Aaeon PICO-APL4, User Manual

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Appendix A – Watchdog Timer Programming 70
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PIC
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PL4
A.1 Watchdog Timer Registers
Table 1 : Watch dog relative IO address
Default Value Note
I/O Base
Address
0x2E
I/O Base address for Watchdog operation.
This address is assigned by SIO LDN7
Table 2 : Watchdog relative register table
Register Offset BitNum Value Note
Watchdog
WDTRST#
Enable
0x00 7 1
Enable/Disable
time out output via
WDTRST#
0: Disable
1: Enable
Pulse Width 0x05 0:1 01
Width of Pulse signal
00: 1ms (do not use)
01: 25ms
10: 125ms
11: 5s
Pulse width is must longer
then 16ms.
Signal Polarity 0x05 2 0
0: low active
1: high active
Must set this bit to 0
Counting Unit 0x05 3 0
Select time unit.
0: second
1: minute
Output Signal
Type
0x05 4 1
0: Level
1: Pulse
Must set this bit to 1
Watchdog
Timer Enable
0x05 5 1
0: Disable
1: Enable
Timeout Status 0x05 6 1
1: timeout occurred. Write a
1 to clear timeout status
Timer Counter 0x06
Time of watchdog timer
(0~255)