Offpage connector symbols

On Jan 20, 9:16=A0am, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

> =A0 =A0Wouldn't it be simpler to have pads for zero ohm resistors to
> configure the port? =A0Or two positions to put the connector to chose the
> right configuration?

The subsystems are designed by different groups, and the adage about
design resembling organizational structure is completely true.

On Jan 19, 1:17 pm, D Yuniskis <not.going.to...@seen.com> wrote:
> Hi,
>
> As a side-comment to the schematic preferences thread
> (hopefully not another lengthy thread  :> ), I'm curious
> as to what folks use as an offpage connector symbol.
>
> Given that I prefer these to be *at* the edges of the schematic
> *and* given that the signal name will be "outboard" of it,
> I try to use very narrow symbols.  And, since it is common for
> other such "offpage" symbols to be located immediately above
> and/or below, I try to keep the height of this symbol to
> "one intersignal spacing unit" (IsSU?  :> ).
>
> I also like to show direction of signal flow in the symbol.
>
> This has led me to a set of six (<frown>) symbols:
> Output Right
> Input Right (blech!)
> BiDir Right
> and the corollaries for "Left". (I.e., left and right refer
> to the edges of the page at which it is most appropriate to
> place these symbols).
>
> For unidirectional signal flow, I use a pair of "concentric"
> (wrong word) arrow heads.  E.g., >> or <<.  These can be spaced
> close enough (horizontally) together that they occupy very little
> space on the page (i.e., 1 IsSU square).
>
> For BiDir signals, I use one of each arrow head (< + >).
> Since BiDir symbols should occupy the same amount of space
> (an arbitrary but desirable condition I impose), I overlap these
> together.
>
> If they don't overlap much (or, at all), you end up with a
> diamond (<>) or an X (><).  I compromise and end up with
> an asymmetrical "stacked pair of X's" -- sort of like a
> slice out of a DNA helix.
>
> This is intentionally asymmetric -- you could shift one or
> the other arrow head to obtain better symmetry throughout the
> X
> X
> but then placing two or more of these BiDir symbols above each
> other ends up looking like *needlepoint* (can't see where one
> signal begins and the previous one ends!)
>
> Other techniques?

I use a CAD program.  It has "input", "output", "bidirectional", and
"passive" (none of the above, AKA don't care) for off-page and off-
sheet.

I've never seen a reason to change them from the default.

AL

mpm wrote:
> Also, try to avoid all nomenclatures that attempt to describe the
> function (such as "in" or "out", etc..) when the interpretation
> depends on some outside intervention (such as the prespective of the
> tech).
> 
> For example, I wouldn't recommend using "Audio Out Right" because that
> same term won't make any sense when it gets to where it's going.
> Try "Unamplified Audio, R+", or something like that.
> 
> You get the idea.

This is, by far, the best idea that this thread has dredged up!
I'm not sure that it can be done universally, though.  E.g.,
you may *think* your signals are "the end of the line"...

To build on your example, designing a home stereo you would *think*
that "left" and "right" are intuitive *and* descriptive.  Yet,
if someone plugs something else into it, all bets are off.

I frequently have to check manuals when hooking up record/playback
devices to stereos, for example:   is Tape In an input *from*
the tape deck or an output *to* the Input on the Tape deck, etc.

I'll have to reexamine designs I have done over the years to
see how I could have changed things to be less "descriptive"  :>

Thanks!

Hi AL,

LittleAlex wrote:
> On Jan 19, 1:17 pm, D Yuniskis <not.going.to...@seen.com> wrote:
>>
>> As a side-comment to the schematic preferences thread
>> (hopefully not another lengthy thread  :> ), I'm curious
>> as to what folks use as an offpage connector symbol.
> 
> I use a CAD program.  It has "input", "output", "bidirectional", and
> "passive" (none of the above, AKA don't care) for off-page and off-
> sheet.
> 
> I've never seen a reason to change them from the default.

Yes, all of the tools I use do this.  I am just not happy
with their symbol choices.  And, since I can change them,
I have.

E.g., I don't like an output on the right side of the page
drawn as  <

On Wed, 20 Jan 2010 12:23:21 -0800 (PST), LittleAlex
<alex.louie@email.com> wrote:

>On Jan 19, 1:17 pm, D Yuniskis <not.going.to...@seen.com> wrote:
>> Hi,
>>
>> As a side-comment to the schematic preferences thread
>> (hopefully not another lengthy thread  :> ), I'm curious
>> as to what folks use as an offpage connector symbol.
>>
>> Given that I prefer these to be *at* the edges of the schematic
>> *and* given that the signal name will be "outboard" of it,
>> I try to use very narrow symbols.  And, since it is common for
>> other such "offpage" symbols to be located immediately above
>> and/or below, I try to keep the height of this symbol to
>> "one intersignal spacing unit" (IsSU?  :> ).
>>
>> I also like to show direction of signal flow in the symbol.
>>
>> This has led me to a set of six (<frown>) symbols:
>> Output Right
>> Input Right (blech!)
>> BiDir Right
>> and the corollaries for "Left". (I.e., left and right refer
>> to the edges of the page at which it is most appropriate to
>> place these symbols).
>>
>> For unidirectional signal flow, I use a pair of "concentric"
>> (wrong word) arrow heads.  E.g., >> or <<.  These can be spaced
>> close enough (horizontally) together that they occupy very little
>> space on the page (i.e., 1 IsSU square).
>>
>> For BiDir signals, I use one of each arrow head (< + >).
>> Since BiDir symbols should occupy the same amount of space
>> (an arbitrary but desirable condition I impose), I overlap these
>> together.
>>
>> If they don't overlap much (or, at all), you end up with a
>> diamond (<>) or an X (><).  I compromise and end up with
>> an asymmetrical "stacked pair of X's" -- sort of like a
>> slice out of a DNA helix.
>>
>> This is intentionally asymmetric -- you could shift one or
>> the other arrow head to obtain better symmetry throughout the
>> X
>> X
>> but then placing two or more of these BiDir symbols above each
>> other ends up looking like *needlepoint* (can't see where one
>> signal begins and the previous one ends!)
>>
>> Other techniques?
>
>I use a CAD program.  It has "input", "output", "bidirectional", and
>"passive" (none of the above, AKA don't care) for off-page and off-
>sheet.
>
>I've never seen a reason to change them from the default.

The canned OrCrap symbols don't include all six varieties.  We don't
have them in our library (gotta talk to the librarian again...) so I
copy them from another schematic when I need them.

"larwe" <zwsdotcom@gmail.com> wrote in message
news:a1ccad26-c017-41c5-a2dd-4cc91c91ab46@p16g2000vbe.googlegroups.com...

> The subsystems are designed by different groups, and the adage about
> design resembling organizational structure is completely true.

Mmm.... time for some company-wide standard design rules?

Meindert

On 19 Jan, 21:17, D Yuniskis <not.going.to...@seen.com> wrote:
> Hi,
>
> As a side-comment to the schematic preferences thread
> (hopefully not another lengthy thread =A0:> ), I'm curious
> as to what folks use as an offpage connector symbol.
>
> Given that I prefer these to be *at* the edges of the schematic
> *and* given that the signal name will be "outboard" of it,
> I try to use very narrow symbols. =A0And, since it is common for
> other such "offpage" symbols to be located immediately above
> and/or below, I try to keep the height of this symbol to
> "one intersignal spacing unit" (IsSU? =A0:> ).
>
> I also like to show direction of signal flow in the symbol.
>
> This has led me to a set of six (<frown>) symbols:
> Output Right
> Input Right (blech!)
> BiDir Right
> and the corollaries for "Left". (I.e., left and right refer
> to the edges of the page at which it is most appropriate to
> place these symbols).
>
> For unidirectional signal flow, I use a pair of "concentric"
> (wrong word) arrow heads. =A0E.g., >> or <<. =A0These can be spaced
> close enough (horizontally) together that they occupy very little
> space on the page (i.e., 1 IsSU square).
>
> For BiDir signals, I use one of each arrow head (< + >).
> Since BiDir symbols should occupy the same amount of space
> (an arbitrary but desirable condition I impose), I overlap these
> together.
>
> If they don't overlap much (or, at all), you end up with a
> diamond (<>) or an X (><). =A0I compromise and end up with
> an assymetrical "stacked pair of X's" -- sort of like a
> slice out of a DNA helix.
>
> This is intentionally assymetric -- you could shift one or
> the other arrow head to obtain better symmetry throughout the
> X
> X
> but then placing two or more of these BiDir symbols above each
> other ends up looking like *needlepoint* (can't see where one
> signal begins and the previous one ends!)
>
> Other techniques?

Something to bear in mind is that many users of your design won't use
the schematic, eg your layout guy isn't going to look at the schematic
for every net he picks up, nor is your firmware guy going to
constantly check when he defines and uses an FPGA pin.
We name almost every net on the board :-

{source}_{destination}_{major function name}_{minor function name}

With not much thought you can define three letter acronyms for every
source and destination and probably major function name. Suddenly you
have a schematic where you don't have to drill up and down through
hierarchy and fewer mistakes are made.

Colin

On Jan 21, 3:31=A0am, "Meindert Sprang" <m...@NOJUNKcustomORSPAMware.nl>
wrote:

> > The subsystems are designed by different groups, and the adage about
> > design resembling organizational structure is completely true.
>
> Mmm.... time for some company-wide standard design rules?

Believe me when I tell you the last thing this company needs is any
more rules or procedures.

"larwe" <zwsdotcom@gmail.com> wrote in message
news:a6f989c3-af19-4b7c-adad-372c4adb5c0b@m25g2000yqc.googlegroups.com...
On Jan 21, 3:31 am, "Meindert Sprang" <m...@NOJUNKcustomORSPAMware.nl>
>> Mmm.... time for some company-wide standard design rules?

> Believe me when I tell you the last thing this company needs is any
> more rules or procedures.

I know (from your earlier posts :-) ). Lucky for me I'm on the other end of
the scale. I'm the only engineer here, accounting for 50% of the eployees
and 100% for management :-)

Meindert

In article <hj88ic$vam$2@speranza.aioe.org>, not.going.to.be@seen.com 
says...
> Hi AL,
> 
> LittleAlex wrote:
> > On Jan 19, 1:17 pm, D Yuniskis <not.going.to...@seen.com> wrote:
> >>
> >> As a side-comment to the schematic preferences thread
> >> (hopefully not another lengthy thread  :> ), I'm curious
> >> as to what folks use as an offpage connector symbol.
> > 
> > I use a CAD program.  It has "input", "output", "bidirectional", and
> > "passive" (none of the above, AKA don't care) for off-page and off-
> > sheet.
> > 
> > I've never seen a reason to change them from the default.
> 
> Yes, all of the tools I use do this.  I am just not happy
> with their symbol choices.  And, since I can change them,
> I have.
> 
> E.g., I don't like an output on the right side of the page
> drawn as  <
> 
I guess your CAD package doesn't have a rotate or flip?
Funny what these guys will forget. ;)