Intel NuPRO-850 - Manual (Page 47)

ePCI-X Bus Details
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6
ePCI-X Bus Details
6.1 NuPRO-850 ePCI-X Bus
The NuPRO-850 provides PCI-X/PCI buses. Bus-A can run up to 64-bit PCI-X
66. Bus-B can run PCI 33MHz.
The ePCI-X Bus pin assignment is compatible with the PICMG 1.2 ePCI-X
specifications. In the following sections, we will describe the detail signal
definition and the design guide for the backplane designer to be compatible
with the NuPRO-850 ePCI-X bus.
6.2 Global Signals
6.2.1 Standby Supply (+3.3Vaux)
The NuPRO-850 onboard circuit generate 3.3Vaux power from the +5Vaux or
+5V. Therefore, NuPRO-850 does not require the backplane to provide
+3.3Vaux.
6.2.2 ATX Support
The ATX support signals include PWRGD, PSON#, PWRBT#, +5Vaux. The
NuPRO-850 design provides the ATX power control capability.
If the backplane did not provide the +5Vaux, then the PWRBT# and PSON#
will not work under ATX power mode. Users have to setup the external wiring to
switch on/off the power supply.
6.2.3 JTAG
NuPRO-850 does NOT implement the JTAG signals.
6.2.4 I
2
C Bus
The onboard SMBus is connected to the SER_SCL and SER_SDA pins.