M30245_06 RENESAS [Renesas Technology Corp], M30245_06 Datasheet - Page 23

• Manufacturer Part Number: M30245_06
• Description: RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES
• Manufacturer: RENESAS [Renesas Technology Corp]

M30245 Group
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
Operation
Note
Figure 2.2.8. Operation timing of timer mode, gate function selected
2.2.3 Operation of Timer A (timer mode, gate function selected)
Timer Ai interrupt
request bit
Count start flag
TAiIN pin
input signal
In timer mode, choose functions from those listed in Table 2.2.2. Operations of the circled items are
described below. Figure 2.2.8 shows the operation timing, and Figure 2.2.9 shows the set-up procedure.
Table 2.2.2. Choosed functions
(1) When the count start flag is set to “1” and the TAi
(2) When the TAi
(3) If an underflow occurs, the content of the reload register is reloaded and the count continues.
(4) Setting the count start flag to “0” causes the counter to hold its value and to stop.
• Make the pulse width of the signal input to the TAi
Count source
Gate function
Pulse output function
FFFF
0000
forms a down count on the count source.
At this time, the timer Ai interrupt request bit goes to “1”.
“H”
16
“1”
“0”
“L”
“1”
“0”
16
n
Item
page 14 of 354
n = reload register content
Set to “1” by software
(1) Start count
IN
pin inputs at “L” level, the counter holds its value and stops.
O
O
O
Internal count source(f
Pulses output
Performs count only for the period in which the TAi
No pulses output
No gate function
Performs count only for the period in which the TAi
(2) Stop count
Cleared to “0” when interrupt request is accepted, or cleared by software
1
/ f
8
/ f
Cleared to “0” by software
32
IN
/ fc
pin not less than two cycles of the count source.
32
IN
)
Set-up
(3) Underflow
pin inputs at “H” level, the counter per-
IN
IN
pin is at “H” level
pin is at “L” level
(4) Stop count
Set to “1” by software
Start count again.
Time
2. Timer A