change notification CN in dsPIC

void InitICandCN(void)
{            
       TRISB = 0x38;             // Ensure the CN pins to be input
       CNPU1 = 0;                 // Disable all CN pull ups
       CNEN1 = 0x20;            // Enable CN5
       IFS0bits.CNIF = 0;       // Clear interrupt flag
       IEC0bits.CNIE = 1;       // Enable interrupts on CN5
       return;
}
 
void __attribute__((interrupt, no_auto_psv)) _CNInterrupt (void)
{
       IFS0bits.CNIF = 0;           // Clear interrupt flag
       SendData('U');                // Sending data to PC using UART communication
       return;
}