MB95310L/370L Series
Document Number: 002-07519 Rev. *A
Page 24 of 80
10. Pin Connection
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Treatment of unused input pins
If an unused input pin is left unconnected, a component may be permanently damaged due to malfunctions or latch-ups. Always pull
up or pull down an unused input pin through a resistor of at least 2 k
. Set an unused input/output pin to the output state and leave
it unconnected, or set it to the input state and treat it the same as an unused input pin. If there is an unused output pin, leave it
unconnected.
■
Notes on handling the external clock pins while using the CR clock
Connect the X0 pin and the X0A pin to the V
SS
pin and leave the X1 pin and the X1A pin unconnected.
■
Power supply pins
To reduce unnecessary electro-magnetic emission, prevent malfunctions of strobe signals due to an increase in the ground level,
and conform to the total output current standard, always connect the V
CC
pin and the V
SS
pin to the power supply and ground
outside the device. In addition, connect the current supply source to the V
CC
pin and the V
SS
pin with low impedance.
It is also advisable to connect a ceramic capacitor of approximately 0.1 µF as a bypass capacitor between the V
CC
pin and the V
SS
pin at a location close to this device.
■
DBG pin
Connect the DBG pin directly to an external pull-up resistor.
To prevent the device from unintentionally entering the debug mode due to noise, minimize the distance between the DBG pin and
the V
CC
or V
SS
pin when designing the layout of the printed circuit board.
The DBG pin should not stay at “L” level after power-on until the reset output is released.
■
RST pin
Connect the RST pin directly to an external pull-up resistor.
To prevent the device from unintentionally entering the reset mode due to noise, minimize the distance between the RST pin and the
V
CC
or V
SS
pin when designing the layout of the printed circuit board.
