Specifications

Application Examples
Program Code
;
EXAMPLE #3
PROGRAMMING ABSTRACT
; Ziatech Corporation
; San Luis Obispo, CA
; 06/01/89
; THIS PROGRAMMING EXAMPLE ILLUSTRATES THE CODE USED TO ARM AND
; STROBE THE WATCHDOG TIMER. ALSO INCLUDED IS A NON-MASKABLE
; INTERRUPT SERVICE ROUTINE THAT FLAGS A WATCHDOG TIMEOUT IN
; DUAL PORT RAM. NOT SHOWN IS THE ZT 8832 STARTUP CODE THAT
; TESTS THE FLAG LOCATION TO SEE WHETHER THE RESET WAS CAUSED
; BY A WATCHDOG TIMEOUT OR BY ANOTHER SOURCE OF RESET.
;
SYSTEM EQUATES
; 82050 SERIAL PORT
SER_PORT EQU 03F8H ; 82050 BASE PORT
SER_PORT_CTRL EQU SER_PORT+4 ; MODEM CONTROL PORT
SER_PORT_OUT2 EQU 00001000B ; OUT2 BIT USED FOR
; PARALLEL PORT OUTPUT
; ENABLE
; PARALLEL PORT
PAR_PORT_0 EQU 200H ; PARALLEL PORT 0 ADDRESS
PAR_PORT_1 EQU 210H ; PARALLEL PORT 1 ADDRESS
PAR_PORT_2 EQU 220H ; PARALLEL PORT 2 ADDRESS
PAR_PORT_INIT EQU 0 ; INITIALIZE VALUE
PAR_PORT_WD EQU 10000000B ; WATCHDOG STROBE BIT
;
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