Re: gEDA-user: inverted pins?

["John Luciani" <jluciani@xxxxxxxxx>]

For the inverted signals I prefix the pin name with a forward
slash. A reset line that is negative true could be labeled "/RST".

Here is a quick summary of the way I usually make symbols
(assuming a grid box is 100x100 units) ---

* make the pins 100 units long.

For rectangular parts

  * For left and right pins place the anchor point of the pin number
    50 units above the pin and 50 units outside the component
    rectangle. For top and bottom pins place the anchor point of the
    pin number 50 units to the right of the pin and 50 units outside
    the component rectangle. Anchor points are SE for left-side pins,
    SW for top-side and right-side pins, NW for bottom-side pins.

  * center the pin labels by aligning pin label anchor point with the
    pin. Anchor points are W for left-side pins, S for bottom-side
    pins, N for top-side pins and E for right-side pins

  * group related pins 200 units apart. A minimum space of 300 units between
    pin groups.

  * I try to keep inputs on the left, outputs on the right, power on the top,
    and ground on the bottom. Sometimes I will place power and ground on the
    same side leaving sufficient space between them for a decoupling cap.

  * I usually place the refdes in the upper left corner and the mfg part
    number in the lower left corner.

(* jcl *)

On 2/19/06, DJ Delorie <dj@xxxxxxxxxxx> wrote:
>
> Ok, what's the standard for inverted pins in symbols?  How do I (or do
> I) put the bar over the text?  Specifically, I'm adding the pinlabel
> attribute to a pin on a symbol, and having it displayed inside the big
> box that's the "component", and adding the inversion bubble.  But I'd
> like to have the bar over the name, either also or instead, like:
>
>       40   | ___
>     -----()| BHE
>            |
>
> Net names should have the bar over them too, once I get to that point.
>
> Also, is there some standard for:
>
> 1. Where pin numbers get placed
>
> 2. Where pin labels get placed
>
> 3. Spacing and text angle for pins on the top/bottom of box-symbols
>
> I've written a program to extract/insert attributes into .SYM files
> (gattrib seems to want whole schematics, not symbols), using open
> office's spreadsheet to sort/edit/fill.  The script knows where to put
> "new" attributes (you can add a column and it inserts them, plus it
> knows about the standard attributes), assuming I've guessed OK about
> where to put them.
>
> DJ
>


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