Compatibility between Lattice GAL16V8 (obsolete) and Atmel ATF16V8 (suggested replacement)

Question

Can anyone advise on the compatibility between these two nominally similar PLDs? Are there any 'gotchas'?

In particular, are the programming specifications identical i.e. can I use a GAL programmer to program the Atmel device?

I have a GAL programmer, but am struggling to find the appropriate specifications to see if I can program the ATF device as if it was a GAL...

I appreciate that this is old technology, but I have a part replacement problem, and want to use reputable devices.

With many thanks in anticipation...

jc2048 · Answer

It's not easy to say. I've got an old Lattice GAL databook, but it doesn't give any programming information for the device in the datasheet. They really didn't expect you to be building your own programmer. Back then (early 1990s) the company I worked for had a programmer and it had long menus of manufacturers and all their parts including GALs. We even had a subscription to keep it all updated for the latest devices. The memory is an EEPROM cell and it needs a high voltage to give the electrons enough energy to tunnel. I presume that there was some variation between the manufacturers for the voltages for the erase and then the subsequent writes. If it's for something that has to be reliable and work over the long term, you'd probably best look for a certified programmer for the replacement part (or maybe find someone to program them for you if it's just a couple of devices). If it's not critical, try it and see what happens (though the programmer might not let you - didn't the devices have a manufacturer code in them?)