PEX 8509RDK Hardware Reference Manual v1.1
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© 2007, PLX Technology, Inc. All rights reserved.
3.4
JTAG Header (JP1)
Header JP1 provides a direct connection to the PEX 8509 JTAG interface. The 10-pin connector is
designed to allow a direct interface to 3rd party JTAG controllers, such as the Corelis USB-1149.1/E
controller.
3.5
PCI Express Fatal Error Indication (D9)
The PEX 8509 provides an output status pin (FATAL_ERR#), which reports the event of a PCI Express
fatal error condition. The RDK connects this output to D9, which is lit when a fatal error is detected.
Examples of fatal error conditions are data link layer protocol errors, receiver overflow, malformed TLPs,
etc… The PCI Express Base specification provides a complete listing of fatal error conditions.
3.6
PEX INTA# (D19)
PEX 8509 provides a side-band interrupt pin for signaling various programmable events.
3.7
Slots J1/J2/J3 Power Fault Indication (D20)
Slots J1, J2, and J3 are power by the ATX 4-pin hard disk connector and a DC/DC converter (U12). No
circuitry is provided to current limit the power consumed by those three slots; however, a voltage
supervisor is provided to monitor under-voltage conditions on the +12V and +3.3V supply rails going to
those slots. If either rail drops below 15% of its nominal supply voltage, the power good signal from U3 is
used to clear a D-flip flop (U15), which will in turn light a red indicator LED (D14). Once the LED is lit, it
remains lit until board power is cycled.
4. Serial EEPROM Registers
4.1
Serial EEPROM Contents
The PEX 8509RDK is shipped with a programmed AT25080A EEPROM. PLX Technology provides the
necessary binary image files and software tools required to program the EEPROM. Install a jumper
between JP2 pins 1 and 2, before applying power to the RDK.
5. FAQ/Troubleshooting
5.1
Frequently Asked Questions
Q1) I have purchased an RDK Port Expansion Kit to enable my PEX 8509RDK to work as an 8-
port/8-lane switch. What steps must I take to get my RDK working behind the RDK Port Expander?
A1) The RDK Port Expansion Kit has a separate Hardware Reference Manual, which provides of a list of
steps that should be taken prior to plugging the RDK into the RDK Port Expander. In general, since the
RDK Port Expansion Kit is intended to operate as a bench-top platform, the PCI Express bracket should
be removed, nylon stand-offs must be mounted onto to RDK, the PEX 8509’s Port Configuration should
be changed from x4x1x1x1x1 to x1x1x1x1x1x1x1x1 by changing SW3 from 11b to 00b.
Q2) Since the RDK Port Expansion Kit may use a different power than my host PC, is there a
power-up ordering requirement?
A2) Yes. The RDK Port Expander/PEX 8509RDK must have power applied before the PC is powered on.
This will ensure than the PC BIOS enumeration will see the PEX 8509 and it’s downstream components.
