Hey, everyone. I've gotten myself thoroughly confused (again)!
I started writing a new https://community.freescale.com/message/67982#67982, using the MTIM module as my timer. I'm writing this on a JS16 (but I've found that QG8 seems nearly identical for MTIM purposes). In hardware degugging, I find that my code gets stuck in ISR. The datasheet isn't very clear about any sort of interrupt flag clearing, or any such procedure.
The other threads here that were helpful are:
These got me to ask myself, 'what is the difference between the MTIM and the TPM modules?' TPM seems to be able to run in free-running mode and with modulus! So why need a separate modulo timer module? Also, the TPM module has much more explicit procedures for clearing interrupt flags.
At any rate, my MTIM code is as such:
MTIMCLK_CLKS = 0b00; // select BUSCLK
MTIMCLK_PS = 0b0111; // MTIM clock source divided by 128 = 46.875KHz
MTIMMOD = 0x7F;
MTIMSC_TOIE = 1; // enable overflow interrupts
SPARE1 = 0; // PTA2
MTIMSC_TRST = 1; // clear the counter
MTIMSC_TSTP = 0; // start the timer counter
overflow_flag = 0; // reset flag
// do something else here
interrupt VectorNumber_Vmtim void IntMtim(void)
SPARE1 = !SPARE1;
overflow_flag = 1;
__RESET_WATCHDOG(); // feed the dog