Re: 6502 illegal opcodes

From: Segher Boessenkool <*segher_at_kernel.crashing.org*> Date: Fri, 4 Nov 2011 20:12:52 +0100 Message-Id: <9F37645E-9713-400A-8DCE-082E446BD4E2@kernel.crashing.org> · segher_at_kernel.crashing.org

> Those companies were licensed to make the chips based on the same  
> design
> in order to be a second-source option, so I assume the die is  
> identical.

It is almost identical.  I'm not sure if I have seen a Synertek chip;  
but
the Rockwell chips have a different layout around the pads, it looks  
to me
that they wanted more clearance around the pads (the MOS parts have much
less clearance than anything else I've seen).  There is also an extra
(redundant) contact from metal to active area, on the DBE signal.   
Oh, and
the Rockwell chip has the ground pads doubled, and it has different test
structures.

For most purposes, the chips are identical.

Segher

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