I have a DEVKIT-S12G128, 8Mhz crystal. CodeWarrior 5.9.0. The issue I have is with the PWM. I have setup a 24Mhz bus clock and a 24kHz PWM (16bit) channel (10%duty) . Everything looks ok if you look at a few cycles of the PWM. After about 230ms the output STOPS and restarts in another 230ms.
//---------------------------------
// example devkit-s12g128 with 8MHz crystal
// output on pin PP1 (J2-01)
//
// 24khz pwm signal with a 10% duty cycle.
// After about 230ms the output STOPS. It restarts after about 230ms.
//
// At 1% duty the output stops after 22ms. It restarts after about 440ms
#include <hidef.h>
#include "derivative.h"
void SetPEEmodeBUSCLK(byte _synr, byte _refdv, byte _postdiv);
void main(void)
{
ECLKCTL_NECLK = 0;
DDRP =0x02;
SetPEEmodeBUSCLK(0x02, 0x80, 0x00); // 24MHz BUSCLK from 8 MHZ oscclk, PEE mode
//------------------------------------------------
PWME = 0x00; // Disable all PWM channels
PWMPOL =0xFF; // All channels are high an go low
PWMCLK = 0x00; // All channels are clocked from A or B clock source
PWMCLKAB = 0x00; // Clock A is the source clock for all channels
PWMPRCLK = 0x00; // Clock A & B equal to BUS clock
PWMCAE = 0x00; // left aligned
PWMCTL = 0x10; // 0-1 concatenated to form 16-bit PWM
PWMPER01 = 1000; // PWM channel 01 period
PWME = 0x02; // Enable the channel
PWMDTY01 = 100; // set duty cycle for 01
//-------------------------------------------------
for(;;)
{
_FEED_COP();
}
}
void SetPEEmodeBUSCLK(byte _synr, byte _refdv, byte _postdiv)
{
CPMUSYNR = _synr;
CPMUREFDIV = _refdv;
CPMUPOSTDIV = _postdiv;
CPMUOSC_OSCE = 1; //enable external oscillator OSCE
while(!CPMUFLG_UPOSC)
{// you can check for timeot here with error message report
};
while(!CPMUFLG_LOCK)
{// you can check for timeot here with error message report
};
//--- select clocks --------------------
CPMUCLKS = 0B10000011; // bus=fPLL/2; COP is clocked from OSCCLK
if(CPMUCLKS != 0B10000011) // After writing CPMUCLKS register, it is strongly recommended to read
{ // back CPMUCLKS register to make sure that write of PLLSEL,
asm nop; // RTIOSCSEL, COPOSCSEL0 and COPOSCSEL1 was successful.
}
}
