Is the 8051 architecture public domain?

Lots of companies have 8051 compatible chips... Atmel, Dallas, Philips, 
Siemens...

Is the 8051 CPU public domain, which could explain why so many guys chose
to use it?
Or do these guys still have to pay royalties to Intel?

Thanks.

On Mon, 25 Apr 2005 16:14:46 GMT, "Jean Nicolle" <jeannicolle@sbcglobal.net> wrote:
>Or do these guys still have to pay royalties to Intel?

They pay a license fee to the provider of the IP for the 8051.  The provider pays a license to
Intel.


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Kevin D Quitt  USA 91387-4454         96.37% of all statistics are made up

> They pay a license fee to the provider of the IP for the 8051.  The
> provider pays a license to Intel.

Sounds reasonable although Intel designed the 8051 in the 1980s, 25 years 
ago...
Do you know if the 8051 will eventually become public domain (like their 
patents will expire or something like that).
Jean

Jean Nicolle wrote:
>>They pay a license fee to the provider of the IP for the 8051.  The
>>provider pays a license to Intel.
> 
> 
> Sounds reasonable although Intel designed the 8051 in the 1980s, 25 years 
> ago...
> Do you know if the 8051 will eventually become public domain (like their 
> patents will expire or something like that).
> Jean
> 

Well, there is an OpenCore for that (actually several):

http://www.opencores.org/projects.cgi/web/8051/overview
http://www.oregano.at/ip/8051.htm
http://www.opencores.org/projects.cgi/web/t51/overview

Which implies that people out there aren't being sued.

I don't believe your question is that simple. Companies have tried,
I believe unsucessfully, to patent instruction sets. So if someone
makes a microprocessor that happens to execute the same code, but
was designed without copying the internal logic, that is not
a problem. Busses are a bigger problem. One of the reasons AMD
came out with different bus standards than Intel was to get
around that.

Now Intel has sued people who cloned their instruction sets based
on the very dubious idea that "they must have used our ideas to
do that", but again, they have failed to make their case in court,
and in one case, were given a stern lecture from the judge for
attempting what amounted to a "blind legal attack" using that
tactic.

Kevin D. Quitt writes about 8051 clone chips
> They pay a license fee to the provider of the IP for the 8051.

Probably, unless they designed the IP themselves, which I expect most
of them did.  Though I don't have any hard facts.

> The provider pays a license to Intel.

Not bloody likely.  Any patents on the 8051 have expired.

On Mon, 25 Apr 2005 11:06:56 -0700, Scott Moore <samiamsansspam@Sun.COM> wrote:
>Well, there is an OpenCore for that (actually several):

In that case, I take it all back.


--
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Kevin D. Quitt					  Kevin@Quitt.net
	      96.37% of all statistics are made up

Jean Nicolle <jeannicolle@sbcglobal.net> wrote:

> Is the 8051 CPU public domain, 

No, because there isn't really such a thing as "the" 8051 CPU.  There
are dozens of apparently indepedent designs that all share a single
machine language and core features (timers, UARTs, ...), but differ in
various ways, starting from the number of clock cycles it takes for
one machine cycle to execute being anywhere between the original 12
and 1, and extending to CPUs that changed even some aspects of the
machine language.

> Or do these guys still have to pay royalties to Intel?

No.  Some of them may have done so in some time long gone, but not
these days.

-- 
Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.