UPD75312B Datasheet, PDF (76/77 Pages) NEC – 4-BIT SINGLE-CHIP MICROCOMPUTER

µPD75312B, 75316B
NOTES FOR CMOS DEVICES
1 PRECAUTION AGAINST ESD FOR SEMICONDUCTORS
Note: Strong electric field, when exposed to a MOS device, can cause destruc-
tion of the gate oxide and ultimately degrade the device operation. Steps
must be taken to stop generation of static electricity as much as possible,
and quickly dissipate it once, when it has occurred. Environmental control
must be adequate. When it is dry, humidifier should be used. It is recom-
mended to avoid using insulators that easily build static electricity. Semi-
conductor devices must be stored and transported in an anti-static con-
tainer, static shielding bag or conductive material. All test and measure-
ment tools including work bench and floor should be grounded. The opera-
tor should be grounded using wrist strap. Semiconductor devices must
not be touched with bare hands. Similar precautions need to be taken for
PW boards with semiconductor devices on it.
2 HANDLING OF UNUSED INPUT PINS FOR CMOS
Note: No connection for CMOS device inputs can be cause of malfunction. If no
connection is provided to the input pins, it is possible that an internal input
level may be generated due to noise, etc., hence causing malfunction.
CMOS devices behave differently than Bipolar or NMOS devices. Input
levels of CMOS devices must be fixed high or low by using a pull-up or pull-
down circuitry. Each unused pin should be connected to VDD or GND with a
resistor, if it is considered to have a possibility of being an output pin. All
handling related to the unused pins must be judged device by device and
related specifications governing the devices.
3 STATUS BEFORE INITIALIZATION OF MOS DEVICES
Note: Power-on does not necessarily define initial status of MOS device. Pro-
duction process of MOS does not define the initial operation status of the
device. Immediately after the power source is turned ON, the devices
with reset function have not yet been initialized. Hence, power-on does
not guarantee out-pin levels, I/O settings or contents of registers. Device
is not initialized until the reset signal is received. Reset operation must be
executed immediately after power-on for devices having reset function.
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