Method for Thread Reduction in a Multi-Thread Packet Processor

Abstract

Key lookup operations are broken into two instructions: a Key Dispatch Instruction (KDI), and a Return Result Instruction (RRI). The thread uses KDI to dispatch key information to a selected coprocessor to initiate a key lookup operation. Upon dispatch of the key value to the coprocessor, the KDI is retired to enable the thread to continue to dispatch and retire addition instructions in the pipeline and does not go idle. Subsequently, the thread will issue a RRI to obtain the key lookup result from the coprocessor. While a thread is executing, it maintains, as part of its context, a busy flag per coprocessor in a scoreboard register and a return result register per coprocessor. KDI causes the corresponding busy flag in the scoreboard register to be set. When the key lookup operation is complete, the busy flag is cleared and the result is stored in the return result register.

Dependencies are inferred from the claim text.