WO2021147005A1

WO2021147005A1 - Apparatus for executing re-timing and path switching method

Info

Publication number: WO2021147005A1
Application number: PCT/CN2020/073835
Authority: WO
Inventors: 聂耳; 马玉龙; 郭健
Original assignee: 华为技术有限公司
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2021-07-29
Also published as: CN115004165A

Abstract

Provided in the embodiments of the present application are an apparatus for executing re-timing and a path switching method, the apparatus comprising: a first path, a second path, and a controller, the controller being used for switching from the first path to the second when it is determined that the transmission rate of first data transmitted on the first path meets a pre-arranged first condition, in order to transmit second data on the second path; the latency of the second path is lower than the latency of the first path, the first data is path training data, and the second data is service data. In the present apparatus, after determining that the transmission rate of the first data transmitted on the first path meets a pre-arranged first condition, the controller can switch the currently used first path to the second path in order to transmit second data by means of the second path; as the latency of the second path is lower than the latency of the first path, transmitting service data on the second path can effectively reduce latency to meet the requirements of different service scenarios.

Description

Device for performing retiming and method for path switching

Technical field

The embodiments of the present application relate to the field of computer technology, and in particular, to a path switching method and related devices.

Background technique

In computer systems, high-speed serial links based on the high-speed Peripheral Component Interface Express (PCIE) standard have been widely used. In order to reduce the medium insertion loss during the use of the link, a retimer can be serialized in the link to relay the signal in the link and filter out the link jitter.

After the receiver of the retimer receives the data, the controller will perform a series of complex processing on the data before forwarding, such as asynchronous and frequency offset removal processing first, then descrambling and data alignment processing, and then corresponding modification , And perform scrambling and encoding processing, and finally forward the data through the transmitter.

However, because the controller in the retimer needs to perform complicated processing on the received data before forwarding, the data delay in the retimer is very large (usually up to 40ns), and certain business scenarios that are sensitive to delay will Have a greater impact.

Summary of the invention

The embodiments of the present application provide a device for performing retiming and a method for path switching, which can effectively reduce the delay to meet the requirements of different business scenarios.

The first aspect of the embodiments of the present application provides a device for performing retiming. The device may be a retimer and includes: a first path, a second path, and a controller.

The controller is configured to switch the first path to the second path to transmit the second data based on the second path when it is determined that the transmission rate of the first data transmitted by the first path satisfies the preset first condition. The delay of the second path is lower than the delay of the first path, the first data is path training data, and the second data is service data.

It can be seen from the above retimer that the second path has a lower delay than the first path. After the retimer judges that the transmission rate of the first data transmitted by the first path meets the preset first condition, the first path can be switched to the second path, that is, exit from the normal path and enter the low-delay path, based on the low-delay path Perform business data transmission. Therefore, through path switching, the transmission of service data based on the second path can effectively reduce the delay to meet the requirements of different service scenarios.

With reference to the first aspect of the embodiments of the present application, in the first implementation manner of the first aspect of the embodiments of the present application, the first data is training ordered set TS2 data, which improves the flexibility and selectivity of the solution.

In combination with the first implementation manner of the first aspect of the embodiments of the present application, in the second implementation manner of the first aspect of the embodiments of the present application, the preset first condition includes: the transmission rate is equal to the preset rate, which improves the solution Flexibility and selectivity.

In combination with the second implementation manner of the first aspect of the embodiments of the present application, in the third implementation manner of the first aspect of the embodiments of the present application, the preset first condition further includes: TS2 data does not have a rate switching request, There is no request to enter the loopback state and no request to enter the prohibited state, which improves the flexibility and selectivity of the scheme.

In combination with the first aspect of the embodiments of the present application and any one of the first to third implementation manners of the first aspect of the embodiments of the present application, in the fourth implementation manner of the first aspect of the embodiments of the present application , The device further includes: a receiver for receiving the first data and the second data, a receiver for sending the first data and the second data, the first path is coupled to the receiver and the transmitter, and the first path is also connected To the controller, the second path is coupled to the receiver and transmitter;

The controller is also used to set the first path to the unavailable state and the second path to the available state when it is determined that the transmitter has completed the handover preparation, so as to transmit the second data based on the second path, which improves the solution Flexibility and selectivity.

In combination with the fourth implementation manner of the first aspect of the embodiments of the present application, in the fifth implementation manner of the first aspect of the embodiments of the present application, before switching the first path to the second path, the controller is also used for Modifying the data that the transmitter can send into pseudo-random binary sequence PRBS data improves the flexibility and selectivity of the scheme.

In combination with the fifth implementation manner of the first aspect of the embodiments of the present application, in the sixth implementation manner of the first aspect of the embodiments of the present application, after the first path is switched to the second path, the controller is also used for Modifying the data that the transmitter can send to the data received by the receiver improves the flexibility and selectivity of the scheme.

In combination with the first aspect of the embodiments of the present application and any one of the first to sixth implementation manners of the first aspect of the embodiments of the present application, in the seventh implementation manner of the first aspect of the embodiments of the present application , In the second path, a polarity reversal circuit is also provided between the receiver and the transmitter;

When the polarity of the second data transmitted by the second path is opposite, the polarity inversion circuit is used to invert the polarity of the second data, which improves the flexibility and selectivity of the solution.

With reference to the seventh implementation manner of the first aspect of the embodiments of the present application, in the eighth implementation manner of the first aspect of the embodiments of the present application, the controller is further configured to determine that the first data transmitted by the second path meets the predetermined requirements. When the second condition is set, the second path is switched to the first path to transmit the second data based on the first path, which improves the flexibility and selectivity of the solution.

In combination with the eighth implementation manner of the first aspect of the embodiments of the present application, in the ninth implementation manner of the first aspect of the embodiments of the present application, the preset second condition includes: TS2 data has a request for rate switching, and has a balance Redo requests, requests with exit prohibited state, or requests with exit hot reset state, improve the flexibility and selectivity of the solution.

In combination with the ninth implementation manner of the first aspect of the embodiments of the present application, in the tenth implementation manner of the first aspect of the embodiments of the present application, the controller is further configured to: The second path is set to an unavailable state, and the first path is set to an available state to transmit the second data based on the first path, which improves the flexibility and selectivity of the solution.

In combination with the tenth implementation manner of the first aspect of the embodiments of the present application, in the eleventh implementation manner of the first aspect of the embodiments of the present application, before switching the second path to the first path, the controller also uses In order to modify the data that the transmitter can send into PRBS data, the flexibility and selectivity of the scheme are improved.

With reference to the eleventh implementation manner of the first aspect of the embodiments of the present application, in the twelfth implementation manner of the first aspect of the embodiments of the present application, after switching the second path to the first path, the controller further It is used to modify the data that the transmitter can send to the data received by the receiver, which improves the flexibility and selectivity of the scheme.

A second aspect of the embodiments of the present application provides a method for path switching, which is implemented by a device for performing retiming. The device includes: a first path, a second path, and a controller; the method includes:

When it is determined by the controller that the transmission rate of the first data transmitted by the first path meets the preset first condition, the controller switches the first path to the second path to transmit the second data based on the second path, wherein , The delay of the second path is lower than the delay of the first path, the first data is path training data, and the second data is service data.

It can be seen from the above method: because the second path has a lower delay than the first path. After the retimer judges that the transmission rate of the first data transmitted by the first path meets the preset first condition, the first path can be switched to the second path, that is, exit from the normal path and enter the low-delay path, based on the low-delay path Perform business data transmission. Therefore, through path switching, the transmission of service data based on the second path can effectively reduce the delay to meet the requirements of different service scenarios.

With reference to the second aspect of the embodiments of the present application, in the first implementation of the second aspect of the embodiments of the present application, the first data is training ordered set TS2 data, which improves the flexibility and selectivity of the solution.

With reference to the first implementation manner of the second aspect of the embodiments of the present application, in the second implementation manner of the second aspect of the embodiments of the present application, the preset first condition includes: the transmission rate is equal to the preset rate, which improves the solution Flexibility and selectivity.

In combination with the second implementation manner of the second aspect of the embodiments of the present application, in the third implementation manner of the second aspect of the embodiments of the present application, the preset first condition further includes: TS2 data does not have a request for rate switching, There is no request to enter the loopback state and no request to enter the prohibited state, which improves the flexibility and selectivity of the scheme.

In combination with the second aspect of the embodiments of the present application and any one of the first to third implementation manners of the second aspect of the embodiments of the present application, in the fourth implementation manner of the second aspect of the embodiments of the present application , The device further includes: a receiver for receiving the first data and the second data, a receiver for sending the first data and the second data, the first path is coupled to the receiver and the transmitter, and the first path is also connected To the controller, the second path is coupled to the receiver and transmitter;

Switching the first path to the second path by the controller to transmit the second data based on the second path includes:

When it is determined by the controller that the transmitter has completed the handover preparation, the controller sets the first path to the unavailable state and sets the second path to the available state to transmit the second data based on the second path, which improves the solution Flexibility and selectivity.

In combination with the fourth implementation manner of the second aspect of the embodiments of the present application, in the fifth implementation manner of the second aspect of the embodiments of the present application, before the first path is switched to the second path by the controller, the method further include:

The controller modifies the data that the transmitter can send into pseudo-random binary sequence PRBS data, which improves the flexibility and selectivity of the scheme.

With reference to the fifth implementation manner of the second aspect of the embodiments of the present application, in the sixth implementation manner of the second aspect of the embodiments of the present application, after the first path is switched to the second path by the controller, the method further include:

The controller modifies the data that the transmitter can send to the data received by the receiver, which improves the flexibility and selectivity of the scheme.

In combination with the second aspect of the embodiments of the present application and any one of the first to sixth implementation manners of the second aspect of the embodiments of the present application, in the seventh implementation manner of the second aspect of the embodiments of the present application In the second path, a polarity reversal circuit is also provided between the receiver and the transmitter, and the method further includes:

When the polarity of the second data transmitted by the second path is reversed, the polarity of the second data is reversed by the polarity reversal circuit, which improves the flexibility and selectivity of the solution.

With reference to the seventh implementation manner of the second aspect of the embodiments of the present application, in the eighth implementation manner of the second aspect of the embodiments of the present application, the method further includes:

When the controller determines that the first data transmitted by the second path meets the preset second condition, the controller switches the second path to the first path to transmit the second data based on the first path, which improves the solution Flexibility and selectivity.

In combination with the eighth implementation manner of the second aspect of the embodiments of the present application, in the ninth implementation manner of the second aspect of the embodiments of the present application, the preset second condition includes: TS2 data has a request for rate switching, and has a balance Redo requests, requests with exit prohibited state, or requests with exit hot reset state, improve the flexibility and selectivity of the solution.

In combination with the ninth implementation manner of the second aspect of the embodiments of the present application, in the tenth implementation manner of the second aspect of the embodiments of the present application, the second path is switched to the first path by the controller, so as to be based on the first path. The path transmission of the second data includes:

The controller is also used to set the second path to an unavailable state and set the first path to an available state when it is determined that the transmitter has completed the handover preparation, so as to transmit the second data based on the first path, which improves the solution Flexibility and selectivity.

With reference to the tenth implementation manner of the second aspect of the embodiments of the present application, in the eleventh implementation manner of the second aspect of the embodiments of the present application, before switching the second path to the first path, the controller also uses In order to modify the data that the transmitter can send into PRBS data, the flexibility and selectivity of the scheme are improved.

With reference to the eleventh implementation manner of the second aspect of the embodiments of the present application, in the twelfth implementation manner of the second aspect of the embodiments of the present application, after switching the second path to the first path, the controller further It is used to modify the data that the transmitter can send to the data received by the receiver, which improves the flexibility and selectivity of the scheme.

A third aspect of the embodiments of the present application provides a device for performing retiming, and the device includes:

Receiver, used to receive data;

Transmitter, used to send data;

The first path is coupled to the receiver and the transmitter, and the first path is also connected to the controller;

The second path, which is coupled to the receiver and the transmitter, is used to transmit the data received by the receiver to the transmitter;

The controller is configured to switch the second path to the first path to transmit the second data based on the first path when it is determined that the first data transmitted by the second path meets the preset second condition, where the second path The delay of is lower than the delay of the first path, the first data is path training data, and the second data is service data.

With reference to the third aspect of the embodiments of the present application, in the first implementation manner of the third aspect of the embodiments of the present application, the first data is training ordered set TS2 data, which improves the flexibility and selectivity of the solution.

In combination with the first implementation manner of the third aspect of the embodiments of the present application, in the second implementation manner of the third aspect of the embodiments of the present application, the preset second condition includes: TS2 data has a request for rate switching, and has a balance Redo requests, requests with exit prohibited state, or requests with exit hot reset state, improve the flexibility and selectivity of the solution.

With reference to the second implementation manner of the third aspect of the embodiments of the present application, in the third implementation manner of the third aspect of the embodiments of the present application, the device further includes: a receiver for receiving the first data and the second data , A receiver for transmitting the first data and the second data, the first path is coupled to the receiver and the transmitter, the first path is also connected to the controller, and the second path is coupled to the receiver and the transmitter;

In combination with the third implementation manner of the third aspect of the embodiments of the present application, in the fourth implementation manner of the third aspect of the embodiments of the present application, before switching the second path to the first path, the controller is also used for Modifying the data that the transmitter can send into PRBS data improves the flexibility and selectivity of the scheme.

In combination with the third implementation manner or the fourth implementation manner of the third aspect of the embodiments of the present application, in the fifth implementation manner of the third aspect of the embodiments of the present application, after the second path is switched to the first path , The controller is also used to modify the data that the transmitter can send to the data received by the receiver, which improves the flexibility and selectivity of the scheme.

The fourth aspect of the present application also provides a method for path switching, which is implemented by a device for performing retiming. The device includes: a first path, a second path, and a controller; the method includes:

When it is determined by the controller that the first data transmitted by the second path meets the preset second condition, the controller switches the second path to the first path to transmit the second data based on the first path, where the second path The delay of the path is lower than the delay of the first path, the first data is path training data, and the second data is service data.

With reference to the fourth aspect of the embodiments of the present application, in the first implementation manner of the fourth aspect of the embodiments of the present application, the first data is training ordered set TS2 data, which improves the flexibility and selectivity of the solution.

In combination with the first implementation manner of the fourth aspect of the embodiments of the present application, in the second implementation manner of the fourth aspect of the embodiments of the present application, the preset second condition includes: TS2 data has a request for rate switching, and has a balance Redo requests, requests with exit prohibited state, or requests with exit hot reset state, improve the flexibility and selectivity of the solution.

With reference to the second implementation manner of the fourth aspect of the embodiments of the present application, in the third implementation manner of the fourth aspect of the embodiments of the present application, the device further includes: a receiver for receiving the first data and the second data , A receiver for transmitting the first data and the second data, the first path is coupled to the receiver and the transmitter, the first path is also connected to the controller, and the second path is coupled to the receiver and the transmitter;

Switching the second path to the first path by the controller to transmit the second data based on the first path includes:

When it is determined by the controller that the transmitter has completed the handover preparation, the second path is set to the unavailable state by the controller, and the first path is set to the available state to transmit the second data based on the first path, which improves the solution Flexibility and selectivity.

In combination with the third implementation manner of the fourth aspect of the embodiments of the present application, in the fourth implementation manner of the fourth aspect of the embodiments of the present application, before the second path is switched to the first path by the controller, the method Also includes:

The data that can be sent by the transmitter is modified into PRBS data through the controller, which improves the flexibility and selectivity of the scheme.

In combination with the third implementation manner or the fourth implementation manner of the fourth aspect of the embodiments of the present application, in the fifth implementation manner of the fourth aspect of the embodiments of the present application, the second path is switched to the second path through the controller. After a path, the method also includes:

The fifth aspect of the embodiments of the present application also provides a PCIE system, which includes:

The first PCIE device;

The second PCIE device;

The apparatus for performing retiming as in any one of the first aspect and the third aspect, which is coupled to the first PCIE device and the second PCIE device, so that two PCIE devices are provided between the first PCIE device and the second PCIE device. Data flow in the direction.

An embodiment of the present application provides a device for performing retiming and a method for path switching, where the device includes: a first path, a second path, and a controller, and the controller is used to determine the first path to transmit in the first path. When the data transmission rate meets the preset first condition, the first path is switched to the second path to transmit the second data based on the second path, where the delay of the second path is lower than the delay of the first path, One data is path training data, and the second data is business data. In the above device, the controller can switch the currently used first path to the second path to transmit the second data through the second path after judging that the transmission rate of the first data transmitted by the first path satisfies the preset first condition, Since the delay of the second path is lower than the delay of the first path, the transmission of service data based on the second path can effectively reduce the delay to meet the requirements of different service scenarios.

Description of the drawings

FIG. 1 is a schematic structural diagram of a PCIE system provided by an embodiment of the application;

FIG. 2 is a schematic structural diagram of a retimer provided by an embodiment of the application;

FIG. 3 is a schematic diagram of another structure of a retimer provided by an embodiment of the application;

FIG. 4 is a schematic diagram of another structure of a retimer provided by an embodiment of the application;

FIG. 5 is a schematic flowchart of a path switching method provided by an embodiment of the application.

Detailed ways

The technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application.

The embodiment of this application can be applied to a PCIE system set based on the PCIE standard. FIG. 1 is a schematic structural diagram of the PCIE system provided by an embodiment of this application. As shown in FIG. 1, the PCIE system includes: a first PCIE device, a first PCIE device, and a second PCIE device. Two PCIE equipment and a device for performing retiming, where the first PCIE device and the second PCIE can be personal computers, servers, data centers, etc., and there is no specific limitation here, but the device for performing retiming can be To retimer, two PCIE devices can be coupled to one or more retimers (only one retimer is shown in Figure 1). The retimer provides a link (path) for two PCIE devices, so that the two PCIE devices can communicate and realize information exchange.

FIG. 2 is a schematic structural diagram of the retimer provided by the embodiment of the application. Please refer to FIG. 2. The retimer includes a receiver 201, a transmitter 202, and a controller 203. The receiver 201 can start from the first PCIE The device receives the data, the controller 203 can perform corresponding processing on the data received by the receiver 201, and the transmitter 202 can send the processed data to the second PCIE device. Furthermore, the retimer further includes: a first path 204 (normal path) and a second path 205 (low delay path), wherein the first path 204 is coupled to the receiver 201 and the transmitter 202, and the first path 204 Also connected to the controller 203. The second path 205 is coupled to the receiver 201 and the transmitter 202.

When two PCIE devices perform data transmission based on the first path 204, the receiver 201 first sends the data to the controller 203 for processing after receiving the data from the first PCIE device, and the transmitter 202 then transmits the processed data It is sent to the second PCIE device, so the delay of the first path 204 includes the delays of the receiver 201, the controller 203, and the transmitter 202. However, the second path 205 does not include the controller 203. When data is transmitted based on the second path 205, the data does not need to be processed by the controller 203. After the data from the first PCIE device passes through the receiver 201, the transmitter 202 can directly send data to the second PCIE device, so the delay of the second path 205 only includes the delays of the receiver 201 and the transmitter 202, that is, the second path 205 has a lower delay than the first path 204.

It should be understood that in the above example, the first PCIE device is used as a device for sending data, and the second PCIE device is used as a device for receiving data. In a possible implementation manner, the second PCIE device can be used as a device for sending data, and the first PCIE device Can be used as a device for receiving data.

Based on the PCIE standard, when the PCIE system is in the normal working state (that is, the L0 state), if an error or a certain demand occurs in the path state (for example, the path state changes), the system can enter the recovery state (recovery state) from the L0 state , To retrain the path. During the path retraining process, the retimer can switch between the first path 204 and the second path 205.

The path switching performed by the retimer includes two situations. One is to enter the low-delay path, that is, from the first path 204 to the second path 205, and the other is to exit the low-delay path, that is, from the second path 205. Entering the first path 204, the case of entering the low-delay path will be introduced first.

As shown in FIG. 2, suppose that the path currently used by the PCIE system to transmit data is the first path 204. When the PCIE system enters the recovery state from the L0 state, the retimer can switch the path. During the path retraining stage, the PCIE system can transmit the first data (that is, path training data) through the first path to implement path retraining. The controller 203 of the retimer switches the first path 204 to the second path 205 when it determines that the transmission rate of the first path 204 to transmit the first data satisfies the preset first condition. At this time, the PCIE system is currently used for The data transmission path is changed to the second path 205, so the second data, that is, service data, can be transmitted based on the second path 205 in the subsequent stage.

When the controller 203 determines whether the transmission rate meets the preset first condition, that is, when it determines that the PCIE system meets the preset first condition for entering the second path 205, it may switch the first path 204 to the second path 205, to transmit the second data through the second path 205. Since the second path 205 does not include the controller 203, after the receiver 201 receives the data, the data does not need to be processed by the controller 203 and can be directly sent The relay 202 performs forwarding, which can effectively reduce the delay to meet the requirements of different business scenarios.

When the PCIE system enters the recovery state from the L0 state, the first PCIE device and the second PCIE device can start to transmit data for path training, such as TS1 data, TS2 data, etc., based on the first path. After the TS1 data transmission stage is completed between the first PCIE device and the second PCIE device, the TS2 data transmission stage is entered. In a possible implementation manner, the first data transmitted by the first path 204 is TS2 data. Specifically, the controller 203 of the retimer will detect in real time whether the receiver 201 has received TS2 data. If the controller 203 determines that the receiver 201 has received TS2 data, it will obtain the current transmission rate of the PCIE system, which is the first A path 204 transmits the transmission rate of the first data. After acquiring the transmission rate, the controller 203 can determine whether the transmission rate satisfies the preset first condition to determine whether the second path 205 can be entered from the first path 204.

In order to enter the second path 205 from the first path 204, the controller 203 needs to determine whether the transmission rate of the first data transmitted by the first path 204 meets a preset first condition, which can be set according to actual needs. In a possible implementation manner, the preset first condition includes: the transmission rate is equal to the preset rate (a rate set in advance). Furthermore, the preset first condition further includes: TS2 data does not have a request for rate switching, does not have a request to enter a loopback state, and does not have a request to enter a prohibited state. Specifically, the controller 203 can analyze the TS2 data and the transmission rate. If the controller 203 determines that the TS2 data does not have the request for rate switching, the request for entering the loopback state, and the request for entering the prohibited state, and the transmission rate is equal to the preset Rate, it is determined that the PCIE system satisfies the preset first condition for entering the second path 205.

The controller 203 can switch between the first path 204 and the second path 205 after determining that the PCIE system meets the preset first condition for entering the second path. In a possible implementation manner, the controller 203 can first modify the data that the transmitter 202 can send to PRBS data. Because the type of data that the transmitter 202 can send has changed, the transmission of TS2 data is restricted. . After the controller 203 determines that the transmitter is ready to switch, the controller 203 sets the first path 204 to an unavailable state and sets the second path 205 to an available state to complete the connection between the first path 204 and the second path 205 Switch. After entering the second path 205, the controller 203 then modifies the data that the transmitter 202 can send to the data received by the receiver 201, so no matter what type of data the receiver 201 receives (for example, the subsequent first PCIE device The data used for negotiation with the second PCIE device, and the service data transmitted between the first PCIE device and the second PCIE device, etc., can be transmitted through the second path 205. In order to facilitate the understanding of the foregoing process, the foregoing forward switching process will be further introduced with reference to FIG. 2. As shown in FIG. 2, the retimer also includes a data selector (multiplexer, MUX) 206, and the input end of the MUX 206 is coupled to the first The output ends of the path 204 and the second path 205 are coupled to the transmitter 202. It is worth noting that the MUX 206 can be used for switching between the first path 204 and the second path 205. Specifically, after determining that the PCIE system meets the preset first condition, the controller 203 may send a low-latency entry request to the transmitter 202, and modify the data that the transmitter 202 can send into PRBS data. The transmitter 202 can prepare for switching based on the low-latency entry request (for example, switch its own state from the normal state to the low-latency state). After the preparation is completed, it feeds back the preparation completion response to the controller 203. After the controller 203 receives the response, Then, the first path switching request is sent to the MUX 206, so that the MUX 206 sets the first path 204 to an unavailable state and sets the second path 205 to an available state. After the controller 203 receives the switching completion response sent by the MUX 206, it modifies the data that the transmitter 202 can send to the data received by the receiver 201 to transmit the data based on the second path 205.

After the PCIE system is switched from the first path 204 to the second path 205, the negotiation phase based on the PCIE protocol can be carried out. In this phase, the first PCIE device and the second PCIE device can negotiate through the second path 205 For details, please refer to the PCIE protocol, which will not be repeated here. After the PCIE system completes the negotiation, it enters the LO state, and the two PCIE devices can transmit the second data (service data) through the second path 205 to complete the service requirements.

In a possible implementation manner, as shown in FIG. 2, a polarity reversal circuit 207 is further provided in the second path 205. In the second path 205, the input terminal of the polarity reversal circuit 207 is coupled to the receiver 201, The output terminal is coupled to the transmitter 202, and the polarity inversion circuit 207 can invert the polarity of the service data. In general, the service data sent by the transmitter 202 to the second PCIE device usually needs to carry a positive polarity. If the service data from the first PCIE device received by the receiver 201 carries a negative polarity, that is, the service data exists In the case of opposite polarity, polarity reversal is required to make the business data obtain the correct polarity. Specifically, in the second path 205, after the receiver 201 receives the service data, the controller 203 can detect the polarity of the service data. If the controller 203 determines that the polarity of the service data is opposite, it will switch to the polarity inversion circuit. 207 sends a polarity reversal request. Based on the request, the polarity reversal circuit 207 can reverse the polarity of the service data from the receiver 201, and send the reversed service data to the transmitter 202, so that the transmitter 202 forwards the service data. The business data after the flip.

The above is an introduction to the case of entering the low-delay path, and the following will specifically explain the case of exiting the low-delay path.

After the PCIE system enters the low-latency path (that is, the path currently used for data transmission is the second path 205), after the PCIE system is negotiated, the service data can be transmitted when the system is in the LO state. If the PCIE system enters the recovery state again from the L0 state, the path retraining needs to be performed again. At this time, the path currently used by the PCIE system to transmit data is the second path 205, and the first PCIE device and the second PCIE device can communicate with each other. Based on the second path 205, data used for path training, such as TS1 data, TS2 data, and so on, are transmitted again. When the TS1 data transmission stage is completed between the first PCIE device and the second PCIE device, the TS2 data transmission stage is entered. At this time, the retimer controller 203 will detect in real time whether the receiver 201 has received TS2 data. If the controller 203 determines that the receiver 201 has received the TS2 data, it determines whether the TS2 data (first data) transmitted by the second path meets the preset second condition to determine whether it can enter the first path 204 from the second path 205.

If the controller 203 of the retimer determines that the TS2 data meets the preset second condition, the controller 203 can switch the second path 205 to the first path 204, so that the PCIE system uses the first path 204 after the path switching is completed. The service data (second data) is transmitted as the currently used path, that is, the low-delay path enters the normal path.

In order to enter the first path 204 from the second path 205, the controller 203 needs to determine whether the TS2 data meets the preset second condition, and the preset second condition can be set according to actual needs. In a possible implementation manner, the preset second condition includes: the TS2 data has a request for rate switching or a request for equalization redo or a request for exiting the prohibited state or a request for exiting the hot reset state. Specifically, the controller 203 can analyze the TS2 data. If the controller 203 determines that the TS2 data has a rate switching request or a balance redo request or a request to exit the prohibition state or a request to exit the hot reset state, it determines that the PCIE system meets the requirements of entering the first state. The preset second condition of the path 204.

After the controller 203 determines that the PCIE system satisfies the preset second condition for entering the first path 204, it may switch between the first path 204 and the second path 205. In a possible implementation manner, the controller 203 can first modify the data that the transmitter 202 can send to PRBS data. Because the type of data that the transmitter 202 can send has changed, the transmission of TS2 data is restricted. . After the controller 203 determines that the transmitter 202 is ready to switch, the controller 203 sets the second path 205 to an unavailable state and sets the first path 204 to an available state to complete the connection between the first path 204 and the second path 205 Switch. After entering the first path 204, the controller 203 then modifies the data that the transmitter 202 can send to the data received by the receiver 201, so no matter what type of data the receiver 201 receives (for example, the subsequent first PCIE device The data used for negotiation with the second PCIE device, the service data transmitted between the first PCIE device and the second PCIE device, etc., can be transmitted through the first path 204. Specifically, after determining that the PCIE system meets the preset second condition, the controller 203 may send a low-latency exit request to the transmitter 202, and modify the data that the transmitter 202 can send into PRBS data. The transmitter 202 can prepare for switching based on the low-latency exit request (for example, switch its own state from the low-latency state to the normal state). After completing the preparation, it will feed back the preparation completion response to the controller 203. After the controller 203 receives the response, Then, a second path switching request is issued to the MUX 206, so that the MUX 206 sets the second path 205 to an unavailable state and sets the first path 204 to an available state. After the controller 203 receives the switching completion response sent by the MUX 206, it modifies the data that the transmitter 202 can send to the data received by the receiver, so as to transmit the data based on the first path 204.

After the PCIE system is switched from the second path 205 to the first path 204, the negotiation phase based on the PCIE protocol can be carried out. In this phase, the first PCIE device and the second PCIE device can negotiate through the first path 204 For details, please refer to the PCIE protocol, which will not be repeated here. After the PCIE system completes the negotiation, it enters the LO state, and the two PCIE devices can transmit service data through the first path 204 to complete the service requirements.

It is worth noting that the retimer controller 203 provided in this application can be presented in various forms, which will be introduced separately as follows:

In a possible implementation manner, as shown in FIG. 3 (FIG. 3 is another structural diagram of the retimer provided in an embodiment of this application), the retimer includes a receiver 201, a transmitter 202, and a controller 203. Wherein, the controller 203 may include a first physical coding sub-layer (PCS) 2031, a link training and status machine (LTSSM) 2032, and a second PCS 2033, the first PCS 2031 The input end is coupled to the receiver 201, the output end of the first PCS 2031 is coupled to the LTSSM 2032, the input end of the second PCS 2033 is coupled to the LTSSM 2032, and the output end of the second PCS 2033 is coupled to the transmitter 202. Specifically, the first PCS2031 is used to decode the data of the receiver 201, the LTSSM2032 is used to process the decoded data, and the second PCS2033 then encodes the processed data, and then sends the encoded data to the transmitter 202. It should be noted that the steps performed by the controller 203 in the foregoing embodiment are mainly performed by the LTSSM2032. For example, the LTSSM2032 can detect the type of data received by the receiver 201, and the LTSSM2032 can also determine whether the TS2 data and the current data transmission rate meet the preset requirements. Set the first condition, LTSSM2032 can also determine whether TS2 data meets the preset second condition, LTSSM2032 can also control MUX206 for path switching, LTSSM2032 can also modify the type of data that the transmitter 202 can send, and LTSSM2032 can also control the polarity reversal circuit 207 Perform polarity reversal on business data and so on.

In a possible implementation manner, as shown in FIG. 4 (FIG. 4 is another structural schematic diagram of the retimer provided in an embodiment of this application), the retimer includes a receiver 201, a transmitter 202, and a controller 203. Among them, the controller 203 may include a first 2031, a plurality of LTSSM 2032 (for the convenience of drawing, only two are shown in Figure 4) and a second PCS 2033, the input of the first PCS 2031 is coupled to the receiver 201, the first PCS 2031 The output end is coupled to the first LTSSM 2032, the input end of the second PCS 2033 is coupled to the last LTSSM 2032, the output end of the second PCS 2033 is coupled to the transmitter 202, and multiple LTSSM 2032 are connected in series. Specifically, the first PCS2031 is used to decode the data of the receiver 201, multiple LTSSM2032 are used to process the decoded data, the second PCS2033 then encodes the processed data, and then sends the encoded data to Transmitter 202. It should be noted that the steps executed by the controller 203 in the foregoing embodiment are mainly executed by multiple LTSSMs 2032 at the same time. For the steps executed by multiple LTSSMs 2032, please refer to the relevant descriptions in the foregoing implementation manner, which will not be repeated here.

The above is a specific description of the retimer provided by the embodiment of the present application. The path switching method provided by the embodiment of the present application will be introduced below. FIG. 5 is a schematic flowchart of the path switching method provided by the embodiment of the present application. Please refer to FIG. 5, the method is implemented by the retimer corresponding to any one of the embodiments in FIG. 2 to FIG. 4, and the method includes:

501. When it is determined by the controller that the transmission rate of the first data transmitted by the first path meets the preset first condition, switch the first path to the second path by the controller to transmit the second data based on the second path , Where the delay of the second path is lower than the delay of the first path, the first data is path training data, and the second data is service data.

In a possible implementation manner, the first data is training ordered set TS2 data, which improves the flexibility and selectivity of the solution.

In a possible implementation manner, the preset first condition includes: the transmission rate is equal to the preset rate, which improves the flexibility and selectivity of the solution.

In a possible implementation, the preset first condition also includes: TS2 data does not have a request for rate switching, does not have a request to enter the loopback state, and does not have a request to enter the prohibited state, which improves the flexibility and flexibility of the solution. Optional.

In a possible implementation manner, switching the first path to the second path by the controller to transmit the second data based on the second path includes:

In a possible implementation manner, before switching the first path to the second path through the controller, the method further includes:

In a possible implementation manner, after the first path is switched to the second path by the controller, the method further includes:

In a possible implementation manner, in the second path, a polarity reversal circuit is further provided between the receiver and the transmitter, and the method further includes:

In a possible implementation manner, the method further includes:

In a possible implementation, the preset second conditions include: TS2 data has a request for rate switching, a request for balanced redo, a request for exiting the prohibited state, or a request for exiting the warm reset state, which improves the solution’s performance Flexibility and selectivity.

In a possible implementation manner, switching the second path to the first path by the controller to transmit the second data based on the first path includes:

In a possible implementation manner, before switching the second path to the first path, the controller is also used to modify the data that the transmitter can send into PRBS data, which improves the flexibility and selectivity of the solution.

In a possible implementation manner, after the second path is switched to the first path, the controller is also used to modify the data that the transmitter can send to the data received by the receiver, which improves the flexibility and flexibility of the solution. Optional.

In this embodiment, since the second path does not include a controller, the second path has a lower delay than the first path. When the retimer determines that the current data transmission rate meets the preset first condition, the first path can be switched to the second path, that is, exit from the normal path and enter the low-delay path to perform data transmission based on the low-delay path. Therefore, in the second path, after the receiver receives the data, the data can be directly forwarded through the transmitter without complicated processing by the controller, which can effectively reduce the delay to meet the requirements of different business scenarios.

The embodiment of the present application also provides a device for performing retiming, which includes:

Receiver, used to receive data;

Transmitter, used to send data;

In a possible implementation manner, the device further includes: a receiver for receiving the first data and the second data, a receiver for sending the first data and the second data, the first path is coupled to the receiver and the transmitter The first path is also connected to the controller, and the second path is coupled to the receiver and the transmitter;

It should be noted that the structure of the above device and the connection relationship of each part can refer to the retimer in the embodiment shown in Figures 2 to 4, and the related description of the device can refer to the in the embodiment shown in Figures 2 to 4 The situation of exiting the low-delay path will not be repeated here.

An embodiment of the present application also provides a method for path switching, which is implemented by a retimer corresponding to any one of the embodiments in FIG. 2 to FIG. 4, and the method includes:

In a possible implementation manner, before switching the second path to the first path by the controller, the method further includes:

In a possible implementation manner, after the second path is switched to the first path by the controller, the method further includes:

It should be noted that, for the related description of the foregoing method, reference may be made to the case of exiting the low-delay path in the embodiments shown in FIG. 2 to FIG. 4, which will not be repeated here.

Claims

A device for performing retiming, characterized in that the device comprises:

First path

Second path

The controller is configured to switch the first path to the second path based on the second path when it is determined that the transmission rate of the first data transmitted by the first path meets the preset first condition. The path transmits second data, wherein the delay of the second path is lower than the delay of the first path, the first data is path training data, and the second data is service data.
The device according to claim 1, wherein the first data is training ordered set TS2 data.
The apparatus according to claim 2, wherein the preset first condition comprises: the transmission rate is equal to a preset rate.
The device according to claim 3, wherein the preset first condition further comprises: the TS2 data does not have a request for rate switching, does not have a request to enter a loopback state, and does not have a request to enter a prohibited state .
The device according to any one of claims 1 to 4, wherein the device further comprises: a receiver for receiving the first data and the second data, for sending the first data And the receiver of the second data, the first path is coupled to the receiver and the transmitter, the first path is also connected to the controller, and the second path is coupled to the receiver器和The transmitter;

The controller is further configured to set the first path to an unavailable state and set the second path to an available state in the case where it is determined that the transmitter has completed the handover preparation, so as to be based on the second path. The path transmits the second data.
The device according to claim 5, wherein, before switching the first path to the second path, the controller is further configured to modify the data that the transmitter can send to pseudo-random Binary sequence PRBS data.
The device according to claim 5 or 6, wherein after the first path is switched to the second path, the controller is further configured to modify the data that the transmitter can send to The data received by the receiver.
The device according to any one of claims 1 to 7, wherein in the second path, a polarity reversal circuit is further provided between the receiver and the transmitter;

In the case that the second data transmitted by the second path has an opposite polarity, the polarity inversion circuit is used to invert the polarity of the second data.
8. The device according to claim 8, wherein the controller is further configured to switch the second path to the second path when it is determined that the first data transmitted by the second path satisfies a preset second condition. The first path to transmit second data based on the first path.
The device according to claim 9, wherein the preset second condition comprises: the TS2 data has a request for rate switching, a request for equalizing redo, a request for exiting a prohibited state, or a request for exiting a hot reset. Status request.
A method for path switching, characterized in that the method is implemented by a device for performing retiming, and the device includes: a first path, a second path, and a controller; the method includes:

When it is determined by the controller that the transmission rate of the first data transmitted by the first path meets the preset first condition, the controller switches the first path to the second path to The second data is transmitted based on the second path, wherein the delay of the second path is lower than the delay of the first path, the first data is path training data, and the second data is service data.
A high-speed peripheral component interconnection PCIE system, characterized in that, the PCIE system includes:

The first PCIE device;

The second PCIE device;

The apparatus for performing retiming according to any one of claims 1 to 10, which is coupled to the first PCIE device and the second PCIE device, and the first PCIE device and the second PCIE device Provide data flow in both directions between devices.