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MULTIJUNCTION TIMERS
10.3 TOP (Output-Related 16-Bit Timer)
32180 Group User’s Manual (Rev.1.0)
Figure 10.3.15 Typical Operation in TOP Delayed Single-shot Output Mode when Count is Corrected
H'FFFF
H'0000
H'9000+H'0008
H'F000
H'A000
H'F000
H'(F000+0008+1)
H'0008
Write to the
correction register
H'9000
Data inverted
by underflow
Data inverted
by underflow
Correction register
F/F output
TOP interrupt request
due to underflow
Enable bit
Note: • This diagram does not show detailed timing information.
Reload register
Counter
Count clock
Underflow
(first time)
Underflow
(second time)
Enabled
(by writing to the enable bit
or by external input)
Undefined
In the example below, the counter and the reload register are initially set to H’A000 and H’F000, respectively.
When the timer is enabled, the counter starts counting down and when it underflows after reaching the
minimum count, the counter is loaded with the content of the reload register and continues counting down. In
the diagram below, the value H’0008 is written to the correction register when the counter has counted down
to H’9000. As a result of this correction, the counter has its count value increased to H’9008 and counts
(H’F000 + 1 + H’0008 + 1) after the first underflow before it stops.