NEC PD78214 - Manual (Page 247)

218
µ
PD78214 Sub-Series
Fig. 7-137 Example of PPG Output Period Made Longer
n3
n1 n2
n4
n2
0H
CRn0
CRn1
TOp
(p = 0,2)
n1
n3
n1
n4
n2
n1
Full count value
n3
n5
TMn
The PPG period is extended when a value,
n2 less than TMn value, n5 is written to
CRn1 here.
TOp becomes inactive when CRn0 coincides with TM0;
otherwise, TOp remains active.
Remark ALVp = 1
(c) If the PPG period is too short for interrupt acceptance, the measures described in (a) and (b) above do not
lead to solution. Consider other measures (such as masking all interrupts and polling interrupt request
flags by software).
(11) In PWM output, the actual pulse width is longer than a value obtained with the approximate expression by
two clock pulses of f
CLK
for the active level, and is shorter than such an approximate value by two clock pulses
of f
CLK
for the inactive level. Take this point into consideration when high-precision output is required or a
high-speed count clock is used. For details, see Section 7.1.7 and Section 7.3.9.
(12) If timer output is disabled (ENTOn = 0: n = 0, 1, or 2, 3), the output level on the TOn (n = 0, 1, or 2, 3) is the inverted
value of the value set in ALVn (n = 0, 1, or 2, 3). Accordingly, note that if timer output is disabled when the
PWM output function or PPG output function is selected, the active level is output.
(13) In PPG output, the actual pulse width is longer than a value obtained with the approximate expression by two
clock pulses of f
CLK
for the active level, and is shorter than such an approximate value by two clock pulses of
f
CLK
for the inactive level. Take this point into consideration when high-precision output is required, the PPG
pulse period is short, or a high-speed count clock is used.
For details, see Section 7.1.8 and Section 7.3.10.
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