Patent ID: 8212824
Filing Date: 2012-07-03
Classification: G06F

Abstract:
1. A graphics processing unit, comprising: an interface to receive a context switch command from a central processing unit, the context switch command resulting in the generation of a context switch token; a first processing controller controlling a first set of multi-threaded processors; a second processing controller controlling a second set of multi-threaded processors; a cache communicating with the first processing controller and the second processing controller via a closed loop serial bus arranged to communicatively couple the first processing controller and the second processing controller to the cache in a serial closed loop path that originates at the cache and terminates back at the cache, the closed loop serial bus having a first portion coupling the first processing controller to the cache, a second portion coupling the second processing controller to the cache, and at least one intermediate portion coupling the first processing controller to the second processing controller; wherein the context switch token is passed from the cache to the first processing controller and is subsequently passed to the second processing controller via the closed loop serial bus to initiate preservation of state information from the first processing controller and the second processing controller for a context switch; and wherein the context switch token is directed over the closed loop serial bus from the second processing controller to the cache to indicate completion of receipt of state information from the first processing controller and the second processing controller.