3820_03 Datasheet, PDF (143/349 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Timer X and timer Y
qTimer Y counter
The Y counter counts the count source. Figure 2.3.16 shows the structure of the timer Y counter.
The contents of the Y counter are decremented by 1 each time a count source is input.
The division ratio of the counter is represented by the following expression.
Division ratio of the Y counter =
1
the Y counter initial value + 1
In the period measurement mode or the pulse width HL coutinuously measurement mode, the value
immediately before reload is held until it is read out once after reload. The count operation is coutinued.
qTimer Y counter
Timer Y (high-order, low-order)
b7 b6 b5 b4 b3 b2 b1 b0
Timer Y (high-order, low-order) (TYH, TYL) [Address 2316, 2216]
B
Functions
At reset R W
0 ^{•Set “000016 to FFFF16” as timer Y count value.} 1
to ^{•The value of the Y counter is decremented}
7 ^{by 1 each time a count source is input.}
•The values of each Y counter are read out
by reading the respective timer Ys.
•The Y counter value immediately before
reload is held until it is read out once after
reload.
(period measurement mode/pulse width HL
continuously measurement mode)
Notes 1 : Write both registers in the order of TYL and TYH.
2 : Read both registers in the order of TYH and TYL.
Fig. 2.3.16 Structure of timer Y counter
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3820 GROUP USER’S MANUAL