Digitalker, SP0256, and SC-01 speech chips
mcguire at neurotica.com
Fri Feb 15 11:54:01 CST 2008
On Feb 14, 2008, at 8:56 PM, Chuck Guzis wrote:
>> Doubtful, as it's just the same architecture, and far from the
>> same implementation. The 8X30x chips are bipolar, if memory
>> serves. But
>> either way, I'm not sure what the point would be, aside from
>> building new boards using an existing 8X30x MSCP implementation.
> As one who has had the extreme displeasure of programming both the
> 8X300 and an 8X305,
Are they really that bad? How so?
> I'd have to say that the two have about as much
> in common with a PIC as a pocket knife to an CNC EDM system. The
> instruction sets aren't even close, nor is the data path
> architecture. In some respects, the bipolar chip has a bit more
> flexibility (e.g. variable-length operations and an "execute"
> instruction) even with its limitation of an instruction set of size
> Do you have a cite that states that the PIC1640 is a direct
> descendent of the SMS 300? Microchip certainly doesn't admit it--and
> I'd be hard pressed to find the similarity beyond both being Harvard
> architecture binary CPUs.
I went to gather references and I found that I may have
misunderstood something a very long time ago! Here's a quote from
the PIC FAQ:
> The roots of the PIC originated at Harvard university for a Defense
> Department project, but was beaten by a simpler (and more reliable
> at the time) single memory design from Princeton. Harvard
> Architecture was first used in the Signetics 8x300, and was adapted
> by General Instruments for use as a peripheral interface controller
> (PIC) which was designed to compensate for poor I/O in its 16 bit
> CP1600 CPU. The microelectronics division was eventually spun off
> into Arizona Microchip Technology (around 1985), with the PIC as
> its main product.
I (more than a decade ago) took that to mean that the processor
architecture (the instruction set and register layout, not just
"Harvard") was traced back to the 8X300. It was *Harvard
architecture* that was used by GI, not the 8X300 architecture...does
that make more sense? In that case, I stand corrected and apologize
for my error!
That said, what can you tell us about the 8X30x processors? I
don't think I've ever known anyone else who designed with them.
Port Charlotte, FL
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