US 5,862,338 A · Polling system that determines the status of network ports and that stores values indicative thereof

Abstract

A multiport polling system for a network switch including a plurality of network ports, each including receive and transmit buffers. Each port includes port status logic for providing status signals indicative of whether a corresponding port has received data from a network device and whether a corresponding port has available space to receive data to transmit to a network device. The network switch further includes a switch manager for controlling data flow between the ports. The switch manager includes polling logic for periodically polling the port status logic of each port for receiving the status signals, and a memory for storing values indicative of the status signals for each port. In this manner, all of the ports are simultaneously polled in a singe query and the receive and transmit status of each port is maintained in the memory. This facilitates arbitration and control logic, which continuously reviews the memory to determine when to retrieve data from a source port and when to transmit data to one or more destination ports. The ports are preferably implemented with quad cascade devices for providing multiplexed status signals.

Claims18

Dependent claims

A network switch for enabling communication among a plurality of network devices, comprising:

a plurality of network ports that receive data from and transmit data to the network devices, each of said plurality of network ports including port status logic that provides status signals indicative of whether a corresponding network port has received data from a network device and whether a corresponding network port has available space to receive data to transmit to a network device;
and
a switch manager coupled to said plurality of network ports that controls data flow between said plurality of network ports, said switch manager including:
polling logic that periodically polls said port status logic of each of said plurality of network ports and that receives said status signals from said plurality of ports in response to each poll;
and
a memory that stores values indicative of said status signals for each of said plurality of network ports.

3 more elements

A network system, comprising:

a plurality of network devices to send and receive data packets;
and
a network switch coupled to said plurality of network devices that transfers data packets between said network devices, said network switch comprising:
a plurality of network ports, each for coupling to at least one of said plurality of network devices to receive and transmit data packets, each of said plurality of network ports including:
a receive buffer that stores data received from a network device;
a transmit buffer that stores data for transmission to at least one network device;
and
port status logic that provides status signals indicative of whether said receive buffer has received data from a network device and whether said transmit buffer has enough room to receive data to transmit to a network device;
and
a switch manager coupled to said plurality of network ports to control data flow between said plurality of network ports, said switch manager including:
a memory that stores values indicative of said status signals for each of said plurality of network ports;
and
polling logic that periodically polls said port status logic of each of said plurality of network ports, that receives said status signals from the plurality of network ports in response to each poll and that updates said memory.

10 more elements

A polling system for a network switch that continuously determines the receive and transmit status of each of a plurality of ports of the network switch, each of the ports responding to a query signal by providing a corresponding receive status signal indicative of the receive status of that port and providing a corresponding transmit signal indicative of the transmit status of that port, the polling system comprising:

a memory, including:
a receive list indicative of which of the ports have indicated having received data from a network device;
and
a transmit list indicative of which of the ports have indicated being able to receive data to transmit to a network device;
and
polling logic for coupling to each of the ports that periodically asserts a query signal, said polling logic including:
a receive state machine that receives the receive status signal of each of the plurality of ports and that updates said receive list;
and
a transmit state machine that receives the transmit status signal of each of the plurality of ports and that updates said transmit list.

6 more elements

Dependencies are inferred from the claim text.

Polling system that determines the status of network ports and that stores values indicative thereof

Life of this patent

Polling system that determines the status of network ports and that stores values indicative thereof

Life of this patent

Abstract

Claims18