High-speed network switch bus

Claim 2

A network switch suitable for interconnecting networks, the network switch comprising: a plurality of ports configured to receive frames from a network and divide the frames into cells, wherein each of the cells include a source port field; a receive FIFO operationally coupled with the plurality of ports and configured to receive the cells from the plurality of ports; a switch bus interface operationally coupled with the receive FIFO and configured to receive the cells from the receive FIFO and transmit the cells over a switch bus, wherein the switch bus interface comprises a bandwidth counter configured to increment after detection of a start-of-frame cell and to decrement after detection of an end-of-frame cell; an end-of-frame timer configured to measure a time since a last end-of-frame cell; a decrement timer configured to reset when the bandwidth counter is decremented; and a decrement FIFO configured to store the time since the last end-of-frame cell, wherein the bus interface is configured to decrement the bandwidth counter when the decrement timer exceeds the time since the last end-of-frame cell.

Claim 3

The network switch of claim 1 , and wherein each of the plurality of ports comprises a media access controller.

Claim 4

The network switch of claim 1 , and wherein the receive FIFO comprises a receive manager and a bus FIFO and wherein the receive manager is configured to coordinate transferring cells from the plurality ports to the bus FIFO based on cell priority.

Claim 5

The network switch of claim 1 , and wherein the bandwidth counter is configured to decrement one latency period after the detection of an end-of-frame cell.

Claim 6

The network switch of claim 1 , and wherein the switch bus interface is further configured to receive cells from another network switch via the switch bus and to route the cells based upon the source port field.

Claim 7

The network switch of claim 5 , and wherein the switch bus interface further comprises a routing table and wherein the switch bus interface is configured to determine routing information by indexing the routing table using the source port field.

Claim 8

The network switch of claim 6 , and wherein the routing table comprises a plurality of entries, wherein each of the entries includes a source port field and a destination field.

Claim 9

A network switch suitable for interconnecting network devices, the network switch comprising: a plurality of ports configured to send data to and receive data from a plurality of network devices; a receive FIFO configured to receive data from the plurality of ports; a transmit FIFO configured to transmit data to the plurality of ports; a bus interface operationally coupled with the receive FIFO and the transmit FIFO and configured to monitor a switch bus and to transmit and receive data over the switch bus, wherein the bus interface includes a bandwidth counter configured to increment after detection of a start-of-frame field and to decrement after detection of an end-of-frame field; a decrement FIFO operationally coupled with the bandwidth counter wherein the bus interface is configured to store end-of-frame data on the decrement FIFO and to decrement the bandwidth counter after the end-of-frame data has been stored on the decrement FIFO for a latency period, and wherein the bandwidth counter includes a low-priority bandwidth counter configured to increment after detection of a low-priority start-of-frame field and to decrement after detection of a low-priority end-of-frame field; and a total bandwidth counter configured to increment after detection of low-priority and high-priority start-of-frame field and to decrement after detection of low-priority and high-priority end-of-frame fields.

Claim 10

A network switch suitable for interconnecting network devices, the network switch comprising: a plurality of ports configured to send data to and receive data from a plurality of network devices; a receive FIFO configured to receive data from the plurality of ports; a transmit FIFO configured to transmit data to the plurality of ports; a bus interface operationally coupled with the receive FIFO and the transmit FIFO and configured to monitor a switch bus and to transmit and receive data over the switch bus, wherein the bus interface includes a bandwidth counter configured to increment after detection of a start-of-frame field and to decrement after detection of an end-of-frame field; a decrement FIFO operationally coupled with the bandwidth counter wherein the bus interface is configured to store end-of-frame data on the decrement FIFO and to decrement the bandwidth counter after the end-of-frame data has been stored on the decrement FIFO for a latency period, and wherein the bandwidth counter includes a low-priority bandwidth counter configured to increment after detection of a low-priority start-of-frame field and to decrement after detection of a low-priority end-of-frame field; and a total bandwidth counter configured to increment after detection of low-priority and high-priority start-of-frame field and to decrement after detection of low-priority and high-priority end-of-frame fields.

Claim 11

The network switch of claim 8 , wherein the decrement FIFO is configured to hold a plurality of entries, wherein each entry includes a type field and a time field and wherein the bus interface is configured to determine a decrement amount based upon the type field and to determine the latency period based upon the time field.

Claim 12

The network switch of claim 9 , and wherein the bus interface is configured to store a time since a last end-of-frame field value in the time field.

Claim 13

The network switch of claim 10 , and wherein the bus interface further comprises a decrement timer configured to reset after decrementing the bandwidth counter and wherein the bus interface is configured to decrement the bandwidth counter when the decrement timer indicates a value which exceeds the time since the last end-of-frame field value.

Claim 14

The network switch of claim 11 , and wherein the data received by the bus interface includes a source port identifier and wherein the bus interface is configured to select an entry from a routing table based upon the source port identification.

Claim 15

The network switch of claim 9 , and wherein the bus interface further comprises a routing table having source field and destination field entries and wherein the bus interface is further configured to route data received over the switch bus based upon the routing table.

Claim 16

The network switch of claim 13 , and wherein the bus interface is further configured to add selectively an entry to the routing table after receiving start-of-frame data.

Claim 17

The network switch of claim 14 , and wherein the bus interface is further configured to invalidate selectively an entry of the routing table after receiving end-of-frame data.

Claim 20

The method of claim 16 , and wherein the step of receiving start-of-frame data comprises receiving high-bandwidth and low-bandwidth start-of-frame data, and wherein the step of incrementing the bandwidth counter comprises incrementing the bandwidth counter by a first amount after receipt of high-bandwidth start-of-frame data and incrementing the bandwidth counter by a second amount after receipt of low-bandwidth start-of-frame data, and wherein the first amount is greater than the second amount.