m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 118

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

Note: The counter does not count while the TAi
Fig. 7.3.4 Example of operation with gate function selected
Table 7.3.2 Count valid levels
7.3.3 Select function
The following describes the gate and pulse output functions.
n : Reload register’s contents
(1) Gate function
input signal
TAi
The counter counts while the count start bit = “1” and the TAi
The counter stops counting while the TAi
value is retained.
Gate function select bits
to 5A
depending on the TAi
to the TAi
pulse width equal to or more than two cycles of the count source.
The gate function is selected by setting the gate function select bits (bits 4 and 3 at addresses 56
Figure 7.3.4 shows an example of operation with the gate function selected.
When selecting the gate function, set the port P6, P2, and P4 direction registers’ bits which correspond
IN
b4
1
1
pin’s
Count start bit
Timer Ai interrupt
16
Invalid level
Count valid
, D6
request bit
IN
FFFF
0000
16
level
pins for the input mode. Additionally, make sure that the TAi
to DA
n
16
16
b3
16
0
1
) to “10
IN
pin’s input signal. Table 7.3.2 lists the count valid levels.
Set to “1” by software.
2
IN
” or “11
pin’s input signal is not at the count valid level, and the counter
Starts counting.
7905 Group User’s Manual Rev.1.0
While TAi
While TAi
2
Count valid level (Duration while counter counts)
.” The gate function makes it possible to start or stop counting
IN
IN
IN
IN
Stops counting.
pin’s input signal is not at the count valid level.
pin’s input signal level is at “L” level
pin’s input signal level is at “H” level
pin’s input signal is at the count valid level.
IN
pin’s input signal has a
Cleared to “0” when
interrupt request is
accepted or cleared
by software.
7.3 Timer mode
TIMER A
Time
7-15
16