Appendix
CPC-1814CLD5NA-N
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Watchdog Programming Guide
The board provides a programmable watchdog timer (WDT) up to 255 levels and time
by minute or second. Watchdog timeout event can be programmed to reset system or
generate maskable interrupts.
The available IRQ numbers for this board are: 3, 4, 7, 9, 10 and 11.
Please modify the corresponding IRQ number in PCIPnP of BIOS Setup
interface into “Reserved” before using.
The following describes WDT program in C language. The steps to program WDT are
listed as follows:
Enter WDT programming mode;
Set WDT operating mode/enable WDT/disable WDT.
(1)
Enter
WDT
Programming Mode
#define INDEX_PORT
0x2E
#define DATA_PORT 0x2F
outportb(INDEX_PORT, 0x87);
outportb(INDEX_PORT, 0x87);
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,0x2d);
oldval = inportb(DATA_PORT);
a.
Configure WDT to reset mode