A network processor that has multiple processing elements, each supporting multiple simultaneous program threads with access to shared resources in an interface. Packet data is received from high-speed ports in segments and each segment is assigned to one of the program threads. Each packet may be assigned to a single program thread, two program threads - one for header segment processing and the other for handling payload segment(s) - or a different program thread for segment of data in a packet. Dedicated inputs for ready status and sequence numbers provide assistance needed for receiving the packet data over a high speed port. The dedicated inputs are used to monitor ready flags from the high speed ports on a cycle-by-cycle basis. The sequence numbers are used by the assigned threads to maintain ordering of segments within a packet, as well as to order the writes of the complete packets to transmit queues.

Method and apparatus for gigabit packet assignment for multithreaded packet processing

Microengine for parallel processor architecture

A lookup mechanism provides an input value to a datapath element disposed in an execution datapath of a processor and causes the datapath element to compare the input value to stored identifier values. The lookup mechanism receives from the datapath element a result based on the comparison.

A software controlled content addressable memory in a general purpose execution datapath

A method and apparatus for merging multiple misses to a multi-level cache is provided to improve the performance of the cache. A first and second non-blocking cache are each provided with miss queues storing entries corresponding to access requests not serviced by the respective caches. The first and second miss queues have an indicator associable with each of said entries in the respective miss queues indicating that the entry is a primary reference to data located at the address associated with said entry. If a subsequent instruction generates a cache miss accessing data associated with an entry in a miss queue, the subsequent miss is merged with the appropriate entry in the miss queue and serviced when the primary reference is serviced.

Apparatus and method for handling multiple mergeable misses in a non-blocking cache

Managing memory access to random access memory includes fetching a read lock memory reference request and placing the read lock memory reference request at the end of a read lock miss queue if the read lock memory reference request is requesting access to an unlocked memory location and the read lock miss queue contains at least one read lock memory reference request.

Read lock miss control and queue management

A data processor (40) keeps track of misses to a cache (71) so that multiple misses within the same cache line can be merged or folded at reload time. A load/store unit (60) includes a completed store queue (61) for presenting store requests to the cache (71) in order. If a store request misses in the cache (71), the completed store queue (61) requests the cache line from a lower-level memory system (90) and thereafter inactivates the store request. When a reload cache line is received, the completed store queue (61) compares the reload address to all entries. If at least one address matches the reload address, one entry's data is merged with the cache line prior to storage in the cache (71). Other matching entries become active and are allowed to reaccess the cache (71). A miss queue (80) coupled between the load/store unit (60) and the lower-level memory system (90) implements reload folding to improve efficiency.

Betty Y. Kikuta

Papers

Method and apparatus for processing multiple cache misses using reload folding and store merging