Wondering if anyone actually uses IEEE symbols, or the xx_IEEE libraries in KiCad?
These have not been maintained for years. Rather than spend a lot of effort bringing them up to date, I am wondering if it is time to shuffle them off into the obsolete folder.
IEEE symbols AFAIK are used for PLC designs. It is a good addition IMO and should stay (with the hope for some reworking…) *I do not know their current status…
I use them for MSI functions (counters, registers etc.).
Instead of scrapping them, I’d suggest integrating them into the “normal” libraries as alternative symbols (aka DeMorgan).
This would also clean up the libraries list a bit.
Here’s an example:
Current status is poor. Apart from hidden power pins, they need a complete rework to get to acceptable level.
I recently ran a health check on the libraries: https://gitlab.com/kicad/libraries/kicad-symbols/-/issues/3117
These libraries are ranked 159th and 188th (out of 200) by some quality metric, with <1% symbols passing current KLC checks.
Rank Name num.sym tot.err tot.warn sym.err sym.warn qual% err/sym warn/sym
--------------------------------------------------------------------------------------------------------------
159 74xx_IEEE 185 3015 1591 184 185 0.5% 16.3 8.6
188 4xxx_IEEE 99 1415 1343 99 99 0.0% 14.3 13.6
I kinda like that idea, but the deMorgan variants are being officially deprecated.
I know. There was another thread about this some time ago.
But as I understood it, the “DeMorgan” terminology was being dropped in favour of a more general alternative symbol mechanism, which would fit here.
Or has that been dropped?
No, the official line is that there should be a separate symbol for each shape.
DeMorgan is about different Logic, but at the same library symbols. I mean IEC symbol use DeMorgans style as IEC symbols, and so does IEEE.
I do not think it is wise to mix symbol styles.
But after seeing what is going on in there, i like the idea of a complete rework, or replacement by a new fresh lib…
DeMorgan is still there, a change was about alias terminology to derived symbols…
I don’t understand that sentence, please clarify. A big problem in KiCAD is, that the terminology is hazy, and not everyone reads the same in a name.
That would be nice, but with 406 open issues and 941 open merge requests, the reality is that the xx_IEEE libraries in question will probably never get updated.
Short answer: The DeMorgan feature is going to vanish at some point.
Symbols in the official libs making use of it are probably going to be replaced with two separate _NOR / _NAND symbols instead, according to the style used.
Is there much point in that? Currently you can select deMorgan at a unit level, so the proposed alternative is not a good substitute.
Personally, I would/will not spend any time creating deMorgan symbols. I don’t think anyone uses them anyway. The 74xxGxx library does not have them, I don’t think anyone ever noticed.
OK, so the terminology is:
“Symbol” = the part listed in the library directory, eg, 74VHC1G00.
“Shape” = the graphic depicting the logic symbol.
However, the “symbol” right now ideally has two “shapes”, aka, the DeMorgan equivalents.
This works fine for logic gates, but not for more complex functions.
My suggestion was renaming DeMorgan to “alternate shape” and integrating the 74xx_IEEE into the normal 74xx library, having two shapes for the same symbol.
The whole point is that depending on what you’re doing with it, one variant makes for a more salient schematic than the other, nothing else.
If no one finds the time and/or motivation two draw a second second style, well, then there isn’t going to be one, I guess 
Personally, I think this is pretty much a non-issue and I don’t know if it really warrants further discussion.
Wrong. I built my own 74xxGxx library including the DeMorgan shapes, as I wasn’t happy with the official library.
That’s not the same. One would generally choose IEEE/ANSI style per schematic while the DeMorgan equivalent is more of a per gate decision.
I’d like to come back to this metric.
KiCAD is normally installed on a local PC with the default library. How do you make a ranking on how this library is used? That there’s not a lot of activity on GitLab on those libraries could also mean that they’re OK and that there’s no need to work on them.
At least, that’s my experience.
I’ve used them for some time and have had no problems.
True.
My intention was more of an idea to simplify the library list, which is excessive.
They are kind of OK, as in, they’re not especially buggy overall and generally usable. The main issues are that they don’t match the current visual style and that most make use of hidden power pins.