Abstract: A packet processor for processing a data unit received from a network includes a header analyzer unit configured to obtain indications of locations in a header of the data unit of one or more fields to be parsed from the data unit to perform a packet processing operation on the data unit. The header analyzer unit comprises a ternary content addressable memory (TCAM), and a memory separate from the TCAM and coupled to an output of the TCAM, wherein a content of the TCAM and a content of the memory are programmable. The header analyzer unit is configured to obtain, responsive to a lookup of at least one portion of the data unit in the TCAM, indications of locations in a header of the data unit of one or more fields to be parsed from the data unit to perform a packet processing operation on the data unit. The packet processor further comprises a parser configured to parse the header using the indications of locations of one or more fields in the header to obtain data from the one or more fields.

Abstract: A method and apparatus that controls the clock of a digital circuit, and therefore power consumption, without substantially comprising performance is provided. The apparatus may include monitoring the utilization of a First in First Out (FIFO) buffer. For example in a systems and methods according to the invention, clock speed may be reduced when the FIFO is relatively empty and increased when the FIFO is relatively full. The clock speed may be controlled by a phase locked loop, a clock divider, a clock masking device or a combination of more than one of these methods. Power reduction may also be obtained by controlling the clocking of different stages of a pipelined device. One or more aspects of the inventions may be implemented in combination with other aspects of the invention to further reduce power use.

Abstract: In a data transfer interface, at least one deserializer receives a serial data stream at a first clock speed and outputs a first parallel data stream at a second clock speed. The first parallel data stream includes data symbols representing data and alignment symbols for aligning the data symbols at a downstream location. A demultiplexer demultiplexes the first parallel data stream into a plurality of second parallel data streams based on the alignment symbols.

Abstract: A switching device comprises a plurality of switch cores, each switch core having a plurality of ports associated with the switch core. Each switch core is configured to perform ingress processing of a data frame using a local source port indicator corresponding to an ingress port selected from a first plurality of ports associated with the switch core. Ingress processing of a data frame includes applying a global target port indicator corresponding to an egress port selected from a second plurality of ports including ports associated with one or more other switch cores among the plurality of switch cores.

Abstract: A method and apparatus that controls the clock of a digital circuit, and therefore power consumption, without substantially comprising performance is provided. The apparatus may include monitoring the utilization of a First in First Out (FIFO) buffer. For example in a systems and methods according to the invention, clock speed may be reduced when the FIFO is relatively empty and increased when the FIFO is relatively full. The clock speed may be controlled by a phase locked loop, a clock divider, a clock masking device or a combination of more than one of these methods. Power reduction may also be obtained by controlling the clocking of different stages of a pipelined device. One or more aspects of the inventions may be implemented in combination with other aspects of the invention to further reduce power use.

Abstract: A method and apparatus that controls the clock of a digital circuit, and therefore power consumption, without substantially comprising performance is provided. The apparatus may include monitoring the utilization of a First in First Out (FIFO) buffer. For example in a systems and methods according to the invention, clock speed may be reduced when the FIFO is relatively empty and increased when the FIFO is relatively full. The clock speed may be controlled by a phase locked loop, a clock divider, a clock masking device or a combination of more than one of these methods. Power reduction may also be obtained by controlling the clocking of different stages of a pipelined device. One or more aspects of the inventions may be implemented in combination with other aspects of the invention to further reduce power use.

Abstract: A method and a computer readable medium having executable instructions are provided. The method and instructions when executed generates a first look-up key from a group of look-up key units stored in a data storage, generation of the first look up key being completed prior to the completion of a key generation processing cycle. A next look-up key unit from the group of look-up key units stored in the data storage may be skipped over when the next look up key corresponds to a second look-up key that has a key length equal to or smaller than a predetermined key length. A third look-up key unit may be selected from the group of look-up key units, the third look-up key unit associated with a third look-up key having a key length greater than a second predetermined key length, the second predetermined key length being greater than the first predetermined key length. The first look-up key and a portion of the third look-up key sequentially may be output during the same output processing cycle.

Abstract: A packet processor for processing a data unit received from a network includes a header analyzer unit configured to obtain indications of locations in a header of the data unit of one or more fields to be parsed from the data unit to perform a packet processing operation on the data unit. The header analyzer unit comprises a ternary content addressable memory (TCAM), and a memory separate from the TCAM and coupled to an output of the TCAM, wherein a content of the TCAM and a content of the memory are programmable. The header analyzer unit is configured to obtain, responsive to a lookup of at least one portion of the data unit in the TCAM, indications of locations in a header of the data unit of one or more fields to be parsed from the data unit to perform a packet processing operation on the data unit. The packet processor further comprises a parser configured to parse the header using the indications of locations of one or more fields in the header to obtain data from the one or more fields.

Abstract: A header analyzer unit generates attribute information regarding headers of a data unit. The header analyzer unit includes a programmable memory unit having a content addressable memory (CAM) with an input to receive a first portion of the data unit and a second portion of the data unit. The programmable memory unit also includes a memory separate from the CAM and coupled to an output of the CAM. The CAM stores indications of locations within the memory separate from the CAM, and the memory separate from the CAM programmably stores header attribute information regarding a plurality of different types of headers for data units having different formats.

Abstract: Resources allocated to a group of ports include a plurality of storage regions. Each storage region includes a committed area and a shared area. A destination storage region is identified for a packet. A packet queuing engine stores the packet in the committed area of the determined destination storage region if it has a first drop precedence value, and if available storage space in the committed area exceeds a first threshold. The packet queuing engine stores the packet in the shared area of the determined destination storage region if the packet is not stored in the committed area, and if available storage space exceeds a second threshold defined by the packet's drop precedence value. If the packet is not stored either in the committed or shared area, it may be dropped.

Abstract: A method and a computer readable medium having executable instructions are provided. The method and instructions when executed generates a first look-up key from a group of look-up key units stored in a data storage, generation of the first look up key being completed prior to the completion of a key generation processing cycle. A next look-up key unit from the group of look-up key units stored in the data storage may be skipped over when the next look up key corresponds to a second look-up key that has a key length equal to or smaller than a predetermined key length. A third look-up key unit may be selected from the group of look-up key units, the third look-up key unit associated with a third look-up key having a key length greater than a second predetermined key length, the second predetermined key length being greater than the first predetermined key length. The first look-up key and a portion of the third look-up key sequentially may be output during the same output processing cycle.

Abstract: At least a portion of a data unit is provided to a programmable memory unit to identify an attribute of a field in a header of the data unit. The header is parsed in response to an output of the programmable memory unit.

Abstract: Systems and techniques for producing a signal with a known phase relationship to a source clock at an output of an indeterminate circuit element such as a clock divider. The systems and techniques may be used to allow circuit test data to be accurately compared with simulation data.

Abstract: Resources allocated to a group of ports include a plurality of storage regions. Each storage region includes a committed area and a shared area. A destination storage region is identified for a packet. A packet queuing engine stores the packet in the committed area of the determined destination storage region if it has a first drop precedence value, and if available storage space in the committed area exceeds a first threshold. The packet queuing engine stores the packet in the shared area of the determined destination storage region if the packet is not stored in the committed area, and if available storage space exceeds a second threshold defined by the packet's drop precedence value. If the packet is not stored either in the committed or shared area, it may be dropped.