Owner manual

Secure Microcontroller User’s Guide
91 of 187
10.5 Transient Voltage Protection
The microprocessor provides protection from transients through a built in power-fail/power-on reset and
Watchdog Timer. Each of these functions should be initialized by the user as part of the reset routine. The
following code demonstrates the set up for a user that will support the Watchdog function.
TA EQU 0C7h
ORG 00h
SJMP Start
Org 30h
Start :
MOV TA, #0Aah ;Timed
MOV TA, #55h ; Access
ORL IP, #80h ;Set RWT to restart the Watchdog Timer
MOV TA, #0Aah ;Timed
MOV TA, #55h ; Access
ORL PCON, #44h ;Set POR (PCON.6) bit for power-on reset detect
; and enable Watchdog Timer by setting EWT
(PCON.2)