Fujitsu FR81S User Manual
CHAPTER 17: PPG
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER
: PPG
FUJITSU SEMICONDUCTOR CONFIDENTIAL
42
5.2. PWM Operation (Center Aligned Wave Form Selected)
The PWM operation (Center Aligned Wave Form selected) is explained.
During the PWM operation, variable-duty pulses are output at the PPG pin. If the PPG output waveform
selection bit (PCN:OWFS)="1" is selected (Center Aligned Wave Form), the output waveform is generated
by doubling the value of the PPG cycle setting register (PCSR) and the value of the PPG duty setting
register (PDUT)
Figure 5-2 Example of PWM Operation (Center Aligned Wave Form Selected)
CNTE
Activation trigger
PCSR
8000
8000
PDUT
0007
0005
Buffer
(cycle value)
(cycle value)
8000
8000
Down count value
(PTMR)
(PTMR)
7FF8
(1)
(2)Writing
(3)
Enable PPG operation
(4)
(5)Load
(5)Load
(6)Rewriting
(7)Down count
8008
7FF8
(8)Match
(9)Inversion
(12)Clear
(14)Borrow
Inversion
Clear
Inversion
(10)Down count
Duty X2
Cycle X2
Normal plarity
Inverted polarity
PPG pin output
Interrupt factor
Valid edge
Duty match
Counter borrow
Duty match
Counter borrow
Buffer
(Duty value end-point)
(Duty value end-point)
(13)Down count
(11)Match
8008
Buffer
(Duty value)
(Duty value)
Match
Match
7FFC
8006
8006
7FFC
Borrow
(15)Clear
(16)Load
(16)Load
Clear
MB91520 Series
MN705-00010-1v0-E
583