Ports for Embedded Systems The OpenUSART function enables the receive interrupt by setting the second
parameter to USART_RX_INT_ON:
OpenUSART (USART_TX_INT_OFF &
USART_RX_INT_ON &
USART_ASYNCH_MODE &
USART_EIGHT_BIT &
USART_CONT_RX &
USART_BRGH_LOW,
77);
Another way to enable the serial-port receive interrupt is to set the bit directly:
PIE1bits.RCIE = 1;
If not using interrupt priority (IPEN = 0), set these bits:
// Disable using interrupt priority.
RCONbits.IPEN = 0;// Enable all unmasked interrupts.INTCONbits.GIE = 1;// Enable all unmasked peripheral interrupts.INTCONbits.PEIE = 1;
If using interrupt priority (IPEN = 1) and the serial interrupt is high priority,
set these bits:
// Enable using interrupt priority.RCONbits.IPEN = 1;// Configure the receive interrupt as high priority.IPIR1bits.RCIP = 1;// Enable all high-priority interrupts.INTCONbits.GIEH = 1;