Steve,
Is there a reason why you're trying to design your own 2708 programmer instead of
using a commercail one? I have a DATA I/O model 19 with a Gang Programming Module and 2708
personality module if you need to use it.
Joe
At 08:21 AM 5/6/02 -0700, you wrote:
I obtained a bunch of 2708 UVEPROM's, and I'd
like to
be able to program them. As you may know, they require
a different algorithm than the 2716 and on, and three
voltages, +5, +12, and -5.
I'm building a little board that will program 1/2 (the
upper or lower) of a 2716 to a 2708 (I can program
2716's). But I can't find a description of the
algorithm that is detailed enough. What I think I know
is:
1. The /OE line must be high
2. select address and data (start at addr 0)
3. bring PGM line from 0 to 27 volts for 1 mSec, then
drop back to 0 (this seems very strange)
4. repeat 100 times per address (not all at once,
increment the address lines and loop to avoid
"overheating" a byte.
5. drop /OE and verify.
Does anybody have an authoritative description, and a
current requirement for the +5, +12, -5, and
programming pulse? Thanks.
__________________________________________________
Do You Yahoo!?
Yahoo! Health - your guide to health and wellness
http://health.yahoo.com