On 06:05 AM 6/06/2002 -0700, Mira said: >Abd, >I found out that there are as many opinions about >negation as the people are. >I just tried to debugg a board, which schematic was in >Protel and the net names were RESET and RESET_. Do >figure which one where is connected if you have it >only on paper. >Due to the way the net labels are attached to the wire >in Protel, the underscore overlaps the wire and hardly >could be seen. >That was what I meant. > >Mira
Mira, I don't think anyone including Abd ulRahman would suggest that a simple trailing (or leading underscore) could work. Basically *any* suitable character can be used to indicate negation *unless* you want to use the same net names inside other tools (such as VHDL compilers) in which case one must be careful to make legal net names and not accidentally include an operator. There are well recognised issues with the overscore in Protel (with either the single character negation mode or the "negate each character mode"). Some of these problems relate to the standard grid size used by Protel. Some relate to various printer effects. Some users live with these or have developed work-arounds. Others use prefixes or suffixes. I know of no-one that uses a simple "_". But I have seen virtually everything else. I happen to use n_RESET as it is safe in every package I have seen and clear enough. Others use RESET_n. I don't use nRESET as this is converted to NRESET by some tools which for some net names is very unclear. A net label that looks like n RESET due to the underscore disappearing is as it lies on a wire is still clear enough and satisfies all those pesky other tools. As for things looking ugly on a sch - people do not consider my sch very pretty but they are complete and detailed. Every pin is shown, NoErc markers clutter things up - all part of the quest for single pass engineering. So I am happy to have good looking but only after all the other requirements are met first. I have seen a overscore negation disappear on a fax of a poor quality printout. Why was I in the field debugging with a bad fax? Forgot to take the Sch with me. This was all I could get. It made no difference to me as I knew the design well enough - but someone else? When we do our work we should consider the poor sucker, with head stuck in a dark road side box on a wet night trying to make that thingy-you-designed work. Good-looking doesn't work for me in that case *unless* it is also complete and I am not flicking excessively from sheet to sheet. I'm out of this thread on that note. Ian Wilson >--- Abd ulRahman Lomax <[EMAIL PROTECTED]> wrote: > > At 03:50 AM 6/5/2002 -0700, Mira wrote: > > >"Net_names" like this look awful on the schematic > > and > > >the printouts. Not recognizable at all. > > > > I'm not sure what this means. Using an asterisk at > > the end, as I mentioned, > > such as RD and RD*, is a long-used and recognized > > convention for negation, > > and I have never had trouble reading it, nor do I > > consider that it looks > > "awful." Perhaps Mira was referring to something > > else, perhaps the negation > > bar, created in Protel with a backslash, which can > > have problems on some > > printers. > > > > The use of a forward slash also is widely > > recognized, i.e., WR and /WR. > > Databooks most commonly use a full bar over a signal > > name to negate it, > > which I am not going to attempt to represent in > > ASCII.... > > > > I don't do simulation and the like, so the > > limitations of some netlist > > interpreters don't personally affect me; however, if > > they did, and the > > method I liked to use in documentation did not work > > with the interpreter, > > I'd be tempted to write a small utility to do the > > conversion to whatever > > would work, instead of making everything hang on the > > limitations of the > > program. > > > > > > > > > > * * * * * * * * * * * * * * * * * * * * * * * * * * > > * * * * > > * To post a message: > > mailto:[EMAIL PROTECTED] > > * > > * To leave this list visit: > > * http://www.techservinc.com/protelusers/leave.html > > * > > * Contact the list manager: > > * mailto:[EMAIL PROTECTED] > > * > > * Forum Guidelines Rules: > > * > > >http://www.techservinc.com/protelusers/forumrules.html > > * > > * Browse or Search previous postings: > > * > > >http://www.mail-archive.com/proteledaforum@techservinc.com > > * * * * * * * * * * * * * * * * * * * * * * * * * * > > * * * * > > >__________________________________________________ >Do You Yahoo!? >Yahoo! - Official partner of 2002 FIFA World Cup >http://fifaworldcup.yahoo.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
