t60x_blinky.c

来自「芯科原厂所有c8051fxx程序的例子。」· C语言 代码 · 共 139 行

//-----------------------------------------------------------------------------
// T60x_Blinky.c
//-----------------------------------------------------------------------------
// Copyright 2007 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program flashes the green LED on the C8051T60x target board about
// five times a second using the interrupt handler for Timer2.
//
// FID:
// Target:         C8051T60x
// Tool chain:     Keil C51 7.50 / Keil EVAL C51
// Command Line:   None
//
// Release 1.1
//    -Added include for compiler_defs.h (HA)
//    -22 AUG 2007
//
// Release 1.0
//    -Initial Revision (BD)
//    -17 JAN 2007

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <compiler_defs.h>             // compiler declarations
#include <C8051T600_defs.h>            // SFR declarations


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

#define SYSCLK       24500000 / 8      // SYSCLK frequency in Hz

sbit LED = P0^6;                       // LED='1' means ON
sbit SW1 = P0^3;                       // SW1='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 -
// P0.3 - SW1
// P0.4 -
// P0.5 -
// P0.6 - LED (push-pull)
// P0.7 - C2D
//
void PORT_Init (void)
{
   XBR0     = 0x40;                    // skip P0.6 (LED) in crossbar pin
                                       // assignments
   XBR1     = 0x00;                    // no digital peripherals selected
   XBR2     = 0x40;                    // Enable crossbar and weak pull-ups
   P0MDOUT |= 0x40;                    // enable LED as a push-pull output
}

//-----------------------------------------------------------------------------
// Timer2_Init
//-----------------------------------------------------------------------------
//
// 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
   LED = ~LED;                         // change state of LED
}