TC1796
Peripheral Units (Vol. 2 of 2)
Controller Area Network (MultiCAN) Controller
User’s Manual
22-168
V2.0, 2007-07
MultiCAN, V2.0
The application watchdog event occurs when the value of AWDV is decremented and
reaches zero. When writing 0 to AWDV by software, the application watchdog is
switched off without generating an application watchdog event.
AWDR
Application Watchdog Register
(2A4
H
)
Reset Value: 0000 0000
H
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
0
r
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
AWDV
r
rwh
Field
Bits
Type Description
AWDV
[7:0]
rwh
Application Watchdog Value
This bit field contains the current value of the
application watchdog. The falling edge of bit
LTR.LT[7] (1-to-0 transition) indicates that the time of
256 NTUs has elapsed and the application watchdog
value is automatically decremented by 1. If the value
0 is reached after decrementing, an S3 error is
signaled by bit TTIRR.AWDERR. AWDV is not
decremented below 0.
The application watchdog is serviced by the program
by writing a new value to the bit field AWDV. In the
case of a collision between the write by software and
the automatic decrement, the write is taken into
account.
Due to the fact that the counter counting the NTU
(register LTR) is not reset when the application
watchdog is serviced, the total time between the
write to AWDV and the signaling of an S3 error has
an uncertainty of one step of AWDV.
0
[31:8]
r
Reserved
Read as 0; should be written with 0.