摘要:
An example network device includes a processor that is configured to apply specific fields from a packet to an associated memory device and comparing means for comparing input to the memory device with entries in the memory device. The example network device is configured to enable selection of bits, by the memory device, that are required to match exactly with bits from the input to the memory device. The specific fields include a plurality of fields some of which include multiple field values and definitions. An input bit map field of one of the plurality of fields is used to provide an additional global mask that is ANDed to associated masks in selected entries in the memory device thereby enabling the memory device to output an OR of the data in the selected entries and thereby allowing multiple ports to share a rule within a memory device entry.
摘要:
A network device for processing packets. The network devices includes a ingress module for performing lookups for layer 2 switching and performing operations for maintaining a layer 2 table. When the ingress module updates the layer 2 table, the ingress module records the operation performed on the layer 2 table in a modification buffer. Entries are added to the modification buffer when the layer 2 table is modified and in the order in which the layer 2 table was modified. The network device thus enables reconstruction of the layer 2 table by performing the operations in the modification buffer.
摘要:
A network device for processing packets. The network device includes an ingress module for performing switching functions on an incoming packet. The network device also includes a memory management unit for storing packets and performing resource checks on each packet and an egress module for performing packet modification and transmitting the packet to an appropriate destination port. Each of the ingress module, memory management unit and egress module includes multiple cycles for processing instructions and each of the ingress module, memory management unit and egress module processes one packet every clock cycle.
摘要:
A method of handling a datagram in a network device is disclosed. The steps include receiving a datagram, with the datagram having multiple field values, at a port of a network device, parsing the received datagram to obtain the field values, applying the parsed field values to a Ternary Content Addressable Memory (TCAM), determining matches between the parsed field values and predetermined criteria in the TCAM, indexing into a policy table based on the determined matches to obtain an action entry and taking an action based on the obtained action entry.
摘要:
An apparatus for transforming pixel data from a data bus into an expected format for storage in a frame buffer has a first multiplexor, a second multiplexor and a controller. The first multiplexor includes two data inputs coupled to the data bus so that the first data input provides pass-through of received data, and the second data input provides end-for-end byte swapping of bus data. Input selection is made by a byte-swap control signal. The second multiplexor includes an output and four data inputs. The output of the first multiplexor is coupled to each of the four inputs of the second multiplexor so as to provide for end-for-end byte swapping from two of the inputs, end-for-end word swapping from another one of the inputs, and end-for-end half-word swapping from a fourth input. The second multiplexor is responsive to a reorder control signal that alternatively selects one of the first, second, third and fourth inputs of the second multiplexor to be gated to the output of the second multiplexor. The controller generates the byte swap control signal and the reorder control signal. Generation of the byte swap control signal is based on an endian-ness characteristic of the data bus. Generation of the reorder control signal is based on a pixel depth of pixel data on the data bus and is based further on a pixel endian-ness type of pixel data on the data bus.
摘要:
A network device for processing packets. The network devices includes a ingress module for performing lookups for layer 2 switching and performing operations for maintaining a layer 2 table. When the ingress module updates the layer 2 table, the ingress module records the operation performed on the layer 2 table in a modification buffer. Entries are added to the modification buffer when the layer 2 table is modified and in the order in which the layer 2 table was modified. The network device thus enables reconstruction of the layer 2 table by performing the operations in the modification buffer.
摘要:
A network device for processing packets. The network devices includes a ingress module for performing lookups for layer 2 switching and performing operations for maintaining a layer 2 table. When the ingress module updates the layer 2 table, the ingress module records the operation performed on the layer 2 table in a modification buffer. Entries are added to the modification buffer when the layer 2 table is modified and in the order in which the layer 2 table was modified. The network device thus enables reconstruction of the layer 2 table by performing the operations in the modification buffer.
摘要:
A network device for processing packets. The network device includes applying specific fields from a packet to an associated memory device and comparing means for comparing input to the memory device with entries in the memory device. The network device also includes enabling means for enabling selection of bits, by the memory device, that are required to match exactly with bits from the input to the memory device. The network device further includes outputting means for outputting an address for a matched entry by the memory device and applying means for applying a match from the memory device to an associated entry in a table for applying actions from the table that are associated with the match to the packet.
摘要:
In a computer system an apparatus interconnects a first bus, a second bus and a frame buffer, wherein the first bus and the second bus are of incompatible bus architecture types. For example the first bus may be a loosely coupled bus having split-bus transaction capability, such as the ARBus, and the second bus may be a tightly ordered bus, such as the PCI local bus. The apparatus includes bridge hardware for converting access requests from the first bus into suitable requests for the second bus. Data paths within the apparatus allow data to be routed from one bus to another. The apparatus further includes a frame buffer controller that is accessible from either of the first or second buses for performing read or write operations from/to the frame buffer. Data path logic allows data to be routed from any of the first bus, second bus and frame buffer to any other one of these three locations. In a preferred embodiment, the data paths are fabricated on a first integrated circuit, and all of control logic is fabricated on a second integrated circuit. The partitioning of hardware in this manner allows for an efficient interface to be provided between the two chips.
摘要:
The present invention reduces the overhead commonly associated with computer queues by not requiring direct addressing of each location in the queue and by not requiring specialized underflow logic. Furthermore, reads and writes to the computer queue of the present invention can be asynchronous. Lastly, the computer queue of the present invention requires less circuitry and is thus physically smaller, requires less power to operate and can operate more quickly than can queues of the prior art.