From: Uwe Zimmermann
Subject: Re: What would you want in an EPROM programmer?
Date: Wed, 25 Sep 2002 13:01:54 +0200
Organization: Royal Institute of Technology, Stockholm, Sweden
X-Mailer: Mozilla 4.79 [en] (Windows NT 5.0; U)
except for the fact that there is a zillion good designs already out
there, I don't want to disencourage you. I myself wokred out a design a
while ago, but then finally decided to buy a complete kit instead...
some comments to your questions:
Al Borowski wrote:
> I'm in the middle of designing an EPROM programmer.
> 1. The programming voltage is 13V - is this OK for most modern
> EPROMS's? I could make it varible by the PIC, but I don't know if it's
> worth the effort.
no chance, without a programmable voltage I would not dare to use such a
thing. It should at least comply to burning and verifying conditions
according to the spec sheets of different memory chips, i.e. a varibale
supply voltage 5V and 6V of the memory chip and different programming
voltages, at least something like 5V (Flash), 12V, 12.5V and perhaps
14V. Neverheard of any memory chip being programmed with 13V.
> 2. In order to allow many devices to be programmed, I was planning on
> having a header, like an 8 bit ISA slot, on the programmer. Different
> daughterbaords for different devices could be placed into this header.
> I was planning on getting the PIC to recogonize which daughterboard
> had been inserted and adjust the programming parameters accordingly.
> Does this sound like a good idea?
not to me.
If you are planing to build a decent programmer, it should read out the
chip ID to determine the programming parameters. The need to use
different adapters for chips in similar packages increases the
probability of user error while at the same time reducing the ease of
> 3. Since FLASH ROM's are popular nowadays, would it be useful to
> include flash rom support into this thing?
should be fairly easy to implement, once you get the programming voltage
set correctly. The programming algorithms of Flash ROMs are very similar
to those of EPROMS.
> 4. Finally, what LED indicators would be useful? I was thinking power,
> RS-232 comms and Write.
nice add on, but not even worth discussing. Just add those to the
corresponding lines in your design (e.g. TxD, RxD, /PGM) and it will be