Content originally posted in LPCWare by andrei.badila on Wed Sep 05 05:06:25 MST 2012
i read section PWM in this book.
I start from this example:"
#include "driver_config.h"
#include "target_config.h"
#include "timer32.h"
#include "timer16.h"
#include "gpio.h"
extern volatile uint32_t timer32_0_counter;
volatile uint32_t period = 1000; //48Khz PWM frequency
/* Main Program */
int main (void) {
/* Initialize 32-bits timer 0 */
init_timer32(0, TIME_INTERVAL);
enable_timer32(0);
/* Initialize the PWM in timer32_1 enabling match0 output */
init_timer32PWM(1, period, MATCH0);
setMatch_timer32PWM (1, 0, period/4);
enable_timer32(1);
/* Initialize the PWM in timer16_1 enabling match1 output */
init_timer16PWM(1, period, MATCH1, 0);
setMatch_timer16PWM (1, 1, period/8);
enable_timer16(1);
/* Enable AHB clock to the GPIO domain. */
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<6);
/* Set port 2_0 to output */
GPIOSetDir( 2, 0, 1 );
while (1) /* Loop forever */
{
/* I/O configuration and LED setting pending. */
if ( (timer32_0_counter > 0) && (timer32_0_counter <= 50) )
{
GPIOSetValue( 2, 0, 0 );
}
if ( (timer32_0_counter > 50) && (timer32_0_counter <= 100) )
{
GPIOSetValue( 2, 0, 1 );
}
else
while ( timer32_0_counter < 100 ); //wait for
timer32_0_counter = 0;
}
}"
I don't fiind in this example what port is use to out pwm, where where the duty cycle is set
