//-----------------------------------------------------------------------------
// F500_Blinky.c
//-----------------------------------------------------------------------------
// Copyright (C) 2008 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program flashes the green LED on the C8051F500 target board about
// five times a second using the interrupt handler for Timer2.
//
//
// How To Test:
//
// 1) Download code to the 'F500 target board
// 2) Ensure that the P1.3 pins are shorted together on the J19 header
// 3) Run the program.  If the LED flashes, the program is working
//
//
// Target:         C8051F500 (Side A of a C8051F500-TB)
// Tool chain:     Keil C51 8.0 / Keil EVAL C51
// Command Line:   None
//
// Release 1.1 / 09 JUN 2008 (ADT)
//    -Edited formatting
//
// Release 1.0 / 18 MAR 2008 (GP)
//    -Initial Revision

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

#include <compiler_defs.h>             // Compiler declarations
#include <C8051F500_defs.h>            // SFR declarations

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

#define SYSCLK       24000000/8        // SYSCLK frequency in Hz

SBIT (LED, SFR_P1, 3);                 // LED='1' means ON

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

void OSCILLATOR_Init (void);
void PORT_Init (void);
void TIMER2_Init (U16 counts);

//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
void main (void)
{
   SFRPAGE = ACTIVE_PAGE;              // Configure for PCA0MD

   PCA0MD &= ~0x40;                    // Disable the watchdog timer

   OSCILLATOR_Init ();                 // Configure system clock

   PORT_Init ();                       // Initialize crossbar

   TIMER2_Init (SYSCLK / 12 / 10);     // Init Timer2 to generate interrupts
                                       // at a 10 Hz rate.

   EA = 1;                             // Enable global interrupts

   while (1);                          // Spin forever
}


//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value:  None
// Parameters:    None
//
// Configure the internal oscillator to maximum internal frequency / 8
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
   U8 SFRPAGE_save = SFRPAGE;
   SFRPAGE = CONFIG_PAGE;

   OSCICN = 0x84;                      // Set oscillator divide to /8

   SFRPAGE = SFRPAGE_save;
}


//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value:  None
// Parameters:    None
//
// Configure the Crossbar and GPIO ports.
//
// P1.3 - digital  push-pull   LED
//
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
   U8 SFRPAGE_save = SFRPAGE;
   SFRPAGE = CONFIG_PAGE;

   P1MDOUT |= 0x08;                    // Enable LED as a push-pull output
   P1SKIP  |= 0x08;                    // Skip the LED pin on the crossbar

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

   SFRPAGE = SFRPAGE_save;
}

//-----------------------------------------------------------------------------
// TIMER2_Init
//-----------------------------------------------------------------------------
//
// Return Value:  None
// Parameters:    U16 counts - number of system clock cycles between interrupts
//                             range is 0 to 65535
//
// Configure Timer2 to 16-bit auto-reload and generate an interrupt at
// interval specified by <counts> using SYSCLK/12 as its time base.
//
//-----------------------------------------------------------------------------

void TIMER2_Init (U16 counts)
{
   U8 SFRPAGE_save = SFRPAGE;
   SFRPAGE = ACTIVE_PAGE;

   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

   SFRPAGE = SFRPAGE_save;
}

//-----------------------------------------------------------------------------
// 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
   LED = !LED;                         // Change state of LED
}

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