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> > Okay, wait a minute here. Protel, PowerPCB, Cadence, Mentor, they are all > just tools. If you are designing a board outside the limits of any > "autorouter" then you need to use the "skill sets" that made you able to > design pcb's in the first place! I've used many different CAD packages and > NONE of them can route a layout as good as "I" can. I have always routed > fine pitch fan-outs by hand anyways, then let the router try, when it fails > or gets like 98% completion, I know that my job is to make it right! And I > like it! Any monkey can push a "route all" button!!!! > > Well stated Jeff, I am glad we are on this topic, because this topic is one of the most important requirements for any autoroouter to perform. As one of the first functions, it will control how well the router later performs. I hope Protel is placing much emphasis on this issue before release of the new router. I have found that even with a high end tool like Spectra , the fan out interface is clunky, slow and the graphics is dos looking. The interface is not good enough for anyone to look at it for more than 30 minutes. I fan out everything manually in Protel as do some of you . Protels graphics are easy on the eyes, commands are at most two keys, and I can hit the center of every pin. To fan out components, I use that $5000.00 option (PADS pun intended) called cut and paste. Several the reasons I fan out in Protel are: I can control direction of the fan out, I can control the length of the fan out, I can inspect my layout to see if decoupling is installed backwards, ( ie the power node is the furthest from the pin I wish to decouple ), And most importantly I can control the size of routing channels. This is something that no router with "fan out" takes into consideration, Size of the routing channel. I will also manually route critical nets, and short stubs that obviously should not drop a layer. Spectra has control both in numeric (mils) and scaled ( 0-256) values for different features including fan out. Direction of fannout can also be controlled, in verses out. However the size of the routing channel is a still a guess as it in Protels router. Calculating fan out in mils , in vs. out , etc is awkward and is not of much use. I know we have all seen the canned Spectra demos, but in reality I can manually fanout about 10 times faster in Protel than Spectra. Neither Spectra and Protel will automatically fanout to the center of the pin, though spectra has a command to tell it to hit the center of the pin. Again awkward, my cut and paste snaps to center everytime. Neither router can fanout a pattern that is usable for good routing. A good routing channels is open both vertically and horizontally to allow room for tracks and spacing. Much has been written about leaving routing channels open. , a good router should make the calculation before fanning out, That router does not yet exist. Mike Reagan EDSI Frederick MD * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
