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I want to program some ATF16V8B chips for a project. Naturally I don't have a programmer. No problem, I'll homebrew it with a Raspberry Pi. It will be fun.

I only need one thing - I need the programming waveforms. Specific sequence enter programming mode, what voltage to apply and for what duration for each byte to be programmed, etc. All the stuff that they used to put in the datasheets before they replaced that whole section with "Program PLDs using a programmer".

Can anyone provide?

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  • \$\begingroup\$ There was never anything there; it has always been proprietary. \$\endgroup\$
    – Ignacio Vazquez-Abrams
    Commented Nov 19, 2016 at 15:02
  • \$\begingroup\$ @IgnacioVazquez-Abrams Even for a JEDEC standard SPLD like the 16V8? \$\endgroup\$
    – ThreePhaseEel
    Commented Nov 19, 2016 at 16:07
  • \$\begingroup\$ Also, SPLD devices are terribly obsolete -- can you post more details about your usecase for them? (Perhaps replacing them with a JTAGable device such as a more modern CPLD would be a better option) \$\endgroup\$
    – ThreePhaseEel
    Commented Nov 19, 2016 at 16:08

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The programming algorithm for standard GALs, including the 16V8, is documented on this web page. It's too long to reproduce in its entirety here, but there are a couple of "quirks" that will make it difficult to perform using a Raspberry Pi:

  1. The GAL is a 5V part. The Raspberry Pi uses 3.3V I/O.

  2. To program the GAL, you have to supply 12V to the EDIT pin, and an even higher programming voltage (14 to 16V, depending on the part) on another pin.

My advice? Get a prebuilt programmer to handle it for you. I use a TL866 USB programmer, which can handle GALs as well as many other programmable parts (parallel EEPROMs, serial flash, AVRs and other microcontrollers...). It's a handy thing to have around.

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