www.pudn.com > C8051F30x.rar > Blinky.c

//----------------------------------------------------------------------------- 
// Blinky.c 
//----------------------------------------------------------------------------- 
// Copyright (C) 2004 Silicon Laboratories, Inc. 
// 
// AUTH: BW 
// DATE: 11 OCT 01 
// 
// This program flashes the green LED on the C8051F30x target board about  
// five times a second using the interrupt handler for Timer2. 
// 
// Target: C8051F30x 
// 
// Tool chain: KEIL Eval 'c' 
// 
 
//----------------------------------------------------------------------------- 
// Includes 
//----------------------------------------------------------------------------- 
#include                     // SFR declarations 
 
//----------------------------------------------------------------------------- 
// 16-bit SFR Definitions for 'F30x 
//----------------------------------------------------------------------------- 
 
sfr16 DP       = 0x82;                    // data pointer 
sfr16 TMR2RL   = 0xca;                    // Timer2 reload value 
sfr16 TMR2     = 0xcc;                    // Timer2 counter 
sfr16 PCA0CP1  = 0xe9;                    // PCA0 Module 1 Capture/Compare 
sfr16 PCA0CP2  = 0xeb;                    // PCA0 Module 2 Capture/Compare 
sfr16 PCA0     = 0xf9;                    // PCA0 counter 
sfr16 PCA0CP0  = 0xfb;                    // PCA0 Module 0 Capture/Compare 
 
//----------------------------------------------------------------------------- 
// Global CONSTANTS 
//----------------------------------------------------------------------------- 
 
#define SYSCLK       24500000 / 8         // SYSCLK frequency in Hz 
 
sbit LED = P0^2;                          // LED='1' means ON 
sbit SW2 = P0^3;                          // SW2='0' means switch pressed 
 
//----------------------------------------------------------------------------- 
// Function PROTOTYPES 
//----------------------------------------------------------------------------- 
void SYSCLK_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) 
	 
   SYSCLK_Init ();                        // Initialize system clock to  
                                          // 24.5MHz 
   PORT_Init ();                          // Initialize crossbar and GPIO 
   Timer2_Init (SYSCLK / 12 / 10);        // Init Timer2 to generate  
                                          // interrupts at a 10Hz rate. 
 
   EA = 1;											// enable global interrupts 
 
   while (1) {                            // spin forever 
   } 
} 
 
//----------------------------------------------------------------------------- 
// SYSCLK_Init 
//----------------------------------------------------------------------------- 
// 
// This routine initializes the system clock to use the internal 24.5MHz / 8  
// oscillator as its clock source.  Also enables missing clock detector reset. 
// 
void SYSCLK_Init (void) 
{ 
   OSCICN = 0x04;                         // configure internal oscillator for 
                                          // its lowest frequency 
   RSTSRC = 0x04;                         // enable missing clock detector 
} 
 
//----------------------------------------------------------------------------- 
// PORT_Init 
//----------------------------------------------------------------------------- 
// 
// Configure the Crossbar and GPIO ports. 
// P0.0 -  
// P0.1 - 
// P0.2 - LED (push-pull) 
// P0.3 - SW2 
// P0.4 -  
// P0.5 -  
// P0.6 -  
// P0.7 - C2D 
// 
void PORT_Init (void) 
{ 
   XBR0     = 0x04;                       // skip P0.2 (LED) in crossbar pin 
                                          // assignments 
   XBR1     = 0x00;                       // no digital peripherals selected 
   XBR2     = 0x40;                       // Enable crossbar and weak pull-ups 
   P0MDOUT |= 0x04;                       // enable LED as a push-pull output 
} 
 
//----------------------------------------------------------------------------- 
// Timer2_Init 
//----------------------------------------------------------------------------- 
// 
// Configure Timer2 to 16-bit auto-reload and generate an interrupt at  
// interval specified by  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 
   LED = ~LED;                            // change state of LED 
}