Flexible on-die fabric interface

A method comprising:

• receiving in a first clock cycle:
• an asserted valid signal on a set of valid lanes of a particular channel of an interface, a first header signal on a set of header lanes of the particular channel, a virtual channel identifier (VC_ID) signal on a set of VC_ID lanes of the particular channel, and a protocol identifier signal on a set of protocol identifier lanes of the particular channel, wherein the interface is to couple an agent to a fabric, the first header signal is to be aligned with the valid signal, the first header signal comprises at least a portion of a header of a packet, the protocol identifier signal identifies a particular one of a plurality of coherent protocols supported on the interface to apply to the packet, and the particular channel comprises one of a plurality of channels of the interface, wherein the plurality of channels comprises a request channel, a data channel, and a response channel;
• receiving, in a subsequent clock cycle:
• the asserted valid signal, an asserted end of packet (EOP) signal on a set of EOP lanes of the particular channel, and a second header signal on the set of header lanes, wherein the second header signal comprises at least a portion of the header of the packet;
• and
• determining an end of the packet based on the asserted EOP signal in the subsequent clock cycle with the asserted valid signal.

A system comprising:

• a fabric;
• and
• a plurality of compute blocks communicatively coupled through the fabric, wherein a particular compute block in the plurality of compute blocks comprises:
• agent circuitry to support a set of coherent interconnect protocols;
• and
• an interface to couple to the fabric, wherein the interface is configured to support the set of coherent interconnect protocols, and the interface comprises:
• a global channel to couple to a first plurality of physical lanes, wherein the global channel is to communicate control signals to support the interface;
• a number of request channels to couple to a second plurality of physical lanes, wherein each of the request channels is to communicate messages associated with requests to other agents on the fabric;
• a number of response channels to couple to a third plurality of physical lanes, wherein each of the response channels is to communicate messages associated with responses to other agents on the fabric, and the responses comprises responses without payload data;
• and
• a number of data channels to couple to a fourth plurality of physical lanes, wherein each of the data channels is to communicate messages associated with data transfers to other agents on the fabric, wherein the data transfers comprise payload data.