Enable data memory PIC 18F4550 - microcontroller

Question

I'm using the PIC18F4550 from microchip with the c compiler: by default the 'program memory' is used, but now I want to use the 'data memory' because it gives me a big more functionality, can enyone just tell me how can I to that in the program language C.
That the code:
#pragma code
/******************************************************************************/
void main (void)
{
TRISD = 0x00; // PORTD als uitgang
TRISB = 0b00110000; // RB4 en RB5 als ingang
TRISA = 0x00; // RA output
RCONbits.IPEN = 0; // prioriteit uit
INTCONbits.GIE = 1; // enable interrupt
INTCONbits.RBIE = 1; // interrupt portB aan
while(1)
{
_asm sleep _endasm
}
}
#pragma interrupt ISR
void ISR (void)
{
int rood[] = {0,0,1,0,1,0,1,0,1,0,1,1,1,0,0,0,0,1,1,0,1,0,1,0,1,0,0,0,1,1,0,1,1,1,0,1,0,1,0,1,0,0,0,1,1,1,1,0,1,1,};
if (INTCONbits.RBIF==1)
{
if(PORTBbits.RB5==0) // S3 ingedrukt ?
{
int i = 0;
int b;
do {
LATAbits.LATA2 = rood[i];
LATDbits.LATD1 ^= 1;
b = 0;
do {
b++;
}while(b <= 1500);
i++;
}while(rood[i] <= 50);
//LATDbits.LATD1 ^= 1; // D2 togglen
}
}
INTCONbits.RBIF = 0;
}

Answer 1

The data sheets for this device seem to indicate that the Data Memory is static ram, and that there is no data path from there to the instruciton decode logic, ie, the data memory cannot be used to store program code for execution. If that was your goal, you are out of luck.
In terms of allocating volatile storage, since the program memory does not appear to include any RAM, my guess is that the C compiler will automatically allocate all variables, etc from the data ram.
That leaves only the choice between the "data" EEPROM and the "program" flash for storage of non-volatile (or semi-volatile) data. There you may have to dig into the documentation - it could be this is done with compiler pragmas, or a linker map file, or it could be that access has to be handled indirectly and explicitly through registers.