f93x_blinky.c

芯科原厂所有c8051fxx程序的例子。

//-----------------------------------------------------------------------------
// F93x_Blinky.c
//-----------------------------------------------------------------------------
// Copyright (C) 2007 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program flashes the yellow LED on the C8051F930 target board about
// five times a second using the interrupt handler for Timer2.
//
//
// How To Test:
//
// 1) Download code to the 'F93x target board 
// 2) Ensure that pins 2 and 3 are shorted together on the J8 header
// 3) Run the program.  If the Yellow LED flashes, the program is working
//
//
// Target:         C8051F93x-C8051F92x
// Tool chain:     Generic
// Command Line:   None
//
// Release 1.0
//    -Initial Revision (FB)
//    -4 OCT 2007
//

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <compiler_defs.h>             // compiler declarations
#include <C8051F930_defs.h>            // SFR declarations

//-----------------------------------------------------------------------------
// Pin Declarations
//-----------------------------------------------------------------------------

SBIT (RED_LED,    SFR_P1, 5);          // '0' means ON, '1' means OFF
SBIT (YELLOW_LED, SFR_P1, 6);          // '0' means ON, '1' means OFF
SBIT (SW2,        SFR_P0, 2);          // SW2 == 0 means switch pressed
SBIT (SW3,        SFR_P0, 3);          // SW3 == 0 means switch pressed

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

#define SYSCLK       20000000/8        // SYSCLK frequency in Hz

#define LED_ON           0
#define LED_OFF          1

//-----------------------------------------------------------------------------
// Function PROTOTYPES
//-----------------------------------------------------------------------------
void PORT_Init (void);
void Timer2_Init (int counts);

//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
void main (void)
{
   PCA0MD &= ~0x40;                    // WDTE = 0 (clear watchdog timer
                                       // enable)
   PORT_Init ();

   Timer2_Init (SYSCLK / 12 / 10);     // Init Timer2 to generate interrupts
                                       // at a 10 Hz rate.

   EA = 1;                             // Enable global interrupts

   while (1) {}                        // Spin forever
}

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function configures the crossbar and ports pins.
//
// P0.2   digital   open-drain    Switch 2
// P0.3   digital   open-drain    Switch 3
// P1.5   digital   push-pull     Red LED
// P1.6   digital   push-pull     Yellow LED
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
   P0MDIN |= 0x0C;                     // P0.2, P0.3 are digital
   P1MDIN |= 0x60;                     // P1.5, P1.6 are digital

   P0MDOUT &= ~0x0C;                   // P0.2, P0.3 are open-drain
   P1MDOUT |= 0x60;                    // P1.5, P1.6 are push-pull

   P0     |= 0x0C;                     // Set P0.2, P0.3 latches to '1'

   XBR2    = 0x40;                     // Enable crossbar and enable
                                       // weak pull-ups
}

//-----------------------------------------------------------------------------
// 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.
//
INTERRUPT(Timer2_ISR, INTERRUPT_TIMER2)
{
   TF2H = 0;                              // clear Timer2 interrupt flag
   YELLOW_LED = !YELLOW_LED;              // change state of LEDs

}

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