anteo c

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9 years, 6 months ago.

writing to and reading from eprom

i have also checked the forum but what i only find is writing to and reading from eeprom like for example here

https://developer.mbed.org/questions/4195/writing-and-reading-to-and-from-EEPROM/ where this library https://developer.mbed.org/users/bborredon/code/eeprom/file/925096a4c7f0/eeprom.cpp is referenced.

What i want to do is write to and read from (E)PROM (one time programmable memory) like for example this one http://www.kessler-electronic.de/Halbleiter/integrierte_Schaltkreise/Speicher/EPROMs/CMOS/27C040-100_EPROM__M27C4001-10F1_i665_14637_0.htm

Is there some library or example in mbed for it or is there no difference between the two memory types so i can use the library above?

thnx

1 Answer

Sanjiv Bhatia
9 years, 6 months ago.

Hi Anteo. The referenced EPROM devices are very old style and the one you show is UV (ultraviolet lamp) erasable only. That is, first you must have special programming tools to program the target memory device and if there is a fault or you wish to erase the device, you will then need to source a UV lamp and allow that lamp to erase the target device (takes maybe 5-15 minutes - varying with the lamp properties). DO NOT EVER LOOK INTO THE UV LAMP as it can cause permanent eye damage / blindness. That is another reason to avoid working with this older technology.

Suggestion - if you must work with such target memory devices, search out a low cost finished product from Aliexpress, Ebay, etc. Many are under $100 USD. It is not impossible to make your own such device since the more modern version of these memory devices are now electrically erasable. Search for the 28F / 49F series or similar.

Example: http://www.mouser.com/catalog/specsheets/Atmel_AT49F040.pdf

These are the same devices but can R/W often with lower voltages yet are able to function in the same footprint. If you have specifics, post back and will try to help.

The library from MBED supports I2C serial memory devices. They are NOT the same as your requested PARALLEL memory devices.

Are you trying to service an older piece of equipment ?

Accepted Answer

Thanks Sanjiv for your answer and sorry for replying so late. Well we are trying to evaluate something that partially does not depend on our decision and wanted to know if mbed supports EPROM devices.

posted by anteo c 08 Apr 2016