Outline Of Each Mode Of Tid - Renesas M32R/ECU Series User Manual

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10.7.6 Outline of Each Mode of TID

Each mode of TID is outlined below. TID modes can be selected from the following, only one at a time.
(1) Fixed period count mode
In fixed period count mode, the timer uses a reload register to generate an interrupt request at intervals of
(reload register set value + 1).
When the timer is enabled (by writing to the enable bit in software) after setting the reload register (initial
value being undefined), the counter is loaded with the content of the reload register and starts counting
synchronously with the count clock. The counter counts down and when it underflows after reaching the
minimum count, the counter is loaded with the content of the reload register and continues counting. To stop
the counter, disable count by writing to the enable bit in software. An interrupt request can be generated each
time the counter underflows.
The (reload register set value + 1) is effective as count value.
Count clock
Enable bit
H'FFFF
Counter
H'0000
Reload register
TID0 interrupt request
due to underflow
Note: • This diagram does not show detailed timing information.
Figure 10.7.3 Typical Operation in TID Fixed Period Count Mode
Enabled
(by writing to the enable bit)
H'E000
H'(E000-1)
Count down from
the reload register
Undefined
value
H'E000
MULTIJUNCTION TIMERS
10.7 TID (Input-Related 16-Bit Timer)
Underflow
(first time)
H'(E000-1)
H'E000
Count down from
the reload register
set value set value
10-145
Underflow
(second time)
H'(E000-1)
Count down from
the reload register
set value
32180 Group User's Manual (Rev.1.0)