Sense1 / Sense0 (Required)
These two sideband signals provide important information from the PSU to the Add-in Card and are therefore required from the power supply. These signals allow the PSU to tell the Add-in Card how much power the Add-in Card can use during both Initial Power Up and Maximum Permitted Power. In the PCI CEM Gen 5 spec these levels are called “Connector Initial Permitted Power” and “Connector Maximum Permitted Power” because they refer to the power limits that can be consumed thorough the Auxiliary Power Connector. The Maximum Permitted Power is the maximum supported by this auxiliary power connector alone. It does not correspond to power consumed through motherboard card edge connector.
The PSU providing the 12VHPWR auxiliary power connector must short the appropriate SENSE signals to ground or leave them open (high impedance) to indicate the power limits associated with the power supply. These SENSE signals must not change state while the Add-in Card is operational.
Support of the SENSE0/SENSE1 sideband signals is required for a PSU. Support for the SENSE0/SENSE1 sideband signals does not rely on any of the other optional sideband signals defined for the 12VHPWR connector.
Table 3-6: PCI Express* 12VHPWR Connector Power Limits
Initial Permitted Power at System Power Up
Maximum Sustain Power after Software Configuration