3.1 Built-in PROM version
APPENDIX
3820 GROUP USER’S MANUAL
3–9
3.1.5 Notes on use
Notes on using the built-in PROM version are described below.
(1) All products of built-in PROM version
I
Notes on programming
G
When programming the contents of the PROM, use the dedicated programming adapter. This per-
mits programming with a general-purpose PROM programmer.
At that time, set all of SW1, SW2 and SW3 in the above programming adapter to “OFF.”
G
As a high voltage is used for programming, be careful not to apply overvoltage to pins. Special care
must be exercised at poweron.
I
Notes on reading
When reading out the contents of the PROM, use the dedicated programming adapter as in program-
ming. This permits reading out with a general-purpose PROM programmer.
At that time, set all of SW1, SW2 and SW3 in the programmer to “OFF.”
I
Notes on using port P4
0
When using port P4
0
as an input port in the One Time PROM/EPROM version, connect a resistors
of several k
externally to port P4
0
in series. If this pin is not used, connect a resistor of several k
externally to V
SS
in series (for improvement of the value withstand noise operation failure).
For details, refer to
“3.2 Countermeasures against noise, 3.2.1 Shortest wiring length, (3) Wiring
to the V
PP
pin of the One Time PROM version and the EPROM version.”
(2) EPROM Version
I
Notes on deleting
G
Sunlight and fluorescent lamps include light which may delete programmed information. For use in
the read mode, cover the transparent glass part of the delete window with a seal or others.
G
The seal to cover the transparent glass part is prepared by us.
This seal is metallic (aluminium) for reasons of prevention of information-deleting light and tough-
ness. Be careful not to bring this seal into contact with lead pins of the microcomputer.
G
Before deleting information, clean the transparent glass. Finger marks and seal paste may block
ultraviolet rays and effect delete characteristics.
I
Notes on mounting
G
To mount the EPROM version for a purpose other than evaluation, use a suitable mounting socket.
When mounting a ceramic package on the socket, fix it securely with silicone resin.