Transactional memory that performs a PMM 32-bit lookup operation

摘要

A transactional memory (TM) receives a lookup command across a bus from a processor. The command includes a memory address. In response to the command, the TM pulls an input value (IV). The memory address is used to read a word containing multiple result values (RVs), multiple reference values, and multiple prefix values from memory. A selecting circuit within the TM uses a starting bit position and a mask size to select a portion of the IV. The portion of the IV is a lookup key value (LKV). Mask values are generated based on the prefix values. The LKV is masked by each mask value thereby generating multiple masked values that are compared to the reference values. Based on the comparison a lookup table generates a selector value that is used to select a result value. The selected result value is then communicated to the processor via the bus.

主权项

1. A method comprising:
(a) sending a lookup command to a transactional memory, wherein the lookup command includes a memory address, and wherein the transactional memory includes a memory unit; (b) sending an input value (IV) to the transactional memory, wherein the memory address is used by the transactional memory to read a word out of the memory unit, wherein the word includes a plurality of result values (RVs), a plurality of reference values, and a plurality of prefix values; wherein the plurality of RVs, the plurality of reference values, the plurality of prefix values, and the IV are used to determine a lookup key value and a selector value; and wherein one of the plurality of RVs is selected based on the selector value.