f340_blinky.c

C8051F340测试源程序,C语言开发.

//-----------------------------------------------------------------------------
// F340_Blinky.c
//-----------------------------------------------------------------------------
// Copyright 2005 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program flashes the P2.2 green LED on the C8051F34x target board
// five times a second using the interrupt handler for Timer2.
//
//
// How To Test:
//
// 1) Download code to a 'F34x target board
// 2) Run the code and if the P2.2 LED blinks, the code works
//
//
// FID:            34X000001
// Target:         C8051F34x
// Tool chain:     Keil C51 7.50 / Keil EVAL C51
// Command Line:   None
//
// Release 1.1
//    -27 SEP 2006 (GP)
//    -Fixed #define for SYSCLK from 24.5/8 Mhz to 12/8 Mhz.
//
// Release 1.0
//    -Initial Revision (GP)
//    -01 DEC 2005
//

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

#include <c8051f340.h>                 // SFR declarations

//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F34x
//-----------------------------------------------------------------------------

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

//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------

#define SYSCLK       12000000 / 8      // SYSCLK frequency in Hz

#define BLINK_RATE   10                // Timer2 Interrupts per second

sbit LED1 = P2^2;                      // 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) 
{
   PCA0MD &= ~0x40;                         // WDTE = 0 (clear watchdog timer 
                                            // enable)
	
   OSCILLATOR_Init ();                      // Initialize system clock 
   PORT_Init ();                            // Initialize crossbar and GPIO
   
   Timer2_Init (SYSCLK / 12 / BLINK_RATE);  // Init Timer2 to generate 
                                            // interrupts at a 10Hz rate.

   EA = 1;									// Enable global interrupts

   while (1) {}                             // Spin forever
}

//-----------------------------------------------------------------------------
// Initialization Subroutines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function initializes the system clock to (12 Mhz / 8)
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
   OSCICN = 0x80;                      // Configure internal oscillator for
                                       // its lowest frequency
}

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function configures the crossbar and GPIO ports.
//
// P2.2   digital   push-pull     LED1
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
   XBR0     = 0x00;                    // No digital peripherals selected
   XBR1     = 0x40;                    // Enable crossbar and weak pull-ups
   P2MDOUT |= 0x04;                    // 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/48 as its time base.
//
//-----------------------------------------------------------------------------
void Timer2_Init (int counts)
{
   TMR2CN  = 0x00;                     // Stop Timer2; Clear TF2;
                                       // Use SYSCLK/12 as timebase
   CKCON  &= ~0x60;                    // Timer2 clocked based on T2XCLK;

   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
   LED1 = ~LED1;                       // Change state of LED
}


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