M34282E2GP MITSUBISHI [Mitsubishi Electric Semiconductor], M34282E2GP Datasheet - Page 22

• Manufacturer Part Number: M34282E2GP
• Description: SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

LIST OF PRECAUTIONS
22
Noise and latch-up prevention
Connect a capacitor on the following condition to prevent noise
and latch-up;
• connect a bypass capacitor (approx. 0.01 F) between pins
• equalize its wiring in width and length, and
• use the thickest wire.
In the One Time PROM version, port E
pin. Connect this pin to V
which is assigned to E
shortest distance.
Notes on unused pins
(Note in order to set the output latch to “0” to make pins open)
• After system is released from reset, a port is in a high-
• To set the output latch periodically is recommended
(Note when connecting to V
• Connect the unused pins to V
Timer
• Count source
• Watchdog timer
• Writing to reload register R1
• Timer 1 count operation
• Stop of timer 2
• Writing to reload register R2H
• Timer 2 carrier wave output function
Program counter
Make sure that the program counter does not specify after the
last page of the built-in ROM.
V
impedance state until the output latch of the port is set to
“0” by software.
Accordingly, the voltage level of pins is undefined and the
excess of the supply current may occur.
because the value of output latch may change by noise or
a program run away (caused by noise).
distance and use the thick wire against noise.
Stop timer 1 or timer 2 counting to change its count source.
Be sure that the timing to execute the WRST instruction in
order to operate WDT efficiently.
When writing data to reload register R1 while timer 1 is
operating, avoid a timing when timer 1 underflows.
When the bit 5 of the watchdog timer (WDT) is selected as
the timer 1 count source, the error of maximum ± 256 s
(at the minimum instruction execution time : 8
generated from timer 1 start until timer 1 underflow. When
programming, be careful about this error.
Avoid a timing when timer 2 underflows to stop timer 2.
When writing data to reload register R2H while timer 2 is
operating, avoid a timing when timer underflows.
When to expand “H” interval of carrier wave is valid, set “1”
or more to reload register R2H.
DD
and V
SS
at the shortest distance,
2
/V
SS
PP
SS
through the resistor about 5 k
pin as close as possible at the
and V
SS
DD
and V
)
2
is also used as V
DD
at the shortest
s) is
MITSUBISHI
ELECTRIC
PP
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
4282 Group