From: Yu Wang (email@example.com)
Date: Fri Mar 24 2000 - 07:04:47 PST
Your suggestion is helpful. But the other thing I have
to face is the connections to GND and PWR. If let the
Orcad autoroute them, I am not always satified with
the result. If I do it one by one, it's boring and
time wasting. So I 'm wondering if there is a function
which can remeber what I do and just follow me or I
can combine the ICs and the connections as one unit.
--- Jon Keeble <firstname.lastname@example.org> wrote:
> Orcad supports a concept of autoplace on a grid.
> You could
> (1) auto place the ICs on a grid
> (2) auto place the bypass caps on another grid of
> the same dimensions
> somewhere else
> (3) block move one set of parts over the other set
> of parts
> Orcad also supports the concept of component group.
> If you identify the IC and its bypasses as belonging
> to a group, then all
> the parts in the group can be made to
> move together.
> By the way: there has been some discussion of
> bypassing recently. You may
> want to review the idea of having
> a lot of identically valued bypass caps, and you may
> not need two per chip.
> The latest Orcad revision is 9.1, and it fixes a lot
> of problems in 9.0.
> -----Original Message-----
> From: Yu Wang <email@example.com>
> To: firstname.lastname@example.org
> Date: Wednesday, March 22, 2000 1:52 AM
> Subject: [SI-LIST] : how to combine multi components
> together with Orcad
> >Hi, all experts there,
> >I am using Orcad(Ver.9.0) Layout plus to implement
> >design in which more than 30 pieces SMT
> >and more than 70 pieces SMT 16 bit buffers and
> >latchs(TVSOP48) are used. So I have to lay more
> >250 decoupling capacitors down and connect them to
> >PWR and GND pins. It's a tough work. However,
> >the layout and the connections of the capacitors
> >each FIFO or for each TVSOP48 chip are same. Then I
> >think I can combine one FIFO and its capacitors
> >together and regard them as one unit. It will
> >the job definitely. But I haven't found the tool
> >within Orcad to realize it. What I am doing is
> >creating a new layout pattern in which I use
> >to draw some of the footprints of the chip and all
> >footprints of the capacitors and all the
> >just like the old Orcad layout library did. Right
> >for prototype,
> >it can work good because I can solder the
> >by hand. But, what I am worrying about is that in
> >future when I send it to production, the capacitors
> >would not be assembled by machine. That will be a
> >So please, give any suggestions. Thanks a lot.
> >Yu Wang, Ph.D
> >U.T. MD Anderson Cancer Center
> >1100 Holcombe Blvd., Box 217
> >Houston, TX, 77030
> >Do You Yahoo!?
> >Talk to your friends online with Yahoo! Messenger.
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Yu Wang, Ph.D
U.T. MD Anderson Cancer Center
1100 Holcombe Blvd., Box 217
Houston, TX, 77030
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
**** To unsubscribe from si-list or si-list-digest: send e-mail to email@example.com. In the BODY of message put: UNSUBSCRIBE si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
si-list archives are accessible at http://www.qsl.net/wb6tpu
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