m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 141

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

Count source f
Count operation
PWM period/“H” level width
Count start condition
Count stop condition
Interrupt request occurrence timing
TAi
TAi
Read from timer Ai register
Write to timer Ai register
Note: The trigger is generated with the count start bit = “1.”
TIMER A
7.6 Pulse width modulation (PWM) mode
7.6 Pulse width modulation (PWM) mode
In this mode, the timer continuously outputs pulses which have an arbitrary width. Table 7.6.1 lists the
specifications of the PWM mode. Figure 7.6.1 shows the structure of the timer Ai register, and Figure 7.6.2
shows the structure of timer Ai mode register in the PWM mode.
Table 7.6.1 Specifications of PWM mode
7-38
IN
OUT
pin’s function
pin’s function
i
Item
f
<16-bit pulse width modulator>
<8-bit pulse width modulator>
When the count start bit is cleared to “0.”
At falling edge of PWM pulse
Programmable I/O port pin or trigger input pin
PWM pulse output
An undefined value is read out.
1
, f
Reload register’s contents are reloaded at rising edge of PWM pulse,
and counting continues.
When a value is written to the timer Ai register, it is written to both
of the reload register and counter.
When a value is written to the timer Ai register, it is written only to
the reload register. (Transferred to the counter at the next reload
time.)
Countdown (operating as an 8-bit or 16-bit pulse width modulator)
A trigger generated during counting does not affect the counting.
When a trigger is generated. (Note)
Internal or external trigger can be selected by software.
While counting is stopped
While counting is in progress
7905 Group User’s Manual Rev.1.0
“H” level width =
Period =
Period =
“H” level width =
2
, f
16
, f
64
, f
(2
512
(m + 1)(2
16
, or f
f
–1)
i
f
n(m + 1)
4096
i
[s]
n
f
i
8
–1)
f
i
[s]
Specifications
[s]
[s]
n : Timer Ai register’s set value
m : Timer Ai register’s low-order 8
n : Timer Ai register’s high-order
bits’ set value
8 bits’ set value