SmartPDCode/control/STS/MODBUS/BARE/port/porttimer.c

/*
 * FreeModbus Libary: BARE Port
 * Copyright (C) 2006 Christian Walter <wolti@sil.at>
 *
 * 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: $Id$
 */

/* ----------------------- Platform includes --------------------------------*/
#include "port.h"

/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"
#include "gd32e230x_conf.h"
/* ----------------------- static functions ---------------------------------*/
static void prvvTIMERExpiredISR( void );

/* ----------------------- Start implementation -----------------------------*/
BOOL
xMBPortTimersInit(USHORT usTim1Timerout50us)
{
  timer_parameter_struct timer_initpara;    //timer_initpara用于存放定时器的参数

  //使能RCU相关时钟
  rcu_periph_clock_enable(RCU_TIMER13);     //使能TIMER13的时钟

  timer_deinit(TIMER13);                    //设置TIMER13参数恢复默认值
  timer_struct_para_init(&timer_initpara);  //初始化timer_initpara
 
  //配置TIMER16
  timer_initpara.prescaler         = 3599;               		//设置预分频器值 //72M/3600=20Khz 对应基准50us
  timer_initpara.counterdirection  = TIMER_COUNTER_UP;  		//设置向上计数模式
  timer_initpara.period            = usTim1Timerout50us -1; //设置自动重装载值
  timer_initpara.clockdivision     = TIMER_CKDIV_DIV1;  		//设置时钟分割
  timer_init(TIMER13, &timer_initpara);                 		//根据参数初始化定时器

  timer_interrupt_enable(TIMER13, TIMER_INT_UP);  					//使能定时器的更新中断
  nvic_irq_enable(TIMER13_IRQn, 1);               					//配置NVIC设置优先级
  timer_enable(TIMER13);                          					//使能定时器  
	return TRUE;
	//return FALSE;
}


inline void
vMBPortTimersEnable(  )
{
    /* Enable the timer with the timeout passed to xMBPortTimersInit( ) */
	  timer_counter_value_config(TIMER13,0);						//清零定时器
    timer_interrupt_flag_clear(TIMER13,TIMER_INT_UP);	//清除定时器更新中断
    timer_interrupt_enable(TIMER13,TIMER_INT_UP);			//使能定时器更新中断
    timer_enable(TIMER13);														//使能定时器
}

inline void
vMBPortTimersDisable(  )
{
    /* Disable any pending timers. */
	  timer_counter_value_config(TIMER13,0);						//清零定时器
    timer_interrupt_flag_clear(TIMER13,TIMER_INT_UP);	//清除定时器更新中断
    timer_interrupt_disable(TIMER13,TIMER_INT_UP);		//禁用定时器更新中断
    timer_disable(TIMER13);														//失能定时器
}

/* Create an ISR which is called whenever the timer has expired. This function
 * must then call pxMBPortCBTimerExpired( ) to notify the protocol stack that
 * the timer has expired.
 */
static void prvvTIMERExpiredISR( void )
{
    ( void )pxMBPortCBTimerExpired(  );
}
void TIMER13_IRQHandler(void)
{
    if(RESET != timer_interrupt_flag_get(TIMER13, TIMER_INT_UP))
    {
        /* clear timer update interrupt bit */
        timer_interrupt_flag_clear(TIMER13, TIMER_INT_UP);
        /* clear count number*/
        timer_counter_value_config(TIMER13,0);
        /* use this function to call pxMBPortCBTimerExpired( ) */
        prvvTIMERExpiredISR();
    }
}