//******************************************************************************************
//  PIC16F877 Sample Program
//   Project      :
//   Program Name :
//   Programer    :
//   Create date  :  
//   History      :
//   Laungage     :  XC8 C Laungage Version 2.20
//******************************************************************************************
//   Description
//******************************************************************************************
//
#include <xc.h>
#pragma config FOSC = HS, WDTE = OFF, PWRTE = OFF, CP = OFF, BOREN = OFF, LVP = OFF, CPD = OFF, WRT = OFF, DEBUG = OFF  //For 16F877
//#pragma config FOSC = HS, WDTE = OFF, PWRTE = OFF, BOREN = OFF, LVP = OFF, CPD = OFF, WRT = OFF, DEBUG = OFF, CP = OFF  //For 16F877A

void Timer_1mS(unsigned int);
void Timer_1mS_sub(void);
void main()
{

// *************************
//   1.Initialized Segment
// *************************
// (1)TRIS Register
    TRISA=0xff;   
    TRISB=0xff;
    TRISC=0x00;   
    TRISD=0xff;
    TRISE=0xff;   
// (2)PORT Register
    PORTA=0x00;
    PORTB=0x00;
    PORTC=0x00;
    PORTD=0x00;
    PORTE=0x00;
    
    while(1){  
        PORTCbits.RC0 = ~PORTCbits.RC0;
        PORTCbits.RC1 = ~PORTCbits.RC1;
        PORTCbits.RC2 = ~PORTCbits.RC2;
        PORTCbits.RC3 = ~PORTCbits.RC3;
        PORTCbits.RC4 = ~PORTCbits.RC4;
        PORTCbits.RC5 = ~PORTCbits.RC5;
        PORTCbits.RC6 = ~PORTCbits.RC6;
        PORTCbits.RC7 = ~PORTCbits.RC7;
        Timer_1mS(1000);   
    };
}

//******************************************************************************************
//  Function Name : Timer_1mS
//  Title         : Wait function (1mS) * Number (argument)
//  Input         :
//  Output        :
//******************************************************************************************
void Timer_1mS(unsigned int Number)
{
    unsigned int lp;
    for(lp=0;lp<Number;lp++){
       Timer_1mS_sub(); 
    }    
}  

//******************************************************************************************
//  Function Name : Timer_1mS_sub
//  Title         : Wait function (1mS)
//  Input         :
//  Output        :
//******************************************************************************************
void Timer_1mS_sub(void)
{
// ******************************************************************
// 1.Define T1CON: TIMER1 CONTROL REGISTER (ADDRESS 10h)
//    T1CON[7-6] Unimplemented: Read as '0'
//    T1CON[5-4] T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits
//         11 = 1:8 prescale value
//         10 = 1:4 prescale value
//         01 = 1:2 prescale value
//         00 = 1:1 prescale value
//    T1CON[3] T1OSCEN: Timer1 Oscillator Enable Control bit
//         1 = Oscillator is enabled
//         0 = Oscillator is shut-off (the oscillator inverter is turned off to eliminate power drain)
//    T1CON[2] T1SYNC: Timer1 External Clock Input Synchronization Control bit
//          When TMR1CS = 1:
//                1 = Do not synchronize external clock input
//                0 = Synchronize external clock input
//          When TMR1CS = 0:
//                This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
//    T1CON[1] TMR1CS: Timer1 Clock Source Select bit
//        1 = External clock from pin RC0/T1OSO/T1CKI (on the rising edge)
//        0 = Internal clock (FOSC/4)
//    T1CON[0] TMR1ON: Timer1 On bit
//        1 = Enables Timer1
//        0 = Stops Timer1  
// ******************************************************************   
    T1CON = 0b00000101;

// *******************************************************
// 2.Define TMR1 Register
// *******************************************************
//  (1)TMR1 data ( OSC:16MHz, 1:1 Prescale value, 0.001[S];1000Hz )
//     1mS(1000Hz): 16MHz / 4(FOSC/4) / 1000(1000Hz)==> 0d4000(Count) ==> 0x0FA0(Count)
//     TMR1 = 0xFFFF - 0x0FA0 ==> 0xF05F
//  TMR1H = 0xF0;
//  TMR1L = 0x5F;
//
//  (2)TMR1 data ( OSC:20MHz, 1:1 Prescale value, 0.001[S];1000Hz )
//     1mS(1000Hz): 20MHz / 4(FOSC/4) / 1000(1000Hz)==> 0d5000(Count) ==> 0x1338(Count)
//     TMR1 = 0xFFFF - 0x1338 ==> 0xECC7
    TMR1H = 0xEC;
    TMR1L = 0xC7;
    
// *******************************************************
// 3.Timer
// *******************************************************
    PIR1bits.TMR1IF = 0;
    while(1){
        if(PIR1bits.TMR1IF != 0 )break;
    }
}