Hi,

Have a look at the code below and modify according to your needs to test a stack over/underflow

Code:
INIT:
'BELOW IS A CHECK FOR STACK ResetERROR FOR DEBUG ************************************
IF STKPTR.7 = 1 THEN        ' CHECK FOR STACK POINTER OVERFLOW
HSEROUT ["STACK OVERFLOW"]  ' DUMP DATA TO LCD
STKPTR.7 = 0                ' CLEAR STACK POINTER OVERFLOW BIT
GOSUB DLY5K                 ' CALL THE 5 SECONDS DELAY SUBROUTINE
ENDIF

IF STKPTR.6 = 1 THEN        ' CHECK FOR STACK POINTER UNDERFLOW
HSEROUT ["STACK UNDERFLOW"] ' DUMP DATA TO LCD
STKPTR.6 = 0                ' CLEAR STACK POINTER UNDERFLOW BIT
GOSUB DLY5K                 ' CALL THE 5 SECONDS DELAY SUBROUTINE
ENDIF