UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 695

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

24.5 ERASING PROCEDURE ( PD78P4026KK-T ONLY)
can be written to the program memory.
of approximately 400 nm or shorter through erasure window. Usually, an ultraviolet ray of 254 nm is used. The time required
to completely erase the data contents is as follows:
• Ultraviolet ray intensity x erase time: 28.8 W·s/cm
• Erase time: about 40 minutes (with an ultraviolet lamp of 12,000 W/cm
lamp, remove the filter.
24.6 STICKER ON ERASURE WINDOW ( PD78P4026KK-T ONLY)
or the internal circuits other than EPROM from malfunctioning due to light, attach a protective sticker to the erasure window
when the contents of the EPROM are not being erased.
24.7 QUALITY
for experiments and evaluation of the functions of a trial system.
24.8 CAUTIONS
(1) Ensure that V
(2) Ensure that V
(3) Removing the device while +12.5 V is being applied to V
With the PD78P4026KK-T, the data contents written to the program memory can be erased (to FFH) and new data
To erase the data contents, the erasure window of the program memory must be exposed to a light with a wavelength
performance of the ultraviolet lamp degrades or if the erasure window is dirty.)
To erase the data, place the ultraviolet lamp within 2.5 cm from the erasure window. If a filter is attached to the ultraviolet
To prevent the contents of the EPROM from being erased by accident by light other than that from the erasure lamp,
The PD78P4026KK-T is not intended to be used in your mass-produced systems. Only use the PD78P4026KK-T
DD
PP
does not become +13.5 V or over including overshoot.
is applied before V
CHAPTER 24
PP
, and cut after V
2
PD78P4026 PROGRAMMING
MIN.
PP
.
PP
may have an adverse affect on reliability.
2
used. The longer time may be required if the
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