Ethernet Physical Layer Repeater

• US 20100296519A1
• Filed: 05/21/2009
• Published: 11/25/2010
• Est. Priority Date: 05/21/2009
• Status: Abandoned Application

• Current Assignee: Micrel Incorporated (Microchip Technology Incorporated)
• Original Assignee: Micrel Incorporated (Microchip Technology Incorporated)
• Inventors: Jones, Michael
• Application Number:
  US12/470,368
• Publication Number:
  US 20100296519A1
• Time in Patent Office: Days
• US Class Current: 370/463
• CPC Class Codes: H04L 12/4616 LAN interconnection over a LAN backbone

Abstract

An Ethernet repeater system has a plurality of identical repeaters which add substantially no delay. Each repeater has at least a first port and a second port connected to a medium, and a third port connected to a slave processor or a master processor. The master processor controls all communications on the medium. A receive multiplexer always applies data on the medium to the processor in the event the data is destined for the processor. A first transmit multiplexer has inputs connected to the second port and the processor, and an output connected to the first port. A second transmit multiplexer has inputs connected to the first port and the processor, and an output connected to the second port. The first and second transmit multiplexers act as a bridge between the first and second ports to pass through data without any variable latency since the data does not have to be buffered.

Claims

1. A method performed by nodes in an Ethernet network, at least one node comprising a first slave processor accessing a medium via a first slave repeater, the first slave repeater comprising a plurality of ports including at least a first port and a second port connected to the medium and a third port connected to the first slave processor, the method comprising:

transmitting first data by a master processor onto the medium;

receiving the transmitted first data at the first port of the first slave repeater;

forwarding the first data received at the first port of the first slave repeater to a first input of a receive multiplexer in the first slave repeater;

forwarding, by the receive multiplexer, the first data to the first slave processor connected to the third port of the first slave repeater;

concurrently with forwarding the first data to the first slave processor by the receive multiplexer, passing through the first data between the first port and the second port of the first slave repeater via at least one transmit multiplexer so that the first data continues to travel down the medium for receipt by other slave repeaters and slave processors; and

receiving by a destination slave processor the first data via the destination slave processor'"'"'s repeater, and acting on the first data by the destination slave processor,

wherein the master processor coordinates communications by the slave processors, and wherein passing through the first data between the first port and the second port of the first slave repeater is performed without variable delays requiring buffering.

2. The method of claim 1 wherein the master processor access the medium via a master repeater, and wherein transmitting the first data by the master processor onto the medium comprises:

transmitting the first data by the master processor to an input of the master repeater; and

applying the transmitted first data to a first input of at least a first transmit multiplexer and a second transmit multiplexer in the master repeater, each transmit multiplexer forwarding the first data to an associated port of the master repeater onto the medium.

3. The method of claim 1 wherein forwarding the first data received at the first port of the first slave repeater to the first input of the transmit multiplexer in the first slave repeater comprises forwarding the first data through a physical layer interface between the medium and the transmit multiplexer in the first slave repeater.

4. The method of claim 1 wherein passing through the first data between the first port and the second port of the first slave repeater comprises passing the first data through a physical layer interface between the medium and the first and second ports.

5. The method of claim 1 wherein the first port receives data from an output of a first transmit multiplexer in the first slave repeater, and the second port receives data from an output of a second transmit multiplexer in the first slave repeater,

the first transmit multiplexer having a first input connected to receive data from the second port, and having a second input connected to receive data from the first slave processor;

the second transmit multiplexer having a first input connected to receive data from the first port, and having a second input connected to receive data from the first slave processor;

wherein the first transmit multiplexer connects either its first input or its second input to its output depending on detection of a signal at either its first input or second input; and

wherein the second transmit multiplexer connects either its first input or its second input to its output depending on detection of a signal at either its first input or second input.

6. The method of claim 1 wherein the receive multiplexer has a first input connected to receive data from the first port, has a second input connected to receive data from the second port, and has an output connected to the slave processor,

wherein the receive multiplexer connects either its first input or its second input to its output depending on detection of a signal at either its first input or second input.

7. The method of claim 1 further comprising a plurality of slave processors connected to the medium via an associated slave repeater, wherein each slave repeater is identical to the first slave repeater and operated identically.

8. The method of claim 1 further comprising the first slave processor controlling a device whose actions are coordinated by the master processor.

9. An Ethernet repeater system comprising:

a first repeater having a plurality of ports comprising at least a first port and a second port connected to a medium and a third port connected to a first processor;

the first repeater comprising;

a receive multiplexer having a first input connected to receive data from the first port and having a second input connected to receive data from the second port, an output of the receive multiplexer being connected to the third port;

a first transmit multiplexer having a first input connected to receive data from the second port and having a second input connected to receive data from the third port, an output of the first transmit multiplexer being connected to transmit data to the first port; and

a second transmit multiplexer having a first input connected to receive data from the first port and having a second input connected to receive data from the third port, an output of the second transmit multiplexer being connected to transmit data to the second port,

wherein the receive multiplexer, the first transmit multiplexer, and the second transmit multiplexer forward data applied to their respective first input terminal to their respective output terminal when it is detected that data is being received at their respective first input terminal, and forward data applied to their respective second input terminal to their respective output terminal when it is detected that data is being received at their respective second input terminal.

10. The system of claim 9 wherein the first processor is a first slave processor, the system further comprising a plurality of repeaters identical to the first repeater, some of the repeaters having a slave processor connected to their third port, and one of the repeaters having a master processor connected to its third port, the master processor controlling communications on the medium.

11. The system of claim 9 further comprising a first serial interface connected between the output of the first transmit multiplexer and the first port, and comprising a second serial interface connected between the output of the second transmit multiplexer and the second port, such that pass-through of data between the first port and the second port is always performed with serial data.

12. An Ethernet repeater comprising:

at least a first port and a second port for connection to a medium and a third port for connection to a processor;

a receive multiplexer having a first input connected to receive data from the first port and having a second input connected to receive data from the second port, an output of the receive multiplexer being connected to the third port;

a first transmit multiplexer having a first input connected to receive data from the second port and having a second input connected to receive data from the third port, an output of the first transmit multiplexer being connected to transmit data to the first port; and

a second transmit multiplexer having a first input connected to receive data from the first port and having a second input connected to receive data from the third port, an output of the second transmit multiplexer being connected to transmit data to the second port,

wherein the receive multiplexer, the first transmit multiplexer, and the second transmit multiplexer forward data applied to their respective first input terminal to their respective output terminal when it is detected that data is being received at their respective first input terminal, and forward data applied to their respective second input terminal to their respective output terminal when it is detected that data is being received at their respective second input terminal.

13. The repeater of claim 12 further comprising a first serial interface connected between the output of the first transmit multiplexer and the first port, and comprising a second serial interface connected between the output of the second transmit multiplexer and the second port, such that pass-through of data between the first port and the second port is always performed with serial data.