Abstract: Prefixes terminating with end node entries each containing identical length prefix portions in a single child table are compressed by replacing the end node entries with one or more compressed single length (CSL) prefix entries in the child table that contain a bitmap for the prefix portions for the end node entries. A different type parent table trie node entry is created for the child table. Where the prefix portions are of non-zero length, the parent table contains a bitmap indexing the end node entries. Where the prefix portions are of length zero, the parent table may optionally contain a bitmap for the prefix portions, serving as an end node. The number of prefix portions consolidated within the CSL node entry is based upon the prefix portion length.

Abstract: A multi-bit trie network search engine is implemented by a number of pipeline logic units corresponding to the number of longest-prefix strides and a set of memory blocks for holding prefix tables. Each pipeline logic unit is limited to one memory access, and the termination point within the pipeline logic unit chain is variable to handle different length prefixes. The memory blocks are coupled to the pipeline logic units with a meshed crossbar and form a set of virtual memory banks, where memory blocks within any given physical memory bank may be allocated to a virtual memory bank for any particular pipeline logic unit. An embedded programmable processor manages route insertion and deletion in the prefix tables, together with configuration of the virtual memory banks.

Abstract: A series of hardware pipeline units each processing a stride during prefix search operations on a multi-bit trie includes, within at least one pipeline unit other than the last pipeline unit, a mechanism for retiring search results from the respective pipeline unit rather than passing the search results through the remaining pipeline units. Early retirement may be triggered by either the absence of subsequent strides to be processed or completion (a miss or end node match) of the search, together with an absence of active search operations in subsequent pipeline units. The early retirement mechanism may be included in those pipeline units corresponding to a last stride for a maximum prefix length shorter than the pipeline (e.g., 20 or 32 bits rather than 64 bits), in pipeline units selected on some other basis, or in every pipeline unit. Worst-case and/or average latency for prefix search operations is reduced.

Abstract: Sparsely distributed prefixes within a bitmapped multi-bit trie are compressed by: replacing a single entry table string terminating with a single prefix end node with a parent table entry explicitly encoding a prefix portion; replacing a table with only two end nodes or only an end node and an internal node with a single parent table entry explicitly encoding prefix portions; replacing two end nodes with a single compressed child entry at a table location normally occupied by an internal node and explicitly encoding prefix portions; and/or replacing a plurality of end nodes with a prefix-only entry located at the table end explicitly encoding portions of a plurality of prefixes. The compressed child entry and the prefix-only entry, if present, are read by default each time the table is searched. Run length encoded allows variable length prefix portions to be encoded.

Abstract: A power estimation tool allows the designer to estimate power usage, at the RTL stage for example, of a high performance electronic system design using available information. This enables power estimation before the circuit schematics are created and early enough for power dissipation to be included in the design optimization. The estimation tool, operable at the RTL level, may provide estimates of power usage of functional blocks and the overall system. The tool can take an HDL description of the proposed design and partition that description into a format which can be analyzed for power usage in an automated fashion. The estimated power use can also be modified to account for different circuit design techniques such domino versus static designs and to account for capacitance and layout considerations. In addition, an empirical estimator for clock and data buffer power usage allows these elements to be accounted for before their design is completed.