M30622MA-XXXFP RENESAS [Renesas Technology Corp], M30622MA-XXXFP Datasheet - Page 307

• Manufacturer Part Number: M30622MA-XXXFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY
• Manufacturer: RENESAS [Renesas Technology Corp]

Timer A
292
Operation
Figure 2.2.12. Operation timing of event counter mode, reload type selected
2.2.5 Operation of Timer A (event counter mode, reload type selected)
In event counter mode, choose functions from those listed in Table 2.2.4. Operations of the circled items
are described below. Figure 2.2.12 shows the operation timing, and Figure 2.2.13 shows the set-up
procedure.
Timer Ai interrupt
request bit
Count start flag
Up/down flag
Table 2.2.4. Choosed functions
Note: j = i – 1, but j = 4 when i = 0.
(1) Setting the count start flag to “1” causes the counter to count the falling edges of the count
(2) If an underflow occurs, the content of the reload register is reloaded, and the count continues.
(3) If switching from an up count to a down count or vice versa while a count is in progress, the
(4) Setting the count start flag to “0” causes the counter to hold its value and to stop.
(5) If an overflow occurs, the content of the reload register is reloaded, and the count continues.
Count source
source.
At this time, the timer Ai interrupt request bit goes to “1”.
switch takes effect from the next effective edge of the count source.
At this time, the timer Ai interrupt request bit goes to “1”.
FFFF
0000
“1”
“0”
“1”
“0”
“1”
“0”
16
Item
16
n
n = reload register content
(1) Start count
Set to “1” by software
O
Timer overflow
(TB2/TAj overflow)
Input signal to TAi
(counting falling edges)
Input signal to TAi
(counting rising edges)
Set-up
(2) Underflow
Cleared to “0” when interrupt request is accepted, or cleared by software
Set to “1” by software
IN
IN
Cleared to “0” by
software
Count operation type
Factor for switching
between up and
down
Pulse output function
(3) Switch count
Item
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(4) Stop count
Set to “1” by software
Start count again
O
O
O
Reload type
Free-run type
Content of up/down flag
Input signal to TAi
(5) Overflow
No pulses output
Pulses output
Mitsubishi microcomputers
M16C / 62 Group
Set-up
Time
OUT