ATX Version 3.0 Multi Rail Desktop Platform Power Supply
Design Guide
PCIe* Add-in Card 12V-2x6 Auxiliary Power Connector Sideband Signals
The new 12V-2x6 connector carries four sideband signals that communicate between the Power Supply and the PCIe* Card. The sideband signals are:
- SENSE0 (Required)
- SENSE1 (Required)
- CARD_PWR_STABLE (Optional)
- CARD_CBL_PRES# (Required/Optional)
For the most current and detailed description of the electrical requirements of the sideband signals, refer to section 5.3 – Optional Sideband Signal in the PCI Express* Card Electromechanical Specification, Revision 5.1 (often shortened to “PCIe CEM 5.1 Spec”). That document is available from www.pcisig.com. Physical specifications for the 12V-2x6 Cable Plug and mating PCB Header are provided in section 5.2.2.4.2 of this document, and are also detailed the PCIe CEM 5.1 Spec.
When multiple 12V-2x6 Auxiliary Power Connectors are present in system, their sideband conductors and the signals they carry are independent among separate connected and unconnected PCIe cards and cables.