> Luigi Rizzo <PICLIST@MITVMA.MIT.EDU> wrote:
>
> > > 5473758:  System having input output pins shifting between
> > >           programming mode and normal mode to program memory
> > >           without dedicating input output pins for
> > >           programming mode
> >
> > this is weird... EPROM have been out for a while and it seems to me
> > that the above description exactly matches the programming method
> > for EPROMs! (yes I know Eproms have a Vpp pin, but just call it
> > RESET...)
>
> Luigi:
>
> Read the patent before jumping to conclusions.

of course :)

> The patent specifically claims a means by which the chip is
> programmed with FEWER PINS than the width of each memory cell... Here
> are some selected quotes from the Background and Summary sections of
> the patent:

well the description you gave above made no mention on the number of
pins used.

Luckily I am not much in patent stuff, but everytime I read a
patent, some of its claims seem so obvious that it is surprising
and highly suspicious that the patent has been granted. This one
is possibly even worse than the average:

>     "It is a principal object of the present invention to provide
>     apparatus and method which permits the use of 14-bit instruction
>     words despite the presence of only 12 I/O pins in the
>     microcontroller.",

ah... someone has finally invented serial communication...

        Cheers
        Luigi
-----------------------------+--------------------------------------
Luigi Rizzo                  |  Dip. di Ingegneria dell'Informazione
email: luigi@iet.unipi.it    |  Universita' di Pisa
tel: +39-50-568533           |  via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522           |  http://www.iet.unipi.it/~luigi/
_____________________________|______________________________________