Intel BS-E098 User Manual page 127

in al, dx
or al, 51h
out dx, al
;-------------------------- Set second as counting unit --------------------------------------
dec dx
mov al, F5h
out dx, al
inc dx
in al, dx
and al, DEh
out dx, al
;-------------------------- Start the watchdog timer --------------------------------------
or al, 20h
out dx, al
;---------------------------------Exit the extended function mode -------------------------
dec dx
mov al, AAh
out dx, al
BS-E098 SERIES USER MANUAL
Appendix B Technical Summary
Page: B-25