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Freescale MCF5213 _DMA Timer_PWM time period calculation problem

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ilamseeker

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Dear All,



I am using two MCF5213 Evaluation kits: one for generating the PWM waveform and the other for checking the period of the generated PWM waveform.



I am using he DMA timers to check the time period of the pulse. I have configured it but it is giving incorrect value in the DTCR(counter) register.



I am using DTIN1 pin for giving the pulse input which has the period of 0.8ms but the value in the counter turns out to be 264244026.



which gives 264244026/(80 * 10^6) = 3.303050325 which is incorrect. Please check the code and let me know if i am doing something wrong here



thanks





I am using the following code:



int main(void)

{





// Enable the directions pins TC[1]

MCF_GPIO_PTCPAR = 0

| MCF_GPIO_PTCPAR_DTIN0_DTIN0

| MCF_GPIO_PTCPAR_DTIN1_DTIN1

| MCF_GPIO_PTCPAR_DTIN2_DTIN2

| MCF_GPIO_PTCPAR_DTIN3_DTIN3;



MCF_DTIM_DTMR(1) =

MCF_DTIM_DTMR_PS(0x00)

| MCF_DTIM_DTMR_CE_RISE

| MCF_DTIM_DTMR_CLK_DIV1

| MCF_DTIM_DTMR_RST;



//Setup the interrupt registers for DTIN[1] & DTIN[3]

MCF_INTC_IMRL &= ~MCF_INTC_IMRL_MASKALL

& ~MCF_INTC_IMRL_INT_MASK20

& ~MCF_INTC_IMRL_INT_MASK22;

MCF_INTC_ICR(20) = MCF_INTC_ICR_IP(4) | MCF_INTC_ICR_IL(4);

mcf5xxx_set_handler(64 + 20, direction12_handler);

mcf5xxx_irq_enable();



while (1)

{

printf("the value of the counter is %d \n", counter);

}







}



__declspec(interrupt) void direction12_handler(void) {



counter = (long int) MCF_DTIM_DTCR(1); //Read the encoder counter



MCF_DTIM_DTCN(1) = 0; //Reset the encorder counter



MCF_DTIM_DTER(1) |= MCF_DTIM_DTER_CAP;

}
 

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