Electronics > FPGA

Reading the programming of PAL chips

<< < (3/3)


--- Quote from: AK6DN on January 26, 2024, 01:17:51 am ---As an example, my TopMaxII supports programming 16L8 PAL devices. Here is a dump of the fuse array of a National 16L8 device.
Pretty much all the vendors of 16L8/16R* devices used compatible fuse map arrays, so one could reprogram an MMI 16L8 with a National 16L8 fusemap, for example.
If you look at an old datasheet for a 16L8 device they will typically have a logic diagram with labeled fuses.
See attached for an example diagram. It shows the location of each of the 2048 fuses listed above.

--- End quote ---

Great information, thanks! I will definitely try this with my Xeltek, which apparently supports reading these. I'm sure I won't so lucky and they may have some security in place to make it fail.

--- Quote from: c64 on January 26, 2024, 03:24:01 am ---
--- Quote from: PCB.Wiz on January 26, 2024, 12:19:14 am ---You could make an adaptor that does what you say, "read the PAL chip like a 27C020 EEPROM", but you need to map the PLD pins to a suitable memory.
Complicating things is that some IO might be used as inputs, so a circuit of the original unit helps here.

--- End quote ---
Or output enable.
Need to use series resistors and then read the value back.

--- End quote ---

Yep I will keep this in mind as well as PCB.Wiz's warning.

The website is still there! But SSL is broken. You can try pure http:



[0] Message Index

[*] Previous page

There was an error while thanking
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod