У меня есть LPC1769 LPCXpresso и LPC-Link 2 для отладки. Моя среда разработки - IAR.
Я хотел испытать простое мигание светодиода с помощью таймера. В сети много примеров кодов. Итак, я выбрал один из образцов, сделанных для платы MCB1700. Я также кое-где прочитал, как таймер работает с LPC.
Код компилируется, и я загрузил программу на устройство (LPC1769).
Я предполагал, что светодиод должен мигать, когда таймер вызывает обработчик на заданный интервал.
Но программа никогда не запускает TIMER0_IRQHandler.
Вот полный код в моем файле main.c:
#include <lpc17xx.h>
void TIMER0_IRQHandler(void);
int main(void)
{
// (1) Timer 0 configuration (see page 490 of user manual)
LPC_SC->PCONP |= 1 << 1; // Power up Timer 0 (see page 63 of user manual)
LPC_SC->PCLKSEL0 |= 1 << 2; // Clock for timer = CCLK, i.e., CPU Clock (page 56 user manual)
// MR0 is "Match Register 0". MR0 can be enabled through the MCR to reset
// the Timer/Counter (TC), stop both the TC and PC, and/or generate an interrupt
// every time MR0 matches the TC. (see page 492 and 496 of user manual)
LPC_TIM0->MR0 = 500; //Toggle Time in mS
//LPC_TIM0->MR0 = 1 << 23; // Give a value suitable for the LED blinking
// frequency based on the clock frequency
// MCR is "Match Control Register". The MCR is used to control if an
// interrupt is generated and if the TC is reset when a Match occurs.
// (see page 492 and 496 of user manual)
LPC_TIM0->MCR |= 1 << 0; // Interrupt on Match 0 compare
LPC_TIM0->MCR |= 1 << 1; // Reset timer on Match 0
// TCR is "Timer Control Register". The TCR is used to control the Timer
// Counter functions. The Timer Counter can be disabled or reset
// through the TCR. (see page 492 and 494 of user manual)
LPC_TIM0->TCR |= 1 << 1; // Manually Reset Timer 0 (forced);
LPC_TIM0->TCR &= ~(1 << 1); // Stop resetting the timer
// (2) Enable timer interrupt;
// TIMER0_IRQn is 1, see lpc17xx.h and page 73 of user manual
NVIC_EnableIRQ(TIMER0_IRQn); // see core_cm3.h header file
// (3) Some more one-time set-up's;
LPC_TIM0->TCR |= 1 << 0; // Start timer (see page 492 and 494 of user manual)
LPC_SC->PCONP |= ( 1 << 15 ); // Power up GPIO (see lab1)
LPC_GPIO1->FIODIR |= 1 << 29; // Put P1.29 into output mode. LED is connected to P1.29
// (4) infinite loop;
while (1) // Why do we need this?
{
//LPC_GPIO1->FIOPIN ^= 1 << 29; // Toggle the LED (see lab1)
}
return 0;
}
// Here, we describe what should be done when the interrupt on Timer 0 is handled;
// We do that by writing this function, whose address is “recorded” in the vector table
// from file startup_LPC17xx.s under the name TIMER0_IRQHandler;
void TIMER0_IRQHandler(void)
{
// IR is "Interrupt Register". The IR can be written to clear interrupts. The IR
// can be read to identify which of eight possible interrupt sources are
// pending. (see page 492 and 493 of user manual)
if ( (LPC_TIM0->IR & 0x01) == 0x01 ) // if MR0 interrupt (this is a sanity check);
{
LPC_TIM0->IR |= 1 << 0; // Clear MR0 interrupt flag (see page 492 and 493 of user manual)
LPC_GPIO1->FIOPIN ^= 1 << 29; // Toggle the LED (see lab1)
}
}
Любой указатель будет принят с благодарностью.
[EDIT]
Для дальнейшего использования у кого есть аналогичный вопрос, вот мой рабочий код;
Я переписал со знанием, которое я собрал отсюда и там.
Теперь это работает, все обработчики запущены. На этот раз я хотел проверить с несколькими таймерами. Вот реализация с двумя Timer-IRQ и SysTick.
#include "LPC17xx.h"
#define SBIT_TIMER0 1
#define SBIT_TIMER1 2
#define SBIT_MR0I 0
#define SBIT_MR0R 1
#define SBIT_CNTEN 0
#define PCLK_TIMER0 2
#define PCLK_TIMER1 4
#define LED1 0 // P2_0
#define LED2 1 // P2_1
#define MiliToMicroSec(x) (x*1000) /* ms is multiplied by 1000 to get us*/
extern unsigned int SystemCoreClock;
unsigned int getPrescalarForUs(uint8_t timerPclkBit);
static int data_main = 0;
static int data_systick = 0;
void Delay(uint32_t Dly)
{
for(volatile uint32_t j = Dly; j; j--) { }
}
void SysTick_Handler(void)
{
data_systick += 10;
}
int main (void)
{
SystemInit();
LPC_SC->PCONP |= (1<<SBIT_TIMER0) | (1<<SBIT_TIMER1); /* Power ON Timer0,1 */
LPC_TIM0->MCR = (1<<SBIT_MR0I) | (1<<SBIT_MR0R); /* Clear TC on MR0 match and Generate Interrupt*/
LPC_TIM0->PR = getPrescalarForUs(PCLK_TIMER0); /* Prescalar for 1us */
LPC_TIM0->MR0 = MiliToMicroSec(100); /* Load timer value to generate 100ms delay*/
LPC_TIM0->TCR = (1 <<SBIT_CNTEN); /* Start timer by setting the Counter Enable*/
NVIC_EnableIRQ(TIMER0_IRQn); /* Enable Timer0 Interrupt */
LPC_TIM1->MCR = (1<<SBIT_MR0I) | (1<<SBIT_MR0R); /* Clear TC on MR0 match and Generate Interrupt*/
LPC_TIM1->PR = getPrescalarForUs(PCLK_TIMER1); /* Prescalar for 1us */
LPC_TIM1->MR0 = MiliToMicroSec(500); /* Load timer value to generate 500ms delay*/
LPC_TIM1->TCR = (1 <<SBIT_CNTEN); /* Start timer by setting the Counter Enable*/
NVIC_EnableIRQ(TIMER1_IRQn); /* Enable Timer1 Interrupt */
LPC_GPIO2->FIODIR = (1<<LED1) | (1<<LED2); /* Configure the LED pins(P2_0,P2_1) as outputs */
SysTick_Config(900000);
while(1)
{
data_main++;
}
}
void TIMER0_IRQHandler(void)
{
unsigned int isrMask;
isrMask = LPC_TIM0->IR;
LPC_TIM0->IR = isrMask; /* Clear the Interrupt Bit */
LPC_GPIO2->FIOPIN ^= (1<<LED1); /* Toggle the LED1 (P2_0) */
}
void TIMER1_IRQHandler(void)
{
unsigned int isrMask;
isrMask = LPC_TIM1->IR;
LPC_TIM1->IR = isrMask; /* Clear the Interrupt Bit */
LPC_GPIO2->FIOPIN ^= (1<<LED2); /* Toggle the LED2 (P2_1) */
}
unsigned int getPrescalarForUs(uint8_t timerPclkBit)
{
unsigned int pclk,prescalarForUs;
pclk = (LPC_SC->PCLKSEL0 >> timerPclkBit) & 0x03; /* get the pclk info for required timer */
switch ( pclk ) /* Decode the bits to determine the pclk*/
{
case 0x00:
pclk = SystemCoreClock/4;
break;
case 0x01:
pclk = SystemCoreClock;
break;
case 0x02:
pclk = SystemCoreClock/2;
break;
case 0x03:
pclk = SystemCoreClock/8;
break;
default:
pclk = SystemCoreClock/4;
break;
}
prescalarForUs =pclk/1000000 - 1; /* Prescalar for 1us (1000000Counts/sec) */
return prescalarForUs;
}