David VanHorn <dvanhorn@microbrix.com> wrote:
> There is a school of thought that puts pins on chips in a schematic in
> the same orientation as on the physical chip. Readability be damned,
> they are determined to make it easy to count pins. (like it was ever
> hard?) This procrustean solution to a non-problem results in gordian
> knot schematics that almost completely obscure the shape of the circuit.

I have to say that there's some merit in the idea. I do this on large
chips that have lots of general-purpose I/O, like microcontrollers and
FPGAs.

First of all, I don't like to create a custom schematic symbol for each
application of a part. Since most pins on these parts can be input, output
or both, there's no particular arrangement of pins on the symbol that's
obviously better than any other. However, there's a distinct advantage
to have them match the physical arrangement when you're trying to probe
the pins of, say, a PQFP to debug it, and so that's what I go with.

Of course, on specific-purpose chips that have definite inputs and outputs,
like logic gates and opamps, etc., I put the inputs on the left and outputs
on the right.

-- Dave Tweed
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