66 Mhz bus clock for EST8260?

[Brian Ford]

How many people have actually done this on an EST board?  I don't doubt
that the chip can do it, but I have my doubts about the EST PLL
(clock) filter circuits being correct to begin with, let alone conforming
to the errata.

On Mon, 11 Dec 2000, Gessner, Matt wrote:

> I had no problem at all getting this to work at 66MHz.
> DO NOT RUN THE CPM FASTER THAN 133MHZ (at least on the chips I had,
> it NEVER worked).
>
Yes.  I'd gladly settle for 200/133/66.

> In fact, I clocked my 166/133/66 chip at 300MHz :-)
> That baby RUNS!  Heh.
>
> > -----Original Message-----
> > From: Brian Ford [mailto:ford at vss.fsi.com]
> > Sent: Friday, December 08, 2000 1:47 PM
> >
> > Is there any magic in getting the EST8260 board to work with
> > a 66 Mhz bus clock?  I haven't had good luck with a Linux or vxWorks
> > image.
> >
> > My board has a 200/166/66 rev A.1 chip.
> >
> > I boot using a vxWorks bootrom.  I have made a few corrections to the
> > bootrom so the decrementer frequency is set correctly from the user
> > dip switches in addition to setting the core, cpm, and bus speeds.
> >
> > The scenerio is as follows:
> >
> > 1.) Burn configuration word to change MODCK_H from 0x0001 to 0x0101
> > 2.) Swap oscillators 33.0 -> 66.0 Mhz
> > 3.) Set MODCK[1-3] switches to 0x111 (200/133/66)
> > 4.) Mirror 3.) on user switches for vxWorks bootrom to read
> > 5.) Hack head_8260.S to put immr in place for Linux
> > 6.) Set linux board info in embed_config.c to 200/133/66/66
> > (core,cpm,bus,brg) making sure there is real space allocated for it
> > instead or whatever was in r3 when vxWorks booted us.
> > 6.) Reboot.
> >
> > vxWorks bootrom runs fine and downloads Linux or vxWorks.
> >
> > Linux pannics just before giving me a shell prompt somewhere
> > in tty init.
> >
> > vxWorks appears to come up fine, but the muxDevBind fails for the Fast
> > Ethernet and thus no network communications.  Even though the bootrom
> > just downloaded us successfully over the same interface.
> >
> > Has anyone had any luck with the 66 Mhz bus clock?
> >

--
Brian Ford
Software Engineer
Vital Visual Simulation Systems
FlightSafety International
Phone: 314-551-8460
Fax:   314-551-8444


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