JP2002171300A - Packet transmission/reception device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the buffer capacity for request packet of a packet transmission/reception device. SOLUTION: The packet transmission/reception device is provided with a means which receives a write transmission request from a higher layer device 101 to calculate the limit length of a packet, a means which divides the write transmission request into a string of one or more write request packets satisfying the limit length, a buffer for write request which can hold one write request packet having the limit length, a means which successively stores write request packets constituting the string in the buffer for write request one by one to transmit them, a means which receives a read transmission request from the higher layer device 101 to calculate the limit length of a packet, a means which divides the read transmission request into such string of one or more read request packets that response packets satisfying the limit length may be returned, a buffer for read request which can hold one read request packet, a means which successively stores read request packets constituting the string in the buffer for read request one by one to transmit them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a packet transmitting / receiving apparatus, and more particularly, to a packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure.

[0002]

2. Description of the Related Art As a communication procedure for performing communication using a packet between a plurality of connected nodes, a large number of nodes can be transmitted within a predetermined time by transmitting a packet at a predetermined interval and omitting confirmation of reception. Synchronous transfer that guarantees data transfer, and every time a node sends one packet,
There is asynchronous transfer in which a node that has received a packet returns a packet confirming reception to a node that has transmitted the packet, thereby guaranteeing reliable transmission and reception of the packet. Synchronous transfer is highly necessary for real-time communications such as video and audio, but high reliability is required as a means of communication between these devices by connecting a hard disk or printer to a computer. Reliable asynchronous transfer is a more desirable communication means. An IEEE high performance serial bus for which the IEEE defines a standard, so-called IEEE13
Also in the 94 bus, both communication means of a synchronous transfer called an isochronous mode and an asynchronous transfer called an asynchronous mode are defined.

In the asynchronous transfer using a packet as described above, generally, in order for a certain node to request another node for some operation, a certain type of packet indicating the content of the requested operation must be transmitted. No. Hereinafter, this packet is referred to as a request packet. In accordance with the protocol of asynchronous communication, a node that has received a request packet first transmits a packet for confirming reception to the node that transmitted the request packet. The node that has received the request packet further transmits the request packet with a packet including information that needs to be returned to the node that transmitted the request packet as a result of the operation that the node that received the request packet requested performs the operation requested by the request packet. It may be sent to the node that did. Hereinafter, this packet is referred to as a response packet. Whether a response packet is transmitted in response to a request packet depends on the content of the request packet.

In the asynchronous transfer using a packet as described above, in order to transmit and receive data having an arbitrary length (hereinafter, referred to as a block) between nodes, the following method is generally used.

In order for a certain node to read a block from another node, as shown in FIG. 10 (a diagram showing an example of a data read procedure in the prior art), a node requesting a block read requests a block read request. A request packet called a packet is transmitted to a node having a block to be read. The block read request packet includes information for specifying the position where the block to be read exists at the node that has received the packet, and information for specifying the length of the block. The node that has received the block read request packet first transmits a packet confirming reception to the transmitting node, then reads the block specified by the block read request packet, and responds to the block read request packet including the read contents. To send a response packet. Upon receiving the response packet corresponding to the block read request packet, the node that has transmitted the block read request packet sends back a packet confirming reception. Thus, one block read is completed.

In order for a certain node to write a block to another node, as shown in FIG. 11 (a diagram showing an example of a data write procedure in the prior art), a node requesting a block write requires a block write request. Send a packet, called a packet, to the node where the block is written. The block write request packet includes the contents of the block to be written to the node that has received the packet, the length of the block, and information for specifying the position where the block is to be written. The node that has received the block write request packet first transmits a packet for confirming reception to the transmitting node, and then reflects the contents of the block that the block write request packet has in the position specified by the packet. Thus, one block writing is completed.

In the asynchronous transfer using packets as described above, it is general that the length of one packet is fixed or the maximum length of the packet is specified. For example, in the IEEE 1394 bus, the maximum allowable packet length is determined for each transfer speed. For example, when transferring at 98.304 Mbits / s, the length is limited to about 500 bytes. Due to such limitations, when reading blocks from other nodes or writing blocks to other nodes by asynchronous transfer, it is not possible to execute only by sending a single request packet. A situation often arises that must be transmitted.

[0008] The block read request packet is sufficient if it can hold information for specifying the node that receives the request and the position and length of the block to be read at that node.
The length does not exceed the maximum allowed packet length. For example, a block read request packet used on the IEEE 1394 bus has a fixed length of 20 bytes and is short. However, since the response packet corresponding to the block read request packet includes the contents of the read block, the length of the response packet is variable, and the length may exceed the maximum allowable length of the packet. For example, IEEE
The response packet corresponding to the block read request packet used in the E1394 bus has the length of the read block + 24 bytes, and may be arbitrarily long depending on the length of the block requested to be read by the block read request packet. Therefore, the length of the response packet may exceed the maximum allowable length of the packet, and the transfer of the block may not be guaranteed.

Therefore, the length of the block requested to be read must be adjusted when the first block read request packet is transmitted so that the response packet does not exceed the maximum allowable length of the packet. If the length of the block to be read is long and an attempt is made to read with one block read request packet, the length of the corresponding response packet exceeds the maximum allowable length of the packet. And the length of any response packet corresponding to the block read request packet must not exceed the maximum allowable packet length.

Since the block write request packet contains the contents of the block to be written, the length of the packet is usually variable. For example, IEEE 1394
The block write request packet used on the bus has a length of a block to be written + 24 bytes. Therefore, if the length of the block to be written is long and transmission is attempted with one block write request packet, if the length of the block write request packet exceeds the maximum allowable length of the packet, the request is written into a plurality of block write requests. It must be split into request packets so that the length of any block write request packet does not exceed the maximum allowed packet length.

[0011] Among a plurality of nodes communicating using the asynchronous transfer using a packet as described above, a certain node may read a block having a length exceeding the maximum allowable length of a packet from another node. The contents of the sequence of a series of block read request packets that must be transmitted are all determined before transmitting the first block read request packet that is located at the head of this sequence and is transmitted. That is, among the packets constituting this column, the content of the block read request packet transmitted thereafter does not have to be different depending on the result of the block read request packet transmitted first.

Similarly, the contents of a series of block write request packets in which one node must transmit a block having a length exceeding the maximum allowable length of a packet in order to write the packet to another node are also transmitted. Before you start,
All are confirmed.

Therefore, conventionally, a node that attempts to read a block having a length exceeding the maximum allowable length of a packet from another node or writes a block to another node has a series of request packets to be transmitted. Is generally stored in a buffer, and packets are sequentially read from the buffer and transmitted.

[0014]

In the prior art described above, in order for a node to realize the above-described structure, a block read requesting to read the longest data among the block read requests that can be performed by the node. It must have a buffer large enough to hold the entire sequence of a series of read block request packets that need to be sent to fulfill the request. Similarly, the node sends the entire sequence of a series of block write request packets that need to be transmitted to fulfill the longest block write request among the block write requests that this node can make. You must also have a buffer large enough to hold.

However, a buffer satisfying the above conditions has a very large capacity. In particular, since the buffer for holding the block write request packet must hold the contents of the block to be written, the buffer must be large. As described above, the provision of a large buffer has a problem that the packet transmitting / receiving apparatus becomes expensive.

Even if a large buffer is provided, for example, when a series of block read request packets are enumerated and stored in this buffer, the same portion of each request packet, such as the destination and transfer speed, is also included in each request packet. Must be completely rewritten, and the number of times of rewriting increases.

Further, when performing packet communication using an asynchronous communication procedure having a protocol for limiting the length of a packet to a finite value, a higher-level device that sends a transmission request to a packet transmitting / receiving device uses There is also a problem that the transmission request must be made while paying attention to the limit length of the packet.

An object of the present invention is to provide a packet transmitting / receiving apparatus that solves at least one of the above problems.

[0019]

A first packet transmitting / receiving apparatus according to the present invention is a packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure, and receives one or a plurality of transmission requests from an upper layer apparatus. Means for dividing a request packet into a sequence of request packets, a buffer having a storage capacity for holding one request packet, and
Second means for sequentially storing and transmitting the data one by one in the buffer.

A second packet transmitting / receiving apparatus according to the present invention, in the first packet transmitting / receiving apparatus according to the present invention, wherein the second means, when sequentially storing the divided request packets in the buffer, For the second and subsequent request packets, only the difference from the first request packet in the column is rewritten.

A third packet transmitting / receiving apparatus according to the present invention is a packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure having a protocol for limiting the length of a packet,
Means for calculating a packet limit length based on the transmission request when a write transmission request is received from an upper layer device;
Means for dividing a transmission request from the upper layer device into one or a plurality of columns of write request packets satisfying the limit length, and storage for holding one write request packet having the same length as the limit length It has a write request buffer having a capacity, and means for sequentially storing and transmitting the write request packets constituting the columns one by one in the write request buffer.

A fourth packet transmitting / receiving apparatus according to the present invention is a packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure having a protocol for limiting the length of a packet,
Means for calculating a limit length of a packet based on the transmission request when receiving a read transmission request from an upper layer device;
Means for dividing a transmission request from the upper layer device into one or a plurality of columns of read request packets such that a response packet satisfying the limit length is returned, and storage for holding one read request packet It has a read request buffer having a capacity, and means for sequentially storing and transmitting read request packets constituting a column one by one in the read request buffer.

A fifth packet transmitting / receiving apparatus according to the present invention is a packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure having a rule for limiting the length of a packet,
Means for calculating a packet limit length based on the transmission request when a write transmission request is received from an upper layer device;
Means for dividing the write transmission request from the upper layer device into one or more columns of write request packets satisfying the limit length, and holding one write request packet having the same length as the limit length A write processing unit comprising: a write request buffer having a storage capacity; a unit for sequentially storing and transmitting write request packets forming a column one by one in the write request buffer; and reading from the upper layer device. Means for calculating a packet limit length based on the transmission request when receiving the transmission request, and a read transmission request from the upper layer device which is one such that a response packet satisfying the limit length is returned. A read request buffer having a storage capacity for holding one read request packet; And a read processing unit and means for sequentially storing and transmitting to the read request buffer one by one the read request packets constituting the column.

According to a sixth packet transmitting / receiving apparatus of the present invention, in the first, second, third, fourth, or fifth packet transmitting / receiving apparatus of the present invention, a transmission request from the upper layer apparatus is transmitted by one.
In a case where the request packet is divided into a plurality of request packets and transmitted, a means for assigning a label to each request packet and recording the assigned label is further provided.

According to a seventh packet transmitting / receiving apparatus of the present invention, in the first, second, third, fourth, or fifth packet transmitting / receiving apparatus of the present invention, the transmission request from the upper layer apparatus is set to one.
When a packet is divided and transmitted in a sequence of one or more request packets, a label is assigned to each request packet, and a serial number indicating the number of the request packet in the sequence when assigning the label And a means for recording the assigned serial number together with the assigned label.

An eighth packet transmitting / receiving apparatus according to the present invention is the first, second, third, fourth, or fifth packet transmitting / receiving apparatus according to the present invention, wherein the packet transmitting / receiving apparatus receives a response packet corresponding to the request packet. Means for sequentially copying the data included in the response packet to a storage device provided in the upper layer device, configuring the divided and received data into one block, and Means for notifying the upper layer device when the reception is completed.

According to a ninth packet transmitting / receiving apparatus of the present invention, in the sixth packet transmitting / receiving apparatus of the present invention, means for receiving a response packet corresponding to the request packet; Means for sequentially copying the data received in the storage device provided in the block, dividing the received data into one block, and confirming the label of the response packet with the same label as the corresponding request packet, The apparatus further includes means for detecting that all the response packets corresponding to the request packet have been received, and means for notifying the upper layer device when the reception of all the response packets has been completed.

The tenth packet transmitting / receiving apparatus of the present invention comprises:
In the seventh packet transmitting / receiving apparatus of the present invention, means for receiving a response packet corresponding to the request packet, and a position where data included in the response packet is copied to a storage device provided in the upper layer device, Means for sequentially copying by specifying the serial number of the label attached to the packet, means for forming the received data divided into one block, and means for copying the response packet having the same label as the corresponding request packet. Means for detecting completion of reception of all response packets corresponding to the request packet by confirming a label, and means for notifying the upper layer apparatus when reception of all response packets is completed And

An eleventh packet transmitting / receiving apparatus according to the present invention comprises:
In the sixth, seventh, ninth, or tenth packet transmitting / receiving apparatus of the present invention, means for recording a time at which use of a label attached to the request packet is started, corresponding to each label, Means for terminating transmission / reception of a packet corresponding to the label which has been left as a timeout.

[0030]

Embodiment of the embodiment of the present invention will be described with reference to the drawings in detail. Here, the embodiment of the present invention is described assuming that the packet transmitting / receiving apparatus of the present invention is based on IEEE1.
The case where the present invention is applied to the 394 bus will be described as an example.
It may be applied to other than the 94 bus.

First, a description will be given of a part of the communication procedure defined by IEEE 1394, which is a premise of the present embodiment.

In the IEEE 1394 bus, the concept of an address is used to specify resources of another node.
Among the resources belonging to a node, those resources that allow other nodes to read and write are arranged in an address space having a format defined by IEEE1394. Other nodes that want to read / write to this resource implement the read / write to the resource by specifying the resource to be accessed using the address and sending a packet containing the address specification.

In asynchronous transfer using the IEEE 1394 bus, a packet for confirming reception of a packet is called a recognition packet. For example, when a certain node transmits a request packet to another node, the node that transmitted the request packet transmits a recognition packet to the node that transmitted the request packet within a predetermined time from the transmission of the request packet.
The IEEE 1394 defines several types of recognition packets in addition to those representing meanings such as “completed” and “pending”, but in this embodiment, recognition packets other than “completed” and “pending” are uniformly “error”. Is treated as meaning. If the node that has transmitted the request packet cannot receive the recognition packet within a predetermined time after the transmission of the request packet, the node handles the recognition packet in a manner similar to the case where the node has received the recognition packet meaning “error”.

When a certain node transmits a request packet to another node and a recognition packet indicating “pending” is transmitted in response to the request packet, the node that has received the request packet thereafter transmits the request packet to the other node. , A packet called a response packet is transmitted. This mainly occurs when the node receiving the request packet has to return some information to the node that sent the request packet as a result of the operation requested by the request packet to another node. All response packets have the same label as the label attached to the request packet, making it possible to identify which response packet corresponds to which previously transmitted request packet.

If the request packet is a block read request packet, the recognition packet is "pending" or "error".
Is one of When a recognition packet meaning “pending” is transmitted, the node that has received the request packet transmits a response packet to the node that transmitted the request packet. The response packet corresponding to the block read request packet includes the length and contents of the block read from another node. The response packet corresponding to the block read request packet is also called a response code,
It contains information indicating the execution result of the block read request packet. IEEE 1394 is used as a response code.
Although several types such as “command execution succeeded” and “address error” are defined, in this embodiment, response codes other than “command execution succeeded” are uniformly treated as errors.

If the request packet is a block write request packet, the recognition packet is "completed" or "pending".
One of "error". When a recognition packet meaning “pending” is transmitted, the node that has received the request packet transmits a response packet to the node that transmitted the request packet. A response packet corresponding to the block write request packet includes a response code. In this embodiment, as in the previous section, response codes other than "command execution succeeded" are uniformly treated as errors.

IEEE 1394 has a limit length rule for limiting the length of a packet transferred between nodes to a finite value, and the limit length of a packet is determined by the speed at which the packet is transferred. In the present embodiment, the maximum allowable block length refers to the maximum length of a response packet corresponding to a block read request packet determined by the transfer rate in the processing of a block read request (the above-described restriction). Length), means the maximum block length that can be held by the response packet. In the processing of a block write request, the block write request packet is the maximum length of the packet determined by the transfer speed. In this case, the maximum length of the block that can be held by the request packet. In other words, in the processing of the block write request, the data of the maximum allowable block length and the check data (IEEE 139) stored in the data block 904 shown in FIG.
4, the total length of the fixed length portion (20 bytes in IEEE 1394) stored in the packet header 903 may be equal to or less than the limit length.
The same applies to the response packet in the processing of the block read request.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an example in which a packet transmission / reception device of the present invention and another device constitute a node connected to an IEEE 1394 bus.

The upper layer device 101 is a part for making a transmission request as a user of the packet transmitting / receiving device. The transmission request made by the upper layer device 101 to the packet transmission / reception device 103 specifies information necessary for transmitting a packet, such as designation of a request destination node and a transfer rate, and an operation of requesting a node that has received the request. Done.

The RAM 102 is a memory that can be accessed by both the upper layer device 101 and the packet transmission / reception device 103. When the upper layer device 101 issues a block write request to the packet transmission / reception device 103, the upper layer device 10
As a place to store the block that 1 wants to send,
When the upper layer apparatus 101 issues a block read request to the packet transmitting / receiving apparatus 103, the packet transmitting / receiving apparatus 10
3 is used as a place for storing the received block.

The packet transmitting / receiving apparatus 103 of the present invention interprets the transmission request of the upper layer apparatus 101 and performs the IEEE 1394
A required number of request packets in a format conforming to the above-mentioned rules are created, and the lower layer packet transmitting / receiving apparatus 104 is requested to transmit. The packet transmitting / receiving apparatus 103 also receives a notification of the reception of a response packet to the request packet from the lower layer packet transmitting / receiving apparatus 104, and interprets the response packet. The packet transmission / reception device 103 also includes the upper layer device 10
The upper layer device 101 is notified of the result of the packet transmission / reception device 103 processing one transmission request.

The lower layer packet transmitting / receiving apparatus 104
This is a device that performs a process of actually transmitting a request packet created in a format in accordance with the rules of EEE1394 to the bus and a process of notifying the packet transmitting / receiving device 103 of the reception of a response packet to the request packet received from the bus.

Once the packet transmission / reception device 104 of the lower layer accepts the packet transmission request of the packet transmission / reception device 103, it transmits the packet, retransmits the packet if necessary, waits for the reception of the recognition packet, To the packet transmitting / receiving apparatus 103. If the recognition packet does not arrive within the time specified by the IEEE 1394 rules after the transmission of the request packet, the notification is made as in the case where the recognition packet meaning "error" is received.

Upon receiving a response packet to the request packet from the bus, the lower layer packet transmitting / receiving apparatus 104 returns a recognition packet and notifies the packet transmitting / receiving apparatus 103 of the reception of the response packet. When the packet transmitting / receiving apparatus 104 receives the next response packet before the packet transmitting / receiving apparatus 103 receives the notification of the reception of the response packet, the lower layer packet transmitting / receiving apparatus 104 returns a recognition packet urging retry, and returns the response packet. I do not accept.

FIG. 2 is a block diagram showing the configuration of one embodiment of the present invention.

The label management unit 201 manages labels attached to all request packets transmitted by the packet transmitting / receiving apparatus 103. As shown in FIG. 3 (a diagram showing details of the label management unit 201 in FIG. 2). , A label management area 501, a clock 505, and callable from all other parts constituting the packet transmitting / receiving apparatus 103.
Each process of a label allocation process 502, a label end process 503, and a label timeout process 504 is provided.

The label management area 501 is a section for holding labels attached to all request packets transmitted by the packet transmitting / receiving apparatus 103. The label management area 501 is
For all the labels allowed by the communication procedure, information on whether the label is in use and, if the label is in use, the start time of the label, i.e., the record of that label was last used since unused In addition, it has a function of storing information about the changed time, recording a specified label as being used, and returning a record of a specified label recorded as being used to unused.

The label assignment process 502 is a process for recording a label in use in the label management area 501. When the label assignment processing 502 is called, the label management unit 201 refers to the label management area 501, selects one label not recorded as being used, records the selected label as being used in the label management area 501, Perform processing to return to the caller as a newly allocated label.
At this time, the current time is known from the clock 505 and recorded in the label management area 501 as the label start time. If the caller specifies a label to be assigned, the label management area 501 is referred to. If the label is not recorded as being used, the label is newly recorded as being used, and then the caller is notified of success. Otherwise, a process for notifying the caller of the failure is performed.

The label end processing 503 is performed in the label management area 5
This is a process for terminating the use of the designated label recorded as being used in 01. When the caller designates the label whose use is to be terminated and calls it, the label management unit 2
01 performs processing to return the recording of the designated label to unused.

The label timeout process 504 is a process for timing out the label use time for all the labels recorded as being used in the label management area 501. The label time-out process 504 sets a time-out for a request packet with a label that is in use even after a certain time has elapsed from the start time among the labels recorded as being used.
If the label is recorded as being used in the block reading label management area 601 shown in FIG. 4 (a diagram showing details of the block reading label management unit 301 in FIG. 2), the block reading label error ends. If the process 604 is performed and the data is recorded as being used in the block write label management area 801 shown in FIG. 6 (a diagram showing the details of the block write label management unit 401 in FIG. 2), the block write label error ends. Process 804
If none of the above is applied (the label management area for block reading 601 and the label management area for block writing 80
In either case, if the label is not recorded as being used), the upper layer device 101 is notified of the failure of the transmission request.

The transmission request interpretation unit 204
1 is a part that receives all the transmission requests made, analyzes the contents of the transmission requests, and distributes the processing of the transmission requests to each part dedicated to the type of the transmission requests.

The transmission request interpreting unit 204 first inquires of the label management unit whether or not the label attached to the transmission request of the upper layer device 101 is in use. Do not accept the request.

The transmission request interpreting unit 204 is a
If the first transmission request is neither a block read request nor a block write request, the general request transmission control unit 202 processes the transmission request of the upper layer device 101.

The transmission request interpreting unit 204 is a
If the transmission request 1 is a block read request and the block read processing unit 205 is not operating, the transmission request of the upper layer device 101 is processed by the block read request transmission control unit 302 of the block read processing unit 205.
If the block read processing unit 205 is already operating,
The transmission request from the upper layer device 101 is not accepted.

The transmission request interpreting section 204
If the transmission request of No. 1 is a block write request and the block write processing unit 207 is not operating, the transmission request of the upper layer device 101 is processed by the block write request transmission control unit 402 of the block write processing unit 207.
If the block write processing unit is already operating, it does not accept the transmission request from the upper layer device 101.

The reception response interpreting unit 206 receives the notification of the reception of the response packet by the packet transmitting / receiving device 104 of the lower layer, analyzes the content of the response packet, and stores the response packet in each part dedicated according to the type of the response packet. This is the part that distributes the processing.

If the content of the response packet is neither a response corresponding to the block read request packet nor a response corresponding to the block write request packet, the reception response interpreter 206 causes the general response reception controller 203 to process the response packet.

If the content of the response packet is a response corresponding to the block read request packet, the reception response interpreting unit 206
Block read response reception control unit 303.

If the content of the response packet is a response corresponding to the block write request packet, the reception response interpreting unit 206 converts the response packet into the block write processing unit 207.
Of the block write response reception control unit 403.

The general request transmission control unit 202 is a part for processing a transmission request when the transmission request from the upper layer device 101 is neither a block read request nor a block write request.

When the response packet received by the lower layer packet transmitting / receiving device 104 is not a response packet corresponding to the block read request packet and is not a response packet corresponding to the block write request packet, the general response reception control unit 203 This is a part for processing the received response packet.

The block read processing unit 205 manages a block read transmission request and a response corresponding to the request.
02, a block read response reception control unit 303, and a block read label management unit 301. If at least one of the block read request transmission control unit 302, block read response reception control unit 303, and block read label management unit 301 is operating,
The block read processing unit 205 is considered to be operating. If none of them is operating, it is considered that the block read processing unit 205 is not operating. Since one block read processing unit can manage only one block read request, the already operating block read processing unit 205 does not accept a new block read transmission request.

Block reading label management unit 301
Is a part for managing a label attached to a block read request packet transmitted to realize a block read transmission request. As shown in FIG. 4, the block has a block read label management area 601 and a block read processing unit 205. , A block read label normal end process 603, and a block read label error end process 604, which can be called from other portions belonging to.

Block reading label management area 601
Is a part for holding all labels attached to a block read request packet transmitted to realize one block read transmission request being processed, requested by the upper layer device 101. Block read label management area 6
01 holds information on whether or not the label is in use by the block read processing unit 205 for all the labels permitted by the communication procedure, records the specified label as being used, and records as the used label. It has a function to return the record of the label being used to unused. Further, the label recorded as being used in the block read label management area 601 indicates that the label being used is initially used by the block read label allocation processing for the third time since the operation of the block read label management area 601 started. It also has a function of assigning a serial number to indicate whether or not it has been managed.

Block read label allocation processing 6
02 is a process for recording a label as being used in the block read label management area 601. When the block reading label allocation processing 602 is called, the block reading label management unit 301 performs the label allocation processing 502, records the obtained label as being used in the block reading label management area 601, and newly stores this label. Performs processing to return to the caller as the label assigned to. When the calling side specifies a label to be allocated, the label is specified and label allocation processing 502 is performed, and the label management unit 201 notifies the calling side whether or not the label allocation is successful, and If the allocation is successful, a process of recording the label as being used in the block read label management area 601 is further performed.

Block read label normal end processing 6
03 is a process for terminating the use of the designated label, which is recorded as being used in the label management area 601 for block reading. When the calling side designates the label to be used and calls the block read label normal end processing 603, the block read label management unit 301 calls the label end processing 503 to specify the designated label in the label management area 501. Records of labels
The processing of returning the record of the designated label in the label management area for block reading 601 to unused is performed. As a result, the label management unit 301 for block reading has one label because there is no label recorded in use in the label management area 601 for block reading and the block reading request transmission control unit 302 is not operating. If it is indicated that the transmission of the packet sequence to be transmitted to realize the block read transmission request has already been completed, the block read processing unit 205
It determines that the processing of the current block read transmission request has been completed, notifies the upper layer device 101 of the normal end as a result of the request, and belongs to the block read processing unit 205.
A process for stopping the block read request transmission control unit 302, the block read response reception control unit 303, and the block read label management unit 301 itself is performed.

The block reading label error end processing 604 terminates the use of all labels recorded in the block reading label management area 601 when any error occurs during the processing of the block reading transmission request. This is a process for notifying the upper layer device 101 of an error. When the calling side invokes the block read label error end process 604, the block read label management unit 301 sends the block read label management area 6
01 for all the labels recorded as being in use in the label management unit 2
The process of returning the record of the label No. 01 to unused and the record of the label in the block management label management area 601 to the unused state is performed. Next, the block read label management unit 301 notifies the upper layer device 101 of an error as a result of the current block read transmission request, and the block read request transmission control unit 3 belonging to the block read processing unit 205.
02, a process of stopping the block read response reception control unit 303 and the block read label management unit 301 itself.

Block read request transmission control section 302
Analyzes the block read transmission request from the upper layer device 101, calculates the maximum allowable block length based on the transfer rate specified by the request, and reads the block requested to be read by this request. Requesting the packet transmission / reception device 104 to read a block having a length equal to the maximum allowable block length, and requesting to read a block having a length equal to or less than the maximum allowable block length. This is a part for performing control to request transmission of one block read request packet in order. As shown in FIG. 5 (a diagram showing details of the block read request transmission control unit 302 in FIG. 2), a block read request transmission buffer 701, and a block read request division control unit 702.

Block read request transmission buffer 701
Has a storage capacity to hold one block read request packet, and the block read request transmission control unit 302
And a buffer that can be accessed from the lower layer packet transmitting / receiving apparatus 104. When the block read request transmission control unit 302 requests the lower layer packet transmitting / receiving device 104 to transmit a block read request packet, the lower layer packet transmitting / receiving device 104 refers to the block read request transmission buffer 701 to send a block read request packet. Send a packet. Since the length of the block read request packet defined by IEEE 1394 is 20 bytes, the block read request transmission buffer 701 also has a size of 20 bytes.

Block read request division control unit 702
Is a part belonging to the block read request transmission control unit 302 and configured to form a sequence of block read request packets to be transmitted to realize the block read request.

The block read request division control unit 702 first sends the block read request transmission control unit 302
The upper layer device 101 is notified of the address of the block to be read and the block length by the block read transmission request, and the address of the block is taken as the next address to be read, and the length of the block to be read is the remaining length of the block. Are respectively stored. Further, it receives the notification of the maximum allowable block length and stores it.

Thereafter, each time the block read request transmission control unit 302 requests the preparation of a block read request packet, the block read request division control unit 702 performs an operation of setting an appropriate value in the block read request transmission buffer 701. Block read request division control unit 702
Sets the value stored as the next address to be read in the portion that specifies the block read address in the block read request packet placed in the block read request transmission buffer 701, and specifies the length of the block to be read. The smaller of the remaining length of the block to be read and the maximum allowable block length is set in the portion to be read. Block read request division control unit 702
After completing the setting, the value specified as the length of the block to be read is added to the address to be read next, and the value specified as the length of the block to be read is subtracted from the remaining length of the block to be read. This is prepared when the read request transmission control unit 302 requests preparation of a block read request packet.

Next, the operation of transmitting a block read request according to the present invention will be described with reference to FIG. FIG.
6 is a flowchart illustrating an operation of transmitting a block read request according to the present invention.

Block read request transmission control section 302
Starts the operation when it receives the block read transmission request from the transmission request interpretation unit 204 (step 1001 in FIG. 8).

The block read request transmission control unit 302 first analyzes a block read transmission request from the upper layer device 101, calculates a maximum allowable block length based on the transfer speed specified by the request, and receives a block read response. The operation of the control unit 303 is started, the position on the RAM 102 of the area prepared for storing the block read by the upper layer device 101 in response to the block read transmission request, and the upper layer device 101 reading out the block in response to the block read transmission request. The block read request division control unit 702 stores the address and the length of the block to be read.

Next, the block read request transmission control unit 302 records the label specified by the upper layer device 101 in the block read transmission request as being in use by using the block read label allocation process 602, and records this label. The attached block read request packet is created in the block read request transmission buffer 701. The block read request transmission control unit 302 further requests the block read request division control unit 702 to prepare the first block read request packet. The block read request division control unit 702 sets the address of the block read request and the length of the block to be read in the block read request packet of the block read request transmission buffer 701, and prepares the first block read request packet. It is completed (step 1002).

Next, the block read request transmission control section 302 sends the block read request transmission buffer 7 to the lower layer packet transmitting / receiving apparatus 104 in step 1002.
A request is made for transmission of one block read request packet created at step 01 (step 1003). When the lower layer packet transmitting / receiving apparatus 104 does not accept the transmission request, the block read request transmission control unit 302 transmits the same request packet to the lower layer packet transmitting / receiving apparatus 10.
4 is periodically repeated, and the process does not proceed to step 1004 until the transmission request is accepted.

Next, the block read request transmission control unit 302 requests the block read request division control unit 702 to prepare for the next block read request packet. If there is a block read request packet to be transmitted next, the block read request division control unit 702 resets the address of the block read request and the length of the block to be read out of the block read request transmission buffer 701 by resetting. The preparation of the next block read request packet is completed except for the label part (step 100).
4 → Step 1005).

Next, the block read request transmission control unit 302 receives the recognition packet corresponding to the block read request packet that has requested the lower layer packet transmitting / receiving apparatus 104 to transmit in step 1003, and the lower layer packet transmitting / receiving apparatus 104 Block read request transmission control unit 30
Wait for notification to the second (step 1006 or 1007). The notification of the reception of the recognition packet by the lower layer packet transmitting / receiving apparatus 104 may occur after the block read request transmission control unit 302 performs the operation of step 1003 and before performing the operation of step 1006 or 1007. Yes, in this case, the block read request transmission control unit 302
Alternatively, the process of step 1007 is immediately completed, and the process proceeds to the next.

Next, if the content of the recognition packet notified in step 1006 or step 1007 is “pending”,
If there is no block read request packet to be transmitted next, the activity is stopped (step 1011), but if not, the block read label allocation processing 602 of the block read label management unit 301 is performed, and the obtained label is read as a block. Attached to the block read request packet placed in the request transmission buffer 701 (step 1
008), preparation for the next block read request packet is completed. Block read request transmission control unit 302
When the label management unit 301 for block reading cannot allocate a label because all the labels have already been allocated, the label management unit 602 periodically calls the label allocation processing 602 for block reading, and the use of one of the labels ends. And waits for a label to be assigned (step 1009), attaches the obtained label to the block read request packet placed in the block read request transmission buffer 701 (step 1008), and completes preparation for the next block read request packet. Let it. When the preparation of the block read request packet is completed, the block read request transmission control unit 302 returns to step 1003,
The transmission of the request packet is requested, and the same processing is repeated thereafter.

If the content of the recognition packet notified in step 1006 or step 1007 is “error”, the block read request transmission control section 302 terminates the block read label error in the block read label management section 301. The process 604 is performed (Step 1010). Block reading label management unit 301
Notifies the upper layer device 101 of an error as a result of the current block read request, and includes the block read request transmission control unit 302 and the block read processing unit 20.
5 are stopped (step 1011).

Block read response reception control section 303
Analyzes the response packet corresponding to the block read transmission request packet received by the lower layer packet transmission / reception device 104, and stores the contents of the block included in the response packet in the area on the RAM 102 designated by the upper layer device. This is a part that performs processing for copying to a proper position and terminating the use of the label attached to the response packet.

Block read response reception control section 303
After the block read request transmission control unit 302 analyzes the block read transmission request from the upper layer device 101, the operation is started by the block read request transmission control unit 302. Block read response reception control unit 3
03 is a block read request transmission control unit 302 at this time.
Thus, it receives and stores the maximum allowable block length calculated by the block read request transmission control unit 302 and the start address of the area prepared on the RAM 102 for storing the block read by the upper layer device 101.

First, the block read response control section 303 enters a loop for periodically checking whether or not the lower layer packet transmitting / receiving apparatus 104 has received a response packet corresponding to the block read request packet.

Block read response reception control section 303
When it is confirmed that the lower layer packet transmitting / receiving apparatus 104 has received a response packet corresponding to the block read request packet, the lower layer packet analyzer analyzes the response packet, obtains a label attached to the response packet, The serial number assigned to this label by the label management unit 201 is obtained.

The block read response control unit 303 then determines, based on the serial number and the maximum allowable block length, which part of the block that the higher layer Ask for the equivalent. Block read request transmission control unit 302
Transmits, in order, zero or more block read request packets for reading the maximum allowable block length and one block read request packet for reading the maximum allowable block length or less. The block of the response packet that is known to be the corresponding response is the head of the block, and the block of the response packet corresponding to the second transmitted block read request packet is the part that starts from the head of the block + the maximum allowable block length. Similarly, the serial number and the maximum allowable block length uniquely determine which part of the entire block to be read corresponds to the block of the response packet. The block read response reception control unit 303 stores the content of the block included in the response packet into an R to store the block read by the upper layer device 101.
Copy is made to the determined part of the area prepared on the AM 102.

Block read response reception control section 303
Notifies the block read label management unit 301 of the label attached to the response packet, and performs the block read label normal end process 603. However, if the response packet indicates an error, the block reading label error ending process 604 of the block reading label management unit 301 is performed. In this case, the block read label management unit 301 notifies the upper layer device 101 of an error as a result of the current block read transmission request, and stops each part belonging to the block read processing unit 205.

Block read response reception control section 303
After the above processing, if the block read response reception control unit 303 is still operating, it waits again for reception of a response packet corresponding to the block read request packet,
Hereinafter, the same operation is repeated.

The block write processing unit 207 is a part for managing a block write transmission request and a response corresponding thereto.
02, a block write response reception control unit 403, and a block write label management unit 401. If at least one of the block write request transmission control unit 402, block write response reception control unit 403, and block write label management unit 401 is operating,
The block write processing unit 207 is considered to be operating. If none is operating, it is considered that the block write processing unit 207 is not operating. Since one block write processing unit can manage only one block write request, the already operating block write processing unit 207 does not accept a new block write transmission request.

Block writing label management unit 401
Is a part belonging to the block write processing unit 207, which manages a label attached to a block transmission request packet transmitted to realize a block write transmission request,
As shown in FIG. 6, the label management area 8 for block writing
01, which can be called from another part belonging to the block write processing unit 207, and provides each of a block write label allocation process 802, a block write label normal end process 803, and a block write label error end process 804. I do.

Block write label management area 801
Is a part for holding all labels attached to a packet to be transmitted in order to realize one block write transmission request being processed instructed by the upper layer device 101. The block write label management area 801 holds information on whether any label is in use by the block write processing unit 207 for all labels permitted by the communication procedure, and records that any label is in use. And a function of returning the label record recorded as being used to unused. The block write label management area 801 includes the block read label management unit 30.
Unlike 1, No. does not have a function of assigning a serial number to a label and managing it.

Block write label allocation processing 8
02 is a process for recording a label in use in the block write label management area 801. When the block write label allocation processing 802 is called, the block write label management unit 401 performs the label allocation processing 502, records the obtained label as being used in the block write label management area 801 and newly writes this label. Performs processing to return to the caller as the label assigned to. When the calling side specifies a label to be allocated, the label is specified and label allocation processing 502 is performed, and the label management unit 201 notifies the calling side whether or not the label allocation is successful, and If the allocation is successful, a process of recording the label as being used in the block write label management area 801 is performed.

Block write label normal end processing 8
03 is a process for terminating the use of the designated label recorded as being used in the block write label management area 801. When the calling side designates a label to end use and calls the block write label normal end process 803, the block write label management unit 401 calls the label end process 503 to specify the designated label in the label management area 501. Records of labels
The processing of returning the records of the designated labels in the label management area 801 for block writing to unused is performed. As a result, the label that has been recorded as being used in the block write label management area 801 disappears, and the block write request transmission control unit 402 does not operate. If it is indicated that the transmission of the packet sequence to be transmitted to realize the block write transmission request has already been completed, the block write processing unit 207 performs
It determines that the processing of the current block write transmission request has been completed, notifies the upper layer device 101 of the normal end as a result of the request, and belongs to the block write processing unit 207.
A block write request transmission control unit 402, a block write response reception control unit 403, and a process of stopping the block write label management unit 401 itself are performed.

The block write label error end processing 804 ends the use of all labels recorded in the block write label management area 801 when any error occurs during the processing of the block write transmission request. This is a process for notifying the upper layer device 101 of an error. When the calling side invokes the block write label error end process 804, the block write label management unit 401 sends the block write label management area 8
01 for all the labels recorded as being in use in the label management unit 2
The process of returning the record of the label No. 01 to unused and returning the record of the label in the label management area 801 for block writing to unused is also performed. Next, the block write label management unit 401 notifies the upper layer device 101 of an error as a result of the current block write transmission request, and the block write request transmission control unit 4 belonging to the block write processing unit 207.
02, the block write response reception control unit 403 and the block write label management unit 401 themselves are stopped.

Block write request transmission control section 402
Analyzes the block write transmission request from the upper layer device 101, calculates the maximum allowable length of the packet based on the transfer rate specified by the request, and determines the block that this request requires writing to the maximum The block is divided into zero or more block write request packets having a length equal to the allowable length, and one block write request packet having a length equal to or less than the maximum allowable length of the packet. FIG. 7 (a diagram showing the details of the block write request transmission control unit 402 in FIG. 2).
As shown in FIG.
1 and a block write request division control unit 902.

Block write request transmission buffer 901
Has a storage capacity to hold one block write request packet, and the block write request transmission control unit 402
And a buffer that can be accessed from the packet transmitting / receiving device 104 in the lower layer. When the block write request transmission control unit 402 requests the lower layer packet transmitting / receiving device 104 to transmit a block write request packet, the lower layer packet transmitting / receiving device 104 refers to the block write request transmission buffer 901 to send a block write request packet. Send a packet. The block write request packet defined by IEEE 1394 has a variable length.
Since it has a length of 24 bytes + the maximum allowable block length, the block write request transmission buffer 901 also has a size capable of holding this. The block write request packet defined by IEEE 1394 is divided into a fixed-length portion of 20 bytes called a packet header and a variable-length portion called a data block. It is divided into a packet header 903 and a data block 904.

Block write request division control unit 902
Is a part belonging to the block write request transmission control unit 402 and configured to form a sequence of block write request packets to be transmitted to realize the block write request.

The block write request division control unit 902 first sends the block write request transmission control unit 402
The RAM 10 in which the address, the length of the block, and the data of the block in which the upper layer device 101 writes the block to be written by the block write transmission request are written.
2 is notified of the start position of the block, the address of the block to be written is set as the next write address, the length of the block is set as the remaining length of the block, and the start position of the block 102 on which the data of the block is written is set as the next position. Each is stored as a block position. Further, it receives the notification of the maximum allowable block length and stores it.

Thereafter, the block write request division control unit 902 performs an operation of setting an appropriate value in the block write request transmission buffer 901 every time the block write request transmission control unit 402 requests preparation of a block write request packet. Block write request division control unit 902
In the portion of the packet header 903 of the block write request transmission buffer 901 that specifies the address to write the block, the value stored as the next address to write is set, and the portion that specifies the length of the block to be written is The smaller of the remaining length of the block to be written and the maximum allowable block length is set.

The block write request division control unit 902 further stores the RAM stored as the position of the next block.
The data having the length specified as the length of the block to be written is read from the position on the block 102, and the data block 904 of the packet in the block write request transmission buffer 901 is read.
Copy from the beginning of After completing the setting, the block write request division control unit 902 adds the value specified as the length of the block to be written to the address to be written next, and subtracts the value specified as the length of the block to be written from the remaining length of the block to be written. By subtracting the value and adding the value specified as the length of the block to be written to the position of the next block, the block write request transmission control unit 402 prepares for the next request for preparation of a block write request packet.

Next, the operation of transmitting a block write request according to the present invention will be described with reference to FIG. FIG.
5 is a flowchart illustrating an operation of transmitting a block write request according to the present invention.

Block write request transmission control section 402
Starts the operation when the block write transmission request from the transmission request interpretation unit 204 is accepted (step 1101 in FIG. 9). At this time, the block write response reception control unit 403 and the block write label management unit 401
Also starts operating at the same time.

The block write request transmission control unit 402 first analyzes a block write transmission request from the upper layer device 101, calculates a maximum allowable packet length based on the transfer speed specified by the request, and Causes the block write request division control unit 902 to store the address at which the block to be written by the block write transmission request is written, the length of the block, and the start position on the RAM 102 where the block data is written.

Next, the block write request transmission control unit 402 records the label specified by the upper layer device 101 in the block write transmission request as being in use by using the block write label allocation processing 802, and records this label. The attached packet header is created in the block write request transmission buffer 901. The block write request transmission control unit 402 further requests the block write request division control unit 902 to prepare a first block write request packet. The block write request division control unit 902 includes a block write request transmission buffer 901
Out of the packet header 903, the address of the block to be written and the length of the block to be written are set, and the data is copied from the RAM 102 to the data block 904 of the packet in the block write request transmission buffer 901 so that the The preparation is completed (step 1102).

Next, the block write request transmission control unit 402 requests the lower layer packet transmitting / receiving apparatus 104 to transmit one block write request packet created in the block write request transmission buffer 901 up to the preceding paragraph (step 1103). When the lower layer packet transmitting / receiving apparatus 104 does not accept the transmission request, the block write request transmission control unit 402 periodically repeats a process of requesting the lower layer packet transmitting / receiving apparatus 104 to transmit the same request packet. Until the request is accepted, the process does not proceed to step 1104. The block write request transmission control unit 402 stores the label attached to the request packet until a recognition packet corresponding to the transmitted block write request packet is received.

Next, the block write request transmission control unit 402 requests the block write request division control unit 902 to prepare for the next block write request packet. If there is a block write request packet to be transmitted next, the block write request division control unit 902 resets the block write address and the write block length in the packet header 903 of the block write request transmission buffer 901. Then, RA is added to the data block 904 of the packet in the block write request transmission buffer 901.
By copying the data from M102, the preparation of the next block write request packet is completed except for the label part (step 1104 → step 110).
5).

Next, the block write request transmission control unit 402 receives the recognition packet corresponding to the block write request packet requested to be transmitted to the lower layer packet transmitting / receiving apparatus 104 in step 1103, and the lower layer packet transmitting / receiving apparatus 104 Block write request transmission control unit 40
Waiting for notification to the second (step 1106 or 1107). The notification of the reception of the recognition packet by the lower layer packet transmitting / receiving apparatus 104 may occur after the block write request transmission control unit performs the operation in step 1103 and before performing the operation in step 1106 or 1107. In this case, the block write request transmission control unit 402 immediately ends the processing of step 1106 or 1107, and proceeds to the next step.

Next, if the content of the recognition packet notified in step 1106 or 1107 is “completed”, the block write request transmission control unit 402
Step 1 is added to the block write label management unit 401.
The label attached to the block write request packet transmitted in 103 is notified, and the block write label normal end processing 803 is performed (step 1110). Next, the block write request transmission control unit 402 performs a block write label allocation process 802, and attaches the obtained label to the block write request packet placed in the block write request transmission buffer 901 (step 110).
8), preparation for the next block write request packet is completed. In this case, it was transmitted immediately before (step 110).
3) The label attached to the block write request packet is changed to the block write label normal end processing 803
(Step 1110), the block writing label management unit 401 is in an unused state.
Always succeeds in label assignment. However, if there is no block write request packet to be transmitted next, the block write request transmission control unit 402 stops the operation (step 1113), and does not call the block write label allocation processing 802. If the content of the recognition packet notified in step 1106 or 1107 is “pending”, the block write request transmission control unit 402 stops the operation if there is no block write request packet to be transmitted next (step 111
3), otherwise, the block write label allocation processing 80 of the block write label management unit 401
2, the obtained label is added to the block write request packet placed in the block write request transmission buffer 901 (step 1108), and preparation for the next block write request packet is completed. The block write request transmission control unit 402 periodically calls the block write label allocation process 802 when the label management unit 401 cannot allocate a label because all the labels have been allocated. After the use of the label is completed, it waits for the label to be assigned (step 1109). The obtained label is added to the block write request packet placed in the block write request transmission buffer 901 (step 110).
8), preparation for the next block write request packet is completed.

If the content of the recognition packet notified in step 1106 or 1107 is "error", the block write request transmission control unit 402 terminates the block write label error in the block write label management unit 401. The process 804 is performed (Step 1111 or Step 1112). The block write label management unit 401 notifies the upper layer device 101 of an error as a result of the current block write transmission request, and stops each part belonging to the block write processing unit 207 including the block write request transmission control unit 402. (Step 1113).

Block write request transmission control section 402
If the block write request transmission control unit 402 is still operating after the above processing, the process returns to step 1103 to request transmission of the block write request packet prepared in the block write request transmission buffer 901. The same processing is repeated.

Block write response reception control section 403
Is a part that analyzes a response packet corresponding to the block write request packet received by the lower layer packet transmitting / receiving apparatus 104 and terminates the use of the label attached to the response packet. The block write response reception control unit 403 includes the block write request transmission control unit 4
When 02 receives the block write transmission request from the transmission request interpretation unit 204, the operation starts at the same time.

First, the block write response reception control section 403 enters a loop for periodically checking whether or not the lower layer packet transmitting / receiving apparatus 104 has received a response packet corresponding to the block write request packet.

Block write response reception control section 403
When it is confirmed that the lower layer packet transmitting / receiving apparatus 104 has received the response packet corresponding to the block write request packet, the lower packet analyzer 104 analyzes the response packet and sends the response packet to the block write request label management unit 201. The attached label is notified, and a block write label normal end process 803 is performed. However, if the response packet has an error, the block write label error ending process 804 of the block write label management unit 401 is performed. In this case, the block write label management unit 401 notifies the upper layer device 101 of an error as a result of the current block write transmission request, and stops each part belonging to the block write processing unit 207. The block write response reception control unit 403 includes:
If the block write response reception control unit 403 is still operating after the above processing, it waits again for the reception of a response packet corresponding to the block write request packet, and thereafter repeats the same operation.

[0115]

According to the above-described packet transmitting / receiving apparatus of the present invention, the request packet storing buffer provided in the packet transmitting / receiving apparatus only needs to have a storage capacity for holding one request packet. Has the effect that the storage capacity of the device can be reduced.

According to the packet transmission / reception device of any one of claims 2 to 11, when the divided request packets are sequentially stored in the buffer, the same part of each request packet, such as the destination and the transfer speed, is used. Re-uses the one prepared for the first packet and rewrites only the difference parts that are not so, so that with a small number of buffer rewrites, There is also an effect that transmission can be performed.

According to the packet transmitting / receiving apparatus of any one of claims 3 to 11, since the packet transmitting / receiving apparatus determines the limit length of the packet, the upper-layer apparatus restricts the packet in the communication procedure used. It also has the effect that it is not necessary to pay attention to the length.

[Brief description of the drawings]

FIG. 1 shows a packet transmitting / receiving apparatus of the present invention and another apparatus
FIG. 2 is a diagram illustrating an example in which a node connected to an EEE1394 bus is configured.

FIG. 2 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 3 is a diagram illustrating details of a label management unit 201 in FIG. 2;

FIG. 4 is a block reading label management unit 301 of FIG. 2;
It is a figure which shows the detail of.

FIG. 5 is a block read request transmission control unit 302 of FIG. 2;
It is a figure which shows the detail of.

6 is a block write label management unit 401 shown in FIG. 2;
It is a figure which shows the detail of.

FIG. 7 is a block write request transmission control unit 402 of FIG. 2;
It is a figure which shows the detail of.

FIG. 8 is a flowchart showing an operation of transmitting a block read request according to the present invention.

FIG. 9 is a flowchart showing an operation of transmitting a block write request according to the present invention.

FIG. 10 is a diagram showing an example of a data reading procedure in a conventional technique.

And FIG. 11 is a diagram showing an example of a data writing procedure in the related art.

[Explanation of symbols]

 Reference Signs List 101 upper layer device 102 RAM 103 packet transmitting / receiving device 104 lower layer packet transmitting / receiving device 201 label management unit 202 general request transmission control unit 203 general response reception control unit 204 transmission request interpretation unit 205 block read processing unit 206 reception response interpretation unit 207 block Write processing unit 301 Block read label management unit 302 Block read request transmission control unit 303 Block read response reception control unit 401 Block write label management unit 402 Block write request transmission control unit 403 Block write response reception control unit 501 Label management area 502 Label allocation processing 503 Label end processing 504 Label timeout processing 505 Clock 601 Block reading label management area 602 Block reading label allocation Processing 603 Block read label normal end processing 604 Block read label error end processing 701 Block read request transmission buffer 702 Block read request division control unit 801 Block write label management area 802 Block write label allocation processing 803 Block write label normal End processing 804 Block write label error end processing 901 Block write request transmission buffer 902 Block write request division control unit 903 Packet header 904 Data block

Claims (11)

[Claims] 1. A packet transmission / reception device for performing packet communication using an asynchronous communication procedure, comprising: first means for dividing a transmission request from an upper layer device into one or a plurality of request packet columns; A buffer having a storage capacity for holding the number of request packets and one
A packet transmission / reception apparatus, comprising: second means for sequentially storing the data in the buffer and transmitting the data sequentially. 2. The method according to claim 1, wherein the second unit sequentially stores the divided request packets in the buffer when the divided request packets are stored in the buffer.
2. The packet transmission / reception apparatus according to claim 1, wherein only the difference between the first and second request packets in the sequence is different from the first request packet. 3. A packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure having a protocol for restricting the length of a packet. Means for calculating a limit length of a packet based on the request, means for dividing a transmission request from the upper layer device into one or a plurality of write request packet columns satisfying the limit length, and a length equal to the limit length. Sano 1
A write request buffer having a storage capacity for holding a plurality of write request packets, and means for sequentially storing and transmitting the write request packets constituting the columns one by one in the write request buffer. Packet transceiver. 4. A packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure having a protocol for limiting the length of a packet, wherein when a read transmission request is received from an upper layer apparatus, this transmission request is transmitted. Means for calculating a limit length of a packet based on the request, and means for dividing a transmission request from the upper layer device into one or a plurality of read request packet sequences such that a response packet satisfying the limit length is returned. A read request buffer having a storage capacity for holding one read request packet, and means for sequentially storing and transmitting read request packets constituting a column one by one in the read request buffer. A packet transmitting / receiving apparatus characterized by the following. 5. A packet transmitting / receiving apparatus for performing packet communication using an asynchronous communication procedure having a protocol for limiting the length of a packet, wherein when a write transmission request is received from an upper layer apparatus, the transmission request is transmitted. Means for calculating the limit length of the packet based on the
Means for dividing the write transmission request from the upper layer device into one or more columns of write request packets satisfying the limit length, and holding one write request packet having the same length as the limit length A write processing unit comprising: a write request buffer having a storage capacity; and a unit for sequentially storing and transmitting write request packets constituting a column one by one in the write request buffer; and reading from the upper layer device. Means for calculating a packet limit length based on the transmission request when receiving the transmission request, and a read transmission request from the upper layer device which is one such that a response packet satisfying the limit length is returned. A read request buffer having a storage capacity for holding one read request packet; And a means for sequentially storing and transmitting the read request packets forming the columns one by one in the read request buffer, and transmitting the read request packets. 6. A means for assigning a label to each request packet and recording the assigned label when the transmission request from the upper layer device is divided into one or a plurality of request packet strings and transmitted. The packet transmitting / receiving apparatus according to claim 1, 2, 3, 4, or 5, further comprising: 7. When a transmission request from the upper layer device is divided into one or a plurality of request packet columns and transmitted, a label assigned to each request packet is allocated, and at the time of allocation, Further comprising: means for assigning a serial number to each label indicating whether the label is a label attached to the request packet, and means for recording the assigned serial number together with the assigned label. Item 6. A packet transmitting / receiving apparatus according to any one of Items 1, 2, 3, 4 and 5. 8. The packet transmission / reception device according to claim 1, wherein said upper layer device includes means for receiving a response packet corresponding to said request packet, and data included in said response packet. Means for sequentially copying data into the storage device, dividing the received data into one block, and notifying the upper layer device when the reception of all response packets corresponding to the request packet is completed. And a packet transmission / reception device. 9. The packet transmission / reception device according to claim 6, wherein: means for receiving a response packet corresponding to the request packet; and sequentially copying data included in the response packet to a storage device provided in the upper layer device. Means for composing the divided and received data into one block, and confirming the label of the response packet labeled with the same label as the corresponding request packet, so that all the response packets corresponding to the request packet A packet transmission / reception apparatus further comprising: means for detecting that reception has been completed; and means for notifying the upper layer apparatus when reception of all response packets has been completed. 10. The packet transmitting / receiving apparatus according to claim 7, wherein: a means for receiving a response packet corresponding to the request packet; and a position at which data included in the response packet is copied to a storage device provided in the upper layer device. Means for sequentially copying by specifying the serial number of the label attached to the response packet, means for forming divided and received data into one block, and the same label as the corresponding request packet. By confirming the label of the response packet, means for detecting that all the response packets corresponding to the request packet have been received, and to the upper layer device when the reception of all the response packets has been completed. A packet transmitting / receiving apparatus, further comprising means for performing notification. 11. A packet transmitting / receiving apparatus according to claim 6, wherein means for recording the time at which use of the label attached to the request packet is started corresponding to each label; Means for interrupting transmission / reception of a packet corresponding to the label that remains in the medium as a timeout, further comprising: