Mips Technologies, Inc.

Consentry Networks, Inc.

Clearwater Networks, Inc.

Other

Bridge Crossing, LLC

Mario D Nemirovsky

Enrique Musoll

Adolfo M Nemirovsky

Narendra Sankar

Stephen Melvin

Enric Musoll

Nandakumar Sampath

Jeffrey Huynh

Rodolfo Alberto Milito

Thomas Y Yeh

Hector Urdaneta

Jeffery T Huynh

Aldofo Nemirovsky

A multi-streaming processor has a plurality of streams for streaming one or more instruction threads, a set of functional resources for processing instructions from streams, and interrupt handler logic. The logic detects and maps interrupts and exceptions to one or more specific streams. In some embodiments, one interrupt or exception may be mapped to two or more streams, and in others two or more interrupts or exceptions may be mapped to one stream. Mapping may be static and determined at processor design, programmable, with data stored and amendable, or conditional and dynamic, the interrupt logic executing an algorithm sensitive to variables to determine the mapping. Interrupts may be external interrupts generated by devices external to the processor software (internal) interrupts generated by active streams, or conditional, based on variables. After interrupts are acknowledged, streams to which interrupts or exceptions are mapped are vectored to appropriate service routines.

Interrupt and exception handling for multi-streaming digital processors

A method for processing multiple data packets includes receiving from a network interface, at a packet management unit (PMU), a data packet for processing, and determining whether to store or drop the data packet. The method further includes queueing the data packet in a queue within a queueing system and preloading a portion of the data packet into a context from a pool of contexts in a stream processing unit (SPU). The queued data packet referenced by the context is processed by the SPU and outputted to the network interface.

Context sharing between a streaming processing unit (SPU) and a packet management unit (PMU) in a packet processing environment

A multi-streaming processor has a plurality of streams for streaming one or more instruction threads, a set of functional resources for processing instructions from streams, and interrupt handler logic. The logic detects and maps interrupts and exceptions to one or more specific streams. In some embodiments, one interrupt or exception may be mapped to two or more streams, and in others two or more interrupts or exceptions may be mapped to one stream. Mapping may be static and determined at processor design, programmable, with data stored and amendable, or conditional and dynamic, the interrupt logic executing an algorithm sensitive to variables to determine the mapping. Interrupts may be external interrupts generated by devices external to the processor software (internal) interrupts generated by active streams, or conditional, based on variables. After interrupts are acknowledged, streams to which interrupts or exceptions are mapped are vectored to appropriate service routines. In a synchronous method, no vectoring occurs until all streams to which an interrupt is mapped acknowledge the interrupt.

A system for managing packets incoming to a data router has a local packet memory (LPM) mapped into pre-configured memory units, to store packets for processing, an external packet memory (EPM), a first storage system to store packets in the LPM, and a second storage system to store packets in the EPM. The system is characterized in that the first storage system attempts to store all incoming packets in the LPM, and for those packets that are not compatible with the LPM, relinquishes control to the second system, which stores the LPM-incompatible packets in the EPM.

Method and apparatus for overflowing data packets to a software-controlled memory when they do not fit into a hardware-controlled memory

A logic system in a data packet processor is provided for selecting and releasing one of a plurality of contexts. The selected and released context is dedicated for enabling the processing of interrupt service routines corresponding to interrupts generated in data packet processing and pending for service. The system comprises, a first determination logic for determining control status of all of the contexts, a second determination logic for determining if a context is idle or not, a selection logic for selecting a context and a context release mechanism for releasing the selected context. Determination by the logic system that all contexts are singularly owned by an entity not responsible for packet processing and that at least one of the contexts is idle, triggers immediate selection and release of an idle one of the at least one idle contexts to an entity responsible for packet processing.

Context selection and activation mechanism for activating one of a group of inactive contexts in a processor core for servicing interrupts

A multi-streaming processor has a plurality of streams for streaming one or more instruction threads, a set of functional resources for processing instructions from streams; and interstream control mechanisms whereby any stream may effect the operation of any other stream. In various embodiments the interstream control mechanisms include mechanisms for accomplishing one or more of enabling or disabling another stream, putting another stream into a sleep mode or awakening another stream from a sleep mode, setting priorities for another stream relative to access to functional resources, and granting blocking access by another stream to functional resources. A Master Mode is taught, wherein one stream is granted master status, and thereby may exert any and all available control mechanisms relative to other streams without interference by any stream. Supervisory modes are taught as well, wherein control may be granted from minimal to full control, with compliance of controlled streams, which may alter or withdraw control privileges. Various mechanisms are disclosed, including a mechanism wherein master status and interstream control hierarchy is recorded and amended by at least one on-chip bit map. In this mechanism each stream maintains and edits a bitmap granting or withdrawing control privileges for each other stream, the settings valid for any stream but a Master stream, which will ignore the settings.

Interstream control and communications for multi-streaming digital processors

In a data-packet processor, a configurable queuing system for packet accounting during processing has a plurality of queues arranged in one or more clusters, an identification mechanism for creating a packet identifier for arriving packets, insertion logic for inserting packet identifiers into queues and for determining into which queue to insert a packet identifier, and selection logic for selecting packet identifiers from queues to initiate processing of identified packets, downloading of completed packets, or for requeuing of the selected packet identifiers.

Queueing system for processors in packet routing operations

In a multi-streaming processor, a system for fetching instructions from individual ones of multiple streams to an instruction pipeline is provided, comprising a fetch algorithm for selecting from which stream to fetch an instruction, and one or more predictors for forecasting whether a load instruction will hit or miss the cache or a branch will be taken. The prediction or predictions are used by the fetch algorithm in determining from which stream to fetch. In some cases probabilities are determined and also used in decisions, and predictors may be used at either or both of fetch and dispatch stages.

Methods and apparatus for improving fetching and dispatch of instructions in multithreaded processors

A background event buffer manager (BEBM) for ordering and accounting for events in a data processing system having a processor includes a port for receiving event identifications (IDs) from a device, a queuing function enabled for queuing event IDs received, and a notification function for notifying the processor of queued event IDs. The BEBM handles all event ordering and accounting for the processor. The BEBM in preferred embodiments queues events by type with priority and by priority within type, and also handles sending acknowledgement to the device when processing on each event is concluded, and buffers the acknowledgement process. In particular embodiments the apparatus and method is taught as a packet processing router engine.

Methods and apparatus for managing a buffer of events in the background

A multi-streaming processor has a plurality of streams for streaming one or more instruction threads, a set of functional resources for processing instructions from streams, and a lock mechanism for locking selected memory locations shared by streams of the processor, the hardware-lock mechanism operating to set a lock when an atomic memory sequence is started and to clear a lock when an atomic memory sequence is completed. In preferred embodiments the lock mechanism comprises one or more storage locations associated with each stream of the processor, each storage location enabled to store a memory address a lock bit, and a stall bit. Methods for practicing the invention using the apparatus are also taught.

Method and apparatus for implementing atomicity of memory operations in dynamic multi-streaming processors

A context-selection mechanism is provided for selecting a best context from a pool of contexts for processing a data packet. The context selection mechanism comprises, an interface for communicating with a multi-streaming processor; circuitry for computing input data into a result value according to logic rule and for selecting a context based on the computed value and a loading mechanism for preloading the packet information into the selected context for subsequent processing. The computation of the input data functions to enable identification and selection of a best context for processing a data packet according to the logic rule at the instant time such that a multitude of subsequent context selections over a period of time acts to balance load pressure on functional units housed within the multi-streaming processor and required for packet processing. In preferred aspects, programmable singular or multiple predictive rules of logic are utilized in the selection process.

Method and apparatus for optimizing selection of available contexts for packet processing in multi-stream packet processing

A dynamic multistreaming processor has instruction queues, each instruction queue corresponding to an instruction stream, and execution units. The dynamic multistreaming processor also has a dispatch stage to select at least one instruction from one of the instruction queues and to dispatch the selected at least one instruction to one of the execution units. Lastly the dynamic multistreaming processor has a queue counter, associated with each instruction queue, for indicating the number of instructions in each queue, and a fetch counter, associated with each instruction queue, for indicating an address from which to obtain instructions when the associated instruction queue is not full. The dynamic multistreaming processor might also have fetch counters for indicating a next instruction address from which to obtain at least one instruction when the associated instruction queue is not full. The dynamic multistreaming processor could also have a second counter for indicating a next instruction address.

Fetch and dispatch disassociation apparatus for multistreaming processors

A shared memory stores packets for a packet processor. The shared memory is arranged into banks that are word-interleaved. All banks may be accessed in parallel during each time-slot by different requesters. A staggered round-robin arbiter connects requesters to banks in a parallel fashion. Requestor inputs to the arbiter are staggered to allow access to different banks in a sequential order over successive time-slots. Multi-processor tribes have many processors that generate random requests to the shared memory. A slot scheduler arranges these random requests into a stream of sequential requests that are synchronized to the staggered round-robin arbiter. A packet interface requestor stores incoming packets from an external network into the shared memory. The packet's offset within pages of the shared memory is determined by the first available bank that the packet can be written to, eliminating delays in storing incoming packets and spreading storage of frequently-accessed fields.

Packet processor that generates packet-start offsets to immediately store incoming streamed packets using parallel, staggered round-robin arbitration to interleaved banks of memory

A resource-lock monitor detects when processors in a multi-processor system are stuck waiting for access to a shared resource. A lock-monitor register has a lock bit and a sticky-lock bit for each processor being monitored. The lock and the sticky-lock bits are both set when the processor executes a lock instruction that also sends a lock-request to a resource arbiter. The lock bit is cleared when the resource arbiter grants access to the processor, but the sticky-lock bit remains set until sticky-lock bits are cleared by monitoring software at the end of a monitoring period. At the end of each monitoring period, monitoring software reads the lock and sticky-lock bits and finds a locked processor when a processor's lock bit is still set, but its sticky-lock bit is cleared. When the locked processor remains locked at the end of another monitoring period, an error handler resets the locked processor.

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Saratoga, CA, United States of America

Mario D Nemirovsky