6
ePCI-X Bus Details
6.1NuPRO-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.
6.2Global Signals
6.2.1Standby 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.
6.2.2ATX 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.
6.2.3JTAG
NuPRO-850 does NOT implement the JTAG signals.
6.2.4I2C Bus
The onboard SMBus is connected to the SER_SCL and SER_SDA pins.
ePCI-X Bus Details • 41
