IXXBB1 Fujitsu Microelectronics, Inc., IXXBB1 Datasheet - Page 23

• Manufacturer Part Number: IXXBB1
• Description: 32-bit Proprietary Microcontroller Cmos Fr60 Mb91301 Series
• Manufacturer: Fujitsu Microelectronics, Inc.

Preventing Latchup
Power supply pins
Crystal oscillators
Treatment of NC and OPEN pins
Treatment of unused input pins
Mode pins (MD0 to MD2)
Remarks for External Clock Operation
When CMOS integrated circuit devices are subjected to applied voltages higher than V
pins, or to voltages lower than V
and V
increase dramatically and may destroy semiconductor elements. In using semiconductor devices, always take
sufficient care to avoid exceeding maximum ratings.
Devices with multiple V
providing internal connections between pins at the same potential. However, in order to reduce unwanted
radiation, prevent abnormal operation of strobe signals due to a rise in ground level, and to maintain the total
output current ratings, all such pins should always be connected externally to power supply or ground. Also,
ensure that the impedance of the V
In addition, it is recommended that a bypass capacitor of approximately 0.1 F be connected between V
V
Noise in proximity to the X0 and X1 pins can cause abnormal operation in this device. Printed circuit boards
should be designed so that the X0 and X1 pins, crystal (or ceramic) oscillator, and bypass capacitor connected
to ground are placed as close together as possible.
Also, to ensure stable operation, it is strongly recommended that the printed circuit board art work be designed
such that the X0 and X1 pins are surrounded by ground.
Please ask the crystal maker to evaluate the oscillational characteristics of the crystal and this device.
Pins marked as "NC" or "OPEN" must be left open-circuit.
If unused input pins are left open, abnormal operation may result. Any unused input pins should be connected
to pull-up or pull-down resistors.
These pins should be connected directly to V
due to noise, design the printed circuit board such that the distance between the mode pins and V
as short as possible and the connection impedance is low.
When external clock is selected, supply it to X0 pin generally, and simultaneously the opposite phase clock to
X0 must be supplied to X1 pin. However, in this case the stop mode must not be used (because X1 pin stops at
“H” output in stop mode) .
When operating at 12.5 MHz or less, the microcontroller can be used with the clock signal supplied only to pin X0.
“Using an external clock (normal) and (12.5 MHz) ” shows examples of how the MB91301 uses the external clock.
SS
. Connect the capacitor close to the V
SS
, a phenomenon known as latchup can occur. When a latchup condition occurs, the supply current can
CC
and V
SS
SS
, as well as when voltages in excess of rated levels are applied between V
supply pins are designed to prevent problems such as latchup occurring by
CC
and V
CC
and V
SS
CC
connections to the power supply are as low as possible.
or V
SS
SS
pins.
. To prevent the device erroneously switching to test mode
MB91301 Series
CC
at input and output
CC
or V
CC
SS
and
CC
is
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