M16C62_M Datasheet, PDF (341/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

Timer A
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
2.2.8 Operation of timer A (2-phase pulse signal process in event counter mode,
multiply-by-4 mode selected)
In processing 2-phase pulse signals in event counter mode, choose functions from those listed in Table
2.2.7. Operations of the circled items are described below. Figure 2.2.18 shows the operation timing, and
Figure 2.2.19 shows the set-up procedure.
Table 2.2.7. Choosed functions
Item
Set-up
Item
Set-up
Count operation type
Reload type
O Free run type
Processing 2 phase
Normal processing
pulses (Note)
O 4-multiplication processing
Note: Timer A3 alone can be selected. Timer A2 is solely used for normal processes, and timer A4 is solely used for 4-
multiplication processes.
Operation _{(1) Setting the count start flag to “1” causes the counter to count effective edges of the count source.}
(2) Even if an underflow occurs, the content of the reload register is not reloaded, but the count
continues. At this time, the interrupt request bit goes to “1”.
(3) Even if an overflow occurs, the content of the reload register is not reloaded, but the count
continues. At this time, the interrupt request bit goes to “1”.
Note
• The up count or down count conditions are as follows:
Table 2.2.8. The up count or down count conditions
Up count
Input signal to the
TAiOUT pin
“H” level
“L” level
Rising
Falling
Input signal to the
TAiIN pin
Rising
Falling
“L” level
“H” level
Down
count
Input signal to the
TAiOUT pin
“H” level
“L” level
Rising
Falling
Input signal to the
TAiIN pin
Falling
Rising
“H” level
“L” level
“H”
TAiOUT _{“L”}
“H”
TAiIN
“L”
(1) Start count
FFFF16
000016
Count start flag ^{“1”}
“0”
Timer Ai interrupt _{“1”}
request bit
“0”
Set to “1” by software
(2) Underflow
Time
(3) Overflow
Cleared to “0” when interrupt request is accepted, or cleared by software
Figure 2.2.18. Operation timing of 2-phase pulse signal process in event counter mode, multiply-by-4 mode selected
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