Abstract: Systems and methods for implementing counters in a network processor with cost effective memory are disclosed. Embodiments include systems and methods for implementing counters in a network processor using less expensive memory such as DRAM. A network processor receives packets and implements accounting functions including counting packets in each of a plurality of flow queues. Embodiments include a counter controller that may increment counter values more than once during a R-M-W cycle. Each time a counter controller receives a request to update a counter during a R-M-W cycle that has been initiated for the counter, the counter controller increments the counter value received from memory. The incremented value is written to memory during the write cycle of the R-M-W cycle. A write disable unit disables writes that would otherwise occur during R-M-W cycles initiated for the counter during the earlier initiated R-M-W cycle.

Abstract: A network switch apparatus, components for such an apparatus, and methods of operating such an apparatus in which data flow handling and flexibility is enhanced by the cooperation of a control point and a plurality of interface processors formed on a semiconductor substrate. The control point and interface processors together form a network processor capable of cooperating with other elements including an optional switching fabric device in executing instructions directing the flow of data in a network.

Abstract: A method and structure for determining when a frame of information comprised of one or more buffers of data being transmitted in a network processor has completed transmission is provided. The network processor includes a plurality of control blocks, one for each data buffer, each containing control information to link one buffer to another for transmission. Each of the control blocks has a last bit feature which is a single bit and indicates when the data buffer having the last bit is transmitted. This last bit feature is a bit which can be set to either zero or one. The last bit feature is in a first position when an additional data buffer is to be chained to a previous data buffer indicating an additional data buffer is to be transmitted and a second position when no additional data buffer is to be chained to a previous data buffer.

Abstract: The present invention relates to a device for combining at least two data signals having an input data rate into a single data stream having an output data rate being higher than the input data rate for transmission on a shared medium or vice versa, particularly, to a single SDH/SONET framer capable of handling a large range of SDH/SONET frames from STM-i to STM-j with an aggregated total capacity corresponding to an STM-j frame where i and j are integers in the range from 1 to 64 or higher according to the STM-N definition of the SDH/SONET standards. More over, the present invention can also be extended to work with STS-1 as lowest range. STS-1 exists in SONET only not SDH and corresponds to a data rate of 51.5 Mb/s a third of the 156 Mb/s of STM-1.

Abstract: Novel data structures, methods and apparatus for finding a full match between a search pattern and a pattern stored in a leaf of the search tree. A key is input, a hash function is performed on the key, a direct table (DT) is accessed, and a tree is walked through pattern search control blocks (PSCBs) until reaching a leaf. The search mechanism uses a set of data structures that can be located in a few registers and regular memory, and then used to build a Patricia tree structure that can be manipulated by a relatively simple hardware macro. Both keys and corresponding information needed for retrieval are stored in the Patricia tree structure. The hash function provides an n->n mapping of the bits of the key to the bits of the hash key. The data structure that is used to store the hash key and the related information in the tree is called a leaf. Each leaf corresponds to a single key that matches exactly with the input key. The leaf contains the key as well as additional information.

Abstract: A parallel processing system includes a plurality of stages operatively coupled in parallel and operating simultaneously. Each stage including a process unit generating a predetermined function and a buffer coupled via a slow output and a slow input ports to the process unit. The buffer also includes a fast input port and a fast output port. A controller drives the buffer to operate in a Slow Read Phase when data is written from the buffer into the process unit, a Slow Write Phase when data is written into the buffer from the process unit, a Fast Write Phase when data is written at a fast rate into the buffer and a Fast Read Phase when data is read from the buffer.

Abstract: A system and method of altering frames being processed by a network processing unit. The system includes a set of defined alterations, with some of the alterations being fixed alterations which are advantageously handled by hardware to accomplish the fixed alterations rapidly and without executing a stored program and other alterations which include a variable portion, with these variable alterations being accomplished through the use of stored programs allowing the variables to be used to effect variable alterations to a frame. The present system accommodates a change in the duration of life of a frame or information unit and addition or deletion of bits and also allows for a new cyclic redundancy checking to be accomplished for a revised information unit. Advantageously, the frame alteration system is on the same substrate as the processors.

Abstract: A method and system for reducing memory accesses by inserting qualifiers in control blocks. In one embodiment, a system comprises a processor configured to process frames of data. The processor may comprise a plurality of buffers configured to store frames of data where each frame of data may be associated with a frame control block. Each frame control block associated with a frame of data may be associated with one or more buffer control blocks. Each control block, e.g., frame control block, buffer control block, may comprise one or more qualifier fields that comprise information unrelated to the current control block. Instead, qualifiers may comprise information related to an another control block. The last frame control block in a queue as well as the last buffer control block associated with a frame control block may comprise fields with no information thereby reducing memory accesses to access information in those fields.

Abstract: A system and method of moving information units from an output flow control toward a data transmission network in a prioritized sequence which accommodates several different levels of service. The present invention includes a method and system for scheduling the egress of processed information units (or frames) from a network processing unit according to service based on a weighted fair queue where position in the queue is adjusted after each service based on a weight factor and the length of frame, a process which provides a method for and system of interaction between different calendar types is used to provide minimum bandwidth, best effort bandwidth, weighted fair queuing service, best effort peak bandwidth, and maximum burst size specifications. The present invention permits different combinations of service that can be used to create different QoS specifications.

Abstract: Novel data structures, methods and apparatus for finding a full match between a search pattern and a pattern stored in a leaf of the search tree. A key is input, a hash function is performed on the key, a direct table (DT) is accessed, and a tree is walked through pattern search control blocks (PSCBs) until reaching a leaf. The search mechanism uses a set of data structures that can be located in a few registers and regular memory, and then used to build a Patricia tree structure that can be manipulated by a relatively simple hardware macro. Both keys and corresponding information needed for retrieval are stored in the Patricia tree structure. The hash function provides an n->n mapping of the bits of the key to the bits of the hash key.

Abstract: A network device including an ingress processor and egress processor which receives frames of data over the network on an input port, and transfers it to an appropriate output port. The received frame is processed by an ingress processor which prepares an intra-switch frame for delivery to an egress processor serving a relevant output port of the switch. The intra-switch frame includes a frame header having parameters which have been determined by the ingress processor, as well as data indicating an address for the egress processor for beginning processing of the frame. By identifying to the egress processor processing which has already taken place, the egress processor is relieved of any redundant processing of the frame. The egress processor provides a hardware frame classifier which decodes the information contained in the intra-frame header to derive parameters which have been previously computed as well as a starting address for the egress processor.

Abstract: A control mechanism is established between a network processor and a tree search coprocessor to deal with latencies in accessing the data such as information formatted in a tree structure. A plurality of independent instruction execution threads are queued to enable them to have rapid access to the shared memory. If execution of a thread becomes stalled due to a latency event, full control is granted to the next thread in the queue. The grant of control is temporary when a short latency event occurs or full when a long latency event occurs. Control is returned to the original thread when a short latency event is completed. Each execution thread utilizes an instruction prefetch buffer that collects instructions for idle execution threads when the instruction bandwidth is not fully utilized by an active execution thread. The thread execution control is governed by the collective functioning of a FIFO, an arbiter and a thread control state machine.

Abstract: A stateless message-passing scheme for interactions between a network processor and a coprocessor is provided. The network processor, when receiving data frames for transmission from a network element to another network element encapsulates the entire packet that it receives within a frame. In this frame, there is provided a header field and a data field. The data field contains the data that needs to be transferred, and the header field contains all of the information regarding the deep-processing that the coprocessor is to perform so that no information of any type need be stored either by the network processor or separately regarding the processing of the data in the data packet. The coprocessor performs the operation designated by the header and returns the altered packet and header to the network processor.

Abstract: A method and system for reducing the number of accesses to memory to obtain the desired field information in frame control blocks. In one embodiment of the present invention, a system comprises a processor configured to process frames of data. The processor may comprise a data flow unit configured to receive and transmit frames of data, where each frame of data may have an associated frame control block. Each frame control block comprises a first and a second control block. The processor may further comprise a first memory coupled to the data flow unit configured to store field information for the first control block. The processor may further comprise a scheduler coupled to the data flow unit where the scheduler is configured to schedule frames of data received by data flow unit. The scheduler may comprise a second memory configured to store field information for the second control block.

Abstract: A Network Processor (NP) is formed from a plurality of operatively coupled chips. The NP includes a Network Processor Complex (NPC) Chip coupled to a Data Flow Chip and Data Store Memory coupled to the Data Flow Chip. An optional Scheduler Chip is coupled to the Data Flow Chip. The named components are replicated to create a symmetric ingress and egress structure.

Abstract: A network switch apparatus, components for such an apparatus, and methods of operating such an apparatus in which data flow handling and flexibility is enhanced by the cooperation of a control point and a plurality of interface processors formed on a semiconductor substrate. The control point and interface processors together form a network processor capable of cooperating with other elements including an optional switching fabric device in executing instructions directing the flow of data in a network.

Abstract: A system and method of transmitting multiple output messages from a single input message system where the system is keeping the messages in order by correlating the output messages with the input messages. For each output message, an indicator is associated with the output message indicating whether this output message is the last message being generated for the given input message. This allows multicasting to occur in a system where the output is matched to the input by allowing multiple output messages to be associated with a single input message.

Abstract: A system and method of moving information units from a network processor toward a data transmission network in a prioritized sequence which accommodates several different levels of service. The present invention includes a method and system for scheduling the egress of processed information units (or frames) from a network processing unit according to stored priorities associated with the various sources of the information units. The priorities in the preferred embodiment include a low latency service, a minimum bandwidth, a weighted fair queueing and a system for preventing a user from continuing to exceed his service levels over an extended period. The present invention includes a weighted fair queueing system where the position of the next service in a best efforts system for using bandwidth which is not used by committed bandwidth is determined based on the length of the frame and the weight of the particular flow.

Abstract: Novel data structures, methods and apparatus for finding the longest prefix match search when searching tables with variable length patterns or prefixes. To find the exact match or the best matching prefix, patterns have to be compared a bit at a time until the exact or first match is found. This requires “n” number of comparisons or memory accesses to identify the closest matching pattern. The trees are built in such a way that the matching result is guaranteed to be a best match, whether it is an exact match or a longest prefix match. Using the trail of all the birds and associated prefix lengths enables determination of the correct prefix result from the trail. By construction, the search tree provides the best matching prefix at or after the first compare during walking of the trail or tree.

Abstract: Data structures, a method, and an associated transmission system for IP fragmentation and IP reassembly on network processors in order to minimize memory allocation requirements. Frame data for IP fragmentation or reassembly on a network processor is read into buffers to which are associated various control structures. The control structures permit IP fragmentation or reassembly to be accomplished without creating multiple copies of the frame or fragments.