
MB90560 series
CHAPTER 12 MULTI-FUNCTION TIMER
337
I
Pulse pin output control
The pulses generated by the operation of the 8/16-bit PPG timer can be output to external pins PPG0
and PPG1.
The external pin output enable can be done by setting bit 5 (POE0) of the PPGC0 register (PPG0
control register) for the PPG0 pin and setting bit 13 (POE1) of the PPGC1 register (PPG1 control
register) for the PPG1 pin. When “0” is written to these bits (initial value), the pulses are not output to
the corresponding external pins; the pins will work as general-purpose ports.
In 16-bit PPG mode, the same waveform is output from PPG0 and PPG1. Thus, the same output can
be obtained by enabling any one external pin.
In 8 + 8-bit PPG mode, the 8-bit prescaler (Ch0 PPG timer) toggle output waveform is output to PPG0,
while the 8-bit PPG waveform (Ch1 PPG timer) is output to PPG1. The Figure 12.4.4-2 below is a
diagram of output waveforms in this mode.
Figure 12.4.4-2 8+8 PPG output operation waveform
L0
L1
H1 :
T
P
H
0:
P
L
0 :
P
H
1:
P
L
1 :
:
:
ch0 PRLL value and ch0 PRLH value
ch1 PRLL value
ch1 PRLH value
Input clock cycle
PPG0 high pulse width
PPG0 low pulse width
PPG1 high pulse width
PPG1 low pulse width
:
P
H
0
P
L
0
P
H
1
P
L
1
PPG0
PPG
1
P
L
0 = T x (L0+1)
P
H
0 = T x (L0+1)
P
L
1 = T x (L0+1) x (L1+1)
P
H
1 = T x (L0+1) x (H1+1)
Note:
Set the same value in ch0 PRLL and ch0 PRLH.