M38203M4 Datasheet, PDF (140/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Timer X and timer Y
qTimer X counter
The X counter counts the count source. Figure 2.3.14 shows the structure of the timer X counter.
The contents of the X 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 X counter =
1
the X counter initial value + 1
qTimer X counter
Timer X (high-order, low-order)
b7 b6 b5 b4 b3 b2 b1 b0
Timer X (high-order, low-order) (TXH, TXL) [Address 2116, 2016]
B
Functions
At reset R W
0 _{•Set “000016 to FFFF16” as timer X count value.} 1
to _{•The value of the X counter is decremented by}
7 _{1 each time a count source is input.}
•When the timer X write control bit is “0,” the
values of TXH and TXL are set to the respec-
tive X latches at the same time.
•The values of each X counter are read out by
reading the respective timer Xs.
Notes 1 : Write both registers in the order of TXL and TXH.
2 : Read both registers in the order of TXH and TXL.
Fig. 2.3.14 Structure of timer X counter
2–54
3820 GROUP USER’S MANUAL