3874 Group User’s Manual
7
Built-in PROM version
SUPPLEMENT Rev.A
5. Notes on using built-in PROM version
(1) All products of built-in PROM version products
s Notes on programming
q When writing the contents of the PROM, use a dedicated programming adapter. This permits using a
general-purpose PROM programmer.
q The programming algorithm of the built-in PROM version is equivalent to the M5M27C256K and
M5M27C101. Since there is no device identification code on the device, the programming conditions of
EPROM programmer are not set automatically. As a high voltage is used for programming, be careful
not to apply overvoltage to pins. Special care must be exercised at power on.
a. Programming voltage: 12.5 V
b. Switch setting of programming adapter: SW1 = OFF
SW2 = OFF
SW3 = OFF
c. Address setting for PROM programmer: The start address is 108016.
The end address is FFFD16.
s Note on using the port P97/INT0
q We recommend that port P97/INT0 not be used for your application purposes to improve noise
immunity. Therefore, connect 5 k
resistor from this pin to VSS.
When using port P97/INT0, please connect 5 k
resistor in series with application circuit.
The mask version does not have this limitation.
(2) EPROM version
s Notes on erasing
q Contents of the window EPROM are erased throuth an ultraviolet light source of the wavelength 253.7
nm. At least 15 J/cm2 are required to erase EPROM contents.
q Sunlight and fluorescent light include light that may erase the information written inthe built-in PROM.
When using the EPROM version in the read mode, be sure to cover the transparent glass portion with
a seal.
q This seal to cover the transparent glass portion is prepared on our side. Be careful not to bring the seal
into contact with the microcomputer lead wires when covering the portion with the seal because this
seal is made of metal (alminum).
q Before erasing data, clean the transparent glass. If any finger stain or seal adhesive is stuck to the
transparent glass, this prevents ultraviolet rays from passing, thereby affecting the erase characteristic
adversely.
q When erasing user’s program, the firmware is erased too at the same time.
s Note on mounting
q To mount the EPROM version for a purpose othe than evaluation, use a suitable mouting socket. When
mouting a ceramic package on the socket, fix it securely with silicone resin.