JP2003198617A - Flow controller and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent loss of data when storing amount of data which wait decision of a transmitting destination increases and cannot be processed. <P>SOLUTION: A decision finish management part 30 manages information of data wherein decision is finished and transmission is not yet performed. A management part 31 to a CPU manages information of data which perform decision wait of a destination. A decision finish monitoring circuit 40 and a decision wait monitoring circuit 41 monitor the amount of the receiving data wherein decision of the transmitting destination is finished and transmission is not yet performed, and the amount of receiving data which wait decision of the transmitting destination, respectively, which data are managed by the management parts 30 and 31. When either of the amounts of the receiving data exceeds a threshold value, a pause indication signal is outputted. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention accumulates data received through any one of a plurality of receiving ports in a memory, determines the transmission destination based on the information in the received data, and determines the transmission destination. The present invention relates to a flow control device and method for reading received data from a memory and outputting it to any one of a plurality of transmission ports according to its destination.

[0002]

2. Description of the Related Art FIG. 16 shows an example of a flow control device.
A transmission device 60 having four transmission / reception ports is shown, and the terminal devices 100 to 103 are signal lines 121 to 124 and 1 respectively.
It is connected to the transmission device 60 by 31-134. The signal lines 121 to 124 are connected from the transmission device 60 to the terminal 1 respectively.
00 to 103, and signal lines 131 to 134
Are signal lines from the terminals 100 to 103 to the transmission device 60, respectively. The transmission device 60 receives the data from each of the terminals 100 to 103, determines the transfer destination based on the address value added to the data, and transfers the transfer destination.

For example, a MAC address and an IP address are known as addresses for determining a transfer destination when using the Ethernet (R) shown in IEEE802.3. The operation when the IP address is used is shown below. The transmission device 60 acquires the destination IP address from the received data, determines the corresponding destination terminal, and outputs the data. At this time, the MAC held by the terminals 100 to 103
The address needs to be added to the transmitted data. The transmission device 60 implements the ARP shown in IETF-RFC826 or the like in order to acquire this MAC address from the terminals 100 to 103. Although the details of the ARP operation are not described here,
The transmission device 60 completes this ARP operation, and the terminal 100
Until the MAC address held by
Holds the received data. The MAC address acquired here is stored together with the corresponding IP address by the transmission device 60, and when data of the same IP address is subsequently received, the stored data causes the corresponding terminal 100-1 to 100-1.
The data is sent to 03.

FIG. 17 shows the configuration of a conventional transmission apparatus 60. The terminal IFs 501 to 504 have transmission ports 121 to 124 and reception ports 131 to 134 (here, the same reference numerals as the signal lines in FIG. 16 are used). Data is transmitted / received to / from the terminals 100 to 103 via (used). In the terminal IFs 501 to 504, when the reception IF unit 51 receives the data from the terminals 100 to 103, the process determination unit 52 extracts the IP address from the received data, and the ARP operation described above is already executed, and the MAC address. Signal line 51a when the correspondence between
The packet-by-output packet management unit 3 is notified via. Here, a case where the received data is stored in the memory 1 via the CPU bus 11 and the data length and the memory storage address are notified to the output-specific packet management unit 3 will be described as an example. Alternatively, the CPU 2 may be configured to notify the CPU 2 of these pieces of information and perform the data management method described below.

Details of an example of a data transmission operation to the terminals 100 to 103 will be omitted here, but an outline will be given below. The transmission IF unit 53 acquires the data length and the memory storage address according to the notification from the output-specific packet management unit 3, and C
It acquires data from the PU bus 11 and outputs it to the destination terminal.

The remaining amount monitoring unit 4 measures the amount of data stored in the transmission device 60 based on the data length stored in the output-specific packet management unit 3 and the memory storage address information,
When the accumulated amount exceeds a certain level, the pause output request 4a is output to the pause transmission unit 54 of each of the terminal IFs 501 to 504, and the pause transmission unit 54 receives this and outputs the pause signal to the terminals 100 to 103. .

The configurations and operations of the output-specific packet management unit 3 and the remaining amount monitoring unit 4 will be described in detail with reference to FIG. The determined management units 301 to 304 of the output-by-output packet management unit 3 store information such as the data lengths and memory storage addresses corresponding to the transmission ports 121 to 124 in the information storage units 3021 to 3024, respectively. Write management unit 3001
To 3004 and read management units 3011 to 3014 respectively control writing and reading to the information storage units 3021 to 3024. Information storage units 3021 to 3024
When the data is composed of a RAM or the like, the RAM address is incremented by 1 each time the received data is written, the information of the next received data is stored in the area corresponding to the next address, and the RAM address is set to 1 when the transmission is completed. Subtract one. With such a method, the write management unit 3001 can display the amount of data that has already been written, and the read management unit 3011 can display the amount of data that has already been read.

In the determined monitoring circuit 40 of the remaining amount monitoring unit 4, each of the difference circuits 4001 to 4004 is transmitted by the difference between the write data amount of the write management units 3001 to 3004 and the read data amount of the read management units 3011 to 3014. Calculate the amount of accumulated data for each port. Adder circuit 40
Reference numeral 1 adds the accumulated data amount for each transmission port from each of the difference circuits 4001 to 4004, and measures the amount of data accumulated in the entire device. The threshold value judgment circuit 402 is an addition circuit 40.
When the output value of 1 exceeds the threshold value set from the outside, the pause signal output instruction 4a including the pause time is issued.

With this configuration, the transmission ports 121 to 12
When the transmission data is concentrated in any one of the four, and the amount of data accumulated in the transmission device 60 increases, the remaining amount monitoring unit 4 informs the information of the data stored in the output-specific packet management unit 3. When the storage data increase is detected by measuring, the transmission data from the transmission source terminals 100 to 104 to the transmission device 60 can be temporarily stopped by outputting a pause instruction signal to each transmission port. By the operation, it is possible to prevent the reception data from the transmission source terminals 100 to 104 from being lost.

[0010]

However, in the above-mentioned conventional example, since the transmission destination is determined and the accumulated amount of only the untransmitted data is measured, as described above, the accumulation of the determination waiting data of the transmission destination is accumulated. No consideration is given to the case where the CPU 2 or the like cannot process due to an increase in the amount, and the sender terminal 1
There is a problem that it is not possible to prevent loss of received data from 00 to 104.

The present invention solves the above-mentioned conventional problems, and is an excellent flow control device capable of preventing data loss even in the case where the data waiting for determination at the transmission destination increases and cannot be processed. And to provide a method.

[0012]

In order to achieve the above object, the present invention accumulates data received through any of a plurality of receiving ports in a memory and transmits the data based on the information in the received data. In a flow control device that determines a destination, reads the received data whose destination has been determined from the memory, and outputs the data to any one of a plurality of transmission ports according to the destination, the received data stored in the memory The first determination means for determining whether or not the destination of transmission is determined and the amount of untransmitted received data exceeds a predetermined value, and waiting for determination of the destination of the received data stored in the memory. The second determination means for determining whether or not the received data amount exceeds a predetermined value, and a transmission stop signal when it is determined that the received data amount exceeds the predetermined value by any of the first and second determination means. Output And means, and having (claim 1). With the above configuration, it is possible to prevent data loss even in the case where the amount of data waiting for determination at the transmission destination increases and the data cannot be processed.

In order to achieve the above object, the present invention accumulates data received through any one of a plurality of receiving ports in a memory and determines the transmission destination based on the information in the received data. In a flow control device that reads out the received data whose destination is determined from the memory and outputs the received data to any of a plurality of transmission ports according to the destination, the destination of the destination of the received data stored in the memory First determining means for determining whether or not the amount of untransmitted received data exceeds a predetermined value after the determination is made, and the amount of received data waiting for the determination of the destination is weighted for each type of the received data. Then, the transmission is stopped when it is determined that the result exceeds the predetermined value by the second determination unit that determines whether the addition result exceeds the predetermined value, or by either the first determination unit or the second determination unit. Signal And means for force, and having (claim 2). With the above configuration, it is possible to prevent data loss in consideration of the variation in processing time depending on the type of data when the storage amount of the data waiting for determination at the transmission destination increases.

Further, in order to achieve the above-mentioned object, the present invention accumulates data received through any of a plurality of receiving ports in a memory, and determines the transmission destination based on the information in the received data. In a flow control device that reads out the received data whose destination is determined from the memory and outputs the received data to any of a plurality of transmission ports according to the destination, the destination of the destination of the received data stored in the memory First determination means for determining whether or not the amount of untransmitted received data exceeds a predetermined value after the determination is made, and received data waiting for determination of the destination of the received data stored in the memory When it is determined that the remaining amount of the memory is calculated based on the amount and the remaining amount is less than or equal to a predetermined value and the first determination unit determines that the amount exceeds the predetermined value, Or the above Remaining the second determination means and means for outputting a transmission stop signal when it is determined that less than a predetermined value, characterized in that it has (claim 3). With the above configuration, it is possible to prevent the accumulation amount of the determination waiting data of the transmission destination from increasing and accumulating and losing up to the maximum capacity of the memory.

Further, in order to achieve the above object, the present invention accumulates data received through any one of a plurality of receiving ports in a memory, and determines the transmission destination based on the information in the received data. In a flow control device that reads out the received data whose destination is determined from the memory and outputs the received data to any of a plurality of transmission ports according to the destination, the destination of the destination of the received data stored in the memory First determination means for determining whether or not the amount of untransmitted received data exceeds a predetermined value after the determination is made, and received data waiting for determination of the destination of the received data stored in the memory The second to determine whether the amount exceeds a predetermined value
Of the received data stored in the memory, and the remaining amount of the memory is calculated based on the amount of received data waiting for the determination of the transmission destination of the number of received data accumulated in the memory. When it is determined that the predetermined value is exceeded by the third determining means or one of the first and second determining means, or the remaining amount is determined to be less than or equal to the predetermined value by the third determining means. And a means for outputting a transmission stop signal in some cases (claim 4). With the above configuration,
It is possible to prevent an increase in the storage amount of the data waiting for determination at the transmission destination and a loss of the maximum storage capacity of the memory.

Further, in order to achieve the above object, the present invention accumulates data received through any of a plurality of receiving ports in a memory and determines the transmission destination based on the information in the received data. In a flow control device that reads out the received data whose destination is determined from the memory and outputs the received data to any of a plurality of transmission ports according to the destination, the destination of the destination of the received data stored in the memory First determining means for determining whether or not the amount of untransmitted received data exceeds a predetermined value after the determination is made, and the amount of received data waiting for the determination of the destination is weighted for each type of the received data. Based on the amount of received data waiting for the determination of the destination of the number of received data stored in the memory, and second addition means for determining whether or not the addition result exceeds a predetermined value. The above In the case where it is determined that the remaining amount of molybdenum exceeds the predetermined value by the third determining unit that determines whether the remaining amount is less than or equal to a predetermined value and the first or second determining unit. Or a means for outputting a transmission stop signal when the remaining amount is determined to be less than or equal to a predetermined value by the third determining means (claim 5). With the above configuration, it is possible to prevent the loss of data by considering the variation in the processing time depending on the type of data when the storage amount of the judgment-waiting data of the transmission destination increases, and to accumulate the judgment-waiting data of the transmission destination. It is possible to prevent the amount from increasing and accumulating and losing up to the maximum capacity of the memory.

Further, the present invention is characterized in that, in the flow control device according to any one of claims 1 to 5, the transmission stop signal is output via all of the plurality of transmission ports ( Claim 6). With the above configuration, it is possible to prevent data loss even in the case where the amount of data waiting for determination at the transmission destination increases and the data cannot be processed.

Further, in the present invention, in the flow control device according to any one of claims 1 to 3, the second determination means makes a determination for each reception port, and the transmission stop signal is transmitted to the plurality of transmissions. It is characterized in that it outputs through all of the ports (claim 7). Further, the present invention provides claim 4 or claim 5.
In the flow control device according to claim 1, the second and third determination means make a determination for each reception port, and output the transmission stop signal through all of the plurality of transmission ports (claim 3). 8). With the above configuration, it is possible to prevent data loss even in the case where the amount of data waiting for determination at the transmission destination increases and the data cannot be processed.

Further, in the present invention, in the flow control device according to any one of claims 1 to 3, the second determination means makes a determination for each reception port, and the transmission stop signal is transmitted to the second transmission stop signal. The data is output via a transmission port corresponding to the reception port determined by the determination means (claim 9). Further, according to the present invention, in the flow control device according to claim 4 or 5, the second and third determination means make a determination for each reception port, and the transmission stop signal is set to the second and third transmission ports.
The data is output via the transmission port corresponding to the reception port determined by the determination means of (1).
0). With the above configuration, it is possible to prevent the loss of data at a port that cannot be processed due to an increase in the accumulated amount of data waiting for determination at the transmission destination.

Further, the flow control method of the present invention stores the data received through any one of the plurality of receiving ports in the memory, determines the destination based on the information in the received data, and determines the destination. In the flow control method of reading the received data determined to be from the memory and outputting to any one of a plurality of transmission ports according to the transmission destination, the determination of the transmission destination of the reception data accumulated in the memory is determined. The first determination step for determining whether or not the amount of unreceived received data exceeds a predetermined value, and the amount of received data waiting for the determination of the destination of the received data accumulated in the memory is predetermined. A second determination step for determining whether or not the value exceeds the value, and a step for outputting a transmission stop signal when it is determined that the value exceeds the predetermined value by any of the first and second determination steps. And flop, and having (claim 11). By the above method, it is possible to prevent the data loss even when the data waiting for determination at the transmission destination increases and cannot be processed.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION <Embodiment 1> Embodiments of the present invention will be described below. 1 is a block diagram showing a flow control device according to the first embodiment, FIG. 2 is a block diagram showing in detail the output-specific packet management unit and the remaining amount monitoring unit of FIG. 1, and FIG. FIG. 4 is a flow chart for explaining, and FIG. 4 is a flow chart showing a specific example of the judgment waiting data measurement process of FIG.

In FIG. 1, the memory 1, the CPU 2, and the terminal IFs 501 to 504 have the same configuration as the conventional example. The output-specific packet management unit 3 stores the data length of the received data, the memory storage address, etc., manages the information of the determined / untransmitted data as shown in the conventional example, and waits for the destination determination. A CPU-addressed management unit 31 that manages the information is added. The storage of this information is
The terminal IFs 501 to 504 perform this via the bus 11.

Further, the remaining amount monitoring unit 4 determines whether or not to perform flow control based on the information stored in the output-specific packet management unit 3, and the determination waiting monitoring circuit 41 and the selector 42.
Has been added. The judgment waiting monitoring circuit 41 measures the accumulation amount of the destination judgment waiting data stored in the CPU destination management unit 31 and gives a pause output instruction when the accumulation amount exceeds the set threshold value. The selector 42 selects one of the pause output instructions from the determination waiting monitoring circuit 41 and the determined monitoring circuit 40, and outputs the pause output instruction 4a to the terminal IF5.
01 to 504 are output.

The configurations and operations of the output-specific packet management unit 3 and the remaining amount monitoring unit 4 will be described in detail with reference to FIG. The determined management units 30 (301 to 304) and the determined monitoring circuits 40 corresponding to the transmission ports # 1 to # 4 (121 to 124) are the same as in the conventional example. Similar to the determined management units 301 to 304, the CPU address management unit 31 includes an information storage unit 3025 that stores information such as a data length and a memory storage address,
It is composed of a write management unit 3005 and a read management unit 3015 which respectively perform the writing and reading control. The judgment waiting monitoring circuit 41 is composed of a difference circuit 4005 and a threshold value judgment circuit 4025 similar to the judgment completed monitoring circuit 40.

The write management unit 3005 determines the number of data addressed to the CPU 2 which has already been written, and the read management unit 30.
Reference numeral 15 indicates the number of data addressed to the CPU 2, which has already been read. The difference circuit 4005 is the write management unit 300.
The number of accumulated data destined for the CPU 2 (amount of data waiting for destination determination) is calculated from the difference between the number of written data of 5 and the number of read data of the read management unit 3015. Threshold value determination circuit 402
Reference numeral 5 instructs the selector 42 to output a pause signal including a pause time when the accumulation of data addressed to the CPU 2 exceeds a threshold value set from the outside.

With this configuration, the transmission ports 121 to 12
It is possible to detect an increase in the amount of data accumulated when the transmission data is concentrated in any one of 4 and when a large amount of CPU-destined data is generated and the processing cannot catch up. When the pause output instruction signal of either the determination waiting monitoring circuit 41 or the determined monitoring circuit 40 is generated, the selector 42 selects the pause output instruction signal and outputs the pause instruction signal 4a to each transmission port. To 104 to transmission device 6
Temporarily stop data sent to 0. By these operations, it is possible to prevent the reception data from the terminal from being lost.

A flow chart of the above flow control method is shown in FIG. As described above, when the packet is received (step S1), if the learning of the destination has already been completed, the received data is stored as the destination-determined packet (step S2 → S3a). If not, the packet is stored as a judgment waiting packet (step S2).
→ S3b). Then, each accumulated amount is compared with a preset threshold value (steps S4a and S4).
b) If any of the accumulated amounts is greater than or equal to the threshold value, the pause instruction flow control is performed from all the transmission ports (step S).
5a, S5b, S6, S7).

FIG. 4 shows a concrete example of the judgment waiting data measuring process. That is, when the received packet is written to the memory 1 (step S3b1), the number of writes is incremented by 1 (step S3b2), and then the pause output instruction signal is output if the number of writes-the number of reads> threshold (step S3b1). S4b1 → S5b).

As described above, according to the first embodiment of the present invention, the amount of received data that has not been transmitted after the determination of the destination of the received data is determined, and the amount of received data that is waiting for the determination of the destination are calculated. It monitors and if any pause output instruction signal occurs, it outputs the pause instruction signal to each transmission port, so
It is possible to prevent the received data from the terminal from being lost.

<Second Embodiment> FIG. 5 is a diagram showing the configuration of the second embodiment. The configurations and operations of the output-specific packet management unit 3 and the remaining amount monitoring unit 4 will be described below. The determined management units 301 to 304 and the determined monitoring circuit 40 have the same configurations as those in the first embodiment. Similar to the determined management units 301 to 304, the CPU-addressed management unit 31 stores an information storage unit 3025 that stores information such as a data length and a memory storage address.
3026, and write management units 3005 and 3006 and read management unit 301 that respectively control writing and reading.
5, 3016. The judgment waiting monitoring circuit 41 includes a weighting unit 403, difference circuits 4005 and 4006 similar to the judgment completed monitoring circuit 40, and a threshold value judgment circuit 4025.
Composed of.

In the second embodiment, the received data is transferred to the terminal IF.
Classification is made according to 501 to 504. Here, a case of classifying into two types will be described as an example, and the types are stored in the information storage units 3025 and 3026. For example, the information storage unit 302 stores information about data that takes time to determine the destination.
5, information of data that can be immediately determined as the destination is stored in the information storage unit 3026. In the case of the Ethernet (R) signal shown in the conventional example, it is possible to make a determination for each MAC address, frame type, IP address, and upper layer protocol type.

As a result, the difference circuits 4005 and 4006
Can display the amount of accumulated data of the above two types. Then, the weighting unit 403 adds the output value from the difference circuit 4005, which takes a long time to determine the destination, with a large weight, and the threshold value determination circuit 4025 compares the added value with the threshold value to make the determination. . With this configuration, when the processing time varies depending on the type of received data,
The processing time can be weighted to detect an increase in the amount of accumulated data. As a result, more accurate pause output including not only the amount of accumulated data but also the CPU processing time can be performed. FIG. 6 shows a case in which the received data of the MAC address is weighted with a weight of 2 and the other received data is weighted with a weight of 1.

<Third Embodiment> FIG. 7 is a diagram showing the structure of the third embodiment. The configurations and operations of the output-specific packet management unit 3 and the remaining amount monitoring unit 4 will be described below. The determined management units 301 to 304, the determined monitoring circuit 40, and the CPU-addressed management unit 31 are the same as those in the first embodiment. The judgment waiting monitoring circuit 41 includes difference circuits 4005 and 404 and a threshold value judgment circuit 4025. The difference circuit 4005 displays the amount of accumulated data addressed to the CPU, and then the difference circuit 404 displays the remaining capacity of the information storage unit 3025 obtained by subtracting the output of the difference circuit 4005 from the total capacity of the information storage unit 3025. Then, the threshold value determination circuit 4025 compares the remaining amount with the threshold value and determines the pause output.

FIG. 8 is a flow chart for explaining the processing of the third embodiment, in which the remaining memory capacity is the writable number-
Since it is equivalent to the number of writes, the number of writable-the number of writes <
A pause signal is output when the threshold value is reached.

<Fourth Embodiment> FIG. 9 is a diagram showing the structure of the fourth embodiment. The operations of the output-based packet management unit 3 and the remaining amount monitoring unit 4 will be described below. Determined management unit 301
To 304, the determined monitoring circuit 40, and the CPU address management unit 3
1 is the same as in the first embodiment. Judgment waiting monitoring circuit 41
Is the difference circuits 4005 and 404 and the threshold value judgment circuit 4
025 and 4026. The difference circuit 4005 is C
The accumulated data amount addressed to the PU is displayed, and the difference circuit 404 displays the remaining capacity of the information storage unit 3025 obtained by subtracting the output of the difference circuit 4005 from the total capacity of the information storage unit 3025.

Then, the threshold judgment circuit 4025 compares the accumulated data amount with the threshold value, and the threshold judgment circuit 4026 compares the remaining amount with the threshold value to judge the pause output. The selector 42 uses the determined monitoring circuit 4
0, if any of the pause output instructions from the threshold value judgment circuits 4025, 4026 is selected, the pause output instruction is selected and the pause output instruction is given.

<Fifth Embodiment> FIG. 10 is a diagram showing the structure of the fifth embodiment. The configurations and operations of the output-specific packet management unit 3 and the remaining amount monitoring unit 4 will be described below. The determined management units 301 to 304, the determined monitoring circuit 40, and the CPU-addressed management unit 31 are the same as those in the second embodiment. The judgment waiting monitoring circuit 41 includes difference circuits 4005, 4006, and 404,
Threshold value determination circuits 4025 and 4026, and weighting unit 4
03 and an adder circuit 405. Similar to the second embodiment, the received data will be classified into two types as an example.

The difference circuits 4005 and 4006 display the amount of accumulated data of different types addressed to the CPU, and the weighting unit 403.
Outputs a weighted value as described in the second embodiment. The adder circuit 405 calculates the sum of the difference circuits 4005 and 4006, and displays the total accumulated data amount addressed to the CPU. The difference circuit 404 includes information storage units 3025 and 3026.
The remaining capacity obtained by subtracting the output of the adding circuit 405 from the total capacity of is displayed. The threshold value determination circuits 4025 and 4026 give a pause instruction when the input values from the weighting unit 403 and the difference circuit 404 exceed the set threshold value, respectively. When there is a pause output instruction from the determined monitoring circuit 40 or the threshold value determination circuits 4025 and 4026, the selector 42 selects it and issues a pause output instruction.

<Sixth Embodiment> A sixth embodiment will be described with reference to FIG. In FIG. 11, the configurations and operations of the output-specific packet management unit 3 and the remaining amount monitoring unit 4 will be described below. The determined management units 301 to 304 and the determined monitoring circuit 40 are the same as those in the first embodiment. In the sixth embodiment,
4 CPUs corresponding to 4 receiving ports # 1 to # 4
The address management units 311 to 314 are provided. The judgment waiting monitoring circuits 411 to 414 are the CPU-addressed management units 311 to 311.
It is provided corresponding to each 314.

If the CPU address management units 311 to 314 and the judgment waiting monitoring circuits 411 to 414 have the same configurations as those shown in the first embodiment, the judgment waiting monitoring circuits 411 to 411 will be described.
Each of the CPU address management units 311 to 314 can issue a pause instruction 414 when the accumulated data amount exceeds a threshold value. When there is any pause output instruction from the determined monitoring circuit 40 or the determination waiting monitoring circuits 411 to 414, the selector 42 selects it and issues a pause output instruction.

FIG. 12 shows a flowchart of the above flow control method. As described above, when the learning of the destination is already completed, the received data is stored as the destination determined. If not, the data is stored as a waiting list for each receiving port. Each accumulated amount is compared with a preset threshold value, and if any accumulated amount is greater than or equal to the threshold value, flow control of pause output instruction is performed from all transmission ports. Note that the CPU address management unit 311 to
314 and the judgment waiting monitoring circuits 411 to 414 have been described by taking the first embodiment as an example, the second embodiment already described.
The same effects can be obtained by adopting the configurations from 5 to 5, respectively.

<Seventh Embodiment> A seventh embodiment will be described with reference to FIGS. 13 and 14. 13 and 14, the memory 1, the CPU 2, the terminal IFs 501 to 504, and the output-specific packet management unit 3 perform the same operations as in the conventional example.
The remaining amount monitoring unit 4 includes a determination waiting monitoring circuit 41, a determined monitoring circuit 40, and a selector 42, and determines whether to perform flow control based on the information stored in the output-specific packet management unit 3. The judgment waiting monitoring circuit 41 is a CPU address management unit 31.
The data storage amount is measured by reading more information, and a pause output instruction is issued when the storage amount exceeds a set threshold value. Each of the selectors 421 to 424 selects one of them according to the pause output instruction from the determination waiting monitoring circuits 411 to 414 and the determined monitoring circuit 40, and outputs the selected pause output instruction 4a1, 4a2, 4a3, 4a4 to the terminal IFs 501 to 504, respectively. Output.

As a result, for example, when the data from the receiving port # 1 enters the judgment waiting state and is accumulated in the CPU-destined management unit 311, the judgment waiting monitoring circuit 411 issues a pause transmission request and outputs the pause instruction signal 4a1. Then, the flow control is performed from the transmission port 121 via the terminal IF 501. Therefore, it is possible to prevent the reception data from the terminal connected to the terminal IF 501 from being lost.
At this time, if there is no accumulation of data from the reception ports # 2 to # 4 and there is no accumulation detection in the determined monitoring circuit 40,
No pause instruction signal is output. Therefore, the terminal IF50
The received data from the terminals connected to 2-504 are processed normally. With such a configuration, it is possible to avoid flow control to another terminal by accumulating the judgment waiting data from the specific terminal.

A flow chart of the above flow control method is shown in FIG. If the learning of the destination has already been completed, the received data is stored as the destination determined. If not, the data is stored as a waiting list for each receiving port. The storage amount for which the destination has been determined is compared with a preset threshold value, and if the storage amount is greater than or equal to the threshold value, flow control is performed from all transmission ports. In addition, the accumulated amount of received data from each receiving port is individually compared with a preset threshold value, and if the accumulated amount is greater than or equal to the threshold value, flow control is performed only from the transmitting port corresponding to each receiving port. To do.

As described above, according to the seventh embodiment of the present invention, it is possible to prevent loss of received data and avoid flow control to another terminal. Although the CPU address management units 311 to 314 and the judgment waiting monitoring circuits 411 to 414 have been described by taking the sixth embodiment as an example, the respective effects can be obtained by using the configurations of the second to fifth embodiments already described. Can be obtained.

[0046]

As described above, according to the present invention, the amount of received data that has not been transmitted after the determination of the destination is determined and the amount of received data that is waiting for the determination of the destination are output and a pause instruction signal is output. Therefore, it is possible to prevent the loss of the received data from the terminal.

[Brief description of drawings]

FIG. 1 is a block diagram showing a flow control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing in detail the output-specific packet management unit and the remaining amount monitoring unit of FIG.

FIG. 3 is a flowchart for explaining processing of the flow control device of FIG.

FIG. 4 is a flowchart showing a specific example of the judgment waiting data measurement process of FIG.

FIG. 5 is a block diagram showing an output-specific packet management unit and a remaining amount monitoring unit according to the second embodiment of the present invention.

FIG. 6 is a flowchart showing an example of determination waiting data measurement processing according to the second embodiment of the present invention.

FIG. 7 is a block diagram showing an output-specific packet management unit and a remaining amount monitoring unit according to the third embodiment of the present invention.

FIG. 8 is a flowchart showing an example of determination waiting data measurement processing according to the third embodiment of the present invention.

FIG. 9 is a block diagram showing an output-specific packet management unit and a remaining amount monitoring unit according to the fourth embodiment of the present invention.

FIG. 10 is a block diagram showing a packet management unit for each output and a remaining amount monitoring unit according to the fifth embodiment of the present invention.

FIG. 11 is a block diagram showing an output-specific packet management unit and a remaining amount monitoring unit according to the sixth embodiment of the present invention.

FIG. 12 is a flowchart showing a flow control method according to the sixth embodiment of the present invention.

FIG. 13 is a block diagram showing a flow control device according to a seventh embodiment of the present invention.

FIG. 14 is a block diagram showing an output-specific packet management unit and a remaining amount monitoring unit according to the seventh embodiment of the present invention.

FIG. 15 is a flowchart showing a flow control method according to the seventh embodiment of the present invention.

FIG. 16 is a block diagram showing a connection form of a conventional flow control device.

FIG. 17 is a block diagram showing a conventional flow control device.

FIG. 18 is a block diagram showing in detail the output-specific packet management unit and the remaining amount monitoring unit of FIG. 17;

[Explanation of symbols]

1 memory 2 CPU Packet management unit for each output 4 Remaining amount monitoring section 30, 301-304 Determined management unit 31, 311 to 314 CPU addressed management unit 40 Judgment monitoring circuit 41, 411 to 414 Judgment waiting monitoring circuit 42, 421-424 selector 54 Pause transmitter 401, 405 adder circuit 403 Weighting unit 404, 4001 to 4006 differential circuit 3001 to 3006 Write management unit 3011 to 3016 Read management unit 3021 to 3026 information storage unit 4021-4026 threshold value judging circuit

Claims (11)

[Claims] 1. The data received through any one of a plurality of receiving ports is accumulated in a memory, the destination of the data is determined based on the information in the received data, and the received data whose destination is determined is stored in the memory. In a flow control device that reads from the memory and outputs to any of a plurality of transmission ports according to the destination, the determination of the destination of the received data accumulated in the memory is determined and the amount of untransmitted received data is determined. Determines whether or not exceeds a predetermined value, and determines whether or not the amount of received data waiting for the determination of the transmission destination of the received data stored in the memory has exceeded a predetermined value. And a means for outputting a transmission stop signal when it is determined by one of the first and second determination means that the predetermined value is exceeded, the flow control device. . 2. The data received via any of a plurality of receiving ports is accumulated in a memory, the destination of the data is determined based on the information in the received data, and the received data whose destination is determined is stored in the memory. In a flow control device that reads from the memory and outputs to any of a plurality of transmission ports according to the destination, the determination of the destination of the received data accumulated in the memory is determined and the amount of untransmitted received data is determined. And a first determination means for determining whether or not exceeds a predetermined value, and the received data amount waiting for the determination of the transmission destination is weighted for each type of the received data and added, and the addition result shows a predetermined value. A second judgment means for judging whether or not the number of times exceeds, and the first judgment means
And a means for outputting a transmission stop signal when it is determined by any one of the second determination means that the predetermined value is exceeded, the flow control device. 3. The data received via any of a plurality of receiving ports is accumulated in a memory, the destination of the data is determined based on the information in the received data, and the received data whose destination is determined is stored in the memory. In a flow control device that reads from the memory and outputs to any of a plurality of transmission ports according to the destination, the determination of the destination of the received data accumulated in the memory is determined and the amount of untransmitted received data is determined. And a first determining means for determining whether or not is greater than a predetermined value, and a remaining amount of the memory is calculated based on the amount of received data waiting for the determination of the destination of the received data stored in the memory. And a second determining means for determining whether the remaining amount is less than or equal to a predetermined value, and the first determining means determines that the remaining amount has exceeded the predetermined value, or the remaining amount is determined by the second determining means. Below a predetermined value And a means for outputting a transmission stop signal when it is determined. 4. The data received via any of a plurality of receiving ports is accumulated in a memory, the destination of the data is determined based on the information in the received data, and the received data whose destination is determined is stored in the memory. In a flow control device that reads from the memory and outputs to any of a plurality of transmission ports according to the destination, the determination of the destination of the received data accumulated in the memory is determined and the amount of untransmitted received data is determined. Determines whether or not exceeds a predetermined value, and determines whether or not the amount of received data waiting for the determination of the transmission destination of the received data stored in the memory has exceeded a predetermined value. And a second determination unit that determines whether the remaining amount of the memory is less than or equal to a predetermined value by calculating the remaining amount of the memory based on the amount of received data waiting for the determination of the destination of the number of received data accumulated in the memory. Determine whether 3rd to do
Transmission is stopped when it is determined that the predetermined value is exceeded by any of the first determination means and the second determination means, or when the remaining amount is determined to be less than or equal to the predetermined value by the third determination means. And a means for outputting a signal. 5. The data received via any of a plurality of receiving ports is accumulated in a memory, the destination of the data is determined based on the information in the received data, and the received data whose destination is determined is stored in the memory. In a flow control device that reads from the memory and outputs to any of a plurality of transmission ports according to the destination, the determination of the destination of the received data accumulated in the memory is determined and the amount of untransmitted received data is determined. And a first determination means for determining whether or not exceeds a predetermined value, and the received data amount waiting for the determination of the transmission destination is weighted for each type of the received data and added, and the addition result shows a predetermined value. A second determination means for determining whether or not it has exceeded, and a remaining amount of the memory is calculated by calculating the remaining amount of the memory based on the amount of received data waiting for the determination of the destination of the number of received data accumulated in the memory. The amount is a predetermined value When it is determined by the third determining means for determining whether it is lower or not and the first or second determining means determines that the predetermined value is exceeded, or the third determining means determines that the remaining amount is the predetermined value. A flow control device comprising: a unit that outputs a transmission stop signal when the following is determined. 6. The flow control device according to claim 1, wherein the transmission stop signal is output via all of the plurality of transmission ports. 7. The second determining means makes a determination for each receiving port, and the transmission stop signal is output via all of the plurality of transmitting ports. Flow control device according to item 1. 8. The method according to claim 4, wherein the second and third determination means make a determination for each reception port, and the transmission stop signal is output via all of the plurality of transmission ports. The flow control device described. 9. The second determination means makes a determination for each reception port, and the transmission stop signal is output via a transmission port corresponding to the reception port determined by the second determination means. The flow control device according to any one of claims 1 to 3. 10. The second and third determination means make a determination for each reception port, and the transmission stop signal is transmitted through a transmission port corresponding to the reception port determined by the second and third determination means. It outputs, The flow control apparatus of Claim 4 or 5 characterized by the above-mentioned. 11. Data received via any one of a plurality of receiving ports is stored in a memory, a destination of the data is determined based on information in the received data, and the received data whose destination is determined is stored in the memory. In a flow control method of reading from the memory and outputting to any of a plurality of transmission ports according to the transmission destination, the determination of the transmission destination of the reception data accumulated in the memory is determined, and the amount of reception data that has not been transmitted is determined. A first determination step for determining whether or not exceeds a predetermined value, and whether or not the amount of received data waiting for determination of the destination of the received data stored in the memory has exceeded a predetermined value And a step of outputting a transmission stop signal when it is determined that the predetermined value is exceeded by any of the first and second determination steps. Flow control method.