[U-Boot-Users] MPC832x EMDS and PCI expansion board

[Randy Vinson <rvinson@mvista.com>]

Richard Parsons wrote:
> Hi all,
Hi Richard,

> 
> I am trying to get the Freescale MPC832X EMDS with a PCI-Exp board to 
> recognise a PCI device.  I have the PCI enabled @66Mhz and all appears to be 
> in working order except there are no sane values are being read from the PCI 
> bus.
> 
> On linux 2.6.22 kernel it registers a lots of PCI devices but they all have 
> the vendor ID of 0. (<sarcasm>I really dont believe the board has a nCipher 
> HSM and a SCSI controller on the PCI board.. unless its so small I cant see 
> it </sarcasm> 
> 
> The Bus powers up, the cards at least get power as far as I can see (blinking 
> light on a 3COM network card :-P 
> 
> Is there anything I am missing? as I cant seem to get this blessed PCI running 
> properly.

I've run into the same problem. The information I received was to run
the PCI bus at 33MHz only. Note that the PCI speed selection in U-Boot
doesn't seem to do anything. The code is trying to set the divider bits
in the OCCR register, but the 832x chip doesn't have those bits. To
change to 33MHz, I had to change SW4-4 (CFG_CLKDVB).

I also experienced problems with the power-on reset. If I used the reset
button on the 8323 processor board, I got much better results.

I think the problem may be caused by the removal of some pullup
resistors in the processor card. The schematic I have for the Rev 1.1
processor board shows the pullups for nXPCI1_DEVSEL, nXPCI1_FRAME,
nXPCI1_IRDY, nXPCI1_TRDY, nXPCI1_PERR, nXPCI1_SERR, and nXPCI1_STOP
marked "DNP" which I infer to mean "Do Not Populate." The Rev 1 board
did not have the DNP marking for those pullups and worked fine for me. I
don't know what Rev processor card you are using, so this may not be
related to your problem.

Randy V.