Shared control bus for graphics processors with intra-substrate and cross-substrate interfaces

Abstract

Techniques are disclosed relating to a shared control bus for communicating between primary control circuitry and multiple distributed graphics processor units. In some embodiments, a set of multiple graphics processor units including at least first and second graphics processors on different semiconductor substrates that are packaged in a multi-chip module, where the first and second graphics processors are coupled to access graphics data via respective memory interfaces. The shared workload distribution bus may include: one or more interfaces between respective graphics processors on the same semiconductor substrate and at least one cross-substrate interface between the different semiconductor substrates. Workload distribution circuitry may transmit, via the shared workload distribution bus, control data that specifies graphics work distribution to the multiple graphics processor units. Packet control circuitry may modify packets from at least one of the one or more interfaces for transmission via the cross-substrate interface.