Die-to-die adapter

A method comprising:

• determining parameters of a die-to-die (D2D) link to couple a first die to a second die;
• selecting, based on the parameters, a particular flit format a plurality of different flit formats supported for use on the D2D link, wherein the D2D link is to comprise a mainband channel utilizing a first set of lanes and a separate sideband channel utilizing a second set of lanes;
• receiving, at a D2D adapter of the first die, a flit according to the particular flit format from a protocol layer block on the first die, wherein the flit comprises a plurality of fields, a first subset of the plurality of fields are populated by the protocol layer block prior to transmission of the flit from the protocol layer block to the D2D adapter, and a second subset of the plurality of fields are reserved to be populated by the D2D adapter;
• generating, at the D2D adapter, information to populate the second subset of the plurality of fields;
• and
• sending the flit with the information inserted in the second subset of the plurality of fields from the D2D adapter to a physical layer (PHY) block on the first die, wherein the PHY block is to transmit the flit over the mainband channel of the D2D link to the second die.

A system comprising:

• a first die;
• a second die coupled to the first die by a die-to-die (D2D) link, wherein the second die comprises a port to connect the second die to the D2D link, and the port comprises:
• protocol layer logic to implement a particular interconnect protocol;
• D2D adapter circuitry;
• and
• physical layer (PHY) circuitry to implement a mainband channel on a first set of lanes of the D2D link and implement a sideband channel on a second set of lanes on the D2D link;
• wherein the D2D adapter circuitry is to:
• identify a particular flit format in a plurality of different flit formats for use on the D2D link;
• receive a flit according to the particular flit format from the protocol layer block, wherein the flit comprises a plurality of fields, a first subset of the plurality of fields are populated by the protocol layer block prior to transmission of the flit from the protocol layer block to the D2D adapter circuitry, and a second subset of the plurality of fields are reserved to be populated by the D2D adapter circuitry;
• generate information to populate the second subset of the plurality of fields;
• and
• send the flit with the information inserted in the second subset of the plurality of fields from the D2D adapter circuitry to the PHY circuitry,
• wherein the PHY circuitry is to send the flit from the first die to the second die over the D2D link.