System and method for enabling a peripheral device expansion card without sideband cable connection

A method comprising:

• determining, by a power management embedded controller, whether a sideband cable is connected to a peripheral device expansion card via a sideband connector, wherein the power management embedded controller is located at the peripheral device expansion card;
• if the sideband cable is connected to the peripheral device expansion card, then transmitting sideband signals from the sideband cable to a card controller for determining a power state of an information handling system;
• and
• if the sideband cable is not connected to the peripheral device expansion card, then transmitting parallelized sideband signals to the card controller for the determining the power state of the information handling system, wherein the parallelized sideband signals were decoded and parallelized from serialized sideband signals, and wherein the serialized sideband signals were serialized by a system board coupled to the peripheral device expansion card.

A peripheral device expansion card to be coupled to an information handling system, comprising:

• a power management embedded controller configured to determine whether a sideband cable is connected to a sideband connector of the peripheral device expansion card, the power management embedded controller is further configured to read serialized sideband signals from a serialized management bus;
• a serial decoder configured to decode and parallelize the serialized sideband signals resulting in parallelized sideband signals, the serial decoder further configured to transmit the parallelized sideband signals to a multiplexer;
• the multiplexer configured to, if the sideband cable is connected to the sideband connector, then transmit sideband signals from the sideband cable to a card controller, wherein the multiplexer is further configured to, if the sideband cable is not connected to the sideband connector, then transmit the parallelized sideband signals to the card controller;
• and
• the card controller configured to receive one of the sideband signals from the sideband cable or the parallelized sideband signals, wherein the card controller is further configured to determine a power state of the information handling system based on the one of the sideband signals from the sideband cable or the parallelized sideband signals.