On Sunday 30 July 2006 21:32, Dieter wrote:
> >    A boot-time video mode that's configurable in the field should be
> > hardware-lockable, to permanently deny software and f irmware any chance
> > to change it.
>
> IIRC, awhile back there was talk of a jumper to write-protect the
> eeram/nvram/flash/whatever-they're-calling-it-this-week ?

That was on OGD1 (to protect the main FPGA configuration PROM), and I can't 
remember if there was a final decision on that one.

In the event that a user-configurable area of non-volatile storage is included 
in the OGC1 chip, yes, having a write-protect jumper on the card seems like a 
good idea.  It'll mean that people who do buy vendor-preconfigured boards 
can't mess up the settings quite so easily when they start playing with the X 
configuration tools.

However, the other alternative is to have it as a flag you can only set using 
the JTAG interface.  That'll save on adding extra components for 
infrequently-used functions.  As Attila suggested, we've already got an 
general purpose interface on there -- all that's needed is to make the JTAG 
registers available.

What about this component (or one like it) for the JTAG header? On the edge of 
the board, for easy access if you've got a number of cards in:

http://rswww.com/cgi-bin/bv/rswww/searchBrowseAction.do?N=0&Ntk=I18NAll&Ntt=468-080

How to build & use a JTAG cable:

http://wiki.openwrt.org/OpenWrtDocs/Customizing/Hardware/JTAG_Cable

An example of a commercial JTAG cable:

http://www.nuhorizons.com/products/digilent/jtag-cable.html

Peter

-- 
Fisher Society publicity officer            http://tinyurl.com/o39w2
CUSBC novices, match and league secretary   http://tinyurl.com/mwrc9
Quake II build tools maintainer             http://tinyurl.com/fkldd

v2sw6YShw7$ln5pr6ck3ma8u6/8Lw3+2m0l7Ci6e4+8t4Eb8Aen5+6g6Pa2Xs5MSr5p4
  hackerkey.com

Attachment: pgpCUYOWJ8Ks4.pgp
Description: PGP signature

_______________________________________________
Open-graphics mailing list
[email protected]
http://lists.duskglow.com/mailman/listinfo/open-graphics
List service provided by Duskglow Consulting, LLC (www.duskglow.com)

Reply via email to