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APPENDIX
3.4 Notes on noise
(5) Wiring to V
pin of One Time PROM version
PP
In the built-in PROM version of the 4513/4514
Group, the CNV
built-in PROM power supply input pin V
When the V
CNV
pin
SS
Connect an approximately 5 k
the V
pin the shortest possible in series
PP
a n d a l s o t o t h e V
connecting the resistor, make the length of
wiring between the V
pin the shortest possible (refer to Figure
3.4.5)
Note: Even when a circuit which included an
approximately 5 k
Mask ROM version, the microcomputer
operates correctly.
Reason
The V
pin of the One Time PROM ver-
PP
sion is the power source input pin for the
built-in PROM. When programming in the
built-in PROM, the impedance of the V
pin is low to allow the electric current for
writing flow into the PROM. Because of
this, noise can enter easily. If noise enters
the V
pin, abnormal instruction codes or
PP
data are read from the built-in PROM, which
may cause a program runaway.
When the V
pin is also used as the CNV
PP
CNV
SS
Fig. 3.4.5 Wiring for the V
PROM version
3-26
pin is also used as the
SS
pin is also used as the
PP
resistor to
p i n . W h e n n o t
S S
pin and the V
PP
resistor is used in the
pin
SS
Approximately
5k
/V
PP
V
SS
In the shortest
distance
pin of the One Time
PP
4513/4514 Group User's Manual
3.4.2 Connection of bypass capacitor across V
line and V
Connect an approximately 0.1 F bypass capacitor
.
across the V
PP
• Connect a bypass capacitor across the V
and the V
DD
• Connect a bypass capacitor across the V
and the V
DD
• Use lines with a larger diameter than other signal
lines for V
SS
• Connect the power source wiring via a bypass
capacitor to the V
SS
V
V
N.G.
PP
Fig. 3.4.6 Bypass capacitor across the V
and the V
line
DD
line and the V
line as follows:
SS
DD
pin at equal length.
pin with the shortest possible wiring.
line and V
line.
DD
pin and the V
SS
DD
SS
line
DD
SS
pin
SS
pin
SS
pin.
DD
V
DD
V
SS
O.K.
line
SS
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