EVOC 104-1814CLDNA Series, User Manual

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Appendix
104­1814CLDNA Series ­ 39 ­
Appendix
Watchdog Programming Guide
This board provides a programmable watchdog timer (WDT) up to 255 levels and
time by minute or second. Watchdog timer overtime event can be programmed to
reset system or generate maskable interrupts.
The available IRQ numbers for this board are: 3, 4, 5, 7, 9, 10 and 11.
Before using, please modify the corresponding IRQ number in PCIPnP of BIOS
Setup interface into “Reserved”.
The following describes WDT program in C language. The steps to program WDT are
listed as follows:
Ø
Enter WDT programming mode
Ø
Set WDT operating mode/enable WDT/disable WDT
(1) Enter WDT programming mode.
#define INDEX_PORT 0x2E
#define DATA_PORT 0x2F
outportb(INDEX_PORT,0x67);
outportb(INDEX_PORT,0x67);
outportb(INDEX_PORT,0x07);
outportb(DATA_PORT,0x08);
outportb(INDEX_PORT,0x30);
outportb(DATA_PORT,0x01);
(2)
Configure
WDT
operating mode, reset mode or interrupt mode:
unsigned char oldval;
outportb(INDEX_PORT,0x70);
oldval = inportb(DATA_PORT);
a. Reset Operating Mode
oldval &= 0xef;
outportb(DATA_PORT, oldval);