485
Watch Timer (WT)
Chapter 14
Preliminary User’s Manual U17566EE1V2UM00
14.3 Watch Timer Operation
This section describes the operation of the Watch Timer counters in detail.
14.3.1
Timing of steady operation
The contents of the reload registers WTnR can be changed at any time,
provided the corresponding counter is enabled. The contents is then copied to
the reload buffer. The counters WTn reload their start value from the buffer
upon underflow.
This is illustrated in the following figure.
Figure 14-2
Reload timing and interrupt generation
D0 and D1 are two different reload values.
Note also that there is a delay between writing to WTnR and making the data
available in the reload buffer, depending on the previous reload value and the
chosen count clock.
D0
D0
D1
D1
D
0
D
0
D
0
D1
D
0
D1
D
0
0000
H
16
-
bit down
counter value
Reload buffer
WTnR
INTWTnUV
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