blinky.c

来自「8051试验程序 基础教材」· C语言 代码 · 共 76 行

// ------------------------------------------------------------------------------------
// Blinky.c
// ------------------------------------------------------------------------------------
// Copyright (C) 2005 Silicon Laboratories, Inc.
//
// This program flashes the green LED on the C8051F000 target board about
// five times a second using the interrupt handler for Timer3.
// Target: C8051F000, C8051F010
//
// Tool chain: IAR Systems EW8051
//

// ------------------------------------------------------------------------------------
// Includes
// ------------------------------------------------------------------------------------

#include <ioc8051f000.h>	// SFR declarations
#include <stdio.h>

// ------------------------------------------------------------------------------------
// Global CONSTANTS
// ------------------------------------------------------------------------------------

#define	LED P1_bit.P16		// green LED: '1' = ON; '0' = OFF
#define TC_100ms	16000	// approx number of counts of 1.9MHz/12 to get 100ms.
// ------------------------------------------------------------------------------------
// Function PROTOTYPES
// ------------------------------------------------------------------------------------
__interrupt void Timer3_ISR(void);

// ------------------------------------------------------------------------------------
// MAIN Routine
// ------------------------------------------------------------------------------------
void main(void)
{

    // disable watchdog timer
    WDTCN = 0xde;
    WDTCN = 0xad;

    // set up Crossbar and GPIO
    XBR2 = 0x40;		// Enable crossbar and weak pull-ups
    PRT1CF |= 0x40;		// enable P1.6 (LED) as a push-pull output

    // set up Timer3 for auto-reload to generate interrupts at 100ms intervals
    TMR3CN = 0x00;		// stop Timer3
    TMR3RLH = ((-TC_100ms >> 8) & 0xff);	// init Timer3 reload value
    TMR3RLL = (-TC_100ms & 0xff);
    TMR3H = 0xff;		// init Timer3 to reload immediately
    TMR3L = 0xff;
    EIE2 = 0x01;		// enable Timer3 OVR interrupt
    TMR3CN = 0x04;		// start Timer3

    IE_bit.EA = 1;		// enable global interrupts

    while (1) {
		PCON |= 0x01;		// set IDLE mode
    }
}

// ------------------------------------------------------------------------------------
// Interrupt Service Routines
// ------------------------------------------------------------------------------------

// ------------------------------------------------------------------------------------
// Timer3_ISR
// ------------------------------------------------------------------------------------
// This routine changes the state of the LED.
//
#pragma vector=0x73
__interrupt void Timer3_ISR(void)
{
    TMR3CN &= ~(0x80);		// clear TF3
    LED = ~LED;				// change state of LED
}