protech PPC-7368, Руководство пользователя

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Chapter 3 Software Configuration
PPC-7368 USER
′
S MANUAL
Page:3-9
3-8. TOUCH SCREEN DRIVER UTILITY (OPTIONAL)
To install, kindly refer to the readme.txt file found each separate file of the
Driver Disc.
3-9. USB CF CARD DRIVER UTILITY (OPTIONAL)
To install, kindly refer to the readme.txt file found each separate file of the
Driver Disc.
3-10. WATCHDOG TIMER CONFIGURATION
This board has watchdog timer function for monitoring whether the system is
still work or not after a period of time. The user can select watchdog timer
to system reset or NMI (Non Maskable interrupt) depending on the jumper
set in “Reset/NMI/Clear Watchdog Selection” found in chapter 2. This is
defined at I/O port
443H . When you want to enable the watchdog timer,
please write I/O port 443H , and then the system will either reset itself or
perform the NMI function. Likewise, when you want to disable the function,
write I/O port
441H , the system will run the command to stop the Watchdog
function.
In PPC-7368 watchdog function, you must write your program so when it
writes I/O port address 443 for enable watchdog and write I/O port address
441 for disable watchdog. The timer
'
s intervals have a tolerance of 25% so
you should program an instruction that will refresh the timer about every
second.
The following program shows you how to program the watch timer in your
program.
Watchdog enable program:
MOV AX, 000FH (choose the values you need; start from 0)
MOV DX, 443H
OUT DX, AX
Watchdog disable program:
MOV AX, 000FH (this value can be ignored)