Hello Gerhard,


2006/8/5, Gerhard Fiedler wrote:

> it seems to me that it is that "semiconductor manufacturer 1" and
> "semiconductor manufacturer 2" from figure 3 ("existing design flow") are
> replaced with "Microchip" in figure 4 ("redesigned to incorporate
> CodeGuard")...  :)

Yes. And in summary, it's something like turning a multi-chip design
into a single chip (Microchip) design.

>
> Probably the main problem with that type of security is that it is not open
> source...

Open source? But I think the CodeGuard is a hardware architecture...
Each party (either an OEM vendor, firmware IP provider or anything
similar) will use the CodeGuard feature to protect a portion of the
ROM, RAM or/and EE, where their firmware resides.  They will then sell
these chips to vendor with next privilege security level. Then a new
portion of firmware is written, code protected , and sold to next
level...  If you see figure 2, that's how an original 3-chip design
turned into a single Microchip design.




Best regards,

-- 
WH Tan
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