Figure 14.4A Ppg Output Operation, Output Waveform - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

14.4 Operations
(2) PPG output operation
In this block, the ch0 PPG is activated to start counting when '1' is written to bit 7 (PEN0) of the PPGC0
(PWM operation mode control) register. Similarly, the ch1 PPG is activated to start counting when '1' is
written to bit 15 (PEN1) of the PPGC1 register. Once the operation has started, counting is terminated by
writing '0' to bit 7 (PEN0) of PPGC0 or in bit 15 (PEN1) of PPGC1. Once the counting is terminated, the
pulse output is maintained at the L level.
In 8-bit prescaler + 8-bit PPG mode, do not set ch1 to be in operation while ch0 operation is stopped.
In 16-bit PPG mode, ensure that bit 7 (PEN0) of PPGC0 register and bit 15 (PEN1) of PPGC1 register are
started or stopped simultaneously. The figure below is a diagram of PPG output operation. During PPG
operation, a pulse wave is continuously output at a frequency and duty ratio (the ratio of the H-level period
of the pulse wave to the L-level period). PPG continues operation until stop is specified explicitly.
PEN
Output pin
PPG
(Start)
(3) Reload value and pulse width
The width of the output pulse is determined by adding 1 to the reload register value and multiplying it by
the count clock cycle. Note that when the reload register value is 00
during 16-bit PPG operation, the pulse width is equivalent to one count clock cycle. In addition, note that
when the reload register value is FF
clock cycles. When the reload register value is FFFF
equivalent to 65536 count clock cycles. An example of pulse width calculation is given below.
P1=T X (L+1)
Ph=T X (H+1)
202 Chapter 14: 8/16-Bit PPG
2.Starts operation based on PEN (from Lside).
T X (L+1) T X (H+1)

Figure 14.4a PPG output operation, output waveform

during 8-PPG operation, the pulse width is equivalent to 256 count
H
L : PRLL value
H : value
T : Input clock cycle
Ph : High pulse width
Pl : Low pulse width
L : PRLL value
H : PRLH value
: Input from peripheral clock (∅, ∅/4, ∅/16)
T
or timer base counter (depending on the
clock selection by PPGC)
during 8-bit PPG operation or 0000
H
during 16-bit PPG operation, the pulse width is
H
H
MB90580 Series