36 lines
853 B
C
36 lines
853 B
C
/*
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* Copyright (c) 2006-2023, RT-Thread Development Team
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Change Logs:
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* Date Author Notes
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* 2023-06-14 muaxiaohei first version
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*/
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#include <rtthread.h>
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#include "drv_common.h"
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#define DBG_TAG "drv.common"
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#define DBG_LVL DBG_INFO
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#include <rtdbg.h>
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void rt_hw_us_delay(rt_uint32_t us)
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{
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rt_uint64_t total_delay_ticks, us_ticks, start, now, delta, reload;
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start = SysTick->CNT;
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reload = SysTick->CMP;
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us_ticks = SystemCoreClock / 8000000UL;
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total_delay_ticks = us * us_ticks;
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if (total_delay_ticks >= reload)
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{
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LOG_E("rt_hw_us_delay: the us parameter exceeds the maximum limit!");
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}
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do {
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now = SysTick->CNT;
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delta = start > now ? start - now : reload + start - now;
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} while(delta < total_delay_ticks);
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}
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