blinky.c

来自「8051试验程序 基础教材」· C语言 代码 · 共 133 行

//------------------------------------------------------------------------------------
// Blinky.c
//------------------------------------------------------------------------------------
// Copyright (C) 2005 Silicon Laboratories, Inc.
//
// AUTH: BD
// DATE: 26 SEP 2002
//
// This program flashes a LED on the C8051F060 target board about five times
// a second using the interrupt handler for Timer3.
// The LED should be connected to P1.6
// Target: C8051F06x
//
//

//------------------------------------------------------------------------------------
// Includes
//------------------------------------------------------------------------------------
#include <ioC8051f060.h>
#include "page_defs.h"

//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F06x
//-----------------------------------------------------------------------------

__sfr __no_init volatile unsigned short RCAP3    @ 0xCA;                    // Timer3 reload value
__sfr __no_init volatile unsigned short TMR3     @ 0xCC;                    // Timer3 counter

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

#define SYSCLK 3062500                    // approximate SYSCLK frequency in Hz

#define  LED P1_bit.P16                         // LED: '1' = ON; '0' = OFF

//------------------------------------------------------------------------------------
// Function PROTOTYPES
//------------------------------------------------------------------------------------
void PORT_Init (void);
void Timer3_Init (int counts);
__interrupt void Timer3_ISR (void);

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

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

   PORT_Init ();

   Timer3_Init (SYSCLK / 12 / 10);        // Init Timer3 to generate interrupts
                                          // at a 10 Hz rate.
   IE_bit.EA = 1;											// enable global interrupts

   SFRPAGE = LEGACY_PAGE;                 // Page to sit in for now

   while (1) {                            // spin forever

   }
}

//------------------------------------------------------------------------------------
// PORT_Init
//------------------------------------------------------------------------------------
//
// Configure the Crossbar and GPIO ports
//
void PORT_Init (void)
{
char old_SFRPAGE;

   old_SFRPAGE = SFRPAGE;                 // Save old SFRPAGE
   SFRPAGE = CONFIG_PAGE;                 // Switch to configuration page

   XBR2    = 0x40;                        // Enable crossbar and weak pull-ups
   P1MDOUT |= 0x40;                       // enable P1.6 (LED) as push-pull output

   SFRPAGE = old_SFRPAGE;                 // restore SFRPAGE
}

//------------------------------------------------------------------------------------
// Timer3_Init
//------------------------------------------------------------------------------------
//
// Configure Timer3 to auto-reload and generate an interrupt at interval
// specified by <counts> using SYSCLK/12 as its time base.
//
//
void Timer3_Init (int counts)
{
char old_SFRPAGE;

   old_SFRPAGE = SFRPAGE;                 // Save old SFRPAGE
   SFRPAGE = TMR3_PAGE;                   // Switch to Timer 3 page

   TMR3CN = 0x00;                         // Stop Timer3; Clear TF3;
                                          // use SYSCLK/12 as timebase
   RCAP3   = -counts;                     // Init reload values
   TMR3    = 0xffff;                      // set to reload immediately
   EIE2   |= 0x01;                        // enable Timer3 interrupts
   TMR3CN_bit.TR3 = 1;                               // start Timer3

   SFRPAGE = old_SFRPAGE;                 // restore SFRPAGE

}

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

//------------------------------------------------------------------------------------
// Timer3_ISR
//------------------------------------------------------------------------------------
// This routine changes the state of the LED whenever Timer3 overflows.
//
// NOTE: The SFRPAGE register will automatically be switched to the Timer 3 Page
// When an interrupt occurs.  SFRPAGE will return to its previous setting on exit
// from this routine.
//
#pragma vector=TF3_int //interrupt 14
__interrupt void Timer3_ISR (void)
{
   TMR3CN_bit.TF3 = 0;                               // clear TF3
   LED = ~LED;                            // change state of LED
}