f41x_blinky.c

来自「芯科原厂所有c8051fxx程序的例子。」· C语言 代码 · 共 157 行

//-----------------------------------------------------------------------------
// F41x_Blinky.c
//-----------------------------------------------------------------------------
// Copyright 2007 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program flashes the green LED on the C8051F41x target board about
// five times a second using the interrupt handler for Timer2.
//
//
// How To Test:
//
// 1) Download code to a 'F41x target board
// 2) Run the program.  If the LED flashes, the program is working
//
//
// FID:            41X000001
// Target:         C8051F41x
// Tool chain:     Keil C51 7.50 / Keil EVAL C51
// Command Line:   None
//
// Release 1.0
//    -Initial Revision (GP)
//    -22 DEC 2005
//

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <c8051f410.h>                 // SFR declarations

//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F41x
//-----------------------------------------------------------------------------

sfr16 TMR2RL   = 0xca;                 // Timer2 reload value
sfr16 TMR2     = 0xcc;                 // Timer2 counter

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

#define SYSCLK       24500000 / 64     // SYSCLK frequency in Hz

sbit LED = P2^1;                       // LED='1' means ON

//-----------------------------------------------------------------------------
// Function PROTOTYPES
//-----------------------------------------------------------------------------

void OSCILLATOR_Init (void);
void PORT_Init (void);
void Timer2_Init (int counts);
void Timer2_ISR (void);

//-----------------------------------------------------------------------------
// main() Routine
//-----------------------------------------------------------------------------

void main (void) {

   // disable watchdog timer
   PCA0MD &= ~0x40;                    // WDTE = 0 (clear watchdog timer
                                       // enable)

   OSCILLATOR_Init ();                 // Initialize system clock to
   PORT_Init ();                       // Initialize crossbar and GPIO
   Timer2_Init (SYSCLK / 10);          // Init Timer2 to generate
                                       // interrupts at a 10Hz rate.

   EA = 1;                             // Enable global interrupts

   while (1) {                         // Spin forever
   }
}

//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This routine initializes the system clock to use the internal 24.5MHz / 64
// oscillator as its clock source.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
   OSCICN = 0x81;                      // Configure internal oscillator
}

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function configures the crossbar and GPIO ports.
//
// P2.1   digital   push-pull     LED
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
   XBR0     = 0x00;                    // No digital peripherals selected
   XBR1     = 0x40;                    // Enable crossbar and weak pull-ups
   P2MDOUT |= 0x02;                    // Enable LED as a push-pull output
}

//-----------------------------------------------------------------------------
// Timer2_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   :
//   1)  int counts - calculated Timer overflow rate
//                    range is postive range of integer: 0 to 32767
//
// Configure Timer2 to 16-bit auto-reload and generate an interrupt at
// interval specified by <counts> using SYSCLK as its time base.
//
//-----------------------------------------------------------------------------
void Timer2_Init (int counts)
{
   TMR2CN  = 0x00;                     // Stop Timer2; Clear TF2;
                                       // use SYSCLK/12 as timebase
   CKCON   = 0x30;                     // Timer2 clocked based on SYSCLK

   TMR2RL  = -counts;                  // Init reload values
   TMR2    = 0xffff;                   // Set to reload immediately
   ET2     = 1;                        // Enable Timer2 interrupts
   TR2     = 1;                        // Start Timer2
}

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

//-----------------------------------------------------------------------------
// Timer2_ISR
//-----------------------------------------------------------------------------
//
//This routine changes the state of the LED whenever Timer2 overflows.
//
//-----------------------------------------------------------------------------
void Timer2_ISR (void) interrupt 5
{
   TF2H = 0;                           // Clear Timer2 interrupt flag
   LED = ~LED;                         // Change state of LED
}

//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------