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P4080 Development System User’s Guide, Rev. 0
34
Freescale Semiconductor
Architecture
A great portion of the OCM is defined by the software. Because this can be changed by the end-user or
updated with new functions at any time, see the OCM documentation for definitive details.
5.2.9
Power
Power for ngPIXIS is supplied from dedicated VCC_HOT_3.3 and VCC_HOT_1.5-V power supplies
based upon the ATX power 5-V standby power, VCC5STDBY.
5.2.10
Register Summary
ngPIXIS contains several registers. For further details, see
Section 7.1, “ngPIXIS Registers.”
5.3
System Power
The 12-V, 5-V, and 3.3-V power requirements are met by the attached ATX-12V compatible power supply
unit (PSU). 5 V and 3.3 V are connected to individual power planes in the P4080DS PCB stackup. The
12-V power from the standard ATX header is treated as separate from the ATX-12V power, which supplies
a large amount of current and is referred to as “VCC_12V_BULK”. The latter is used solely for the
VDD_CA, VDD_CB, and VDD_PL power supply rails, while the former is used for miscellaneous
purposes, such as fan power and PCI slots.
Note that to support ngPIXIS standby operation, video cards, or other high-power-dissipation cards in the
PCIExpress slot, the PSU should support the following minimum specifications:
•
Minimum 450 W overall, 500 W recommended
•
One PCIE 12-V connector
•
PCIE 12 V supports a minimum of 150 W
•
Minimum 5-V, 2-A standby current
All other power sources are derived from the ATX PSU.
shows the principal system power
connections in relationship to FPGA control. For more detail as to P4080 power scheme as implemented
by this system, see