Strange happenings PBP and 12F683

[RussMartin]

The problem still occurs and I seem unable to predict when.

Sometimes, execution seems to go directly to NOTCLR.

I attached the full program (slightly earlier version) to my prior post.

The only changes have been in MAIN, PLAY, NOTCLR, and TIMER, shown below.

Can someone point out where I'm going wrong?

MAIN:   IF TRIGR=1 THEN                 ' Selects "playback"
            PAUSE 9                     ' Pause ~10 milliseconds for debounce
            GOSUB PLAY
            ENDIF                                       
        IF MFLAG=0 AND KEYCHK=1 THEN    ' If mode selection prohibits continuous
            GOSUB NOTCLR                '  switch closure, Await switch opening
            ENDIF            
        IF CONTROL=0 THEN               ' Selects "record"
            PAUSE 9                     ' Pause ~10 milliseconds for debounce
            GOSUB RECORD
            ENDIF
        IF ACTIVE=0 THEN                ' Manual override when idle       
            PAUSE 9                     ' Pause ~10 milliseconds for debounce
            GOSUB MANUAL
            ENDIF
        GOTO MAIN

-----

PLAY:   CYCLE=0 : FLASH=8 : FLASH2=5    ' Status LED indicates "playback"
        CLOCK=0                         ' Reset the clock for read
PLOOP:  IF FRAME=248 THEN GOTO PLEXIT   ' If top of data is reached, exit
        READ FRAME,STATE                ' Read the frame from data memory
        IF STATE=$FF THEN GOTO PLEXIT   ' If end-of-data marker is read, exit
        IF STATE=1 THEN                 ' For state 1,
            RELAY=1 : ALED=1            '  turn the relay and activity LED on,
            ENDIF                       '  otherwise,
        IF STATE=0 THEN                 '  for state 0,
            RELAY=0 : ALED=0            '  turn the relay and activity LED off
            ENDIF 
        GOTO PLOOP                      ' Repeat until an exit condition occurs
PLEXIT: CYCLE=0 : FLASH=16 : FLASH2=9   ' Status LED indicates "idle"
        RETURN

-----

NOTCLR: CYCLE=0 : FLASH=2 : FLASH2=2    ' Status LED indicates "attention!"
        WHILE KEYCHK=1 OR TRIGR=1       ' While the trigger input is active,
            WEND                        '  further execution is prevented
        PAUSE 9                         ' Pause ~10 milliseconds
        CYCLE=0 : FLASH=16 : FLASH2=9   ' Return to the idle state
        RETURN

For some reason, this won't allow me to include TIMER in the above without dropping statements, so I'll do that one this messy way. Note: FRAME above is the low byte of ADDRS below.

TIMER: CYCLE=CYCLE+1
IF CYCLE<FLASH2 THEN
SLED=1
ELSE
SLED=0
ENDIF
IF CYCLE>FLASH THEN CYCLE=0
ADDRS=CLOCK>>1
CLOCK=CLOCK+1
IF TRIGR=1 THEN
KEYCHK=1
ELSE
KEYCHK=0
ENDIF
@ INT_RETURN