I am trying to get the timer to generate a 1 KHz squarewave using the output
compare function. The timer is setup as follows:
// Timer1 Init Run timer at 1 MHz 2 MHz bus clock
TPMSC = 0x01; // select divide by 2 clock disabled
TPMMOD = 0xFFFF; // Set modulus
TPMC0V = 0x01F4; // Set initial half period (500)
TPMC0SC = 0x54; // enable interrupt, toggle pin on compare
TPMSC = 0x09; // enable timer 1us per tick bus clk / 2
The Timer ISR looks like this:
// Timer Channel 0 Interrupt
interrupt VectorNumber_Vtpmch0 void TPMCH0 (void)
{
byte temp;
temp = TPMC0SC; // Clear interrupt flag
TPMC0SC_CH0F = 0;
TPMC0V += 500; // Schedule next interrupt
// Code to toggle another pin to test interrupt etc.
if (PTBD_PTBD6 == 1)
{
PTBD_PTBD6 = 0;
}
else
{
PTBD_PTBD6 = 1;
}
}
I would expect to see Pin 16, PTA0/KBIP0/TPMCH0/ADP0/ACMP+, or Pin 7, PTB5/TPMCH0
toggle at a 1 KHz rate depending on the setting of the SOPT2 register, bit 4.
I added some test code to wiggle pin PTB6 on each interrupt to verify that the ISR and timer
setup is correct. PTB6 wiggles at 1 KHz as expected, verifying the timer setup and ISR functionality.
I have tried writing 0x00 as well as 0x10 to SOPT2 and verified that neither PTA0 or PTB5 wiggle.
I have also verified that neither pin is being loaded (lifted pins or parts removed).
I have tested two PCBs with the same result.
The parts I am using are the samples provided by Arrow, MC9308QB8CTG with markings:
MQB8 CTG 4GXG.
I am using Code Warrior for microcontrollers IDE version 5.9.0 with the latest service packs installed.
Clearly, I am missing something but don’t see it.
Thanks,
John
