62 lines
1.5 KiB
C
62 lines
1.5 KiB
C
#include "DWT.h"
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// 寄存器基地址
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#define DWT_CR (*(uint32_t *)0xE0001000)
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#define DWT_CYCCNT (*(uint32_t *)0xE0001004)
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#define DEM_CR (*(uint32_t *)0xE000EDFC)
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// 定义需使能位
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#define DEM_CR_TRCENA (1 << 24)
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#define DWT_CR_CYCCNTENA (1 << 0)
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// DWT init
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void DWT_init(void)
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{
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DEM_CR |= (uint32_t)DEM_CR_TRCENA;
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DWT_CYCCNT = (uint32_t)0u;
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DWT_CR |= (uint32_t)DWT_CR_CYCCNTENA;
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}
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// get DWT count
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uint32_t DWT_TS_GET(void)
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{
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return ((uint32_t)DWT_CYCCNT);
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}
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// 使用DWT延时time_us微秒
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void DWT_delay_us(uint32_t time_us)
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{
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uint32_t old_counter, current_counter;
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uint32_t delay_us;
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old_counter = DWT_TS_GET();
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current_counter = DWT_TS_GET();
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delay_us = 0;
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while (delay_us < time_us)
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{
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current_counter = DWT_TS_GET();
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if (current_counter > old_counter)
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delay_us = (current_counter - old_counter) / (SystemCoreClock / 1000000);
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else
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delay_us = (current_counter + 0XFFFFFFFF - old_counter) / (SystemCoreClock / 1000000);
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}
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}
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// 使用DWT延时time_ms毫秒
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void DWT_delay_ms(uint32_t time_ms)
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{
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uint32_t old_counter, current_counter;
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uint32_t delay_ms;
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old_counter = DWT_TS_GET();
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current_counter = DWT_TS_GET();
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delay_ms = 0;
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while (delay_ms < time_ms)
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{
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current_counter = DWT_TS_GET();
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if (current_counter > old_counter)
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delay_ms = (current_counter - old_counter) / (SystemCoreClock / 1000);
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else
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delay_ms = (current_counter + 0XFFFFFFFF - old_counter) / (SystemCoreClock / 1000);
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}
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}
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