gEDA-user: Defining parts with REALLY complicated pin labels

["David D. Hagood" <wowbagger@xxxxxxxx>]

First of all:

Thanks for creating gEDA - you guys saved me from following the path of 
sin and running a commercial EDA package!

I am working on a couple of parts for a project I am designing, and will 
contribute them back as soon as I have "put them to the test" and gone 
from schematic to board with them.

The first, the TI SN754410 quad half-H bridge, was pretty straightforward.

But the second, a Microchip PIC16F688 - well, every pin (other than Vss 
and Vdd) has at least 2, and in some cases 5 functions, multiplexed by 
software. This leads to a couple of issues:

1) What do I use as the "pintype" attribute when a pin might be an 
input, an output, tristate, a clock, an analog input, or programming 
voltage, depending upon the mode?

2) The "pinlabel" fields get pretty damn long when you have a pin like 
"RA0/AN0/C1IN+/ICSPDAT/ULPWU" - either this 14 pin part is going to be a 
mile wide in the schematic, or I have to come up with a way to break 
that attribute into a couple of lines. I tried making multiple 
"pinlabel" attributes, but that didn't pass muster for gsymcheck.

Also, how do I add an inversion bar to a label? I tried using a leading 
"*", but that did not seem to work.

Lastly - and this is truly blue-sky dreaming - I have an infrastructural 
question: Given a part like a PIC, would it be possible to create some 
form of scripted part (in Scheme) that would allow the user to select 
what the functions of the pins were, and then create the appropriate 
labels for them, and possibly even emit the register setups for the 
part? It seems to me that this would really help make a multifunction 
part like a PIC pass DRC, as then the device could be tailored to the 
exact setup - inputs could be really marked as inputs, output as 
outputs, etc.