B&B Electronics ATXWDT, ATRWDT manual Appendix B QuickBASIC Example

Appendix B: QuickBASIC Example

Note: An additional test program for the WDT is available on B&B’s ftp site at ftp.bb-elec.com/bb-elec/software.

B&B Electronics Mfg. Co.

Watchdog Timer QuickBASIC Example Program

This code is an example of how the WDT is addressed from within a program. This code would be used when the TIMER RESET INPUT jumper is in the "CODE" position.

PCWDTaddress = &H300	'hex address chosen for the PCWDT
LatchValue = &H7	'hex latch value chosen, in this
	'case about a 16 second timeout
'Main loop of your program
DO WHILE INKEY$ = ""	'repeat loop until keypressed
OUT PCWDTaddress, LatchValue	'This statement must be executed
	'within the timeout period (17
	'seconds for this example) or the
	'PCWDT will reboot the computer.
X = inp(PCWDTaddress)	‘this statement reads the WDT
	‘registers
X = X AND 31	‘This Statement masks out the 5
	‘Least Significant bits
Print HEX$(X)	‘convert to hex
LOOP
Start = TIMER	‘start the timer
DO WHILE INKEY$ = ""	‘loop to print time for timeout
Print using “###.#”; (TIMER – Start):Print “ Seconds”
LOOP
X = inp(PCWDTaddress)
X = X AND 31
Print HEX$(X)
OUT PCWDTaddress, 0	'disable PCWDT before ending
END
Documentation Number ATxWDT-1303	Appendix B	B-1

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