Signetics PLS173 PLA fuse numbering?

Glen Slick glen.slick at
Thu Sep 22 18:23:01 CDT 2016

A Signetics PLS173 PLA has a total of 2178 programmable fuses:

(32 AND gates for logic terms plus 10 AND gates for control terms)
(24 true/complement inputs plus 20 true/complement inputs/outputs)
= 1848 fuses

(10 OR gates)
(32 AND gates logic term outputs)
= 320 fuses

10 fuses for true/complement output selection

For reference see the PLS173 FPLA Logic Diagram on page 5-70 (page 242
of the PDF) of the Signetics PLD Data Manual 1987

The question is for anyone here that knows: How are these fuses in the
FPLA Logic Diagram numbered as they would be in a JEDEC fuse map file
used to program a device, or when read back from a device? I can't
find that information anywhere.

If I read a PLS173 device into a JEDEC fuse map it should be trivial
to generate the logic equations by hand if the fuse numbering is
known, which is what I want to do.

More information about the cctalk mailing list