METHODS TO EXTEND NoC INTERCONNECT ACROSS MULTIPLE DICE IN 3D

Abstract

Embodiments herein describe techniques to extend a network-on-chip (NoC) across multiple IC dice in 3D. An integrated circuit (IC) device includes first and second vertically-stacked IC dice, and an inter-die bus that interfaces between the second die and a NoC packet switch (NFS) of the first die. The inter-die bus may include one or more driver circuits coupled to inter-die links of the inter-die bus. Communications over the inter-die links may be synchronous (e.g., packet-based) or asynchronous with the NFS (e.g., based on a point-to-point protocol, such as an AXI protocol). The inter-die bus may interface with a circuit block of the second IC device via a point-to-point (e.g., AXI) protocol or via a NFS of the second IC die. The IC device may include multiple inter-die buses, which may expand inter-die and intra-die routing options.

Claims

CLAIMSWhat is claimed is:1 . An integrated circuit (IC) device, comprising: first and second vertically-stacked IC dice, wherein the first IC die comprises network-on-chip (NoC) circuitry; and an inter-die bus configured to interface between the packet-switched NoC and the second IC die, wherein the inter-die bus comprises a first driver circuit coupled to inter-die links of the inter-die bus.

2. The IC device of claim 1 , wherein the first driver circuit is further configured to drive packets over the inter-die links synchronous with the NoC circuitry.

3. The IC device of claim 1 , wherein the inter-die bus is further configured to de-packetize a request, and wherein the first driver circuit is further configured to drive the de-packetized request over the inter-die links asynchronous with the NoC circuitry.

4. The IC device of claim 3, wherein the inter-die bus is further configured to de-packetize the request based on a point-to-point protocol, and wherein the first driver circuit is further configured to drive the de-packetized request over the interdie links based on the point-to-point protocol.

5. The IC device of claim 1 , wherein the inter-die bus is configured as a unidirectional inter-die bus.

6. The IC device of claim 1 , wherein the inter-die bus is configured as a bidirectional inter-die bus.

7. The IC device of claim 1 , further comprising one or more additional inter-die buses configured to interface between the packet-switched NoC and the second IC die.

8. The IC device of claim 1 , wherein:the first IC die further comprises a first interface circuit of the inter-die bus and a first NoC packet switch (NPS); the first interface circuit comprises a first master interface circuit configured to receive a first request from the first NPS and de-packetize the first request based on a point-to-point protocol; and the first interface circuit further comprises the first driver circuit, wherein the first driver circuit is further configured to drive the de-packetized first request over the inter-bus links, asynchronously with the NoC circuitry.

9. The IC device of claim 8, wherein: the second IC die comprises a second interface circuit of the inter-die bus and a second NPS; and the second interface circuit comprises a first slave interface circuit configured to receive the de-packetized first request over the inter-die links, re- packetize the de-packetized first request, and forward the re-packetized first request to the second NPS.

10. The IC device of claim 1 , wherein: the first IC die further comprises a first interface circuit of the inter-die bus and a NoC packet switch (NPS); the second IC die further comprises a circuit block configured to output a request based on a point-to-point protocol, and a second interface circuit of the inter-die bus, wherein the second interface comprises the first driver circuit, and wherein the first driver circuit is further configured to drive the request over the inter-die links asynchronous with the packet-switched NoC; and the first interface circuit comprises a NoC slave unit (NSU) configured to receive the request over the inter-die links, packetize the request, and forward the packetized request to the NPS.

11. The IC device of claim 1 , wherein: the first IC die further comprises a first interface circuit of the inter-die bus configured to receive a packetized request from a NoC packet switch (NPS) of the NoC circuitry, wherein the first interface circuit comprises a NoC master unit (NMU) configured to de-packetize the request based on a point-to-point protocol, andwherein the first interface circuit further comprises the first driver circuit configured to drive the de-packetized request over the inter-die links; and the second IC die further comprises a second interface circuit of the inter-die bus, wherein the second interface is configured to provide the de-packetized request to a circuit block of the second IC die.

12. The IC device of claim 11 , wherein: the second IC die further comprises a second driver circuit configured to boost the de-packetized request.

13. An integrated circuit (IC) device, comprising: first and second vertically-stacked IC dice comprising respective first and second network-on-chip (NoC) packet switches (NPSs) of a 3-dimensional (3D) packet-switched NoC; and an inter-die bus configured to interface between the first and second NPSs asynchronous with the 3D packet-switched NoC, wherein the inter-die bus comprises a driver circuit coupled to inter-die links of the inter-die bus.

14. The IC device of claim 13, wherein the first and second IC dice further comprise respective first and second interface circuits of the inter-die bus, and wherein the first and second interface circuits are configured to communicate over the inter-die links based on a point-to-point protocol.

15. An integrated circuit (IC) device, comprising: first and second vertically-stacked IC dice, wherein the first IC die comprises a network-on-chip (NoC) packet switch (NPS) of a packet-switched NoC; and a dedicated inter-die bus configured to interface between the NPS and a circuit block of second IC die asynchronous with the packet-switched NoC based on a point-to-point protocol, wherein the inter-die bus comprises a driver circuit coupled to inter-die links of the inter-die bus.

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