interrupt_timer.c

一、开发环境 1、开发板： AT91SAM7X256-EK 2、仿真器： SAM-ICE（ATMEL） 3、开发软件： ADS1.2 (ARM调试模式) 二、程序功能 1、程序目的：AT

//*----------------------------------------------------------------------------
//* 文件名  :interrupt_timer.c
//* 创建人  :张正锋 2006/2/21  [e-mail]
//*----------------------------------------------------------------------------
// Include Standard LIB  files
#include "project.h"

#define TIMER0_INTERRUPT_LEVEL		1

/*-----------------*/
/* Clock Selection */
/*-----------------*/
#define TC_CLKS                  0x7
#define TC_CLKS_MCK2             0x0
#define TC_CLKS_MCK8             0x1
#define TC_CLKS_MCK32            0x2
#define TC_CLKS_MCK128           0x3
#define TC_CLKS_MCK1024          0x4

//*----------------------------------------------------------------------------
//* 函数名              : timer0_c_irq_handler
//* 功能                : C handler interrupt function called by the interrupts
//*                       assembling routine
//* 输入参数            : none
//* 返回值              : none
//* 创建人              :张正锋 2006/2/21  [e-mail]
//*----------------------------------------------------------------------------
void timer0_c_irq_handler(void)
{
   AT91PS_TC TC_pt = AT91C_BASE_TC0;
    unsigned int dummy;
    //* Acknowledge interrupt status
    dummy = TC_pt->TC_SR;
    //* Suppress warning variable "dummy" was set but never used
    dummy = dummy;
     //* Read the output state
    if ( (AT91F_PIO_GetInput(AT91C_BASE_PIOA) & AT91B_LED3 ) == AT91B_LED3 )
    {
        AT91F_PIO_ClearOutput( AT91C_BASE_PIOA, AT91B_LED3 );
    }
    else
    {
        AT91F_PIO_SetOutput( AT91C_BASE_PIOA, AT91B_LED3 );
    }
}

//*----------------------------------------------------------------------------
//* 函数名              : AT91F_TC_Open
//* 功能                : Initialize Timer Counter Channel and enable is clock
//* 输入参数            : <tc_pt> = TC Channel Descriptor Pointer
//*                       <mode> = Timer Counter Mode
//*                     : <TimerId> = Timer peripheral ID definitions
//* 返回值              : none
//* 创建人              :张正锋 2006/2/21  [e-mail]
//*----------------------------------------------------------------------------
void AT91F_TC_Open ( AT91PS_TC TC_pt, unsigned int Mode, unsigned int TimerId)
//* Begin
{
    unsigned int dummy;

    //* First, enable the clock of the TIMER
    	AT91F_PMC_EnablePeriphClock ( AT91C_BASE_PMC, 1<< TimerId ) ;

    //* Disable the clock and the interrupts
	TC_pt->TC_CCR = AT91C_TC_CLKDIS ;
	TC_pt->TC_IDR = 0xFFFFFFFF ;

    //* Clear status bit
        dummy = TC_pt->TC_SR;
    //* Suppress warning variable "dummy" was set but never used
        dummy = dummy;
    //* Set the Mode of the Timer Counter
	TC_pt->TC_CMR = Mode ;

    //* Enable the clock
	TC_pt->TC_CCR = AT91C_TC_CLKEN ;
//* End
}

//*----------------------------------------------------------------------------
//* 函数名              : timer_init
//* 功能                : Init timer counter
//* 输入参数            : none
//* 返回值              : none
//* 创建人              :张正锋 2006/2/21  [e-mail]
//*----------------------------------------------------------------------------
void timer_init ( void )
//* Begin
{
      //* Open timer0
	AT91F_TC_Open(AT91C_BASE_TC0,TC_CLKS_MCK1024,AT91C_ID_TC0);

     //* Open Timer 0 interrupt
	AT91F_AIC_ConfigureIt ( AT91C_BASE_AIC,
                               AT91C_ID_TC0,
                               TIMER0_INTERRUPT_LEVEL,
                               AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL,
                               timer0_c_irq_handler);
        //设置记数值
        AT91C_BASE_TC0->TC_RC=0x1fff;
        //IRQ enable CPC
	AT91C_BASE_TC0->TC_IER = AT91C_TC_CPCS;
	AT91F_AIC_EnableIt (AT91C_BASE_AIC, AT91C_ID_TC0);
       //* Start timer0
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG ;
//* End
}