void PWM0CH0_IRQHandler(void)
{
static uint32_t cnt;
static uint32_t out;
// Channel 0 frequency is 100Hz, every 1 second enter this IRQ handler 100 times.
if(++cnt == 100) {
if(out)
PWM_EnableOutput(PWM0, 0x3F);
else
PWM_DisableOutput(PWM0, 0x3F);
out ^= 1;
cnt = 0;
}
// Clear channel 0 period interrupt flag
PWM_ClearPeriodIntFlag(PWM0, 0);
}
/**
* @brief PWM0 IRQ Handler
*
* @param None
*
* @return None
*
* @details ISR to handle PWM0 interrupt event
*/
void PWM0_IRQHandler(void)
{
static int toggle = 0;
// Update PWM0 channel 0 period and duty
if(toggle == 0)
{
PWM_SET_CNR(PWM0, 0, 99);
PWM_SET_CMR(PWM0, 0, 39);
}
else
{
PWM_SET_CNR(PWM0, 0, 399);
PWM_SET_CMR(PWM0, 0, 199);
}
toggle ^= 1;
// Clear channel 0 period interrupt flag
PWM_ClearPeriodIntFlag(PWM0, 0);
}
int32_t main (void)
{
/* Init System, IP clock and multi-function I/O
In the end of SYS_Init() will issue SYS_LockReg()
to lock protected register. If user want to write
protected register, please issue SYS_UnlockReg()
to unlock protected register if necessary */
SYS_Init();
/* Init UART to 115200-8n1 for print message */
UART_Open(UART0, 115200);
printf("\nThis sample code will output PWM channel 0 to with different duty\n");
printf(", and enable/disable Precise Center Align function.\n");
printf("Polling 1 period interrupt flag to get PWM channel 0 output.\n");
// PWM-Timer 0 enable and Auto-reload
PWM->CTL = PWM_CTL_CNTEN0_Msk | PWM_CTL_CNTMODE0_Msk;
PWM_SET_PRESCALER(PWM, 0, 1);
PWM_SET_DIVIDER(PWM, 0, PWM_CLK_DIV_1);
// Set the PWM aligned type
PWM_SET_ALIGNED_TYPE(PWM, 0, PWM_CENTER_ALIGNED);
// Enable PWM channel 0 output
PWM_EnableOutput(PWM, BIT0);
// Start
PWM_Start(PWM, BIT0);
/*
Precise Center Align and Center Align PWM channel 0 waveform of this sample shown below:
|<- CNR-(2*(CMR+1)) ->| CNR-(2*(CMR+1) = 401 -(2*(100+1)) CLKs
|<- CNR -( 2 *( CMR + 1)) ->| CNR-(2*(CMR+1) = 402 -(2*(99+1)) CLKs
|<- 2 *(CNR-CMR) clk ->| 2 * (CNR - CMR) = 2 * (401-100) CLKs
|<- 2 * (CNR-CMR) clk ->| 2 * (CNR - CMR) = 2 * (402-99) CLKs
________ ____________ ________ ____________ ________ ____________ ________ ____________
____| 7.96us |_8.08us_| 24.08us |_8.08us_| 8.08us |_8us_| 24.24us |_8us_| 7.96us |_8.08us_| 24.08us |_8.08us_| 8.08us |_8us_| 24.24us |_8us_
*/
while(1)
{
// Enable PWM Precise Center Aligned Type
PWM->PCACTL = PWM_PCACTL_PCAEN_Msk;
// PWM Channel 0 Output : duty = 7.96u, low = 8.08u
PWM_SET_CMR(PWM, 0, 100);
PWM_SET_CNR(PWM, 0, 401);
// Polling, Wait 1 period interrupt flags
while(PWM_GetPeriodIntFlag(PWM, 0) == 0);
PWM_ClearPeriodIntFlag(PWM, 0);
// Disable PWM Precise Center Aligned Type
PWM->PCACTL &= ~(PWM_PCACTL_PCAEN_Msk);
// PWM Channel 0 Output : duty = 24.08u, low = 8.08u
PWM_SET_CMR(PWM, 0, 100);
PWM_SET_CNR(PWM, 0, 401);
// Polling, Wait 1 period interrupt flags
while(PWM_GetPeriodIntFlag(PWM, 0) == 0);
PWM_ClearPeriodIntFlag(PWM, 0);
// Enable PWM Precise Center Aligned Type
PWM->PCACTL = PWM_PCACTL_PCAEN_Msk;
// PWM Channel 0 Output : duty = 8.08u, low = 8u
PWM_SET_CMR(PWM, 0, 99);
PWM_SET_CNR(PWM, 0, 402);
// Polling, Wait 1 period interrupt flags
while(PWM_GetPeriodIntFlag(PWM, 0) == 0);
PWM_ClearPeriodIntFlag(PWM, 0);
// Disable PWM Precise Center Aligned Type
PWM->PCACTL &= ~(PWM_PCACTL_PCAEN_Msk);
// PWM Channel 0 Output : duty = 24.24u, low = 8u
PWM_SET_CMR(PWM, 0, 99);
PWM_SET_CNR(PWM, 0, 402);
// Polling, Wait 1 period interrupt flags
while(PWM_GetPeriodIntFlag(PWM, 0) == 0);
PWM_ClearPeriodIntFlag(PWM, 0);
}
}
