Table of Contents
Advertisement
Appendix A Watchdog Timer
A.1 Watchdog Programming
The ARK-5280 Embedded Box Computer is equipped with a watchdog
timer that resets the CPU if processing comes to a standstill for any rea-
son. This feature ensures system reliability in industrial standalone or
unmanned environments. Below is the programming sample of Watch-
dog.
Watchdog: (Index Port:300H , Data Port:301)
1, Enable Watchdog
Outportb (0x2e,0x87);
Outportb (0x2e,0x87); //Entry Configuration Mode
Outportb (0x2e,0x07); //Select Register Index 0x07
Outportb (0x2f,0x08); //Select LDN 8
Outportb (0x2e,0x30); //Select LDN 8 Register Index 0x30
Outportb (0x2f,0x01); //Enable Watchdog Timer Device
Outportb (0x2e,0xaa); //Exit Configuration Mode
2, Set Watchdog Timer to 20 Second
Outportb (0x2e,0x87);
Outportb (0x2e,0x87); //Entry Configuration Mode
Outportb (0x2e,0x07); //Select Register Index 0x07
Outportb (0x2f,0x08); //Select LDN 8
Outportb (0x2e,0xf6); //Select LDN 8 Register Index 0x30
Outportb (0x2f,0x20); //Set 20 second
Outportb (0x2e,0xaa); //Exit Configuration Mode
3, Disable Watchdog
Outportb (0x2e,0x87);
Outportb (0x2e,0x87); //Entry Configuration Mode
Outportb (0x2e,0x07); //Select Register Index 0x07
Outportb (0x2f,0x08); //Select LDN 8
Outportb (0x2e,0x30); //Select LDN 8 Register Index 0x30
Outportb (0x2f,0x00); //Disable Watchdog Timer Device
Outportb (0x2e,0xaa); //Exit Configuration Mode
ARK-5280 User Manual
72
Advertisement
Table of Contents
