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#include "mbed.h"
extern "C" {
volatile uint32_t msTicks;
void SysTick_Handler(void) {
msTicks++;
}
void Delay(uint32_t dlyTicks) {
uint32_t curTicks;
curTicks = msTicks;
while ((msTicks - curTicks) < dlyTicks);
}
}
int main() {
SysTick_Config(SystemCoreClock / 1000);
SIM->SCGC6 |= SIM_SCGC6_PIT_MASK; // Clock PIT
PIT->MCR = 0; // Enable PIT
// Timer 1
PIT->CHANNEL[1].LDVAL = 0xFFFFFFFF;
PIT->CHANNEL[1].TCTRL = 0x0; // Disable Interrupts
PIT->CHANNEL[1].TCTRL |= PIT_TCTRL_CHN_MASK; // Chain to timer 0
PIT->CHANNEL[1].TCTRL |= PIT_TCTRL_TEN_MASK; // Start timer 1
// Timer 2
PIT->CHANNEL[0].LDVAL = 0xFFFFFFFF;
PIT->CHANNEL[0].TCTRL = PIT_TCTRL_TEN_MASK; // Start timer 0, disable interrupts
DigitalOut led(LED_BLUE);
while (true) {
Delay(1000);
led = !led;
uint64_t ticks = (uint64_t)PIT->LTMR64H << 32;
ticks |= (uint64_t)PIT->LTMR64L;
printf("ticks: 0x%x%x\n", (uint32_t)(ticks>>32), (uint32_t)(ticks & 0xFFFFFFFF));
ticks = (~ticks) / 24;
uint32_t us = (uint32_t)(0xFFFFFFFF & ticks);
printf("us : 0x%x\n", us);
}
}
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