Spend current in MC9S12P64 STOP mode

Lucidfall — Fri, 15 Nov 2013 06:59:26 GMT

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.

Re: Spend current in MC9S12P64 STOP mode

iggi — Wed, 20 Nov 2013 15:44:44 GMT

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

topic Re: Spend current in MC9S12P64 STOP mode in S12 / MagniV Microcontrollers

Spend current in MC9S12P64 STOP mode

Re: Spend current in MC9S12P64 STOP mode