PACKET PROCESSING MATCH AND ACTION UNIT WITH CONFIGURABLE BIT ALLOCATION

摘要

A packet processing block. The block has an input for receiving data in a packet header vector, the vector comprising data representing information for a packet and a match unit for performing match operations between packet header vector data and at least one match table. Various embodiments provide advantages in connection with storing certain action or next table bits outside of the match table, or constants in the table, or by forming the match table from multiple unit match table memories.

主权项

1. A packet processing block, comprising:
an input for receiving data in a packet header vector, the vector comprising data representing information for a packet; a match unit comprising at least one match table and for performing match operations between packet header vector data and the at least one match table, the at least one match table comprising a plurality of match entries, each of the match entries comprising an action memory pointer information field of variable bit width; an action memory; circuitry, responsive to the match operations, for performing actions that comprise modifying the packet header vector data, the actions requiring information in the action memory, wherein the action memory is addressed by an action memory pointer comprising a plurality of bits having an action memory pointer bit width; a global action pointer storage for storing a global action memory pointer, separate from the match table; a global action boundary store for describing boundaries of a contiguous set of bits of the action memory pointer to be sourced from the action memory pointer information field; wherein the variable bit width of the action memory pointer information field may be a maximum of the action memory pointer bit width bits wide; wherein the variable bit width of the action memory pointer information field may be a minimum of zero bits wide; wherein the contiguous set of bits of the action memory pointer are sourced from the action memory pointer information field; and wherein bits other than the contiguous set of bits of the action memory pointer are sourced from the global action pointer storage.