timers.c

最新版IAR FOR ARM（EWARM）5.11中的代码例子

//*****************************************************************************
//
// timers.c - Timers example.
//
// Copyright (c) 2005-2007 Luminary Micro, Inc.  All rights reserved.
// 
// Software License Agreement
// 
// Luminary Micro, Inc. (LMI) is supplying this software for use solely and
// exclusively on LMI's microcontroller products.
// 
// The software is owned by LMI and/or its suppliers, and is protected under
// applicable copyright laws.  All rights are reserved.  You may not combine
// this software with "viral" open-source software in order to form a larger
// program.  Any use in violation of the foregoing restrictions may subject
// the user to criminal sanctions under applicable laws, as well as to civil
// liability for the breach of the terms and conditions of this license.
// 
// THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
// LMI SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
// CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
// 
// This is part of revision 1952 of the Stellaris Peripheral Driver Library.
//
//*****************************************************************************

#include "../../../hw_ints.h"
#include "../../../hw_memmap.h"
#include "../../../hw_types.h"
#include "../../../src/debug.h"
#include "../../../src/gpio.h"
#include "../../../src/interrupt.h"
#include "../../../src/sysctl.h"
#include "../../../src/timer.h"
#include "../pdc.h"

//*****************************************************************************
//
//! \addtogroup dk_lm3s811_list
//! <h1>Timer (timers)</h1>
//!
//! This example application demonstrates the use of the timers to generate
//! periodic interrupts.  One timer is set up to interrupt once per second and
//! the other to interrupt twice per second; each interrupt handler will toggle
//! its own GPIO (port B0 and B1) on each interrupt; the attached LED will
//! indicate the occurrence and rate of interrupts.
//
//*****************************************************************************

//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, unsigned long ulLine)
{
}
#endif

//*****************************************************************************
//
// The interrupt handler for the first timer interrupt.
//
//*****************************************************************************
void
Timer0IntHandler(void)
{
    //
    // Clear the timer interrupt.
    //
    TimerIntClear(TIMER0_BASE, TIMER_TIMA_TIMEOUT);

    //
    // Toggle the GPIO B0 value.
    //
    GPIOPinWrite(GPIO_PORTB_BASE, GPIO_PIN_0,
                 GPIOPinRead(GPIO_PORTB_BASE, GPIO_PIN_0) ^ GPIO_PIN_0);
}

//*****************************************************************************
//
// The interrupt handler for the second timer interrupt.
//
//*****************************************************************************
void
Timer1IntHandler(void)
{
    //
    // Clear the timer interrupt.
    //
    TimerIntClear(TIMER1_BASE, TIMER_TIMA_TIMEOUT);

    //
    // Toggle the GPIO B1 value.
    //
    GPIOPinWrite(GPIO_PORTB_BASE, GPIO_PIN_1,
                 GPIOPinRead(GPIO_PORTB_BASE, GPIO_PIN_1) ^ GPIO_PIN_1);
}

//*****************************************************************************
//
// This example demonstrates how to setup an analog comparator and trigger
// interrupts on output changes.
//
//*****************************************************************************
int
main(void)
{
    //
    // Set the clocking to run directly from the crystal.
    //
    SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
                   SYSCTL_XTAL_6MHZ);

    //
    // Init the PDC, and then the LCD, then write the LCD.
    //
    PDCInit();
    PDCLCDInit();
    PDCLCDBacklightOn();
    PDCLCDSetPos(1, 0);
    PDCLCDWrite("Timers example", 14);

    //
    // Enable the peripherals used by this example.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER1);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);

    //
    // Enable processor interrupts.
    //
    IntMasterEnable();

    //
    // Set GPIOs B0 and B1 as an outputs.  These drive an LEDs on the board
    // that will toggle on timer interrupts.
    //
    GPIOPinTypeGPIOOutput(GPIO_PORTB_BASE, GPIO_PIN_0 | GPIO_PIN_1);
    GPIOPinWrite(GPIO_PORTB_BASE, GPIO_PIN_0 | GPIO_PIN_1, 0);

    //
    // Configure the two 32-bit periodic timers.
    //
    TimerConfigure(TIMER0_BASE, TIMER_CFG_32_BIT_PER);
    TimerConfigure(TIMER1_BASE, TIMER_CFG_32_BIT_PER);
    TimerLoadSet(TIMER0_BASE, TIMER_A, SysCtlClockGet());
    TimerLoadSet(TIMER1_BASE, TIMER_A, SysCtlClockGet() / 2);

    //
    // Setup the interrupts for the timer timeouts.
    //
    IntEnable(INT_TIMER0A);
    IntEnable(INT_TIMER1A);
    TimerIntEnable(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
    TimerIntEnable(TIMER1_BASE, TIMER_TIMA_TIMEOUT);

    //
    // Enable the timers.
    //
    TimerEnable(TIMER0_BASE, TIMER_A);
    TimerEnable(TIMER1_BASE, TIMER_A);

    //
    // Loop forever while the LEDs wiggle in response to timer interrupts.
    //
    while(1)
    {
    }
}