I have 256 pads in package(footprint) with name: A_1, A_2,... A_256.
Now I'm creating the symbol for this device, and then want to tie that symbol to the package to create a device.
Is there a way to create something like a Bus pin with the name A_<1:256>, so I don't need to put down 256 pins instead? Thanks.
Am 27.10.2012 22:46, schrieb Kailiang Chen:
I have 256 pads in package(footprint) with name: A_1, A_2,... A_256.
Now I'm creating the symbol for this device, and then want to tie that symbol to the package to create a device.
Is there a way to create something like a Bus pin with the name A_<1:256>, so I don't need to put down 256 pins instead? Thanks.
No, even if there were a bus someone must define which pin is connected
to which pad 
See the help pin before you really go to work on a 256 pin monster.
The symbol you are going to create should contain the pin NAMES and can
have any form you like. I prefer to draw the symbol pins in a way that
they best suit the function and NOT like they are arranged on the chip.
The package contains the PADS, either as a SMD-pad or a THT-via and they
are named from 1 to... .
You should not use the default values given by eagle (P$x).
The package of course must be EXACT like the chip you gonna use.
Eagle contains some already made packages in the ref-packages.lbr, and
you can check if one suits you.
Now we come to your "buswork". In the CONNECT dialog you must connect
your pin names to your pad numbers and that can be a lot of work.
Even if that is done you are not finished yet. In the symbol you must
define the DIRECTION of each pin if you want to benefit from the
Electrical Rules Check (ERC).
Turn on layer 93 (pins) to see that.
Last not least there is the VISIBLE parameter for each pin you can play
with.
A last word on multiple pins like GND etc. Those pins are named like
GND@1, GND@2 etc. Don't worry, the "@x" will not become visible in your
device.
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Mit freundlichen Grüßen / With best regards
Joern Paschedag
