Content originally posted in LPCWare by NsN on Mon May 24 17:12:14 MST 2010 Hi, i was wondering if it is possible to use Match2 on Timer16_0 to generate an interrupt, while Match_0 and Match_1 are used for PWM outputs? Alternatively I could also adjust the PWM frequency, if it would be possible to generate an Interupt on Match3 before it resets the TC. I tried it, but sofar everything has resulted in Match_0 and Match_1 being always high. My initialization is:
LPC_TMR16B0->TCR = 0;
//prescale to so the TC increments every 0.05ms
LPC_TMR16B0->PR = 200;
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<7);
/* Setup the external match register */
LPC_TMR16B0->EMR = (1<<10)|(0<<8)|(1<<6)|(1<<4)|(1<<3)|(0x05);
LPC_IOCON->PIO0_8 &= ~0x07;
LPC_IOCON->PIO0_8 |= 0x02; /* Timer0_16 MAT0 */
LPC_IOCON->PIO0_9 &= ~0x07;
LPC_IOCON->PIO0_9 |= 0x02; /* Timer0_16 MAT1 */
/* Enable the selected PWMs and enable Match3 */
LPC_TMR16B0->PWMC = 0x08 || 0x02 || 0x01;
/* Setup the match registers */
LPC_TMR16B0->MR3 = 1024;
LPC_TMR16B0->MR0 = 512;
LPC_TMR16B0->MR1 = 512;
LPC_TMR16B0->MR2 = 1000;
/* Set the match control register */
LPC_TMR16B0->MCR = (1<<10) || (1 << 6); /* Reset on MR3, Interrupt on MR2 */
/* Enable the TIMER1 Interrupt */
NVIC_EnableIRQ(TIMER_16_0_IRQn);
LPC_TMR16B0->TCR = 1;
Using breakpoints, i can see, that the Interrupt gets triggered, but the pwm won't work. If I use
LPC_TMR16B0->MCR = (1<<10);
instead the pwm works, but of course i don't have an interrupt anymore...
Content originally posted in LPCWare by NXP_Europe on Wed May 26 02:13:22 MST 2010 Hi NsN, First thing that I noticed is that you use a double OR --> || in stead of a single OR --> |. A double OR will put the logical [B]test[/B] outcome in the register, so only a 1 or a 0.
/* Enable the selected PWMs and enable Match3 */
LPC_TMR16B0->PWMC = 0x08 | 0x02 | 0x01;
instead of
/* Enable the selected PWMs and enable Match3 */
LPC_TMR16B0->PWMC = 0x08 || 0x02 || 0x01;
and
/* Set the match control register */
LPC_TMR16B0->MCR = (1<<10) | (1 << 6);
instead of
/* Set the match control register */
LPC_TMR16B0->MCR = (1<<10) || (1 << 6);
