Recursive lookup with a hardware trie structure that has no sequential logic elements

摘要

A hardware trie structure includes a tree of internal node circuits and leaf node circuits. Each internal node is configured by a corresponding multi-bit node control value (NCV). Each leaf node can output a corresponding result value (RV). An input value (IV) supplied onto input leads of the trie causes signals to propagate through the trie such that one of the leaf nodes outputs one of the RVs onto output leads of the trie. In a transactional memory, a memory stores a set of NCVs and RVs. In response to a lookup command, the NCVs and RVs are read out of memory and are used to configure the trie. The IV of the lookup is supplied to the input leads, and the trie looks up an RV. A non-final RV initiates another lookup in a recursive fashion, whereas a final RV is returned as the result of the lookup command.