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