
VDX-6318 Windows Embedded Compact 7 - Getting Started Guide
Windows Embedded Compact 7 Getting Started Rev 2.00
Page 108
Using WDT1
WDT1 does not use index and data port to access the watchdog timer registers. It uses I/O port 68H
~ 6DH. WDT1 can be configured to trigger system reset, NMI or IRQ.
WDT1 Control Register
Port 68h
Bit 7
Reserved.
Bit 6
0: Disable WDT0
1: Enable WDT0 (default)
Bit 5-0
Reserved.
WDT1 Signal Select Control Register
Port 69h
Bit 7-4
0000: Reserved
0101: IRQ-7
1011: IRQ-15
0001: IRQ-3
0110: IRQ-9
1100: NMI
0010: IRQ-4
0111: IRQ-10
1101: System reset
0011: IRQ-5
1001: IRQ-12
1110: Reserved
0100: IRQ-6
1010: IRQ-14
1111: Reserved
Bit 3-0
Reserved
WDT1 Control 2 Register
Port
6Ch
6Bh
6Ah
D7……D0
D7……D0
D7……D0
Counter
Most Significant Bit ……………………………………. Least Significant Bit
WDT1 Status Register
Port 6Dh
Bit 7
0: WDT1 timeout event does not happen
1: WDT1 timeout event happens (write 1 to clear this flag)
Bit 6-0
Reserved.
WDT1 Reload Register
Port 67h
Bit 7-0
Write to this port to reload WDT1 internal counter.
Here are the steps to setup WDT1:
2.
Write time into register 6Ah - 6Ch
3.
Select signal from register 69h
4.
Set register 68h Bit 8 to enable WDT1.
To clear the watchdog timer counter:
1.
Write any value to register 67H.