PEX 8311RDK
Errata Revision 1.1
August 2007
Errata Documentation
1. Voltage Regulator U9
Note. This erratum only pertains to PEX 8311RDK Revision 1.0 boards.
Description:
On the PCI 8311RDK board, the part originally selected for U9 was incapable of producing 2.5V
output from a 3.3V input. It was replaced with the LT1963A, which fixes the problem. However,
the pinout of the LT1963A does not match the pinout of the original part. For this reason, Revision
1.0 boards are assembled with the LT1963 mounted rotated relative to the the PCB pads, with
pin 2 soldered to pad 1, pin3 soldered to pad 2, and pin1 wired to pad 3. The schematics show
the circuit connections after these reworks are added.
2. PMEOUT# signal pull-up resistor R1147
Note. This erratum only pertains to PEX 8311RDK Revision 1.0 boards.
Description:
PMEOUT# pin of the 8311 is not connected in the Revision 1.0 board. This pin should be pulled
up or tied to ground to prevent possible oscillation of the input. No functional problems have been
associated with this erratum.
Workaround:
R1147 (schematic sheet 3) was added to the schematic to correct the problem in the design,
however, physical constraints prevent addition of this resistor to the current revision PCB.
3. VB14 Resistor R661
Note This erratum only pertains to PEX 8311RDK Revision 1.0 boards.
Description:
The voltage regulator U3 generates the 1.5V supply for the PEX8311RDK. There is relatively little
spare current available from U3 to power additional logic. If FP2 is populated with an Altera
Cyclone array then the FPGA will require more current from the 1.5V supply than can be provided
by U3. Ideally it should be possible to use the uncommitted USRVCC (U14) to provide the 1.5V
supply to the FPGA. Although R321 can be used to link pin 64 of the array to VB14, the link from
VB14 to the USRVCC (R661) is not present on the Revision 1.0 board.
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Workaround:
Either of the following workarounds can be applied.
A) If additional 1.5V current is required U3 can be replaced with a larger voltage regulator
B) If USRVCC (U14) is used to provide the 1.5V supply for the Altera Cyclone array then
connect a wire from PF64 directly to the output of U14.
4. LA29 resistor R51
Note. This erratum only pertains to J-Mode configuration of the PEX 8311RDK
Revision 1.0 boards.
Description:
Resistor R51, normally populated for J-Mode local bus operation only, is wired incorrectly to
Resistor R50. On page three of the schematic, grid E-3, R50 and R51 are shown as they should
be connected. In that case, changing from C-Mode to J-Mode would require removing the 10K
resistor at R50 poplulating 1K at R51. The actual Rev. 1 boards, however are such that R51 is
tied to the wrong end of R50, to 3.3 V insdead of to LA29. A simple rework corrects this problem.
Workaround:
For J-Mode Configuration, connect a 1K ohm resistor between R50.1 (LA29) and R51.2 (GND),
as illustrated below.
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5. JP5 Pin 1, R31 Connected to Ground
A schematic design error has resulted in JP5-Pin1 and pull-up resistor R31 being connected to ground. This
error prevents connection of GPIO3 and LED4 to a pull-up resistor as intended. This error only affects JP5.
The other LED option jumpers, J2, J3, and J4 connect to pull-ups as expected when pins 1-2 are shunted.
This error, an incorrectly placed junction dot, is shown below. Avoid replicating this error in your designs.
Workaround
Rotate R31 90 degrees clockwise about the pad which is closest to the mounting bracket. Wire the
unconnected end of the resistor directly to JP5-Pin2.
Copyright © 2007 by PLX Technology, Inc. All rights reserved. PLX is a trademark of PLX Technology, Inc. which may be
registered in some jurisdictions. All other product names that appear in this material are for identification purposes only
and are acknowledged to be trademarks or registered trademarks of their respective companies. Information supplied by
PLX is believed to be accurate and reliable, but PLX Technology, Inc. assumes no responsibility for any errors that may
appear in this material. PLX Technology reserves the right, without notice, to make changes in product design or
specification.
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