PIC18F27k40 Programming

#include <18F27K40.h>
#fuses NOMCLR RSTOSC_HFINTRC_1MHZ CLKOUT NOWDT NOPROTECT NOCPD
#use delay(internal=64MHZ, clock_out)
#define forever 1       // forever is true

struct IOPort_Definition1
{           // 1st structure
   int unused_A;        // Unused pins RA0..RB7
   int ExperimentSelect:4;     // Pins RB0..3 for selection
   int unused_B:4;      // rest of RB
   int1 Single_Bit_LED; // Pin RC0 LED used for single-bit indication
   int unused_C:7;      // Remaining bits of Port C;
};

struct IOPort_Definition2
{           // 2nd structure
   int unused_A;        // unused A's for 2nd structure
   int ExpSelect:4;     // Pins RB0..3 for selection
   int unused_B:4;      // rest of RB
   int fourbitOutput:4; // Pin RC0..3 LED
   int unused_C:4;      // Remaining bits of Port C;
};

struct IOPort_Definition1 IO_Port;
struct IOPort_Definition1 IO_Direction;
struct IOPort_Definition2 IO_Port_Def2;
struct IOPort_Definition1 IO_Direction_Def2;
//struct IOPort_Definition1 IO_Latch;
#byte IO_Port = 0xF8D       // PORTA register in SFR
#byte IO_Direction = 0xF88  // TRISA register
//#byte IO_Latch = 0xF83

void main(void) {
   IO_Direction.unused_A = 0b00000000;           // all unused outputs
   IO_Direction.ExperimentSelect = 0b1111;              // Pins RA4..7 as output
   IO_Direction.unused_B = 0b0000;               // Pins RB0..7
   IO_Direction.Single_Bit_LED = 0b0;            // Single LED as output
   IO_Direction.unused_C = 0b0000000;            // Unused pins as output

   port_a_pullups(0xFF);
   port_b_pullups(0xFF);

   setup_oscillator(OSC_HFINTRC_64MHZ);

   while(forever)
   {
      switch (IO_Port.ExperimentSelect)
      {
         case 0b0000:
         {
            IO_Port.Single_Bit_LED = 0b0;  // Toggle single LED
            break;
         }
         case 0b1000:
         {
            IO_Port.Single_Bit_LED = ! IO_Port.Single_Bit_LED;  // Toggle single LED
            delay_ms(500); //delays for 0.5 second before restarting loop
            break;
         }
      }
   }
}