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Watch Timer (WT)
Chapter 14
Preliminary User’s Manual U17566EE1V2UM00
14.1.1
Description
The following figure shows the structure of the Watch Timer and its connection
to the Watch Calibration Timer.
Figure 14-1
Watch Timer configuration
As shown in the figure, WT0 is clocked by WTCLK, a clock generated by the
Clock Generator. When WT0 counts down to zero, it generates the INTWT0UV
interrupt.
WT1 is clocked by the interrupts INTWT0UV. When WT1 reaches zero, it
generates the interrupt INTWT1UV.
Two control registers WTnCTL are used to enable the counters. This is done
by setting WTnCTL.WTCE to 1.
As soon as the counters are enabled, it is possible to write a start value to the
reload registers WT0R and WT1R.
WCT is a capture/compare timer. In this application, it measures the time
between two INTWT0UV interrupts. It is clocked by WCTCLK, another clock
generated by the Clock Generator.
WT0CNT1
CR000
Watch Calibration
Timer
Watch
Timer
16-bit up-counter
TM00
Edge
detector
16-bit down-counter
WT0
16-bit down-counter
WT1
PRM00.ES00[1:0]
WT0CNT0
WT0R
Reload buffer
Internal bus
Internal bus
WT1CNT1
WT1CNT0
WT1R
Reload buffer
WT0CTL.CE
WTCLK
WCTCLK
WT1CTL.CE
TMC00.TMC00[3:2]
Mode selector
INTWT0U
(short interval)
INTWT0U
INTTM00
INTWT1U
(long interval)
Reload
Reload
on match
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