Flexible on-die fabric interface

A method comprising:

• sending an initialization signal on a global channel of an interface, wherein the interface is to couple a controller to a fabric, the controller comprises circuitry to implement a CXL.mem protocol and a CXL.cache protocol, and the global channel is implemented using a first set of wires of the interface;
• receiving, at the controller, a request on a request channel from the fabric, wherein the request channel is implemented using a second set of wires of the interface;
• sending, from the controller, a response on a response channel to the fabric, wherein the response is associated with the request, and the response channel is implemented using a third set of wires of the interface;
• and
• sending flit data from the controller to the fabric on a data channel, wherein the data channel is implemented using a fourth set of wires of the interface.

A system comprising:

• a fabric device;
• controller comprising:
• first protocol circuitry to implement one or more layers of a CXL.io protocol layer;
• second protocol circuitry to implement at least one of a CXL.mem protocol layer or a CXL.cache protocol layer;
• first interface circuitry to implement a first interface to couple the first protocol circuitry to the fabric;
• second interface circuitry to implement a different, second interface to couple the second protocol circuitry to the fabric, wherein the second interface comprises:
• a global channel to use a first set of wires, wherein the global channel is to carry signals for initialization of the interface;
• a request channel to use a second set of wires, wherein the request channel is to carry requests to the fabric;
• a response channel to use a third set of wires, wherein the response channel is to carry responses to the fabric;
• and
• a data channel to use a fourth set of wires, wherein the data channel is to carry data transfers to the fabric.