Spend current in MC9S12P64 STOP mode

[Lucidfall]

Hello.

I am implementing full stop mode using S12P64.

     CPMUPROT = 0x26;

     CPMUOSC_OSCE=0; // full stop mode

     CPMUCLKS_PSTP=0; // full stop mode

     CPMUPROT = 0x01;

     asm ANDCC #0x7F;     // Stop Mode Enable

     asm STOP;                   // stop mode

I checked XTAL through Oscilloscope and there is no oscillation.

But still main loop is working and ECU spend current (7mA)

I used external Oscillator (CPMUOSC_OSCE=1) for source clock.

Should I do more thing?

Please help me..Thanks.

[iggi]

Hello,

Use the app note AN3937 MC9S12P Family Demo Lab Software. There are example projects for Low Power Modes and System Clocks which are helpful for your case.

http://cache.freescale.com/files/microcontrollers/doc/app_note/AN3937.pdf
http://cache.freescale.com/files/microcontrollers/doc/app_note/AN3937SW.zip

It seems like you didn't configure the system clock so it was not initialized. I recommend to test it on Internal Clock firstly. This is so called PEI mode:

/* initialise the system clock PEI - 50MHz VCO, 12.5MHz Bus CLK, from 1MHz Internal Clock */

        CPMUPROT = 0x26;                /* Clear PROT bit, disable protection of clock configuration registers */

        CPMUSYNR = 0x58;                /* SYNDIV = 31, VCO frequency 48 - 64 MHz */

        CPMUPOSTDIV = 0x01;          /* POSTDIV = 1 */

        CPMUCLKS = 0x80;                /* PLLSEL = 1 */

        while (CPMUCLKS != 0x80);      /* Verify CPMUCLKS configuration */

        CPMUPROT = 0x01;                /* Set PROT bit, enable protection of clock configuration registers */

        while(!CPMUFLG_LOCK);        /* wait for PLL to lock */

Also, i've attached an example code of STOP mode written for S12XET256 target MCU. This is for a reference only to see how it is done.

Regards,

Ivan