Schematics for Eval Boards

[Scott C. Karlin]

I do see that the new PCB number does match the old PCB number 
(A13033).  However, I'm starting to suspect that there is at least
a small discrepancy between the board and the schematics.

I'm looking carefully at the board and the schematics to convince 
myself that the board will work when plugged into a Pentium 
motherboard.  (The PCI_debug.txt file not withstanding.)

The signals which caught my eye are the PCI signals PRSNT1# and 
PRSNT2# found on pins B9 and B11 of the PCI backplane.  For expansion 
boards, the PCI spec (rev 2.2, section 4.4.1) states that at least 
one of the signals must be grounded to indicate that a board is 
plugged into an expansion slot.  The schematics (page 2, zone D3) 
show that these signals are pulled up to Vdd (3.3V) via 5Kohm 
("R502") resistors R222 and R223.  Both a visual inspection of the 
board and a check with a meter shows that R222 and R223 are 20Kohm 
(marked "203") resistors.  While this is not a big discrepancy, it 
tells me that the schematics may not match in more significant ways.

-Scott


Pat Kelley writes:
>
> The 002 sticker reflects the revision update for B0 200MHz.
>
> The schematics number matches the PCB (look under the sticker!)
>
> Scott Karlin writes:
> >
> > We just received a new version of the IXP1200 development board
> > with the B0 stepping of the IXP1200 chip.  Included in the shipment
> > is the version 1.1.109 of the development environment CD-ROM.
> >
> > I would like to verify that the schematics on this CD-ROM match
> > the board we just received.  The evb_p1.pdf page title block
> > states "TOP DOCUMENT NUMBER K-DD-54-30296-0-1" dated 13-AUG-99.
> >
> > Our older board was marked in the copper layer "A13033-001 A01 L1".
> > Our new boards have a sticker in the same place marked "A13033-002".
> >
> > Can anyone confirm that the 13-AUG-99 schematics match the board
> > we just received?