Talk:Logic level

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Active High/Low

Active High/Low and Logic level is different matter in concept. Logic level is refer to the absolute voltage value represent "1" or "0" state. Active High/Low refer to true or false is represented by higher or lower voltage , not by voltage absolute value (which is Logic level). The separate article "Active high and active low" should be the good to mention as different article and should not be redirect to Logic level. "Active high and active low" should have Logic level in see also and vise versa.--Namazu-tron (talk) 02:56, 7 September 2008 (UTC)

Having section "Active state" with in detail is not appropriate, this section may be better to refer "See main article" Active high and active low ( New titile or Negative logic and Pisitive logic (Electronics). Title name "Active high and active low" is tend to miss leading or confusion. In Japanese edition, I have written literary Negative logic (Electronics). see: POSITIVE AND NEGATIVE LOGIC or negative logic is general term in English also.--Namazu-tron (talk) 04:03, 7 September 2008 (UTC)

More sites:[1], [2], [3],[4]--Namazu-tron (talk) 12:25, 7 September 2008 (UTC)

Active high and Active low redirect to this article and I think this is appropriate. I have made some recent improvements to cover these topics. ---Kvng (talk) 18:55, 29 March 2015 (UTC)

Active low naming conventions

This was [User_talk:Kvng#Logic_level|posted] to my talk page. I am replying here. ~Kvng (talk) 18:54, 7 August 2017 (UTC)

Howdy, I noticed you reverted the logic level edit that I'd made. A bar above doesn't work right for ASCII (either netlists or in HDL's) and has become much less used in industry (hence the reference to historical). With so many boards using differential signals, _N has become less used for negative logic in industry to eliminate confusion... I've seen multiple companies switch to _L as a replacemene (hence that edit). —Mrand ^{Talk • C} 16:37, 7 August 2017 (UTC)

Mrand That would useful information to have in the article. It would be really helpful if we could find a citation that supports these statements. Do you have any idea where to look? Also I am curious, why is "_N" incompatible with differential signals?

The other nit I had with your edit was that it was incomplete in that you added "_L" but did not update the example to show how that is actually used. Of course I would have fixed that, not reverted, if I were able to verify your other changes. ~Kvng (talk) 18:54, 7 August 2017 (UTC)

Kvng It's that reserving _N for differential signals makes for easier filtering of names. If _N is used for both differential and negative logic, now you have to manually filter out the negative logic to find your differential signals (which typically need to be handled differently, along with the _P leg). As for citations, there are random references across the internet. A college class | here], various forum posts there. As for something reasonably definitive, the best I can find is page 9 (or 10) of this: https://wiki.electroniciens.cnrs.fr/images/Xilinx_HDL_Coding_style.pdf —Mrand ^{Talk • C} 15:39, 11 August 2017 (UTC)

Thanks for the background. I have restored your contribution and improved it. ~Kvng (talk) 13:33, 17 August 2017 (UTC)

R/W slash convention

In this edit, the slash convention in R/W is changed to R/(W). However, I think this line originally intended to say that R/W may be interpreted as a combination of R (active high read) and /W (active low write), even if something like R/W (with the slash indicating separation rather than negation in this case) is also common and clearer. If this is right (citation needed), the paragraph should be reverted (and clarified to explain this because it is not obvious). @Wtshymanski: any comments/opinions? —Cousteau (talk) 16:14, 12 March 2018 (UTC)

I've never assumed "R/W" is notation that indicates (due to the slash) active-low write and I don't think that would be a safe assumption to make. I'm happy to be contradicted with some citations. I think for now it would be best to strike the whole statement. ~Kvng (talk) 14:30, 15 March 2018 (UTC)

Drs. Horowitz and Hill in the 2nd edition of "The Art of Electronics" seem to like R/(W), such as in figure 11.10 on page 763. R/W, on the other hand, is just stupid. --Wtshymanski (talk) 16:44, 15 March 2018 (UTC)

The paragraph does say "The slash convention is also used...", and the "slash convention" is the use of a slash to imply negation. If negation is indicated with an overline and the slash is only being used to indicate separation then it's not the same slash convention but a different one, so I'd remove the word "convention". I'll look for sources backing this "high/low" notation because I faintly recall seeing them somewhere, but then again it is possible that it was just in this very article. —Cousteau (talk) 11:30, 16 March 2018 (UTC)

After a brief lookup, it would seem that most references to R/W signals typeset them as R/W, including the I²C specification. I did find one datasheet where A/B is consistently used to denote "A when high/1, B when low/0", but nothing explicitly describing this notation. —Cousteau (talk) 12:21, 16 March 2018 (UTC)

I was having the same trouble as Cousteau with the also used description. I have reordered things in this section recast the statement to avoid an unclear also reference. Feel free to revert and discuss if this does not look like an improvement. ~Kvng (talk) 13:40, 19 March 2018 (UTC)

Coordinated revision of three articles suggested

Please see the paragraph ' 3. The concepts "positive-true logic" and "negative-true logic" ' in my section "Less esoteric usage and better explanation required" in talk:Open collector. — Preceding unsigned comment added by Hedles (talk • contribs) 15:34, 12 February 2020 (UTC)