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64
(M)PPC-240T-HW-01 User Manual
Appendix B: Watchdog
a
PPendIx
B: w
atChdog
1.1 Command Register and Address Description:
Command
Description
0x88
Read watchdog time interval
0x89
Reset watchdog time interval
0x28
Start watchdog
0x29
Stop watchdog
0x2A
Reset watchdog
Address for watchdog:
Watchdog is used to set up time interval and also keep event status. Unit
time interval is 1ms. Time setting requires a word (8 bit) long length. You
can set up watchdog event time from 0 to 0xFFFFFFFE. Write 0xFFFFFFFF to
time interval setting means disable watchdog event. The interval time range
is from 0ms to 497 day (0~0x0xFFFFFFFE)
Address
Description
0x50-0x53
0~0xFFFFFFFE
1.2 Set up Watchdog Time Interval Description:
Step
Action
Description
RW Sample
Code Command
0
Wait IBF clear
x
1
Write 0x89 to
0x66
Send read command
>o 0x66 0x89
2
Wait IBF clear
x
3
Write RAM
address to 0x62
port
Send Watchdog address
0x50~0x53.
>o 0x62 0x50
4
Wait OBF set
x
5
Write watchdog
time interval
value to 0x62
Values from
0~0x0xFFFFFFFE, but
two bit in each address,
please refer to sample
code explanation.
>o 0x62 0x90
Sample explanation:
To set up watchdog time interval to 4 seconds, here are the values that
should be filled in each address.
4sec = 400ms (decimal) = 190 (hexadecimal)
Address
0x50
0x51
0x52
0x53
Data
0x00
0x00
0x01
0x90
