UPD78P322 datasheet(21/56 Pages) NEC

21 / 56 page

µPD78P322

ERASURE CHARACTERISTICS (FOR

µPD78P322K/KC/KD ONLY)

The data written into the

µPD78P322K/KC/KD program memory can be erased (FFH) and new data can be

rewritten into the memory.

To erase data, apply light with a wavelength shorter than 400 nm to the window. Normally, apply ultraviolet rays

having the 254-nm wavelength. The radiation amount required to completely erase data is as follows:

• Ultraviolet strength x erasure time: 15 W•s/cm2 or more

• Erasure time:

15 to 20 minutes when a 12,000

µW/cm2 ultraviolet lamp is used. However, the time may be

prolonged due to ultraviolet lamp performance deterioration, dirty window, etc.

For erasure, place an ultraviolet lamp at a position within 2.5 cm from the window. If a filter is attached to the

ultraviolet lamp, remove the filter before applying ultraviolet rays.

OPAQUE FILM ON ERASURE WINDOW (FOR

µPD78P322K/KC/KD ONLY)

If the

µPD78P322K/KC/KD window is exposed to sunlight or fluorescent lamp light for hours, EPROM data may

be erased and the internal circuit may operate erroneously. To prevent such accidents from occurring, put a

protective seal on the window.

A protective seal whose quality is guaranteed by NEC is attached to every EPROM version with window at

shipment.

ONE-TIME PROM VERSION SCREENING

The one-time PROM versions (

µPD78P322GF-3B9, 78P322GJ-5BJ, 78P322L) cannot be completely tested by

NEC for shipment because of their structure. For screening, it is recommended to verify PROM after storing the

necessary data under the following conditions:

Storage temperature

Storage time

125˚C

24 hours

NEC provides chargeable services ranging from one-time PROM writing to marking, screening and verification

for QTOP microcontroller products. For details, contact an NEC sales representative.

UPD78P322 Datasheet(PDF) 21 Page - NEC