CN116032421B - Ethernet link control device and storage medium - Google Patents

Abstract

The present disclosure relates to an ethernet link control apparatus and a storage medium, the apparatus including a transmitting part including: the frame identifier encapsulation module is used for adding a frame identifier field into the Ethernet message to obtain a data message; the transmitting end retransmission buffer module is used for buffering the data message; a sending end message module for generating a control message; the transmitting end retransmission control module is used for controlling the transmitting end retransmission buffer module and the transmitting end message module; and the transmitting end data selector is used for transmitting the data message and/or the control message to other Ethernet link control devices. The present disclosure provides an ethernet link control device, which adds a frame identifier field in an ethernet packet to accurately implement flow control and packet retransmission, and also can generate a control packet, determine a corresponding operation according to the control packet, accurately and reliably ensure data transmission, ensure high utilization of resources, and simultaneously can be flexibly applicable to various application scenarios.

Description

Ethernet link control device and storage medium

Technical Field

The present disclosure relates to the field of Ethernet flow control, and in particular to an Ethernet link control device and a storage medium.

Background technique

Ethernet is widely used in industrial control, digital finance, smart driving, medical health and other fields due to its low cost, high speed, strong compatibility and large number of supported devices. Traditional Ethernet provides best-effort delivery services and cannot meet the requirements of reliable transmission and zero packet loss. Therefore, in specific fields, corresponding mechanisms need to be added to meet reliability requirements.

Many methods for improving Ethernet reliability have been reported in existing public literature. For example, in order to improve network performance, a large number of redundant protocol methods have been proposed. However, these redundancy-based methods require redundant paths, have high hardware costs, and have low resource utilization. They cannot simultaneously meet the characteristics of high resource utilization and strong flexibility.

Summary of the invention

In view of this, the present disclosure proposes an Ethernet link control device and a storage medium.

According to one aspect of the present disclosure, an Ethernet link control device is provided, comprising a sending component, wherein the sending component comprises:

A frame identifier encapsulation module, used to obtain an Ethernet message, add a frame identifier field to the Ethernet message, obtain a data message, and provide the data message to a sending end data selector and a sending end retransmission buffer module;

A sending end retransmission buffer module, used to buffer the data message; provide the corresponding data message to the sending end data selector according to the instruction of the sending end retransmission control module, or release the buffer space of the corresponding data message;

A sending end message module, used to generate a control message according to the instruction of the sending end retransmission control module, and provide the control message to the sending end data selector;

A sending end retransmission control module, used to control a sending end retransmission buffer module and a sending end message module; when it is determined that a data message needs to be retransmitted according to a control message from another Ethernet link control device, the sending end retransmission buffer module is controlled to provide the corresponding data message to a sending end data selector, and the sending end message module is controlled to generate a corresponding control message and provide the control message to the sending end data selector; when it is determined that the data message is successfully transmitted according to a control message from another Ethernet link control device, the sending end retransmission buffer module is controlled to release the corresponding data message buffer space;

The sending end data selector is used to send the data message and/or control message generated by the Ethernet link control device to other Ethernet link control devices.

In a possible implementation, the device is connected to an Ethernet MAC and a message buffer module:

Wherein, the frame identifier encapsulation module obtains the Ethernet message from the message buffer module;

The transmitting end data selector sends the data message and/or the control message to other Ethernet link control devices through the Ethernet MAC.

In a possible implementation manner, the apparatus further includes a receiving component, and the receiving component includes:

A receiving end distribution module, used for receiving messages from other Ethernet link control devices, and determining whether the message is a data message or a control message; when the message is a data message, used for determining whether the data message meets the transmission requirements, and when it meets the transmission requirements and the message buffer module has available space, providing the data message to the frame identifier deletion module, controlling the receiving end message module to generate a corresponding control message to provide to the sending end data selector; if it does not meet the transmission requirements and/or the message buffer module has no available space, used for controlling the receiving end message module to generate a corresponding control message to provide to the sending end data selector; when the message is a control message, used for providing the control message to the sending end retransmission control module;

A frame identifier deletion module, used for deleting a frame identifier field added to a data message;

The receiving end message module is used to generate a corresponding control message according to the instruction of the receiving end distribution module, and provide the control message to the sending end data selector.

In a possible implementation, the condition that meets the transmission requirement includes that the frame identifier of the data message is correct and the cyclic redundancy check CRC of the data message is correct.

In a possible implementation, the control message generated by the receiving end message module includes:

Successfully receiving a PA message indicates that the data message is successfully transmitted; when the receiving end distribution module determines that the message received from the other Ethernet link control device is a data message, the data message meets the transmission requirements and the message buffer module has available space, the receiving end message module is controlled to generate a PA message; when the other Ethernet link control device receives the PA message, the sending end retransmission control module of the other Ethernet link control device determines that the data message is successfully transmitted;

A PR message needs to be retransmitted, which is used to indicate that a data message needs to be retransmitted; when the receiving end distribution module determines that the message received from other Ethernet link control devices is a data message, and the data message meets the transmission requirements but there is no available space in the message buffer module, the receiving end message module is controlled to generate a PR message; when the other Ethernet link control devices receive the PR message, the sending end retransmission control module of the other Ethernet link control devices determines that the data message needs to be retransmitted;

Failure to successfully receive a PNA message indicates that the data message needs to be retransmitted; when the receiving end distribution module determines that the message received from other Ethernet link control devices is a data message and the data message does not meet the transmission requirements, the receiving end message module is controlled to generate a PNA message; when other Ethernet link control devices receive the PNA message, the sending end retransmission control module of the other Ethernet link control devices determines that the data message needs to be retransmitted.

In a possible implementation, after the receiving end message module of the receiving component sends a PR message or a PNA message according to the instruction of the receiving end distribution module, the receiving component enters a retransmission waiting state;

When the receiving component is in the retransmission waiting state, the receiving end distribution module of the receiving component no longer receives data messages from other Ethernet link control devices.

In a possible implementation, the control message generated by the message module at the sending end includes:

The RFR message for releasing the retransmission state is used to release the retransmission waiting state of the receiving component; when the sending end retransmission control module receives the PR message or the PNA message from other Ethernet link control devices, it determines that the data message needs to be retransmitted, and controls the sending end message module to generate the RFR message; when other Ethernet link control devices receive the RFR message, the receiving components of the other Ethernet link control devices release the retransmission waiting state and resume receiving the data messages from other Ethernet link control devices.

In a possible implementation, the control message generated by the message module at the sending end further includes:

The link status request LReq message is used to request to know the status of the receiving component; when the sending end retransmission control module receives the PNA message with the same frame identifier from other Ethernet link control devices at least twice, the sending end retransmission control module controls the sending end message module to generate the LReq message;

When the Ethernet link control device establishes a connection with other Ethernet link control devices for the first time, it actively generates and sends an LReq message.

In a possible implementation, when the other Ethernet link control device receives the LReq message, the receiving end distribution module of the other Ethernet link control device instructs the receiving end message module to generate a control message including:

Reply link status LRsp message to feedback the status of the receiving component; when the receiving end distribution module receives the LReq message from other Ethernet link control devices, it controls the receiving end message module to generate an LRsp message; wherein the LRsp message includes the frame identifier of the required data message.

In a possible implementation, the device further includes a backup channel Bypass, and the backup channel is used to provide the Ethernet message to the transmitting end data selector to send it to other Ethernet link control devices.

According to another aspect of the present disclosure, an Ethernet link control device is provided, comprising:

processor;

a memory for storing processor-executable instructions;

Wherein, the processor is configured to implement the above-mentioned device when executing the instructions stored in the memory.

According to another aspect of the present disclosure, a non-volatile computer-readable storage medium is provided, on which computer program instructions are stored, characterized in that the computer program instructions implement the above-mentioned device when executed by a processor.

According to another aspect of the present disclosure, a computer program product is provided, including a computer-readable code, or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device implements the above-mentioned device.

Based on this, the present disclosure provides an Ethernet link control device that can simultaneously realize flow control and message retransmission. The present disclosure obtains data messages by adding a frame identifier field in the Ethernet message and caches it, which is equivalent to numbering each Ethernet message, and can accurately process flow control and message retransmission. At the same time, corresponding control messages are generated according to different situations, corresponding operations are determined according to the control messages, and corresponding data messages and/or control messages are sent to other Ethernet link control devices, thereby accurately and reliably ensuring data transmission and ensuring high resource utilization. At the same time, it is applicable to a variety of application scenarios and has high flexibility.

Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

FIG1 is a schematic diagram showing a PFC message format.

FIG2 shows a block diagram of an Ethernet link control device according to an embodiment of the present disclosure.

FIG3 shows a schematic diagram of a data message according to an embodiment of the present disclosure.

FIG. 4 shows a schematic diagram of a control message according to an embodiment of the present disclosure.

FIG5 shows a schematic diagram of six control messages according to an embodiment of the present disclosure.

FIG6 shows a block diagram of an Ethernet link control device according to an embodiment of the present disclosure.

FIG. 7 shows a flow chart of transmission and feedback of control messages according to an embodiment of the present disclosure.

FIG8 shows a block diagram of message transmission between two Ethernet link control devices according to an embodiment of the present disclosure.

Detailed ways

Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present disclosure.

There are two types of Ethernet flow control: one is half-duplex flow control, which generally uses back pressure technology; the other is full-duplex flow control. IEEE 802.3X defines a flow control mechanism, namely the PAUSE flow control mechanism, which is used to eliminate packet loss caused by congestion on a link. When the network is congested, the flow of the entire port will be stopped, thereby interrupting normal flow and causing false positives.

At the same time, in the enterprise data center, multiple different networks deployed for different applications will be integrated. Traditional flow control mechanisms (such as PAUSE flow control) cannot meet the needs of multiple traffic sharing links. For this reason, PFC (Priority-based Flow Control) is proposed. Figure 1 shows a schematic diagram of the PFC message format. In PFC, network traffic can be divided into 0-7, a total of 8 priorities, so 8 virtual channels can be created on an Ethernet link, and an IEEE 802.1P priority level is specified for each virtual channel. Each priority maintains a virtual channel and implements an independent PAUSE mechanism. It can achieve the individual suspension and restart of any virtual channel, isolate each virtual channel, avoid mutual influence, and truly realize multiple traffic sharing links.

The destination address DA (Destination Address), source address SA (Source Address), message type Type, and frame check sequence FCS (Frame Check Sequence) in the PFC message format are similar to those of ordinary flow control messages, as shown in Figure 1. The PFC message also contains a control opcode, a priority enable vector priority_enable_vector, and time[n]. Priority_enable_vector occupies 2 bytes, with the high byte set to 0. Each bit of the low byte (8 bits in total) represents whether the corresponding time[n] (time[0]-time[7]) is valid. When a bit is 0, it means that the time[n] corresponding to the bit is invalid; when a bit is 1, it means that the time[n] corresponding to the bit is valid. Time[n] represents the time when the receiving station should stop sending messages with priority n. When time[n] is valid and time[n] is not 0, if the transmission of priority n has not stopped, it will be stopped, and a timer will be started according to the time represented by time[n]. Before the timer expires, the transmission of the priority will be stopped. When time[n] is invalid or when time[n] is valid and time[n] is 0, if the transmission of the priority is stopped, the corresponding timer can be turned off and the priority can be started to continue sending data. In full-duplex flow control, if one end finds that it has congestion on a certain priority, it can send a PFC message to the other end to notify the other end not to send data on a certain priority for a period of time. If one end finds that its congestion on a certain priority is relieved, it can send a PFC message to the other end to notify the other end that it can send data on a certain priority again. In simple terms, if one end finds that its congestion status on a certain priority has changed, it can send a PFC message to the other end to notify the change. However, in order to eliminate packet loss caused by congestion, the sending of PFC messages must meet certain time requirements. If the PFC message is sent too late, the data will be discarded due to insufficient receiving buffer space; if the PFC message is sent too early, the network utilization rate will be reduced. A more serious problem is that PFC cannot retransmit messages when errors occur in the network.

Based on this, the present disclosure provides an Ethernet link control device that can simultaneously realize flow control and message retransmission. The present disclosure obtains data messages by adding a frame identifier field in the Ethernet message and caches it, which is equivalent to numbering each Ethernet message, and can accurately process flow control and message retransmission. At the same time, corresponding control messages are generated according to different situations, corresponding operations are determined according to the control messages, and corresponding data messages and/or control messages are sent to other Ethernet link control devices, thereby accurately and reliably ensuring data transmission and ensuring high resource utilization. At the same time, it is applicable to a variety of application scenarios and has high flexibility.

FIG2 shows a block diagram of an Ethernet link control device according to an embodiment of the present disclosure. As shown in FIG2 , the device includes a sending component, and the sending component includes:

The frame identifier encapsulation module 11 is used to obtain an Ethernet message, add a frame identifier field in the Ethernet message, obtain a data message, and provide the data message to the sending end data selector 15 and the sending end retransmission buffer module 12.

Among them, after adding the frame identifier field to the Ethernet message, a data message is obtained, and then the data message is provided to the sending end data selector 15 of this device, which can be transmitted through the AXI-Stream (Advanced eXtensibleInterface-Stream) bus, and then the sending end data selector 15 will send the data message to other Ethernet link control devices. At the same time, the frame identifier encapsulation module 11 also provides the data message to the sending end retransmission cache module 12 of this device. The sending end retransmission cache module 12 caches the data message and can record the frame identifier of the data message, which is equivalent to recording the corresponding number. When a data message with a certain frame identifier is needed, it can be conveniently taken out and used.

Among them, FIG3 shows a schematic diagram of a data message according to an embodiment of the present disclosure. The data message shown in the figure includes a destination address DA (Destination Address), a source address SA (Source Address), a type Type, a frame identifier Frame ID, data Data, and a frame check sequence FCS (Frame Check Sequence) from left to right. Compared with the Ethernet message of the prior art (such as the PFC message of FIG1), there is an additional frame identifier field. The frame identifier is used to number the Ethernet message for accurate transmission control. In a specific embodiment of the present disclosure, each time an Ethernet message is received, the value of the frame identifier of the obtained data message can be increased by 1, so as to achieve non-repetitive numbering and facilitate management.

The sending end retransmission buffer module 12 is used to buffer the data message; provide the corresponding data message to the sending end data selector 15 according to the instruction of the sending end retransmission control module 14, or release the buffer space of the corresponding data message.

Among them, the sending end retransmission cache module 12 caches the data message and can record the frame identifier of the data message, which can be equivalent to recording the corresponding number. When a data message with a certain frame identifier needs to be retransmitted, it can be conveniently and quickly provided to the sending end data selector 15 of this device, or when it is determined that a certain data message has been sent successfully and does not need to be retransmitted, the cache space of the data message is released.

Among them, in a specific embodiment of the present disclosure, a list can be established in the retransmission cache module 12 at the sending end, and the data message corresponding to each frame identifier can be recorded with a label when it is stored in the retransmission cache of the sending end, so as to facilitate storage management. At this time, the retransmission cache of the sending end can be equivalent to a drawer. When the data message with a frame identifier of 1 is provided to the data selector 15 at the sending end, the data message is also cached in the drawer, and the drawer layer is numbered 1. If the retransmission cache module at the sending end determines that the data message with a frame identifier of 1 is successfully sent, the drawer layer numbered 1 is found, and the data message with a frame identifier of 1 stored therein is deleted, that is, the cache space is released. If the retransmission cache module 12 at the sending end determines that the data message with a frame identifier of 1 is not successfully sent and needs to be retransmitted, the drawer layer numbered 1 is found, the data message with a frame identifier of 1 stored therein is taken out, and it is re-provided to the data selector 15 at the sending end, and the data selector 15 at the sending end re-sends it to other Ethernet link control devices.

The sending end message module 13 is used to generate a control message according to the instruction of the sending end retransmission control module, and provide the control message to the sending end data selector;

Among them, the control message is also called RTC (Reliable Transmission Control) message. Figure 4 shows a schematic diagram of a control message according to an embodiment of the present disclosure. In the example shown in Figure 4, the first part from left to right is a 6-byte destination address field, which can be defined by itself without restriction, and the default value is 0x01-80-c2-00-00-02. The second part is a 6-byte source address field. The third part is a 2-byte RTC type field, which can be defined by itself without restriction, and the default value is 0x88-88. The RTC type here can be the same as the type of Ethernet message (such as PFC Ethertype in Figure 1), or it can be set by itself. It can be stipulated that the 16 bits of 2-byte cannot be all 0 or all 1 when setting by itself, and no other restrictions are made. The fourth part is a 2-byte control operation code field, the value of which is 02-0x. There can be six operation codes, corresponding to six control messages (such as a schematic diagram of six control messages according to an embodiment of the present disclosure shown in Figure 5). The fifth part is the 2-byte frame identifier field, which corresponds to the frame identifier of the control message. The sixth part is the 2-byte reason field for unsuccessful reception of PNA or need for retransmission of PR, which contains the reason when the control message is a PNA message or a PR message, such as frame check sequence error, frame identifier mismatch, insufficient cache resources, etc. The last part is the 4-byte FCS (frame check sequence), which is the CRC (Cyclic Redundancy Check) function of the message, used for data transmission error detection, which can ensure the accuracy and integrity of data transmission.

The sending end retransmission control module 14 is used to control the sending end retransmission cache module 12 and the sending end message module 13; when it is determined that the data message needs to be retransmitted according to the control message from other Ethernet link control devices, the sending end retransmission cache module 12 is controlled to provide the corresponding data message to the sending end data selector 15, and the sending end message module 13 is controlled to generate a corresponding control message and provide the control message to the sending end data selector 15; when it is determined that the data message transmission is successful according to the control message from other Ethernet link control devices, the sending end retransmission cache module 12 is controlled to release the cache space of the corresponding data message.

Among them, the control message from other Ethernet link control devices can bring two kinds of information, one is that the data message needs to be retransmitted, and the other is that the data message is successfully transmitted. The sending end retransmission control module 14 needs to control the sending end retransmission buffer module 12 and the sending end message module 13 according to the information of the received control message. When it is determined that the data message needs to be retransmitted, the sending end message module 13 is controlled to generate a corresponding control message and the sending end retransmission buffer module 12 is controlled to find the corresponding data message, and the control message and the data message are provided to the sending end data selector 15. When it is determined that the data message is successfully transmitted, the sending end retransmission buffer module 12 is controlled to release the corresponding data message cache space.

The sending end data selector 15 is used to send the data message and/or control message generated by the Ethernet link control device to other Ethernet link control devices.

Among them, there are three modules that can provide data messages or control messages to the sending end data selector 15: data messages from the frame identifier encapsulation module 11, data messages from the sending end retransmission buffer module 12, and control messages from the sending end message module 13. In each sending cycle, the sending end data selector 15 will select one of the messages according to the actual application situation and send it to other Ethernet link control devices.

FIG6 shows a block diagram of an Ethernet link control device according to an embodiment of the present disclosure. As shown in FIG6,

In a possible implementation, the device is connected to an Ethernet MAC and a message buffer module:

The frame identifier encapsulation module 11 obtains the Ethernet message from the message buffer module; the transmitting end data selector 15 sends the data message and/or control message to other Ethernet link control devices through the Ethernet MAC (Medium Access Control). The message buffer module and the Ethernet MAC can be implemented based on the existing technology, that is, the Ethernet link control device of the embodiment of the present disclosure can be located between the original message buffer module and the Ethernet MAC. The transmitting end message buffer module and the receiving end message buffer module in FIG6 can be integrated together, and the transmitting end Ethernet MAC and the receiving end Ethernet MAC can also be integrated together.

In a possible implementation manner, the apparatus further includes a receiving component, and the receiving component includes:

The receiving end distribution module 21 is used to receive messages from other Ethernet link control devices and determine whether the message is a data message or a control message; when the message is a data message, it is used to determine whether the data message meets the transmission requirements. When it meets the transmission requirements and the message cache module has available space, the data message is provided to the frame identifier deletion module 22 to control the receiving end message module 23 to generate a corresponding control message to provide to the sending end data selector 15; if it does not meet the transmission requirements and/or the message cache module has no available space, it is used to control the receiving end message module 23 to generate a corresponding control message to provide to the sending end data selector 15; when the message is a control message, it is used to provide the control message to the sending end retransmission control module 14.

Among them, since the sending end data selector 15 of other Ethernet link control devices can send data messages and/or control messages, the receiving end distribution module 21 can first determine whether the received message is a data message or a control message.

Among them, when the receiving end distribution module 21 determines that what is received is a data message, it can be divided into two situations. One is that when the receiving end distribution module 21 determines that the data message meets the transmission requirements and the receiving end message buffer module has available space, the data message can be provided to the frame identifier deletion module 22, and the receiving end message module 23 can be controlled to generate a corresponding control message to provide to the sending end data selector 15 of this device. Another situation is that when the receiving end distribution module 21 determines that the data message does not meet the transmission requirements and/or the message buffer module has no available space, the receiving end message module 23 can be controlled to generate a corresponding control message to provide to the sending end data selector 15 of this device. The sending end data selector 15 can send the control messages generated in the two situations to the corresponding other Ethernet link control devices that sent the data message.

When the receiving end distribution module 21 determines that what is received is a control message, the control message may be provided to the sending end retransmission control module 14 of the device, and the sending end retransmission control module 14 may perform the next step of processing according to the information of the control message.

In one example, the frame identifier deletion module 22 works as follows. When the receiving end distribution module 21 determines that what is received is a data message, and the data message meets the transmission requirements and the receiving end message buffer module has available space, the data message can be provided to the frame identifier deletion module 22, and the frame identifier deletion module 22 can delete the frame identifier field added by the frame identifier encapsulation module 11, and send the data message after the frame identifier field is deleted, that is, the Ethernet message, to the receiving end message buffer module, and successfully complete the transmission of the Ethernet message from the sending end message buffer module connected to other Ethernet link control devices to the receiving end message buffer module connected to this device.

In one example, the receiving end message module 23 works as follows. When the receiving end distribution module 21 determines that what is received is a data message, it can be divided into two situations. One is that when the receiving end distribution module 21 determines that the data message meets the transmission requirements and the receiving end message module 23 determines that the receiving end message buffer module has available space, the receiving end message module 23 can generate a corresponding control message. Another situation is that when the receiving end distribution module 21 determines that the data message does not meet the transmission requirements and/or the receiving end message module 23 determines that the message buffer module has no available space, the receiving end message module 23 can generate a corresponding control message. Different control messages can be generated in the two situations, and the control messages can be provided to the sending end data selector 15 of this device. The sending end data selector 15 can send the control messages generated in the two situations to the corresponding other Ethernet link control devices that sent the data message.

In a possible implementation, the condition that meets the transmission requirement includes that the frame identifier of the data message is correct and the cyclic redundancy check CRC of the data message is correct.

Among them, the receiving end distribution module 21 can first determine whether the received message is a data message or a control message. When it is determined to be a data message, the receiving end distribution module 21 can then determine whether it meets the transmission requirements. The conditions for meeting the transmission requirements may include that the frame identifier of the data message is correct, that is, it can be a data message corresponding to the frame identifier required or receivable by the receiving end message buffer module, and the cyclic redundancy check CRC of the data message is correct. By checking whether the data message meets the transmission requirements, the accuracy and integrity of data transmission can be guaranteed.

FIG5 shows a schematic diagram of six control messages according to an embodiment of the present disclosure. As shown in FIG5, each time the sending component of the present device sends a data message to other devices, the receiving component of the other devices can feed back a control message to the present device. Similarly, each time the present device receives a data message from other devices, it can feed back a control message to the other devices.

In a possible implementation, the control message generated by the receiving end message module 23 includes:

Successfully receiving a PA message indicates that the data message transmission is successful; when the receiving end distribution module 21 determines that the message received from other Ethernet link control devices is a data message, and the data message meets the transmission requirements and the message cache module has available space, the receiving end message module 23 is controlled to generate a PA message; when other Ethernet link control devices receive the PA message, the sending end retransmission control module 14 of the other Ethernet link control devices determines that the data message transmission is successful.

Among them, the PA message is a control message generated by the receiving end message module 23 in the receiving component. When the sending end data selector 15 in the sending component sends a data message (an Ethernet message with a frame identifier field added), the receiving end distribution module 21 in the receiving component receives the data message and checks the frame identifier and the cyclic redundancy check. If there is no error and the receiving end message module 23 determines that the receiving end message buffer module has available space, the receiving end message module 23 in the receiving component sends the PA message to the sending end data selector 15 in the sending component of this device, and the sending end data selector 15 sends the PA message to the corresponding other Ethernet link control device that sent the data message. The receiving end distribution module of other Ethernet link control devices can determine that the message is a control message and provide it to the sending end retransmission control module. The sending end retransmission control module determines that the data message has been successfully transmitted, controls the sending end retransmission buffer module to release the corresponding data message buffer space, and then continues to send other data messages.

The PR message needs to be retransmitted, which is used to indicate that the data message needs to be retransmitted; when the receiving end distribution module 21 determines that the message received from other Ethernet link control devices is a data message, and the data message meets the transmission requirements but the message cache module has no available space, the receiving end message module 23 is controlled to generate a PR message; when other Ethernet link control devices receive the PR message, the sending end retransmission control module 14 of the other Ethernet link control devices determines that the data message needs to be retransmitted.

Among them, the PR message is a control message generated by the receiving end message module 23 in the receiving component. When the sending end data selector 15 in the sending component sends a data message (an Ethernet message with a frame identifier field added), the receiving end distribution module 21 in the receiving component receives the data message and checks the frame identifier and the cyclic redundancy check. If there is no error but the receiving end message module 23 determines that the receiving end message buffer module has no available space, the receiving end message module 23 in the receiving component sends the PR message to the sending end data selector 15 in the sending component of this device, and the sending end data selector 15 sends the PR message to the corresponding other Ethernet link control device that sent the data message. The receiving end distribution module of other Ethernet link control devices can determine that the message is a control message and provide it to the sending end retransmission control module. The sending end retransmission control module determines that the data message needs to be retransmitted, controls the sending end retransmission buffer module to provide the corresponding data message to the sending end data selector, and then retransmits the data message.

The PNA message is not successfully received, indicating that the data message needs to be retransmitted; when the receiving end distribution module 21 determines that the message received from other Ethernet link control devices is a data message and the data message does not meet the transmission requirements, the receiving end message module 23 is controlled to generate a PNA message; when other Ethernet link control devices receive the PNA message, the sending end retransmission control module 14 of the other Ethernet link control devices determines that the data message needs to be retransmitted.

Among them, the PNA message is a control message generated by the receiving end message module 23 in the receiving component. When the sending end data selector 15 in the sending component sends a data message (an Ethernet message with a frame identifier field added), the receiving end distribution module 21 in the receiving component receives the data message and checks the frame identifier and cyclic redundancy check. If there is an error, the receiving end message module 23 in the receiving component sends the PNA message to the sending end data selector 15 in the sending component of this device, and the sending end data selector 15 sends the PNA message to the corresponding other Ethernet link control device that sent the data message. The receiving end distribution module of the other Ethernet link control device can determine that the message is a control message and provide it to the sending end retransmission control module. The sending end retransmission control module determines that the data message needs to be retransmitted, controls the sending end retransmission buffer module to provide the corresponding data message to the sending end data selector, and then retransmits the data message.

In a possible implementation, after the receiving end message module 23 of the receiving component sends a PR message or a PNA message according to the instruction of the receiving end distribution module 21, the receiving component enters a retransmission waiting state. When the receiving component is in the retransmission waiting state, the receiving end distribution module 21 of the receiving component no longer receives data messages from other Ethernet link control devices.

Among them, when the receiving component is in the retransmission waiting state, the receiving end distribution module 21 may not receive data packets from other Ethernet link control devices, but may receive some control packets from other Ethernet link control devices, such as the release retransmission state RFR packet and the request link state LReq packet.

In a possible implementation, the control message generated by the message module at the sending end includes:

The RFR message for releasing the retransmission state is used to release the retransmission waiting state of the receiving component; when the sending end retransmission control module 14 receives the PR message or the PNA message from other Ethernet link control devices, it determines that the data message needs to be retransmitted, and controls the sending end message module 13 to generate an RFR message; when other Ethernet link control devices receive the RFR message, the receiving components of the other Ethernet link control devices release the retransmission waiting state and resume receiving data messages from other Ethernet link control devices.

Among them, the control message from other Ethernet link control devices can bring two kinds of information, one is that the data message needs to be retransmitted, that is, the control message is a PR message or a PNA message, and the other is that the data message is successfully transmitted, that is, the control message is a PA message. When other Ethernet link control devices send PR messages or PNA messages, the receiving component of the device may enter a retransmission waiting state. At this time, sending an RFR message to the device can release its retransmission waiting state, allowing it to continue to receive the data message resent to it by this device later. In short, after the device receives a PR message or a PNA message from other Ethernet link control devices, it can first send an RFR message to the other Ethernet link control device to release its retransmission waiting state, and then resend the corresponding data message to the device according to the information of the PR message or the PNA message. It can be seen from this that the present disclosure can process problematic Ethernet messages one by one, and if an error occurs, the current problematic Ethernet message can be processed immediately, which can timely ensure the accuracy and reliability of data transmission.

In a possible implementation, the control message generated by the sending end message module 13 further includes:

The link status request LReq message is used to request to know the status of the receiving component; when the sending end retransmission control module 14 receives the PNA message with the same frame identifier from other Ethernet link control devices at least twice (the number can be set as needed), the sending end retransmission control module 14 controls the sending end message module 13 to generate an LReq message. When the Ethernet link control device establishes a connection with other Ethernet link control devices for the first time, it actively generates and sends the LReq message.

In a possible implementation, when the other Ethernet link control device receives the LReq message, the receiving end distribution module of the other Ethernet link control device instructs the receiving end message module to generate a control message including:

Reply link status LRsp message to feedback the status of the receiving component; when the receiving end distribution module receives the LReq message from other Ethernet link control devices, it controls the receiving end message module to generate an LRsp message; wherein the LRsp message includes the frame identifier of the required data message.

Among them, when the retransmission control module 14 of the sending end of this device receives the PNA message with the same frame identifier from other Ethernet link control devices at least twice, because the PNA message indicates that the data message sent before does not meet the transmission requirements, it may be due to a frame identifier error or a cyclic redundancy check error. The present device is not clear about the specific situation, so the sending message module 13 of the sending component of this device can send an LReq message to request to understand the status of the receiving component of other devices. After receiving the receiving end message module 23 of the receiving component of other devices, it can generate an LRsp message for feedback. The LRsp message can include the frame identifier of the required data message, which can indicate to the present device which frame identifier data message other devices expect to obtain.

Among them, when the connection is established with other Ethernet link control devices for the first time, the present device and the other devices are not clear about each other's status. The sending message module 13 of the sending component of the present device can also actively send an LReq message to request to know the status of the receiving component of the other device. The receiving end message module 23 of the receiving component of the other device can generate an LRsp for feedback after receiving it. The LRsp message can include the frame identifier of the required data message, which can indicate to the present device which data message with which frame identifier the other device expects to obtain.

Among them, when the sending end retransmission control module 14 of this device determines which data message other devices need from the LRsp message, it can control the sending end retransmission cache module to provide the data message to the sending end data selector 15 of this device, and the sending end data selector 15 sends it to the corresponding other Ethernet link control devices.

Similarly, when the receiving component of this device receives an LReq message from other Ethernet link control devices, it feeds back an LRsp message, wherein the LRsp message includes the frame identifier of the required data message, and is used to indicate to other devices which data message with which frame identifier this device expects to obtain. At the same time, it can release its own retransmission waiting state due to sending a PNA message, and then it can receive the data messages resent by other devices, thereby realizing the synchronization of data messages between multiple Ethernet link control devices.

In a possible implementation, the device further includes a backup channel Bypass. The backup channel is used to provide the Ethernet message to the transmitting end data selector to send it to other Ethernet link control devices.

Among them, the backup channel mentioned can be equivalent to skipping the Ethernet link control module. In actual applications, there are two channels. The backup channel can be used, that is, data transmission can be performed under the traditional Ethernet (no frame identifier needs to be added when sending, and the frame identifier does not need to be deleted when receiving, and it is directly received into the message cache module). Alternatively, the backup channel may not be used, that is, the Ethernet link control device disclosed in the present invention is used.

Fig. 7 shows a flow chart of transmission and feedback of control messages according to an embodiment of the present disclosure, wherein Tx is a sending component of the device, Rx is a receiving component of other devices, and Msg is a data message.

As shown in Figure 8, after the link is established, the sending component of this device can actively send an LReq message to request the status of other Ethernet link control devices. After receiving the LReq message, the receiving component of other devices can reply with an LRsp message (see Figure 7(a)). If this device receives the LRsp message within the specified time, it can continue to use the device normally; otherwise, it works in the traditional Ethernet mode and can skip the device through the backup channel. When the sending end of this device receives the LRsp message within the specified time, it parses the frame identifier field contained therein, determines the corresponding data message and sends it to other devices to complete the synchronization.

The sending component of this device sends the Ethernet message with the frame identifier added, that is, the data message Msg, to the receiving component of other devices. The receiving component can confirm whether the frame identifier and the cyclic redundancy check are correct. If they are correct, the frame identifier field can be deleted to obtain the Ethernet message, and then the Ethernet message can be sent to the receiving end message cache module. At the same time, the PA message can be sent to the sending end of this device (see Figure 7(b)). After receiving the PA message, the sending component can delete the cached data message that has been successfully sent, and then the sending component can continue to send the data message with the next frame identifier.

When the cache resources of the message cache module of the receiving end of other devices are insufficient, the receiving components of other devices can send PR messages. If the frame identifier and/or cyclic redundancy check are wrong, a PNA message can be sent. After the receiving end sends the PNA/PR message, the receiving components of other devices enter the retransmission waiting state. In the retransmission waiting state, data messages may not be received, but RFR messages or LReq messages may be received. When RFR is received, the retransmission state can be exited and new messages can be received again (see Figure 7(c)). Or after receiving the LReq message, the LRsp message is fed back to this device. At the same time, the receiving end of other devices can exit the retransmission state and wait for the arrival of data messages.

When the sending component of the device receives a PNA/PR message, it can immediately stop sending the current data message, first send an RFR message, and then retransmit the corresponding cached data message. When the sending component receives a PNA message corresponding to the same frame identifier at least twice, it sends an LReq message to request to know the status of other devices (see Figure 7 (d)).

FIG8 shows a block diagram of message transmission between two Ethernet link control devices according to an embodiment of the present disclosure.

As shown in FIG8 , the process when the Ethernet link control device A sends an Ethernet message to the Ethernet link control device B may be:

In the sending component A: the frame identifier encapsulation module A11 obtains the Ethernet message from the sending end message cache module A, adds the frame identifier field to obtain a data message, and sends the data message to the sending end data selector A15, and also caches it in the sending end retransmission cache module A12. The sending end data selector A15 sends the data message to the receiving end distribution module B41 of the receiving component B in the Ethernet link control device B.

In the receiving component B: the receiving end distribution module B41 receives the data message. First, the receiving end distribution module B41 can determine whether the received message is a data message or a control message. At this time, the received message is a data message. The receiving end distribution module B41 then determines whether the frame identifier and the cyclic redundancy check are correct. If one or both of them are incorrect, the receiving end message module B43 can generate a PNA message. If there are no problems with the frame identifier and the cyclic redundancy check, the receiving end message module B43 can then determine whether there is available space in the receiving end message cache module B. If there is no available space, the receiving end message module B43 can generate a PR message, and the receiving end distribution module B41 can discard the data message. If there is available space, the receiving end message module B43 can generate a PA message, and the receiving end distribution module B41 can provide the data message to the frame identifier deletion module B42, and store it in the receiving end message cache module B after deleting its frame identifier, so that the transmission of the Ethernet message can be successfully realized. The above PA/PR/PNA message can be provided to the transmitting end data selector B35 of the transmitting component B. It is worth noting that after sending the PNA/PR message, the receiving component B enters the retransmission waiting state.

In the sending component B: the sending end data selector B35 receives the PA/PR/PNA message and sends it to the receiving end distribution module A21 in the receiving component A in the Ethernet link control device A.

In the receiving component A: the receiving end distribution module A21 receives a message from the Ethernet link control device B. First, the receiving end distribution module A21 can determine whether the received message is a data message or a control message. In this case, it is a control message. The receiving end distribution module A21 can provide the control message to the sending end retransmission control module A14 of the sending component A.

In the sending component A: if the PA message is received by the sending end retransmission control module A14, the sending end retransmission control module A14 can control the sending end retransmission buffer module A12 to release the buffer space of the data message just sent (i.e. delete the buffer); if the PR/PNA message is received, the sending end retransmission control module A14 controls the sending end retransmission buffer module A12 to find the data message just sent and provide it to the sending end data selector A15, and the sending end retransmission control module A14 can also control the sending end message module A13 to generate an RFR message and provide it to the sending end data selector A15, and the sending end data selector A15 can first send an RFR message to release the retransmission waiting state of the receiving component B, and then resend the data message to the receiving end distribution module B41 of the receiving component B for further judgment.

Among them, if the Ethernet link device B sends a PNA message for the same frame identifier at least twice, the sending end retransmission control module A14 of the Ethernet link device A can control the sending end message module A13 to generate an LReq message, and send it to the receiving end distribution module B41 of the device B. The receiving end distribution module B41 determines that it is a control message and provides it to the sending end retransmission control module B34. The sending end retransmission control module B34 can control the sending end message module B33 to generate an LRsp message, and provide the LRsp message to the sending end data selector B35, and send it to the receiving end distribution module A21 of the device A. The receiving end distribution module A21 determines that it is a control message and provides it to the sending end retransmission control module A14. The sending end retransmission control module A14 can control the sending end retransmission buffer module A12 to find the data message indicated in the LRsp message and provide the data message to the sending end data selector A15. The sending end data selector A15 can send the data message to the device B.

Similarly, messages can also be transmitted between multiple Ethernet link control devices, and the process is the same as above. At this time, the data selector of the sending end of a device may include: data messages from the frame identifier encapsulation module of this device, data messages from the sending end retransmission buffer module of this device, control messages from the sending end message module of this device, control messages from the receiving end message module of this device, and Ethernet messages from the sending end message buffer module through the backup channel. The sending end data selector will select one of the messages according to the actual application situation and send it to the corresponding other Ethernet link control devices.

Among them, multiple devices send control messages to each other and perform corresponding operations through control messages, realizing the negotiation and synchronization functions between Ethernet links. At the same time, the control messages and data messages contain unique frame identifier fields, which can accurately realize flow control and error retransmission.

Among them, the sending end retransmission cache module 12, the sending end message module 13, the sending end retransmission control module 14, and the receiving end message module 23 can be combined into a control message generation and processing module. The control message generation and processing module can be implemented based on CGRA (Coarse-grained Reconfigurable Array). CGRA is a parallel computing mode in the airspace, which organizes computing resources of different granularities and functions with the hardware structure of the airspace. At run time, according to the characteristics of the data flow, the configured hardware resources are interconnected to form a relatively fixed computing path, and the calculation is performed in a manner close to a "dedicated circuit"; when the algorithm and application change, they are reconfigured again to perform different tasks through configuration. The delay and energy consumption overhead of instruction fetch and decoding operations can be reduced in the computing architecture without the traditional instruction-driven operation, and can also be executed in a manner close to a "dedicated circuit" during the computing process. In addition, the computing power of the CGRA architecture can be flexibly expanded, which is suitable for scenarios with comprehensive requirements for high energy efficiency and flexibility from the cloud to the edge.

Among them, in a specific embodiment of the present disclosure, in simplex mode, 3220 messages were sent continuously without packet loss. The full-speed bandwidth is 102.4GB/s, the bandwidth utilization rate is 79.03%, and the average bandwidth is 80.93GB/s; in duplex mode, 3287 messages were sent and received continuously without packet loss. The bandwidth utilization rate is 68.92%, and the average bandwidth is 70.58GB/s. The working efficiency is greatly improved compared with the traditional Ethernet MAC controller. At the same time, the present disclosure also adds message retransmission caching and processing functions, realizes flow control and error retransmission through custom control messages, and ensures reliable data transmission.

It should be noted that, although Figures 3, 4, and 5 are used as examples to introduce a data/control message generated by an Ethernet link control device as above, those skilled in the art will understand that the present disclosure should not be limited to this. In fact, the corresponding message can be flexibly set according to personal circumstances and/or actual application scenarios. At the same time, although Figures 2, 6, 7, and 8 are used as examples to introduce an Ethernet link control device as above, those skilled in the art will understand that the present disclosure should not be limited to this. In fact, the modules can also be flexibly used and assembled according to personal circumstances and/or actual application scenarios, and are not limited to the contents given in this example.

The embodiment of the present disclosure also provides a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the above-mentioned device is implemented. The computer-readable storage medium can be a volatile or non-volatile computer-readable storage medium.

The embodiment of the present disclosure further proposes an Ethernet link control device, comprising: a processor; a memory for storing instructions executable by the processor; wherein the processor is configured to implement the above device when executing the instructions stored in the memory.

The embodiments of the present disclosure also provide a computer program product, including a computer-readable code, or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device implements the above-mentioned apparatus.

The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of the module, program segment or instruction includes one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each square box in the block diagram and/or flow chart, and the combination of the square boxes in the block diagram and/or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of special hardware and computer instructions.

The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (9)

1. An ethernet link control device, comprising a transmitting means, the transmitting means comprising:

The frame identifier encapsulation module is used for acquiring an Ethernet message, adding a frame identifier field into the Ethernet message to obtain a data message, and providing the data message to the data selector at the transmitting end and the retransmission buffer module at the transmitting end;

the transmitting end retransmission buffer module is used for buffering the data message; providing corresponding data messages to a data selector of a transmitting end according to the indication of a retransmission control module of the transmitting end, or releasing the buffer space of the corresponding data messages;

The transmitting end message module is used for generating a control message according to the indication of the transmitting end retransmission control module and providing the control message to the transmitting end data selector;

The transmitting end retransmission control module is used for controlling the transmitting end retransmission buffer module and the transmitting end message module; when the data message is determined to need to be retransmitted according to the control messages from other Ethernet link control devices, a control transmitting end retransmission buffer module provides the corresponding data message for a transmitting end data selector, and a control transmitting end message module generates the corresponding control message and provides the control message for the transmitting end data selector; when the successful transmission of the data message is determined according to the control messages from other Ethernet link control devices, the retransmission buffer module of the transmitting end is controlled to release the buffer space of the corresponding data message;

a transmitting end data selector, configured to transmit a data packet and/or a control packet generated by the ethernet link control device to other ethernet link control devices;

the device is connected with an Ethernet MAC and message buffer module:

the frame identifier encapsulation module acquires an Ethernet message from the message cache module;

the transmitting end data selector transmits data messages and/or control messages to other Ethernet link control devices through the Ethernet MAC;

the apparatus further comprises a receiving means comprising:

The receiving end distribution module is used for receiving messages from other Ethernet link control devices and judging whether the messages are data messages or control messages; when the message is a data message, the message buffer module is used for judging whether the data message meets the transmission requirement, and when the data message meets the transmission requirement and has available space, the data message is provided for the frame identifier deleting module to control the receiving end message module to generate a corresponding control message to be provided for the transmitting end data selector; if the transmission requirement is not met and/or the message buffer module has no available space, the message buffer module is used for controlling the receiving end message module to generate a corresponding control message so as to be provided for the transmitting end data selector; when the message is a control message, the message is used for providing the control message to a retransmission control module of a transmitting end;

A frame identifier deleting module for deleting the frame identifier field added in the data message;

The receiving end message module is used for generating a corresponding control message according to the indication of the receiving end distribution module and providing the control message to the transmitting end data selector;

The control message generated by the receiving end message module comprises:

Successfully receiving the PA message, wherein the PA message is used for indicating that the data message is successfully transmitted; when a receiving end distribution module judges that received messages from other Ethernet link control devices are data messages, the data messages meet transmission requirements and a message buffer module has available space, the receiving end message module is controlled to generate PA messages; when other Ethernet link control devices receive the PA message, a transmitting end retransmission control module of the other Ethernet link control devices determines that the data message is successfully transmitted;

PR message needs to be retransmitted to indicate that data message needs to be retransmitted; when the receiving end distribution module judges that the received message from other Ethernet link control devices is a data message, and the data message accords with the transmission requirement but the message buffer module has no available space, the receiving end message module is controlled to generate a PR message; when other Ethernet link control devices receive the PR message, a transmitting end retransmission control module of the other Ethernet link control devices determines that the data message needs to be retransmitted;

The unsuccessful receiving PNA message is used for indicating that the data message needs to be retransmitted; when the receiving end distribution module judges that the received message from other Ethernet link control devices is a data message, and the data message does not accord with the transmission requirement, the receiving end message module is controlled to generate a PNA message; when other Ethernet link control devices receive the PNA message, a transmitting end retransmission control module of the other Ethernet link control devices determines that the data message needs to be retransmitted.

2. The ethernet link control device of claim 1 wherein the condition for meeting transmission requirements includes that the frame identifier of the data message is correct and that the cyclic redundancy check, CRC, of the data message is error free.

3. The Ethernet link control device of claim 1, wherein,

After a receiving end message module of the receiving part sends PR message or PNA message according to the indication of a receiving end distribution module, the receiving part enters a retransmission waiting state;

when the receiving part is in a retransmission waiting state, a receiving end distribution module of the receiving part does not receive data messages from other Ethernet link control devices.

4. The ethernet link control device according to claim 1, wherein the control message generated by the sender message module comprises:

Releasing the retransmission state RFR message, which is used for releasing the retransmission waiting state of the receiving component; when a transmitting end retransmission control module receives PR messages or PNA messages from other Ethernet link control devices, determining that the data messages need to be retransmitted, and controlling a transmitting end message module to generate RFR messages; when the other Ethernet link control device receives the RFR message, the receiving part of the other Ethernet link control device releases the retransmission waiting state and resumes receiving the data message from the other Ethernet link control device.

5. The ethernet link control device according to claim 1, wherein the control message generated by the sender message module further comprises:

A request link state LReq message for requesting knowledge of the state of the receiving element; when the transmitting end retransmission control module receives PNA messages with the same frame identifier from other Ethernet link control devices at least twice, the transmitting end retransmission control module controls the transmitting end message module to generate LReq messages;

When the ethernet link control device establishes connection with other ethernet link control devices for the first time, a LReq message is actively generated and sent.

6. The ethernet link control device of claim 5 wherein the receiving end distribution module of the other ethernet link control device indicates the control message generated by the receiving end message module when the other ethernet link control device receives the LReq message comprises:

A reply link state LRsp message for feeding back the state of the receiving component; when the receiving end distribution module receives LReq messages from other Ethernet link control devices, the receiving end message module is controlled to generate LRsp messages; wherein LRsp messages include the frame identifier of the required data message.

7. The ethernet link control device of claim 1 further comprising a backup tunnel for providing ethernet messages to the sender data selector for transmission to other ethernet link control devices.

8. An ethernet link control device, comprising:

a processor;

a memory for storing processor-executable instructions;

Wherein the processor is configured to implement the apparatus of any one of claims 1 to 7 when executing the instructions stored by the memory.

9. A non-transitory computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the apparatus of any of claims 1 to 7.