rt-thread/bsp/wch/risc-v/Libraries/ch32_drivers/drv_common.c

36 lines
853 B
C

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