7480 Datasheet, PDF (50/98 Pages) Bi technologies – 7/8 Diameter 5-Turn Wirewound Precision Potentiometer

PRELIMINARY _{NSootimcee: pTahriasmisentroict} ^{alimfinitsalasrpeescuifbicjeactitotno. change.}
MITSUBISHI MICROCOMPUTERS
7480/7481 GROUP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
FUNCTIONAL DESCRIPTION OF PROM VERSION
Reading
__
__
To read the PROM, set the CE and OE pins to “L” level, and set
the address signal (A0 to A14). The stored contents will appear to
__
__
data I/O pins (D0 to D7). When the CE and OE pins are set to “H”
level, the data I/O pins will be put into a floating status.
Writing
__
To write to the PROM, apply “H” to the OE pin and VPP to the VPP
pin to set the program mode. Select addresses to be written to
with address input pins (A0 to A14) and give write data to the data
input
__
pins
(D0
to
D7)
in
8-bit
parallel
form.
In
this
status,
when
the
CE pin becomes “L”, writing will be started.
Notes on Writing
When using a PROM programmer, specify the address range to
address 400016 to address 7FFF16.
When data is written between address 000016 and address
7FFF16, fill addresses 000016 to 3FFF16 with “FF16”.
Erasing
Data can be erased only on the ceramic package with window
M37481E8SS. To erase data on this chip, use an ultraviolet light
source with a 2537 Angstrom wave length. The minimum radiation
power required for erasing is 15W·s/cm².
NOTES ON HANDLING
(1) Sunlight and fluorescent light contain wavelengths capable of
erasing data. For use in the read mode, be sure to cover the
transparent window with a seal. (Ceramic package type)
(2) We can supply the seal with which the transparent window is
covered. Be careful not to allow the seal to contact the micro-
computer lead pins. (Ceramic package type)
(3) Before erasing, clean the transparent glass. If the glass is
smeared with greasy hands or paste, ultraviolet light transmis-
sion will be prevented, having a negative effect on erasing
characteristics. (Ceramic package type)
(4) Since a high voltage is used for writing data, care should be
taken not to apply an overvoltage when turning on the power
source.
(5) For the programmable microcomputers (one-time program-
mable version, version shipped in blank), Mitsubishi does not
perform PROM write testing and screening in the assembly
process and subsequent processes. To improve reliability after
writing, perform writing and testing according to the following
operation flow before use.
Writing with PROM programmer
Screening (Leave at 150°C
for 40 hours.) (Note)
Verify test with
PROM programmer
Function check in target device
Note : The screening temperature is up to 150°C.
Never expose to 150°C exceeding 100 hours.
The M37480E8SP/FP, M37481E8SP/FP and
M37481E8SS are not T versions (mountable on
vehicles), so it is impossible to mount them on
vehicles.
The M37481E8SS is for user program
evaluation, so it is impossible to mount it on
vehicles or on user’s mass-production real
machines.
Fig. 53 Writing and testing for one-time programmable version
49