Network switch with shared memory system

Abstract

A network switch including a central memory that stores device identification information, port numbers, control information, and packet data received at the ports of the switch. The memory includes a packet section that stores packet data and a device identification section that stores identification entries, where each entry corresponds to a network device coupled to a port of the switch. The switch includes a switch manager to control data flow between the ports and the central memory. Each of the identification entries includes a unique network address to identify one of the network devices and a port number to identify one of the network ports. Each of the identification entries is located within the central memory at a hash address derived by hashing the unique network address. Hash logic receives and hashes each network address to determine a hash address, which is used to access the identification entries. The memory is organized into a chain structure to enable quick access of entries. The switch manager further includes a control memory for storing control registers, including a freepool control register for identifying a freepool chain of memory sectors, a receive control register for identifying a corresponding receive sector chain and a transmit control register for identifying a corresponding transmit packet chain for each of the ports.