LPC1768 - PWM not working

Hello All,

I've developed customized LPC1768 board & want PWM 4 & 6 in Double Edge mode. However it is not working. Can you please guide after looking into my code as below. O/p pins of PWM3,4,5 & 6 all shows always HIGH.
One more observation is that in the simulator mode the PWM works fine.

I've tested the respective Pins by configuring them as GPIO & LED toggle it works. But the PWM mode is not working.

Thanks & Regards
Raj

pwm.c

#include "lpc17xx.h"
#include "type.h"
#include "datatype.h"
#include "pwm.h"

#define PWM_RATE 10000

volatile uint32_t Pwm_Match0_counter;

/******************************************************************************
** Function name: PWM1_IRQHandler
**
** Descriptions: PWM1 interrupt handler
** For now, it only deals with PWM1 match 0
**
** parameters: None
** Returned value: None
**
******************************************************************************/
void PWM1_IRQHandler (void)
{ uint8 regVal;

regVal = LPC_PWM1->IR; if ( regVal & MR0_INT ) { Pwm_Match0_counter++; } LPC_PWM1->IR |= regVal; /* clear interrupt flag on match 0 */ return;
}

/******************************************************************************
** Function name: PWM_Init
**
** Descriptions: PWM initialization, setup all GPIOs to PWM0~6,
** reset counter, all latches are enabled, interrupt
** on PWMMR0, install PWM interrupt to the VIC table.
**
** parameters: None
** Returned value: true or false, if VIC table is full, return false
**
******************************************************************************/
void PWM_Init(void)
{ Pwm_Match0_counter = 0; LPC_PINCON->PINSEL4 = 0x05500550; /* select PWM3,4,5 & 6 func and P2.10 to 13 as interrupt */

LPC_PWM1->TCR = TCR_RESET; /* Counter Reset */ LPC_PWM1->PR = 0x00; /* count frequency:Fpclk */ LPC_PWM1->MCR = PWMMR0I | PWMMR0R; /* interrupt on PWMMR0, reset on PWMMR0, reset TC if PWM matches */

LPC_PWM1->PCR = PWMSEL3 | PWMSEL4 | PWMSEL5 | PWMSEL6; /* Double Edge selection */ LPC_PWM1->MR0 = PWM_RATE; /* set PWM cycle */

/* all PWM latch enabled */ LPC_PWM1->LER = LER0_EN;

NVIC_EnableIRQ(PWM1_IRQn); return;
}

/******************************************************************************
** Function name: PWM_Set
**
** Descriptions: PWM cycle setup
**
** parameters: Channel number, PWM cycle, and offset
** Returned value: None
**
******************************************************************************/
uint8 PWM_Set(uint8 channelnum, uint32 on_period, uint32 off_period)
{ switch(channelnum) { case PWM4: LPC_PWM1->MR3 = on_period; /* ON time */ LPC_PWM1->MR4 = off_period; /* OFF time */ LPC_PWM1->LER = LER3_EN | LER4_EN; /* latch new ON/OFF period */ break; case PWM6: LPC_PWM1->MR5 = on_period; /* ON time */ LPC_PWM1->MR6 = off_period; /* OFF time */ LPC_PWM1->LER = LER5_EN | LER6_EN; /* latch new ON/OFF period */ break; default: channelnum = ERROR; /* return ERROR incase wrong channalnum */ break; } return(channelnum);
}

/******************************************************************************
** Function name: PWM_Start
**
** Descriptions: Enable PWM by setting the PCR, PTCR registers
**
** parameters: channel number
** Returned value: None
**
******************************************************************************/
uint8 PWM_Start(uint8 channelnum)
{ switch(channelnum) { case PWM4: LPC_PWM1->PCR |= PWMENA4; /* Start PWM4 */ break; case PWM6: LPC_PWM1->PCR |= PWMENA6; /* Start PWM6 */ break; default: channelnum = ERROR; /* return ERROR incase wrong channalnum */ break; } LPC_PWM1->TCR = TCR_CNT_EN | TCR_PWM_EN; /* counter enable, PWM enable */ //???? return(channelnum);
}

/******************************************************************************
** Function name: PWM_Stop
**
** Descriptions: Stop PWM channel
**
** parameters: channel number
** Returned value: None
**
******************************************************************************/
uint8 PWM_Stop(uint8 channelnum)
{ switch(channelnum) { case PWM4: LPC_PWM1->PCR = PWM_DIS4; /* Stop PWM4 */ break; case PWM6: LPC_PWM1->PCR = PWM_DIS6; /* Stop PWM6 */ break; default: channelnum = ERROR; /* return ERROR incase wrong channalnum */ break; } return(channelnum);
}

/******************************************************************************
** End Of File
******************************************************************************/

----------------------------------------------------------------------------------------------

main.c

#include "lpc17xx.h"
#include "datatype.h"
#include "pwm.h"

extern volatile uint32_t Pwm_Match0_counter;

int main (void)
{ /* SystemClockUpdate() updates the SystemFrequency variable */ SystemClockUpdate();

PWM_Init(); PWM_Set(PWM4, 3000, 9000); PWM_Set(PWM6, 2000, 8000); PWM_Start(PWM4); PWM_Start(PWM6);

while(1) { if(Pwm_Match0_counter != 0) { Pwm_Match0_counter = 0; PWM_Set(PWM4, 3000, 7000); PWM_Set(PWM6, 5000, 8000); } }
}