r8a66170dd Renesas Electronics Corporation., r8a66170dd Datasheet - Page 6

• Manufacturer Part Number: r8a66170dd
• Description: 4-ch 16-bit Pwm Generator
• Manufacturer: Renesas Electronics Corporation.

R8A66170DD/SP
PWM WAVEFORM OUTPUT
R8A66170 has a built-in 16-bit prescaler and a PWM counter. The duty cycle of output pulse can be freely specified by
changing the values of the prescaler and the PWM counter. The output is made in one of three modes (Mode 0, Mode 1,
and Mode 2). The description of these modes is given below.
(1) Mode 0
This mode is selected by writing “0” to D4 and D3 in command 1. Figure 9 shows the block diagram in this mode (for
one channel). The 16-bit PWM counter can be used as an 8-bit PWM counter only in this mode (command 1: D2 = 0).
The setting with PWM resolution = 8-bits must be written to the lower 8 bytes of H register.
In this mode, the H output pulse width is determined by the prescaler register value L and PWM register value M.
The PWM output cycle time is determined by the prescaler register value L, irrespective of the PWM register value M.
(See Fig.4)
Fig.4 (When H width polarity is “H”)
REJ03F0272-0100 Rev.1.00 Apr.01.2008
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PWM output
Internal signal
Oscillator source
Prescaler output
(PWM clock)
(at L = 1)
M=65534
M=65535
( ): When PWM resolition is 8-bits
(254)
(255)
M=0
M=1
M=2
M=3
・
・
・
"H"
"L"
f (X
L+1
f (X
L+1
IN
f (X
IN
)
)
・M
1
IN
)
T
f(X
L
M
A
IN
) :Oscillator frequency (MHz)
:
:Prescaler set value
:
:
Cycle time (μs)
Ｈ width set value
PWM resolution (8 or 16)
f (X
L+1
IN
)
・(2
A
-1)