Offpage connector symbols
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From: Meindert Sprang on 21 Jan 2010 03:31 "larwe" <zwsdotcom(a)gmail.com> wrote in message news:a1ccad26-c017-41c5-a2dd-4cc91c91ab46(a)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
From: colin_toogood on 21 Jan 2010 03:59 On 19 Jan, 21:17, D Yuniskis <not.going.to...(a)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 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
From: larwe on 21 Jan 2010 04:52 On Jan 21, 3:31 am, "Meindert Sprang" <m...(a)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.
From: Meindert Sprang on 21 Jan 2010 06:08 "larwe" <zwsdotcom(a)gmail.com> wrote in message news:a6f989c3-af19-4b7c-adad-372c4adb5c0b(a)m25g2000yqc.googlegroups.com... On Jan 21, 3:31 am, "Meindert Sprang" <m...(a)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
From: WangoTango on 21 Jan 2010 10:09
In article <hj88ic$vam$2(a)speranza.aioe.org>, not.going.to.be(a)seen.com says... > Hi AL, > > LittleAlex wrote: > > On Jan 19, 1:17 pm, D Yuniskis <not.going.to...(a)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. ;) |