EUSART Stop Receiving

[CocaColaKid]

I've noticed a problem and can't seem to find an answer. If I run this program everything appears to work great and I get the bytes received back. The problem appears when I trying to send lots of data the program starts to receive and after on or two transmissions is just hangs up and stops responding to data coming in. Anyone have any ideas what might be causing this issue?

DEFINE  LOADER_USED 1

DEFINE  OSC 16
DEFINE  HSER_BAUD 2400
DEFINE  HSER_SPBRG 103 ' 19200 Bauds
DEFINE  HSER_CLROERR 1  ' Automatically clear over-run errors
DEFINE  HSER_RCSTA 90h	' Enable USART receive
DEFINE  HSER_TXSTA 20h	' TXSTA=%00100000. TX enable, BRGH=0 for low-speed


    x       var     byte        ' General purpose variable
    BytesIn var     byte[80]    ' Serial array - can receive up to 80 bytes
    ByteCnt var     byte        ' Indicates number of bytes in buffer
    eom     con     "~"         ' End Of Message marker
    rcif    var     PIR1.5      ' Alias USART received character interrupt flag bit

    ByteCnt = 0             ' Zero counter

INCLUDE "DT_INTS-18.bas"     ' Base Interrupt System
INCLUDE "ReEnterPBP-18.bas"     ' Include if using PBP interrupts

ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler    RX_INT,  _Receive,   PBP,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor

    INT_ENABLE   RX_INT     ; enable external (INT) interrupts
ENDASM

Main:
    pause 1
    goto Main

Receive:
    if rCIF then                                ' If RCIF=1 there's a new character in RCREG
        BytesIn[ByteCnt] = RCREG               ' Yes. Then store it in array
        if BytesIn[ByteCnt] = eom then OutMsg
        ByteCnt = ByteCnt + 1                  ' Increment array index pointer 
    endif
    goto Receive

OutMsg:
    hserout [13,10,dec ByteCnt," Bytes Received",13,10]
    hserout [str BytesIn\ByteCnt,13,10]
    for x = 0 to ByteCnt                        ' Clear array bytes 0 to ByteCnt
        BytesIn[x] = 0
        next x
    ByteCnt = 0                                 ' Reset index pointer back to first element
    while RCIF                                  ' Keep reading until RCIF is clear to flush buffer
     x = RCREG                                  ' after EOM is received
    wend
@ INT_RETURN

[Bruce]

Once in your interrupt handler, interrupts are disabled, so you'll miss new data
that's arriving until you exit & re-enable the interrupt.

I don't think DEFINE HSER_CLROERR 1 is doing any good unless you use
HSERIN, so you would need to clear this manually.

Try reducing the time spent in your interrupt handler. I.E. place;

if BytesIn[ByteCnt] = eom then OutMsg in Main. Remove OutMsg from your int
handler, and let Main take care of displaying messages after eom.

Your interrupt handler should then be fast enough to keep up.

Receive:
    if rCIF then ' do you really need this? ' If RCIF=1 there's a new character in RCREG
        BytesIn[ByteCnt] = RCREG               ' Yes. Then store it in array
        ByteCnt = ByteCnt + 1                  ' Increment array index pointer 
    endif
    @ INT_ENABLE

It wouldn't hurt to allocate time on the sending device for the PIC to respond
with the complete message before sending more data after the eom marker.