Incrementar y decrementar bit PIC 18F4550

unsigned char counter,tmp;
unsigned char umili,dmili,cmili, mmili, num, umili1, dmili1, cmili1, mmili1,umili2,dmili2,cmili2, mmili2 ;
int numero,numero1, mnum, mnum1;
unsigned char seg7[]={0x63,0x02,0x5B,0x4F,0x66,0x6D,
0x7D,0x07,0x7f,0x6f,0x77,
0x7C,0x39,0x5E,0x79,0x71};
unsigned char seg71[]={0x5C,0x04,0x5B,0x4F,0x66,0x6D,
0x7D,0x07,0x7f,0x6f,0x77,
0x7C,0x39,0x5E,0x79,0x71};
void separa_digitos(void);
void muestra_digitos(void);
void separa_digitos1(void);
void muestra_digitos1(void);

void main() {
ADCON1 =0x0F;
TRISC=0;
TRISD=0;

numero=0;
PORTC=0;
PORTD=0;
while(1)
{
 separa_digitos();
 muestra_digitos();
 numero++;
 if(numero==256)
 {
 numero=0;
 }

 separa_digitos1();
 muestra_digitos1();
 numero1--;
 if(numero1==0)
 {
 numero1=255;
 }
 }
}



void muestra_digitos(void)
{     
 num=seg7[mmili];
 PORTC=0x00;
 PORTD=num;
 Delay_ms(2);
 num=seg7[cmili];
 PORTC=0x01;
 PORTD=num;
 Delay_ms(2);
 num=seg7[dmili];
 PORTC=0x02;
 PORTD=num;
 Delay_ms(2);
 num=seg7[umili];
 PORTC=0x03;
 PORTD=num;
 Delay_ms(2);
  num=seg7[mmili2];
 PORTC=0x04;
 PORTD=num;
 Delay_ms(2);
 num=seg7[cmili2];
 PORTC=0x05;
 PORTD=num;
 Delay_ms(2);
 num=seg7[dmili2];
 PORTC=0x06;
 PORTD=num;
 Delay_ms(2);
 num=seg7[umili2];
 PORTC=0x07;
 PORTD=num;
 Delay_ms(2);
}
void separa_digitos(void)
{
 mnum=numero;
 umili2=(unsigned char)mnum%2;
 mnum=mnum/2;
 dmili2=(unsigned char)mnum%2;
 mnum=mnum/2;
 cmili2=(unsigned char)mnum%2;
 mnum=mnum/2;
 mmili2=(unsigned char)mnum%2;
 mnum=mnum/2;
 umili=(unsigned char)mnum%2;
 mnum=mnum/2;
 dmili=(unsigned char)mnum%2;
 mnum=mnum/2;
 cmili=(unsigned char)mnum%2;
 mnum=mnum/2;
 mmili=(unsigned char)mnum%2;
}
 void muestra_digitos1(void)
{
 num=seg7[mmili]|seg71[mmili];
 PORTC=0x00;
 PORTD=num;
 Delay_ms(2);
 num=seg71[cmili];
 PORTC=0x01;
 PORTD=num;
 Delay_ms(2);
 num=seg71[dmili];
 PORTC=0x02;
 PORTD=num;
 Delay_ms(2);
 num=seg71[umili];
 PORTC=0x03;
 PORTD=num;
 Delay_ms(2);
 num=seg71[mmili2];
 PORTC=0x04;
 PORTD=num;
 Delay_ms(2);
 num=seg71[cmili2];
 PORTC=0x05;
 PORTD=num;
 Delay_ms(2);
 num=seg71[dmili2];
 PORTC=0x06;
 PORTD=num;
 Delay_ms(2);
 num=seg71[umili2];
 PORTC=0x07;
 PORTD=num;
 Delay_ms(2);
}
void separa_digitos1(void)
{
 mnum1=numero1;
 umili2=(unsigned char)mnum1%2;
 mnum1=mnum1/2;
 dmili2=(unsigned char)mnum1%2;
 mnum1=mnum1/2;
 cmili2=(unsigned char)mnum1%2;
 mnum1=mnum1/2;
 mmili2=(unsigned char)mnum1%2;
 mnum1=mnum1/2;
 umili=(unsigned char)mnum1%2;
 mnum1=mnum1/2;
 dmili=(unsigned char)mnum1%2;
 mnum1=mnum1/2;
 cmili=(unsigned char)mnum1%2;
 mnum1=mnum1/2;
 mmili=(unsigned char)mnum1%2;
}