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CHAPTER 14 16-BIT RELOAD TIMER (WITH EVENT COUNT FUNCTION)
■ Input Pin Functions of 16-bit Reload Timer (in Internal Clock Mode)
The TIN pin can be used as either a trigger input or a gate input when an internal clock is selected as the
clock source. When used as a trigger input, input of an active edge causes the timer to load the reload
register contents to the counter and then start count operation after clearing the internal prescaler. Input a
pulse width of at least 2T (T is the machine cycle) to TIN.
Figure 14.3-2 shows the trigger input operation of 16-bit reload timer.
Count clock
TIN
Prescaler clear
Counter
Load
When used as a gate input, the counter only counts while the active level specified by the MOD0 bit of the
control register is input to the TIN pin. In this case, the count clock continues to operate unless stopped.
The software trigger can be used in gate mode, regardless of the gate level. Input a pulse width of at least
2T (T is the machine cycle) to the TIN pin. Figure 14.3-3 shows the gate input operation of 16-bit reload
timer.
Count clock
TIN
Counter
■ External Event Counter
The TIN pin functions as an external event input pin when an external clock is selected. The counter counts
on the active edge specified in the register. Input a pulse width of at least 4T (T is the machine cycle) to the
TIN pin.
232
Figure 14.3-2 Trigger Input Operation of 16-bit Reload Timer
Rising edge detected
0000
H
2T to
2.5T
Figure 14.3-3 Gate Input Operation of 16-bit Reload Timer
When MOD0 = 1 (Count when "H" is input)
Reload data
-1
-1
-1
-1
-1
-1
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