then Clear the S bit and finally execute the Stop command?


Currently my initialisation code for the RTI (use this in my application) and COP are:

CPMURTI = 0b11111111;     //Divide clock bt 3.2x10^6

CPMUPROT = 0x26;         //Disable write protection to CPMUCLKS register

CPMUCLKS |= 0b10000011;  //PLL Clk source, Disable Osc in stop mode, COP clk source is OSCCLK


CPMUINT_RTIE = 1;   //Real Time Int Enable


CPMUCOP_RSBCK = 1; //Don't reset while debugging


Below is the instructions I execute when I stop

_asm nop

_asm nop

_asm nop

_asm ANDCC #$7F;

_asm nop

_asm nop

_asm STOP


What am I missing, don't understand why I get reset after the Stop is executed?


MCU used, MC9S12G96, Codewarrior IDE, Code is running without debugger connected