PWM use of the lpc1768

p2.0 pwm1.1

void Als_init(void) //initialization

{

LPC_SC, Pconp |= (1<<1) | ( 1<<2) | (1<<); Turn on the clock

LPC_SC-PCLKSEL0 &= ~ (3<<2); Clock 25M

LPC_SC-PCLKSEL0 &= ~ (3<<4);

p2.0

Lpc_pincon-PINSEL4 &= ~ (0x03l<<0); GPIO

Lpc_pincon-PINMODE4 &= ~ (0x03l<<0); To enable pull-up

Lpc_pincon-pinmode_od2 &= ~ (0x01<<1); Push-Pull Normal mode

P2dir(0) = 1; Output

Lpc_tim1, TCR |= (1<<1); Reset Timer

LPC_TIM1-CTCR = 0x00; Timer mode

LPC_TIM1PC = 0x00;

LPC_TIM1-PR = 1; Prescaler, Count frequency 1m

LPC_TIM1-MR0 = ; 25*100 2500 Frequency 10K

LPC_TIM1-MR1 = +;

Lpc_tim1, MCR |= ( (1<<0) | ( 1<<3) |                (1<<4)); MR0 when the TC value is matched will result in a reset resulting in an interrupt MR1 match when the interrupt disappears

LPC_TIM1-IR |= 0XFF; Clear all interrupt flag bits

Lpc_tim1, TCR = (1<<0); Start timer

Nvic_enableirq(timer1_irqn);

}

void Als_set_duty(u8 Duty) //Set duty ratio

{

Lpc_tim1, TCR = 0; Pause Timer

if (duty >= )Duty = ;

if (duty = = 0)Duty = 1;

LPC_TIM1-MR0 = duty;

Lpc_tim1, TCR = (1<<0); Start timer

}

void Als_stop(void)

{

Lpc_tim1, TCR = 0; Pause Timer

P2low(0) = 1; Constant level

}

void Timer1_irqhandler(void)

{

Nvic_clearpendingirq(timer1_irqn);

if ( lpc_tim1-IR &0x01) //mr0 Interrupt

{

P2low(0) = 1;

Lpc_tim1, IR |= (1<<0); Clear Interrupt Flag

}

Else if (lpc_tim1, IR &0x02)

{

P2high(0) = 1;

Lpc_tim1, IR |= (1<<1); Clear Interrupt Flag

}

}

PWM use of the lpc1768