EEPROM Programmer
news0504
access to lots of old flash eeproms, it would be better for me to
change the design to support eeproms.
Apart from the lack of 12.5V vpp, are there any other things i should
be aware of, any voltages to make other than 5V logic? also are there
some designs out there i can take a peek at?
Michael Baeuerle
>
> I'm designing an eprom programmer, but realised that since i have
> access to lots of old flash eeproms, it would be better for me to
> change the design to support eeproms.
Note that there are different variants of EEPROM and Flash memories.
EEPROM can normally written byte by byte (like EPROM), Flash can only
write whole pages of several bytes at a time!
> Apart from the lack of 12.5V vpp, are there any other things i should
> be aware of, any voltages to make other than 5V logic?
Physically all EEPROM and Flash memories are based on floating gate
MOSFETs. They all need a special Vpp voltage (Example: The AMD 28F010
flash memory needs external +12V programming voltage). Of course there
are devices like the AMD 29F010 that have internal voltage converters
(to create Vpp internally) so you only have to provide +5V externally.
> also are there
> some designs out there i can take a peek at?
Looking at the datasheets of the chips should give you all information
... more than enough to build programming hardware (IMHO).
Here is a datasheet for a 1MBit EEPROM from SGS Thomson:
http://batronix.com/pdf/m28010.pdf
Micha
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