m3819 Renesas Electronics Corporation., m3819 Datasheet - Page 189

• Manufacturer Part Number: m3819
• Description: Mitsubishi 8-bit Single-chip Microcomputer 740 Family / 38000 Series
• Manufacturer: Renesas Electronics Corporation.

3. APPENDIX
Fig. 3.2.2 Wiring for clock I/O pins
(3) Wiring for the V
Reason
The V
version is the power source input pin for the built-in
PROM. When programming in the built-in PROM, the
impedance of the V
current for wiring flow into the PROM. Because of this,
noise can enter easily. If noise enters the V
abnormal in struction codes or data are read from the
built-in PROM, which may cause a program runaway.
3.2.2 Connection of a bypass capacitor across the
Connect an approximately 0.1 F bypass capacitor
across the V
Make the length of wiring which is connected to the
Connect an approximately 5 k resistor to the V
Connect a bypass capacitor across the V
Connect a bypass capacitor across the V
Use lines with a larger diameter than other signal
V
pin in serial.
the V
the V
lines for V
PP
version and the eprom version
Vss line and the Vcc line
PP
pin as short as possible.
CC
CC
pin of the One Time PROM and the EPROM
pin with the shortest possible wiring.
pin at equal length .
SS
SS
line and V
line and the V
Noise
PP
PP
pin is low to allow the electric
pin of the One Time PROM
CC
V
X
X
SS
IN
OUT
line.
CC
line as follows:
3819 Group USER’S MANUAL
SS
SS
3.2 Countermeasures against noise
X
X
V
SS
pin and
IN
OUT
pin and
PP
pin,
PP
Separate the V
Fig. 3.2.3 Wiring for the V
Fig. 3.2.4 Bypass capacitor across the V
Oscillator wiring
pattern example
SS
An example of V
underside of a printed circuit board
and the EPROM version
the V
line for oscillation from other V
CC
3819 group
line
P4
V
0
CC
MITSUBISHI MICROCOMPUTER
/V
SS
PP
PP
V
patterns on the
pin of the One Time PROM
Approximately
SS
5k
X
X
V
3819 Group
IN
OUT
SS
SS
lines
SS
line and
175