SSTV-Decoder/include/systick.h

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2023-04-17 21:56:42 +08:00
#pragma once
#include "derivative.h"
#include <stdbool.h>
extern volatile uint32_t ms_ticks;
static inline void spin(volatile uint32_t count) {
while (count--) asm("nop");
}
// t: expiration time, prd: period
static inline bool timer_expired(uint32_t *t, uint32_t prd) {
if (ms_ticks + prd < *t) *t = 0; // Time wrapped? Reset timer
if (*t == 0) *t = ms_ticks + prd; // First poll? Set expiration
if (*t > ms_ticks) return false; // Not expired yet, return
*t = (ms_ticks - *t) > prd ? ms_ticks + prd : *t + prd; // Next expiration time
return true; // Expired, return true
}
static inline void delay_ms(uint32_t ms) {
uint32_t start = ms_ticks;
while (ms_ticks - start < ms) asm("nop");
}