JPH0879310A - Transmission buffer data storage method and transmission buffer data storage device - Google Patents

Abstract

PURPOSE: To reduce transfer processing of transmission data by a transmission buffer when a protocol header is added. CONSTITUTION: Transmission data are stored so as to be packed backward (toward tail end address AE) in a transmission data storage area provided to a transmission buffer together with a management information storage area having data head address information SA. Idle areas not in use are obtained in preceding areas of the area SD in which the transmission data are stored. Since a protocol header is stored in the idle area, it is not required to transfer the transmission data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention According to the present invention, after a transmission data transfer process for storing transmission data in a transmission buffer memory having a storage capacity L, a protocol header added at the time of transmitting the transmission data is arranged in a data arrangement order at the time of transmission. The present invention relates to a transmission buffer data storage method and a transmission buffer data storage device that perform header addition processing centered on processing for storing the protocol header in the transmission buffer, in particular, transmission according to a predetermined protocol. In order to organize the data, when adding a protocol header to the transmission data, the transfer processing of the transmission data stored in the transmission buffer is further reduced, and the required transmission buffer The present invention relates to a transmission buffer data storage method and a transmission buffer data storage device capable of suppressing the number and size of areas.

[0002]

2. Description of the Related Art A local area network (local ar
ea network, hereafter also referred to as LAN).
It is a network that transmits digital data at a transmission rate of about 0.1 to 100 MBPS (megabits / second) within a range of about 1 to 10 km. Further, the LAN has a certain kind of exchange function as an integrated communication system, and it is possible to organically combine distributedly installed computers, computer peripheral devices, communication terminal devices and the like.

Therefore, according to such a LAN, the hardware (including peripheral devices) of distributed computers and databases, etc. are set within a limited range such as the premises of offices, factories, research laboratories, and universities. Can be effectively shared.

In addition, digital data public network (digital data
exchange (hereinafter, also referred to as DDX network) enables data communication not only in Japan but also in foreign countries. or,
CCITT (international telegr
ath and telephone consultative committee) Recommendation X.
There are packet switching networks that comply with standards such as 25.

In this packet exchange, a protocol header containing destination information and the like is added to a block called a packet in units of predetermined bytes, and packets with different destinations are multiplexed and transmitted using the same transmission path. Such a packet-switched network has features such that extremely high transmission quality can be obtained.

Here, in the above-mentioned LAN and packet switching network, it is generally defined by a plurality of layers.

For example, as shown in FIG. 17, the above-mentioned CCIT
OSI (open systems interconnec) applied by T recommendation
I) together with the layer structure defined by the reference model, etc.
EEE (institute of electrical and electronics en
gineers) The layer structure of the LAN defined by the 802 committee etc. is shown.

First, the layer structure defined by OSI or the like has a total of 7 layer structures as shown in FIG.

In such a layer structure, firstly, the first layer, that is, the physical layer (Ph layer) is more directly connected to the hardware and mainly relates to the transmission control, and mechanical / electrical for bit transmission. Control. The second layer, namely the data link layer (DL
The layer) transfers data, and particularly controls transmission errors. The third layer, namely the network layer (N
The layer) is for relaying data communication performed via one or a plurality of communication networks. Also, the fifth layer,
That is, the session layer (S layer) controls data transmission / reception, synchronization, and the like. In addition, the fourth layer between the third layer and the fifth layer, that is, the transport layer (T layer), performs transparent data transfer especially to a layer higher than the fifth layer. It is something to set.
Further, as a higher layer, a presentation layer (P layer) of the sixth layer, an application layer (A layer) of the seventh layer, and the like are set.

In the following description, in such a layer structure, as the above-mentioned first layer, second layer, third layer, ... It shall be in the higher rank.

On the other hand, in a layer structure applied to a LAN such as IEEE, for example, the data link layer of the above-mentioned second layer is divided into a logical link control sublayer (LLC layer) and a medium access control sublayer (MAC).
Layers). Together with these two sublayers, for example, a physical layer (Ph layer), a network layer (N layer), a transport layer (T layer), and the like are configured.

As described above with reference to FIG. 17, the standardized protocol is usually defined by many layers.

Further, in each layer, protocol headers defined respectively are sequentially added. That is, when the transmission data is organized into a prescribed protocol from a higher layer such as an application layer and a presentation layer to a lower layer, protocol headers regulated by each are sequentially added. .

FIG. 18 is a block diagram showing the configuration of an example of a conventional communication control device.

FIG. 18 shows the configuration of the communication control device 2 connected to the CPU 1 for transmitting and receiving data according to a predetermined protocol. In particular, a T layer, such as the layer structure shown on the right side of FIG.
Transmission data is sequentially organized according to the protocols of the N layer and the LLC layer. The communication control device 2 includes the CPU 1
Is used when performing data communication using the transmission line 3. The communication control device 2 is composed of a bus control unit 11, a protocol control unit 12B, a line control unit 14, and a buffer memory 16B.

First, in the communication control device 2, the protocol control unit 12B is connected to the CPU 1 by the bus control unit 11. The bus control unit 11 uses the C
Control as a CPU interface such as reception of commands from PU1 and transmission / reception of transmission / reception data.

On the other hand, the protocol control unit 12B is connected to the transmission line 3 via the line control unit 14.
The line control unit 14 controls an interface for connecting the protocol control unit 12B to the transmission line 3.

The buffer memory 16B connected to the protocol control unit 12B is composed of a transmission buffer memory 16c and a reception buffer memory 16b.

The transmission buffer memory 16c is used when the CPU 1 transmits data to another CPU or the like via the communication control device 2 and the transmission path 3.
That is, when the CPU 1 transmits data, the transmission data is temporarily stored in the transmission buffer memory 16c by the protocol control unit 12B. On the other hand, the reception buffer memory 16b temporarily stores the received data when the CPU 1 receives data from another CPU or the like via the transmission path 3 and the communication control device 2 or the like. That is, the data received from the transmission path 3 is temporarily stored by the protocol control unit 12B and the like.

FIG. 19 is a block diagram showing the structure of the protocol control unit used in the conventional communication control apparatus.

As shown in FIG. 19, the protocol control unit 12B shown in FIG. 18 includes a CPU transmission data processing unit 12j, a T layer data processing unit 12k, an N layer data processing unit 12m, and LLC layer data. It is composed of a processing unit 12n and a frame transmission processing unit 12p.

The protocol control unit 12B uses these CPs.
U transmission data processing unit 12j, T layer data processing unit 12k,
N layer data processing unit 12m, LLC layer data processing unit 12n
The frame transmission processing unit 12p performs addition of a protocol header, division of transmission data, etc. while using the buffer memory 16B.

Here, the addition of the protocol header means that, when the transmission data is organized according to the regulation regarding the protocol of each layer, a protocol header regulated by the layer is created and is added to the transmission data. . Also, because the division of transmission data is limited in the data length that can be transferred at one time by the protocol of each layer, when transmitting a larger amount of data than this data length, the transmission data received from the upper layer is divided into multiple transmission data. It is to divide into. By dividing in this way, the length of the transmission data can be suppressed within the limit range of the data length in each layer.

FIG. 20 is a block diagram of a transmission buffer used in a conventional communication control device.

The transmission buffer shown in FIG. 20 shows one of a plurality of transmission buffers set in the transmission buffer memory 16c shown in FIG. The transmission buffer secures a predetermined area in the transmission buffer memory 16c and is prepared by this.

As shown in FIG. 20, the area of the control information CD and the data length LD are sequentially arranged in the ascending direction of the address of the transmission buffer memory 16c (that is, in the ascending direction of the address of the buffer memory 16B). It is composed of an area, a transmission data area SD, and an unused area, that is, an empty area.

Here, an area composed of the area of the control information CD and the area of the data length LD is defined as a management information storage area. Further, the transmission data is actually stored.
A transmission data storage area including the transmission data area ST and the empty area is provided. In addition, the transmission buffer configured by the management information storage area and the transmission data storage area as described above has a start address AS to a tail end address A.
The area up to E. Further, in the transmission data storage area, an area where transmission data is actually stored, that is, the transmission data area SD is a transmission data start address AD.
It is an area from S to the tail end address ADE of the transmission data.

Here, the control information CD is information used for managing the transmission buffer. For example, the buffer total length of the transmission buffer (AE-AS + 1) and the like. The data length LD includes the transmission data head address ADS to the transmission data tail address ADE.
Up to the data length of the transmission data area SD is written. That is, the data length LD includes (ADE-ADS +
The value of 1) is written.

While using the transmission buffer shown in FIG. 20, the protocol control unit 12B operates as shown in FIG.
As shown in order in FIG. 24, a predetermined protocol is organized while sequentially adding protocol headers corresponding to each layer. That is, the protocol header HTA of the T layer, the protocol header HNA of the N layer, and the protocol header HLLCA of the LLC layer are sequentially added in this order while the above-mentioned FIG.
Finally, the transmission data as shown in 4 is obtained.

That is, first, as shown in FIG.
The transmission data sent from PU1, that is, the CPU transmission data SDA is written in the transmission buffer by the protocol control unit 12B. At this time, the transmission data tail address is ADE1 as shown in FIG.
The data length at this time, that is, LDA1 is (ADE1-
ADS + 1). The organization of the protocol shown in FIG. 21 is performed by the CPU transmission data processing unit 12j.

Then, as shown in FIG. 22, the transmission data is organized according to the protocol of the T layer. This is mainly the addition of the protocol header HTA of the T layer.

When adding the T layer protocol header HTA, first, in order to obtain an area to which the T layer protocol header HTA is added, the CPU transmission data SDA is moved rearward of the transmission data storage area (transmission). Data movement process). For example, if the data length of the T layer protocol header HTA is (ADS2-ADS + 1), the transmission data tail address of the CPU transmission data SDA is (ADE + (ADS2-ADS + 1)) (=
The CPU transmission data SDA is moved rearward of the transmission data storage area until ADE2) is reached. Therefore, the empty area is reduced by this movement.

When the process of moving the transmission data is performed in this manner, an area for storing the T-layer protocol header HTA is secured just above the CPU transmission data SDA. Therefore, the T layer protocol header HTA
After the generation of the T layer protocol header HTA, the T layer protocol header HTA is stored in the storage area of the data length LDA2 and the CPU transmission data SDA.
Stored in the storage area of.

After that, the value of the data length LDA2 is updated to (ADE2-ADS + 1).

The organization of transmission data according to the T layer protocol as described above is performed by the T layer data processing unit 12k shown in FIG.

Further, similar to the organization of the transmission data of the T layer protocol, the N layer data processing unit 12m organizes the transmission data according to the N layer protocol as shown in FIG. It The transmission data of the N-layer protocol is mainly performed by adding the N-layer protocol header HNA to the transmission data of the T-layer protocol.

Further, the LLC layer data processing unit 12n adds the protocol header HLLCA of the LLC layer to the transmission data according to the protocol of the N layer. By this, the transmission data according to the protocol of the LLC layer as shown in FIG. 24 is organized.

As described above, when the protocol headers of the T layer, the N layer, and the LLC layer are sequentially added, the process of moving the transmission data is performed each time.
Accordingly, the transmission data start address and the transmission data tail address of the CPU transmission data SDA are ADS and ADE1, ADS2 and ADE.
2, ADS4 and ADE4 are sequentially moved backward.

Here, when the data length of the transmission data to be stored is longer than the size of the transmission data storage area shown in FIG. 20, the transmission data to be stored is divided as shown in FIG. It

That is, as shown in FIG. 25, the entire length of one transmission data, which is composed of the transmission data SD1 to SD3 and is stored in the transmission buffer, is the transmission data storage of the transmission buffer. If it is longer than the storage capacity L of the area, the transmission data is sequentially divided from the beginning by the storage capacity L. That is, the transmission data SD1 having the same data length as the storage capacity L, the transmission data SD2 having the same data length as the storage capacity L, and the storage capacity L.
The transmission data S having a data length (A4-A3 + 1) less than
And D3.

Further, when dividing the transmission data in this way, a transmission buffer having a structure as shown in FIG. 26 is used. The transmission buffer shown in FIG. 26 is different from that shown in FIG. 20 in that it has a link pointer LP. The link pointer LP indicates the start address of another transmission buffer subsequent to each transmission buffer when the transmission data divided into a plurality of pieces are stored in the different transmission buffers as described above. It is a thing.

For example, the transmission data S as shown in FIG.
The transmission data SD1 having the same data length as the storage capacity L and the storage capacity L with respect to one transmission data which is composed of DB1 and transmission data SDB2 and has a total data length longer than L and 2L or less. The transmission data SD2 having the following data length (A8-A7 + 1) is divided. This is divided from the head side of the transmission data. In this case, as shown in FIG. 28, the two transmission buffers are used. These transmission buffers are those shown in FIG.

Here, in FIG. 28, the control information C
DB1, link pointer LPB1 and data length LDB1
First, the transmission data SDB1 is stored in the transmission buffer composed of the above. Also, control information CD
B2, a link pointer LPB2, a data length LDB2, and the like.
DB2 is stored. Thus, the transmission data SDB
1 and SDB2 are stored, the transmission data SD
The link pointer LP of the transmission buffer storing B1
The head address of the transmission buffer storing the transmission data SDB2 is stored in B1 as indicated by the arrow in FIG.

Here, as shown in FIG. 28, the protocol header HTB is added to the transmission data stored across the two transmission buffers in order to organize the transmission data of the protocol of the T layer, When adding the protocol header HNB for organizing the transmission data of the N layer protocol and adding the protocol header HLLCB for organizing the transmission data of the LLC layer protocol, It is also conceivable to perform the above-described movement processing of the transmission data SDA across two transmission buffers. That is, it is also conceivable to carry out a process of moving transmission data in each layer across the two transmission buffers shown in FIG. 28 with the addition of the protocol headers HTB, HNB and HLLCB in each layer.

On the other hand, with respect to the transmission data spanning the two transmission buffers as shown in FIG. 28, the protocol header H of the T layer, the N layer or the LLC layer is transmitted.
With the addition of TB, HNB and HLLCB, FIG.
As shown in FIG. 31, it is possible to allocate one transmission buffer for each protocol header.

That is, first, when the transmission data of the T layer protocol is organized, a protocol header HT added
In order to store B, one dedicated transmission buffer is prepared as shown in FIG. Also, the protocol HT
In the transmission buffer storing B, the head address of the transmission buffer storing the transmission data SDB1 is written to the link pointer LPB3.

Subsequently, when organizing the transmission data of the N-layer protocol, as shown in FIG. 30, one dedicated transmission buffer is prepared and the protocol header HNB of the N-layer is stored. The link pointer LPB4 of the transmission buffer in which the protocol header HNB is stored stores the start address of the transmission buffer in which the protocol header HTB is stored.

Further, when organizing the transmission data of the LLC layer protocol, as shown in FIG. 31, one dedicated transmission buffer is prepared and the transmission data storage area of the transmission buffer is prepared. The protocol header HLLCB is stored in. Further, the link pointer LPB5 of the transmission buffer in which the protocol header HLLCB is stored stores the start address of the transmission buffer in which the protocol header HNB is stored.

As shown in FIG. 25 and FIG. 27, when one transmission data is divided into a plurality of pieces, the storage capacity of the transmission buffer is set to the maximum transmission data length of each layer (each layer). Of these, it is preferable to set it to a divisor of the smallest one. As a result, the transmission data can be divided more efficiently so as to fit in the storage capacity L of the transmission buffer. In addition, the linking of a plurality of transmission buffers associated with this can be performed more easily.
It is also possible to disconnect the link of the transmission buffer, insert a new transmission buffer, and store the protocol header, if necessary.

[0050]

However, in the above-mentioned conventional communication control device, in order to organize the transmission data according to the predetermined protocol, when adding the protocol header to the transmission data, the transmission buffer etc. Had to perform a movement process of the transmission data stored in the.

For example, in FIGS. 21 to 24, the CPU transmission data is added every time the protocol header HTA of the T layer, the protocol header HNA of the N layer and the protocol header HLLCA of the LLC layer are added. The move process for SDA had to be done.
That is, in the transmission data storage area, each time a protocol header is added in this way, the protocol header HTA, HNA, or HLL to be added at that time is added backward.
The CPU transmission data SDA had to be moved by the length of CA.

Further, for example, as shown in FIG. 28, when the divided wet transmission data SDB1 and SDB2 are respectively stored in the two transmission buffers, such a movement process of the transmission data is more complicated. Become. That is, such movement processing of transmission data must be performed across two transmission buffers each time a protocol header is added.

As shown in FIGS. 29 to 31, protocol headers HTB, HNB and H to be added are added.
In the case where one dedicated transmission buffer is prepared for each LLCB and sequentially linked, it is not necessary to perform such movement processing of transmission data. However,
Since one dedicated transmission buffer is used for each protocol header, there is a problem that the number of required transmission buffers and the size of the area increase.

Further, in order to acquire a large number of transmission buffers in this way, processing for this is required. The process of acquiring the transmission buffer is relatively time-consuming because it is necessary to search for an empty area in the transmission buffer memory 16c and to integrate or organize small empty areas in some cases. . Therefore, when a large number of transmission buffers are acquired in this way, there arises a problem that the entire processing time is extended.

The present invention has been made to solve the above-mentioned conventional problems, and in order to organize transmission data according to a predetermined protocol, when adding a protocol header to the transmission data, a transmission buffer, etc. Buffer memory data storage method and transmission buffer memory capable of suppressing the number of transmission buffers and the size of the area required while further reducing the movement processing of the transmission data stored in An object is to provide a data storage device.

[0056]

First, in the transmission buffer data storage method of the first invention of the present application, after the transmission data transfer process of storing the transmission data in the transmission buffer of the storage capacity L, the transmission of the transmission data is performed. In the transmission buffer data storage method for performing header addition processing centered on processing for storing the protocol header at the head side of the transmission buffer so as to add the protocol header to be added at the time of data arrangement at the time of transmission, At the time of the transmission data transfer process, the transmission data is stored in the transmission buffer so that the transmission data tail end is packed rearward with respect to the head and tail end of the transmission data, and the transmission data transfer process is performed. In this case, the storage location of the head of the transmission data in the transmission buffer after the transmission data is stored in the transmission buffer. By which is adapted to store information indicating a is obtained by providing a transmit buffer data storage method achievable the problems.

In the transmission buffer data storing method of the first invention, if the data amount M of the transmission data is larger than the storage capacity L, {(M / L) ≤N <
According to a natural number N of ((M + 1) / L)}, a total of at least N transmission buffers are secured, and the transmission data is sequentially divided from the tail end of the transmission data by the storage capacity L. The divided object is sequentially stored in each of the transmission buffers while preserving the information of the storage order according to the division order, thereby achieving the above-mentioned object and the data amount of the transmission data. M
Even when the storage capacity is larger than the storage capacity L, it is possible to cope more effectively.

In the transmission buffer data storage method of the first aspect of the invention, the information indicating the storage position of the head of the transmission data to be stored during the transmission data transfer process is:
By using the address in the transmission buffer, the above-mentioned problems can be achieved, and the efficiency of processing required for reading the information written in the transmission buffer can be improved and the processing speed can be improved. It is a thing.

In the transmission buffer data storage method of the first invention, the division order storage order information is stored in a link pointer prepared for each of the transmission buffers. According to the first address of the next transmission buffer, which follows each transmission buffer in accordance with the division order of the stored data, the above problem can be achieved and the data amount M of the transmission data can be achieved.
Is more effective than the storage capacity L, the processing efficiency in reading the transmission buffer at that time is improved, and the processing speed is improved. is there.

On the other hand, the transmission buffer data storage device of the second invention of the present application, after the transmission data transfer process of storing the transmission data in the transmission buffer of the storage capacity L, adds the protocol header added when the transmission data is transmitted. In the transmission buffer data storage device that performs header addition processing centered on the processing of storing the protocol header at the head side of the transmission buffer in order to add the data in the data array order at the time of transmission, A data transfer unit for storing the transmission data in the transmission buffer so that the transmission data tail end is packed backward with respect to the head and tail end of the transmission data; The storage position of the head of the transmission data in the transmission buffer after the transmission data is stored in the transmission buffer. By and a leading address information storage unit for storing information indicating a is obtained by providing a transmit buffer data storage device that can achieve the above objects.

[0061]

After the transmission data transfer process for storing the transmission data in the transmission buffer having the storage capacity L, the protocol headers are added so that the protocol headers added at the time of transmitting the transmission data are added in the data arrangement order at the time of transmission. When the protocol header is stored in the transmission buffer, the protocol header is stored immediately before the front (front end) of the transmission data. Both the first invention and the second invention of the present application have been made paying attention to the fact that the transmission data is stored immediately before the transmission data.

As described above, since the protocol header is added and stored immediately before the front of the transmission data, a vacant area is already present in front of the transmission data without performing the moving process of the transmission data as described above. Is desirable.
Therefore, in the present invention, in the transmission data transfer process, the transmission data tail end is stored in the transmission buffer so that the transmission data tail end is packed backward. Data is stored in the transmission buffer.

By packing the data in the rearward direction and storing the data in this way, when the data length M of the transmission data to be stored is shorter than the storage capacity L of the transmission buffer, the front side of the transmission data ( There is an empty area to the last minute. Therefore, according to the first invention and the second invention of the present application, it is possible to provide an empty area in front of the transmission data without performing the moving process of the transmission data. Moreover, the required protocol header can be added immediately by effectively using the empty area.

FIG. 1 shows the first invention and the second invention of the present application.
3 is an address map of a transmission buffer used therefor showing the gist of the invention.

In FIG. 1, one of the transmission buffers used in the transmission buffer data storage method of the first invention, or the transmission buffer data storage device of the second invention is used. A memory map for one of the transmit buffers used is shown.

In FIG. 1, the transmission buffer used in the first invention or the second invention is composed of a management information storage area and a transmission data storage area. In particular, the management information storage area includes a control information CD storage area and a data start address information SA storage area. On the other hand, the transmission data storage area is particularly the transmission data area SD in which the transmission data is stored.
And, in particular, an unused free area in which the transmission data is not stored.

First, regarding the control information CD, the first invention and the second invention are not limited to having the same, and the contents thereof are not limited. However, in general, each transmission buffer has some kind of control information, and has such a control information CD area.

Further, the data head address information SA is
This is information indicating the start address (storage position) of the transmission data area SD stored in the transmission data storage area, that is, the transmission data start address. The transmission data stored in the transmission data storage area has various data lengths. Therefore, it is necessary to store some information (data) corresponding to the data length LD shown in FIG. 20 or FIG. The present invention
The information indicating the storage position at the beginning of the transmission data stored in the transmission buffer is not particularly limited.

For example, when the data head address information SA is an address in the transmission buffer, for example, its absolute address or an address relative to the head address SA, the transmission data head shown in FIG. The address ADS can be known immediately. Normally, when reading the transmission data, first, the transmission data start address ADS is required. Therefore, in such a case, the transmission data head address ADS can be immediately obtained, so that the calculation speed and processing speed can be improved.

Further, in FIG. 1, as described above,
The transmission data is stored rearward in the transmission buffer, particularly in the transmission data storage area. Therefore, the empty area is, as shown in FIG.
It is on the head side of the transmission data area SD. The start address of the transmission data area SD is the transmission data start address ADS as shown in FIG.

As shown in FIG. 1, according to the first invention or the second invention, the transmission data area SD is
The empty area is generated at the head side of the, and, for example, when organizing transmission data according to a predetermined protocol, it is possible to easily add the protocol header to the head of the transmission data. Therefore, it is possible to further reduce the movement processing of the transmission data. Further, when a plurality of transmission buffers are used, it is possible to further reduce the movement processing of the transmission data while suppressing the required number of transmission buffers and the size of the area.

The first invention and the second invention of the present application do not link a plurality of transmission buffers like the conventional transmission buffer shown in FIG. 20 and the conventional transmission buffer shown in FIG. However, the present invention is not limited to one such as linking a plurality of transmission buffers. That is, like the conventional one shown in FIG. 26, the one using a plurality of transmission buffers by using a link pointer or the like can be applied. Conventionally, in the case of using a plurality of transmission buffers in this way, the movement processing of the transmission data as described above has to be performed across a plurality of transmission buffers, and the processing has become quite complicated. .

However, by applying the first invention or the second invention to the one using the plurality of transmission buffers in this way, it is possible to reduce such complicated processing. At this time, it is not particularly necessary to use a large number of the transmission buffers as shown in FIGS. 29 to 31, and it is possible to suppress the number of transmission buffers and the size of the area required.

When the first invention or the second invention is applied to the use of a plurality of the transmission buffers, the link pointer LP shown in FIG. 26 or the like is used. When the transmission data after division is sequentially stored in the plurality of transmission buffers, it is necessary to store information on the storage order with respect to the division order. In the present invention, such storage order information is not particularly limited, but the transmission data stored in the transmission buffer can be stored by using a link pointer as shown in FIG. 26, for example. It is possible to immediately link a plurality of transmission buffers at the time of reading, to improve the efficiency of the processing required for reading, and to further reduce the processing time.

[0075]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of a communication control device to which the transmission buffer data storage method of the first invention and the transmission buffer data storage device of the second invention are applied. .

As is apparent from a comparison between FIG. 2 and the above-mentioned conventional communication control device shown in FIG. 18, the protocol control unit 12A and the buffer memory 16A of this embodiment are different from those of FIG. Further, particularly in the buffer memory 16A, the transmission buffer memory 16 of FIG.
a is different from the transmission buffer memory 16c of FIG.

With respect to the protocol control unit 12A and the buffer memory 16A, the processes for the bus control unit 11 and the line control unit 14 are performed by the protocol control unit 12B and the buffer memory 16B shown in FIG.
And the like. These protocol control units 12A
The internal processing of the buffer memory 16A is different from the conventional one of FIG. 18 in that the first invention and the second invention are applied.

FIG. 3 is a block diagram showing the configuration of the protocol control unit used in the above embodiment.

The protocol control section 12A shown in FIG. 3 has a CPU transmission data processing section 12a and a T
A layer data processing unit 12b, an N layer data processing unit 12c,
LLC layer data processing unit 12d and frame transmission processing unit 1
2e and.

Regarding these, the respective functions are the same as the corresponding ones shown in FIG. 19 having the same names. That is, these CPU transmission data processing unit 12a, T layer data processing unit 12b, N layer data processing unit 12c, LLC
The layer data processing unit 12d and the frame transmission processing unit 12e are different from each other only in the internal processing for achieving their functions, especially those having the same names shown in FIG.

FIG. 4 is a block diagram showing the configuration of the CPU transmission data processing unit 12a of the above embodiment.

As shown in FIG. 4, the CPU transmission data processing unit 12a includes, in particular, a transmission request reception unit 13a, a buffer memory acquisition unit 13b, a data transfer unit 13c,
It is composed of a head address information storage unit 13d. In addition, such a CPU transmission data processing unit 12a
The actual processing of (1) will be described in more detail later using the flowchart of FIG.

FIG. 5 is a memory map showing the structure of one of the transmission buffers used in this embodiment.

In the transmission buffer memory 16a shown in FIG. 2, an area of the transmission buffer having the structure shown in FIG. 5 is appropriately secured as needed.
In some cases, a plurality of transmission buffers may be prepared.

As shown in FIG. 5, the transmission buffer of this embodiment has a control information CD area, a link pointer LP area, a data head address information SAC area, a transmission data area SD, and an empty space. And a region.

In particular, the transmission buffer used in this embodiment further includes the link pointer LP in addition to the above-mentioned one shown in FIG. The link pointer L
P is the same as that described above with reference to FIGS. 26 to 31.

In this embodiment, the data head address information SAC corresponding to the data head address information SA shown in FIG. 1 is provided. The data head address information SAC is the head address of the transmission data area SD, that is, the transmission data head address ADS shown in FIG.
Is memorized. In particular, the transmission data start address ADS
The absolute address of is stored.

The method of using the transmission buffer in this embodiment will be described more specifically below.

First, regarding the storage capacity L of the transmission buffer of this embodiment, the CP sent from the CPU 1
The data length of the U transmission data SDC, the data length of the protocol header HTC added at the time of the protocol composition of the T layer, and the data length of the protocol header HNC added at the time of the protocol composition of the N layer with respect to the CPU transmission data. , And the data length of the protocol header HLLCC added when the protocol of the LLC layer is organized, when the sum of these data lengths is shorter than the storage capacity L, FIG.
~ As shown in FIG.

That is, first, as shown in FIG.
When the CPU transmission data SDC is sent from PU1,
The CPU transmission data SDC is stored in the transmission buffer of this embodiment so as to be packed backward.
Therefore, the empty area is above the transmission data storage area. That is, a space is provided between the data head address information SAC1 and the CPU transmission data SDC.

Next, when the protocol header HTC is added when the protocol of the T layer is organized, it becomes as shown in FIG. That is, the C stored so as to be packed backward in the transmission data storage area
The protocol header HTC is stored immediately before the PU transmission data SDC. Such a protocol header H
When storing the TC, since the storage position is the empty area, the moving process of the transmission data SDC is not particularly required.

Similarly, when the protocol of the N layer and the LLC layer is organized, each protocol header HNC
Alternatively, the empty area in the transmission data storage area is also used when the HLLCC is added. Therefore, if the empty area exists, as shown in FIGS. 8 and 9, the protocol header HN at the time of organizing such a protocol.
The C or HLLCC can be stored immediately,
The movement process of the CPU transmission data SDC for obtaining the space for the storage becomes unnecessary. That is, the protocol header HNC is first stored as shown in FIG. 8, and then the protocol header HLLCC is stored as shown in FIG.

Next, FIG. 10 shows transmission data SDD1 to SDD.
This is a case where one CPU transmission data of DD4 is targeted. In FIG. 10, in particular, the total data length of the CPU transmission data is longer than 3L with respect to the storage capacity L of the transmission buffer of the present embodiment, and
This is the case of 4 L or less.

In such a case, as shown in FIG. 10, corresponding to the four transmission buffers, the storage capacity L is sequentially divided from the tail end side of the transmission data, and divided. The obtained data are sequentially stored in different transmission buffers. The values of the link pointers LPD1 to LPD4 of the respective transmission buffers are stored and stored as the information of the storage order with respect to the division order.

Here, since the transmission data is sequentially divided from the tail end as described above, a vacant area exists at the head side portion of the transmission data, that is, the portion immediately before the transmission data SDD1. To do. Therefore, the T layer and the N layer
Layer or the transmission data of the LLC layer protocol,
Each corresponding protocol header HTD1, HND
1 and HLLCD1 can sequentially write to such an empty area in front of the transmission data SDD1. Therefore, at the time of writing such a protocol header, it is not necessary to perform a moving process or the like on the transmission data SDD1 to SDD4.

The transmission data S stored in each of the transmission buffers as shown in FIG.
In some cases, it is necessary to divide DD1 to SDD4 into two completely separated messages (messages).

For example, there is a case where the length (maximum length) of transmission data in a lower layer than a certain layer is limited. For example, when the length of the three transmission buffers is the upper limit, in FIG. 10, it is necessary to divide into two telegrams in front of the data of the transmission buffer in which the transmission data SDD4 is stored. That is, the transmission data S
It is necessary to divide between the one in which the DD3 is stored and the one in which the transmission data SDD4 is stored.

In such a case, the transmission data SD
Other protocol headers HTD2, HND2 and HLLCD2 may be newly provided in front of the data in the transmission buffer in which D4 is stored. That is, FIG. 11 and FIG.
As shown in 2.

In FIG. 11, the transmission data SDD1
.About.SDD3 are stored and three sequentially linked transmission buffers are shown. On the other hand, in FIG. 12, together with the transmission buffer in which the transmission data SDD4 is stored, the protocol header H of the T layer is used as a protocol header for the data of the transmission buffer.
One transmission buffer used for adding the TD2, the protocol header HND2 of the N layer and the protocol header HLLCD2 of the LLC layer is used.

As described above, according to this embodiment, as shown in FIG.
Also, when dividing into two telegrams as shown in FIG. 12 and the like, only the processing relating to the transmission buffer in which the protocol headers HTD2, HND2 and HLLCD2 are stored is performed, and the transmission data SDD1 to SDD
There is no need to perform a data movement process regarding D4.

FIG. 13 is a flow chart showing the processing performed by the protocol control unit in this embodiment.

In FIG. 13, first, step S11
0, the CPU transmission data processing unit 12a of FIG.
The process of transmitting the transmission data is shown in FIG. In this transmission data transfer processing, in FIG. 2, the CPU transmission data processing unit 12a transfers the transmission data from the CPU 1 while using the bus control unit 11. The process performed in step S110 will be described later in more detail with reference to the flowchart of FIG.

Subsequently, in step S112, the T in the T layer data processing unit 12b of the protocol control unit 12A is processed.
Layer protocol processing is shown. In step S114, the N-layer protocol processing performed by the N-layer data processing unit 12c is shown. In step S116, the LL
The LLC layer protocol processing performed by the C layer data processing unit 12d is shown. Each of the protocol processes performed in these steps S112 to S116 is as shown in FIG.
This will be described later with reference to the flowchart of FIG. Each of the protocol processes shown in steps S112 to S116 corresponds to one process shown in FIG. All of these protocol processes are mainly performed on the transmission buffer memory 16a.

Subsequently, in step S118, a frame transmission process is performed by the frame transmission processing unit 12e and the line control unit 14. This frame transmission processing is to transmit the final transmission data obtained in the transmission buffer memory 16a to the other party's CPU or the like via the line control unit 14 and the transmission path 3.

FIG. 14 is a flow chart showing the transfer processing of transmission data performed in this embodiment.

In the flowchart of FIG. 14, the transfer processing of the transmission data in step S110 shown in FIG. 13 is shown as a subroutine thereof.

In FIG. 14, first, in step S13.
In 2, the CPU transmission data processing unit 12a of the protocol control unit 12A accepts a data transmission request from the CPU 1 transmitted via the bus control unit 11 or the like. Then, in step S134, the step S1
The data length of the transmission data corresponding to the data transmission request accepted at 32 is acquired from the CPU 1.
In the following step 136, an actually used transmission buffer is acquired in the transmission buffer memory 16a based on the data length of the transmission data obtained in step S134.

After that, by repeating the loop of steps S138 and S140, the transmission data is transferred from the CPU 1 to the transmission buffer memory 16a. At this time, the transmission data is stored in the transmission buffer shown in FIG. 5 obtained in step S136 so as to be packed from the rear side of the transmission data storage area.

Further, all the transmission data are stored in the transmission buffer memory 16a, and the step S138 is performed.
When S140 and S140 are completed, the data head address information SAC shown in FIG. 5 is stored in step S142. This data start address information SAC
Is the transmission data start address A shown in FIG.
It is DS.

The transmission data head address ADS may be obtained based on the data length obtained in step S134. Alternatively, the transmission data start address AD
S may be obtained by detecting the transmission data start address ADS in which the final transmission data is written during the data transfer in steps S138 and S140.
Further, the data head address information is set in the step S134.
If it is determined from the data length in step S142,
Can be executed at any timing after step 134.

FIG. 15 is a flow chart showing the protocol processing performed in this embodiment.

This protocol processing is the T layer protocol processing performed in step S112, which is performed in the T layer data processing section 12b. Alternatively, the step S114 is performed in the N-layer data processing unit 12c.
The N-layer protocol processing of FIG. Alternatively, the LL
This is the LLC layer protocol processing performed by the C layer data processing unit 12d.

In FIG. 15, first, step S16.
In 2, the PDU length indicating the data length of the transmission data of the protocol generated in the protocol processing layer is cleared to “0”. That is, "0" is written in the register that stores the PDU length.

Here, the PDU length is the sum of the data length of the transmission data handled by a certain layer and the data length of the protocol header. That is, the PDU length is the entire data length of the transmission data including the protocol header added in that layer. The register for storing the PDU length is used to store a variable indicating the length of the data already written in the buffer. Also, the maximum data length that can be handled by that layer is determined by the protocol, and this is called the maximum PDU length. Transmission data exceeding such a maximum PDU length in a certain layer needs to be divided into a plurality of completely separated messages (messages) each having a protocol header in the layer.

Subsequently, in step S164, it is determined whether or not the transmission data has ended. If finished, then S1
Proceed to 66. On the other hand, if it is not completed, then step S
Proceed to 170.

First, in step S170, the P
The data length of the data stored in the transmission buffer is added to the DU length.

Then, in step S172, the PDU is
Based on the length, it is determined whether or not to divide the transmission data into a plurality of transmission buffers. If the PDU length added in step S170 is within the maximum PDU length, it is determined not to be divided, and the process branches from step 172 to the front of step S164. On the other hand, if the PDU length becomes larger than the maximum PDU length, it is determined to divide, and the process proceeds to step S174.

In step S174, the transmission data is divided immediately after the transmission buffer processed at the present time. After this, the point immediately before the transmission buffer next to the division point is reached, and header addition processing is performed in step S176.

On the other hand, if it is determined in step S164 that the transmission data has ended, in step S166 the same header addition processing as in step S176 is performed. The header addition processing performed in steps S176 and S166 will be described later in detail with reference to FIG. Further, after the step S166, all the processes shown in FIG. 15 are ended, and the process returns to the next process that calls the protocol process.

FIG. 16 is a flow chart showing the header addition processing performed in this embodiment.

This header addition process is a process called in step 176 or step 166 in the protocol process shown in FIG.

In FIG. 16, first, step S21.
In step 2, it is determined whether the area for storing the protocol header to be added is in the free area shown in FIG. If there is a storage area, the process proceeds to step S214.
On the other hand, when there is no storage area, the process proceeds to step S220.

First, in step S214, the protocol header in the layer is stored in the empty area shown in FIG. 5 immediately before the transmission data area SD. Further, the data length of the protocol header is set to the PD
Add to U length. As described above, since the PDU length is the sum of the data length of the transmission data and the data length of the protocol header at that time, the data length of the protocol header stored this time is added to the PDU length in this way.

Further, the data head address information SAC
Update the value of. That is, the value of the data head address information SAC is subtracted by the length of the protocol header stored this time. This is because the protocol header is stored this time, so the free space is shortened by the data length of the protocol header, the address at the end of the free space is also reduced, and the transmission data head is reduced by that amount. This is because the address ADS becomes smaller.

On the other hand, in step S220, the protocol header of the layer at that time is stored in the storable area of the transmission buffer at that time.
After such storage, the data head address information SAC of the transmission buffer and the value of the PDU length are updated. In addition, since the free space is insufficient, another new transmission buffer is acquired in step S220. Further, in step S222, the unstored portion of the protocol header to be stored this time is stored in the transmission buffer acquired this time, and is stored in the transmission buffer acquired this time, and the data head address information SAC and the like are updated. . At this time, in step S224, the value of the link pointer LP of the last transmission buffer before acquisition is updated to the head address of the acquired transmission buffer.

As described above, in this embodiment,
For example, as shown in the memory map of FIG. 5, the transmission buffer data storage method of the first invention can be applied. Further, as shown in FIG. 5 and FIG. 4 etc., it is possible to provide a communication control device to which the second invention is applied.

Therefore, according to this embodiment, when the transmission data according to a predetermined protocol is organized in the T layer, the N layer, the LLC layer, etc., in order to add a protocol header for each, It is possible to omit the movement processing of the transmission data. In addition, FIG. 10 to FIG.
As described above, even when a plurality of transmission buffers are used, it is possible to further reduce the number of transmission buffers and the size of the area required while reducing the movement processing of the transmission data. . For example, in this embodiment, there is no need to unnecessarily acquire a transmission buffer because a protocol header is added unlike the conventional case shown in FIG.

[0129]

As described above, according to the present invention, in order to organize transmission data according to a predetermined protocol, when a protocol header is added to the transmission data, it is stored in a transmission buffer or the like. Provided are a transmission buffer data storage method and a transmission buffer data storage device capable of suppressing the number of transmission buffers and the size of the area required while further reducing the transfer processing of the transmission data. It is possible to obtain an excellent effect of being able to.

[Brief description of drawings]

FIG. 1 is a memory map diagram of a transmission buffer showing a summary of a transmission buffer data storage method of a first invention and a transmission buffer data storage device of a second invention of the present application.

FIG. 2 is a block diagram showing a configuration of an embodiment of a communication control device to which the first invention and the second invention are applied.

FIG. 3 is a block diagram showing the configuration of a protocol control unit used in the above embodiment.

FIG. 4 is the CP of the protocol control unit of the embodiment.
Block diagram showing the configuration of the U transmission data processing unit

FIG. 5 is a memory map diagram of a transmission buffer used in the embodiment.

FIG. 6 is a memory map diagram of the transmission buffer in the first step for explaining the operation when one transmission buffer is used in the embodiment.

FIG. 7 is a memory map diagram of the transmission buffer in the second step for explaining the operation when one transmission buffer is used in the embodiment.

FIG. 8 is a memory map diagram of the transmission buffer in a third step for explaining the operation when one transmission buffer is used in the embodiment.

FIG. 9 is a memory map diagram of the transmission buffer in the fourth step for explaining the operation when one transmission buffer is used in the embodiment.

FIG. 10 is a memory map diagram of the transmission buffer for explaining the operation when a plurality of the transmission buffers are used in the embodiment.

FIG. 11 is a first memory map diagram of the transmission buffer when a plurality of transmission buffers are used and transmission data is divided in the embodiment.

FIG. 12 is a second memory map diagram of the transmission buffer when a plurality of transmission buffers are used and the transmission data is divided in the embodiment.

FIG. 13 is a flowchart showing processing performed by a protocol control unit used in the above embodiment.

FIG. 14 is a flowchart showing a transfer process of transmission data, which is performed by the protocol control unit.

FIG. 15 is a flowchart showing particularly protocol processing performed by the protocol control unit.

FIG. 16 is a flowchart showing a header addition process performed in the protocol process of the embodiment.

FIG. 17 is a configuration diagram showing a layer configuration of protocol communication generally used and applied conventionally.

FIG. 18 is a block diagram showing a configuration of a conventional communication control device.

FIG. 19 is a block diagram showing a configuration of a protocol control unit of the conventional communication control device.

FIG. 20 is a first memory map diagram of a transmission buffer used in the conventional communication control device.

FIG. 21 is a memory map of the first step of the transmission buffer for explaining the operation of the conventional communication control device.

FIG. 22 is a memory map of the second step of the transmission buffer for explaining the operation of the conventional communication control device.

FIG. 23 is a memory map of a third step of the transmission buffer for explaining the operation of the conventional communication control device.

FIG. 24 is a memory map of a fourth step of the transmission buffer for explaining the operation in the conventional communication control device.

FIG. 25 is a first data configuration diagram showing division of transmission data in the conventional communication control device.

FIG. 26 is a second memory map diagram of a transmission buffer used in the conventional communication control device.

FIG. 27 is a second data configuration diagram showing division of transmission data in the conventional communication control device.

FIG. 28 is a memory map diagram of the transmission buffer in the first step for explaining the operation when the plurality of transmission buffers are used in the conventional communication control device.

FIG. 29 is a memory map diagram of the transmission buffer in the second step for explaining the operation when the plurality of transmission buffers are used in the conventional communication control device.

FIG. 30 is a memory map diagram of the transmission buffer in the third step for explaining the operation when the plurality of transmission buffers are used in the conventional communication control device.

FIG. 31 is a memory map diagram of the transmission buffer in the fourth step for explaining the operation when the plurality of transmission buffers are used in the conventional communication control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... CPU 2 ... Communication control device 3 ... Transmission path 11 ... Bus control section 12A, 12B ... Protocol control section 12a, 12j ... CPU transmission data processing section 12b, 12k ... T layer data processing section 12c, 12m ... N layer data processing Part 12d, 12n ... LLC layer data processing part 12e, 12p ... Frame communication processing part 13a ... Transmission request acceptance part 13b ... Buffer memory acquisition part 13c ... Data transfer part 13d ... Head address information storage part 14 ... Line control part 16A, 16B ... buffer memory 16a, 16c ... transmission buffer memory 16b ... reception buffer memory

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H04L 29/02 // H04L 12/56 9466-5K H04L 11/20 102 F

Claims (5)

[Claims] 1. A protocol header for adding a protocol header, which is added when transmitting the transmission data, in a data array order when the data is transmitted, after the transmission data transfer process for storing the transmission data in a transmission buffer having a storage capacity L. In the transmission buffer data storage method for performing a header addition process centered on a process of storing the transmission data at the head side of the transmission buffer, the transmission data transfer process is performed with respect to the head and tail end of the transmission data. The transmission data is stored in the transmission buffer so that the tail end of the data is packed backward, and at the time of the transmission data transfer process, after the transmission data is stored in the transmission buffer, , Buffer information for transmission, characterized in that information indicating a storage position of the head of the transmission data in the transmission buffer is stored Paid method. 2. The natural number N according to claim 1, wherein when the data amount M of the transmission data is larger than the storage capacity L, {(M / L) ≦ N <((M + 1) / L)} Accordingly, at least a total of N transmission buffers are secured, the transmission data is sequentially divided by the storage capacity L from the end of the transmission data, and the divided data is stored according to the division order. A method for storing transmission buffer data, characterized in that the sequential information is stored in the respective transmission buffers while being stored. 3. The transmission buffer according to claim 1, wherein the information indicating the storage position of the head of the transmission data, which is stored in the transmission data transfer process, is an address in the transmission buffer. Data storage method. 4. The division order storage order information according to claim 2, wherein the division order storage order information is stored in a link pointer prepared for each of the transmission buffers, according to a division order of data stored in the transmission buffer. A transmission buffer data storage method, characterized in that it is the start address of the next transmission buffer following the transmission buffer. 5. The protocol header for adding a protocol header to be added when transmitting the transmission data in a data arrangement order at the time of transmission after the transmission data transfer process for storing the transmission data in a transmission buffer having a storage capacity L. In a transmission buffer data storage device that performs a header addition process centered on a process of storing the transmission data at the head side of the transmission buffer, the transmission data transfer process is performed with respect to the head and tail ends of the transmission data. A data transfer unit for storing the transmission data in the transmission buffer so that the tail end of the data is packed to the rear side; and, in the transmission data transfer process, for transmitting the transmission data to the transmission buffer. A head address information storage unit that stores information indicating the storage position of the head of the transmission data in the transmission buffer after storing Transmit buffer data storage device, characterized in that.