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FUJITSU F2MCTM-16LX User Manual

Page 38

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CHAPTER 1 OVERVIEW

Using external clock

To use external clock, drive the X0 (X0A) pin and leave X1 (X1A) pin open.

Figure 1.7-1 Using External Clock

Precautions for when not using a sub clock signal

If you do not connect pins X0A and X1A to an oscillator, use pull-down handling on the X0A pin, and

leave the X1A pin open.

Notes on during operation of PLL clock mode

If the PLL clock mode is selected, the microcontroller attempts to be working with the free-running

frequency of self-oscillating circuit in the PLL even when there is no external oscillator or external clock

input is stopped. Performance of this operation, however, cannot be guaranteed.

Power supply pins (V

CC

/V

SS

)

If there are multiple V

CC

and V

SS

pins, from the point of view of device design, pins to be of the same

potential are connected the inside of the device to prevent such malfunctioning as latch up.

To reduce unnecessary radiation, prevent malfunctioning of the strobe signal due to the rise of ground

level, and to keep the recommended DC characteristics specified as the total output current, be sure to

connect the V

CC

and V

SS

pins to the power supply and ground externally (see Figure 1.7-2 ).

Connect V

CC

and V

SS

to the device from the power supply source with lowest possible impedance.

It is recommended to connect a capacitor of about 0.1

µF as a bypass capacitor between V

CC

and V

SS

in

the vicinity of V

CC

and V

SS

pins of the device

X0 (X0A)

X1 (X1A)

MB90360 series

Open