Interrupt driven Buffered Serial Input

[johnmiller]

Hi, I'm going mad for the past few days here since my interrupts are not working. I am trying to make a interrupt driven buffered serial input but without success since my program doesn't do anything when it should deal with the interrupts (it just stays on that "While CounterA <= 70 : WEND" forever) (nothing is printed out when I send something to it's serial port). Here is my code (part of it at least that deals with the serial part)

    DEFINE OSC 20
    
    DEFINE HSER_TXSTA 24h
    DEFINE HSER_RCSTA 90h
    DEFINE HSER_BAUD 19200
    DEFINE HSER_SPBRG 64 ' 19200 Bauds
    DEFINE HSER_CLROERR 1

    RCIF	VAR	PIR1.5		' Alias RCIF (USART Receive Interrupt Flag)
    OERR	VAR	RCSTA.1		' Alias OERR (USART Overrun Error Flag)
    CREN	VAR	RCSTA.4		' Alias CREN (USART Continuous Receive Enable)
    LED     VAR	PORTD.0 	' Alias LED to PORTD.0

    buffer_size	CON	32		' Sets the size of the ring buffer
    buffer	VAR	BYTE[buffer_size]	' Array variable for holding received characters
    index_in	VAR	BYTE	' Pointer - next empty location in buffer
    index_out	VAR	BYTE	' Pointer - location of oldest character in buffer
    bufchar	VAR	BYTE		' Stores the character retrieved from the buffer
    i		VAR	BYTE		' loop counter 
    errflag	VAR	BYTE		' Holds error flags

    CMCON=%00000111		' Disable Comparators
    TRISA=%00000000		' PORTA all set to Output 
    TRISB=%11111111		' PORTB all set to Input
    T0CON=%00000111     ' OFF,16BIT,PRESCALE=256
    ADCON0 = 0
    CMCON=7
    INTCON.5=1          'T0IE : TMR0 Overflow Interrupt Enable bit

ON interrupt GOTO GestIntrerupts        ' Deal with interrupts

ReadSerial:
   DataRec var byte[5] : DataRec = 0
   PIE1.5 = 1   			' Enable interrupt on USART
   While CounterA <= 70 : WEND
   PIE1.5 = 0				' Disable interrupt on USART
        
   FOR COUNTERB=0 to COUNTERA
        SEROUT2 SerWRT,16416,[SerDATA(COUNTERB)]
        NEXT COUNTERB

   Goto ReadReadyLoop 


' Subroutines
Disable					' Don't check for interrupts in this section

getbuf:					' move the next character in buffer to bufchar
	index_out = (index_out + 1)			' Increment index_out pointer (0 to 63)
	IF index_out > (buffer_size-1) Then index_out = 0	' Reset pointer if outside of buffer
	bufchar = buffer[index_out]			' Read buffer location
Return

error:					' Display error message if buffer has overrun
	errflag = 0			' Reset the error flag
	CREN = 0			' Disable continuous receive to clear overrun flag
	CREN = 1			' Enable continuous receive
	GoTo display		' Carry on

buffer_error:
	errflag.1 = 1		' Set the error flag for software
' Move pointer back to avoid corrupting the buffer. MIN insures that it ends up within the buffer.	
	index_in = (index_in - 1) MIN (buffer_size - 1)	
	HSerin [buffer[index_in]]	' Overwrite the last character stored (resets the interrupt flag)

usart_error:
	errflag.0 = 1		' Set the error flag for hardware
Resume					' Return to program

GestIntrerupts:
    IF INTCON.2 = 1 then
        T0CON.0 = 0 ' Disable timer
        TMR0L = 0   ' Reset timer
        TMR0H = 0   ' Reset timer
        TimeCount = TimeCount + 1
        T0CON.0 = 1 ' Enabled timer
        INTCON.2 = 0
    ELSE : IF RCIF = 1 THEN
        IF OERR Then usart_error			' Check for USART errors
	    index_in = (index_in + 1)			' Increment index_in pointer (0 to 63)
	    IF index_in > (buffer_size-1) Then index_in = 0	'Reset pointer if outside of buffer
	    IF index_in = index_out Then buffer_error	' Check for buffer overrun
	    HSerin [buffer[index_in]]			' Read USART and store character to next empty location
        SEROUT2 SerWRT,16416,[buffer(index_in)]
        SerData(CounterA)=buffer(index_in)
        CounterA = CounterA + 1	    
	    IF RCIF Then GestIntrerupts   		' Check for another character while we're here 
    ENDIF : ENDIF
    resume
ENABLE

Any input is appreciated!