rt-thread/components/net/freemodbus-v1.6.0/port/porttimer.c

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/*
* FreeModbus Libary: STM32 Port
* Copyright (C) 2013 Armink <armink.ztl@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* File: $Id: porttimer.c,v 1.60 2013/08/13 15:07:05 Armink $
*/
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"
/* ----------------------- static functions ---------------------------------*/
static void prvvTIMERExpiredISR(void);
/* ----------------------- Start implementation -----------------------------*/
BOOL xMBPortTimersInit(USHORT usTim1Timerout50us)
{
uint16_t PrescalerValue = 0;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
//====================================时钟初始化===========================
//使能定时器3时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
//====================================定时器初始化===========================
//定时器时间基配置说明
//HCLK为72MHzAPB1经过2分频为36MHz
//TIM3的时钟倍频后为72MHz硬件自动倍频,达到最大)
//TIM3的分频系数为3599时间基频率为72 / (1 + Prescaler) = 20KHz,基准为50us
//TIM最大计数值为usTim1Timerout50u
PrescalerValue = (uint16_t) (SystemCoreClock / 20000) - 1;
//定时器1初始化
TIM_TimeBaseStructure.TIM_Period = (uint16_t) usTim1Timerout50us;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
//预装载使能
TIM_ARRPreloadConfig(TIM3, ENABLE);
//====================================中断初始化===========================
//设置NVIC优先级分组为Group20-3抢占式优先级0-3的响应式优先级
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
//清除溢出中断标志位
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
//定时器3溢出中断关闭
TIM_ITConfig(TIM3, TIM_IT_Update, DISABLE);
//定时器3禁能
TIM_Cmd(TIM3, DISABLE);
return TRUE;
}
void vMBPortTimersEnable()
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
TIM_SetCounter(TIM3, 0);
TIM_Cmd(TIM3, ENABLE);
}
void vMBPortTimersDisable()
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
TIM_ITConfig(TIM3, TIM_IT_Update, DISABLE);
TIM_SetCounter(TIM3, 0);
TIM_Cmd(TIM3, DISABLE);
}
void prvvTIMERExpiredISR(void)
{
(void) pxMBPortCBTimerExpired();
}
void TIM3_IRQHandler(void)
{
rt_interrupt_enter();
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
{
TIM_ClearFlag(TIM3, TIM_FLAG_Update); //清中断标记
TIM_ClearITPendingBit(TIM3, TIM_IT_Update); //清除定时器T3溢出中断标志位
prvvTIMERExpiredISR();
}
rt_interrupt_leave();
}