/* * Copyright (c) 2006-2021, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2021-08-20 breo.com first version */ #include "drv_common.h" #include "board.h" #ifdef RT_USING_SERIAL #ifdef RT_USING_SERIAL_V2 #include "drv_usart_v2.h" #else #include "drv_usart.h" #endif #endif #ifdef RT_USING_FINSH #include static void reboot(uint8_t argc, char **argv) { rt_hw_cpu_reset(); } MSH_CMD_EXPORT(reboot, Reboot System); #endif /* RT_USING_FINSH */ /** * This function will delay for some us. * * @param us the delay time of us */ void rt_hw_us_delay(rt_uint32_t us) { rt_uint32_t ticks; rt_uint32_t told, tnow, tcnt = 0; rt_uint32_t reload = SysTick->LOAD; ticks = us * reload / (1000000 / RT_TICK_PER_SECOND); told = SysTick->VAL; while (1) { tnow = SysTick->VAL; if (tnow != told) { if (tnow < told) { tcnt += told - tnow; } else { tcnt += reload - tnow + told; } told = tnow; if (tcnt >= ticks) { break; } } } }