JP2005216317A - Queue device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a queue device in which a data writing device can get ready to output data to a queue without waiting until the queue makes an "available space" even when the queue comes full. <P>SOLUTION: The queue device includes a FIFO buffer 41 into which a plurality of processes write packets, a memory means 42, a data saving means 43 and a data restoring means 44. The data saving means 43 takes incomplete packet data written during a process A to save them into the memory means 42 out of the FIFO buffer 41, upon switching of an execution right from a process A to another process B while the process A writes a packet into the FIFO buffer 41. The data restoring means 44, upon transferring of the execution right to the process A again, transfers the packet data saved in the memory means 42 to the FIFO buffer before the process A starts executing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a queue device used for data exchange between a data generation side and a data utilization side.

  The queue is used to absorb a difference in processing timing between a data generation side (data generation device) and a side that inputs and uses the data (data processing device). Examples of the data include a message, a packet, a job, and a transaction. The queue is generally realized by a FIFO (First In First Out) memory (FIFO buffer) or the like. The data generation device puts the generated data into the queue, and the data processing device takes out the data from the queue and performs predetermined processing. .

  The queue has a capacity capable of storing a plurality of data. Therefore, the data processing apparatus can sequentially process data according to its own processing capability while extracting data one by one from the queue. Further, by sharing the queue among a plurality of data generation apparatuses, one data processing apparatus can accept data processing requests from the plurality of data generation apparatuses. Furthermore, each data generation device can move to the next process immediately by immediately putting the generated data into the queue whenever there is a vacancy in the queue, so that an efficient operation is possible.

However, the conventional queue device has the following problems.
(1) Since there is a limit on the data capacity of the queue, when the queue is full and there is no free capacity, the side that inputs data into the queue, that is, the data generation device, until the empty area is generated in the queue. You have to wait for data input. For this reason, the data generation device must wait until the queue becomes empty, and the waiting time during that time causes a reduction in processing efficiency.

  (2) When a device that processes a series of data strings as a packet is connected to the output side of the queue as a data processing device, until all the data of the packet is input to the queue, The data processing device cannot end the packet processing. That is, the data processing apparatus must interrupt the process until the data generation apparatus puts all the data of the packet into the queue. Therefore, in this case, if the packet extraction is not started after all the packet data has been put into the queue, a waiting time is generated in the packet processing device and the processing efficiency is lowered.

  (3) In packet processing, it may be necessary to remove the data while putting the packet data into the queue. When the packet processing apparatus has already taken out the data from the queue and started packet processing, It was impossible to get back the output data. That is, in this case, the packet data is discarded. In such a case, for example, the data generation apparatus includes a processor that executes a plurality of programs (processes) in parallel, and each process generates a packet individually and writes the packet to a shared queue. In other words, while a process is writing packet data to the queue, the execution right is switched to another process, and this newly scheduled process tries to continuously write its own packet data to the queue. is there.

  An object of the present invention is to make it possible for a data generation apparatus to perform a data input operation to a queue without waiting until a space is generated in the queue even when the queue is full.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 is a FIFO buffer in which packets are stored, a storage means, a counting means for counting the number of packet data stored in the FIFO buffer, a count value of the counting means, Based on the number of packets of packet data, packet completion detection means for detecting whether or not there is a completed packet in the FIFO buffer; and in the FIFO buffer determined to be incomplete by the packet completion means And a data saving means for saving the data in the storage means.

  According to a second aspect of the present invention, in the queue device according to the first aspect, the packet completion detection means includes a count value of the counting means and a packet size stored in a packet of packet data stored in the FIFO. Based on the information, it is determined whether or not complete data exists in the FIFO buffer.

  According to a third aspect of the present invention, in the queue device according to the first or second aspect, the FIFO buffer is one in which packet data is written by a plurality of processes, and the packet completion unit is configured such that the process A is the FIFO buffer. When the execution right is switched to another process B in the middle of writing a packet to the data buffer, it is determined whether or not incomplete data exists in the FIFO buffer, and the data saving means When it is determined by the completion means that there is incompletely written data in the FIFO buffer, the incompletely written data in the FIFO buffer is saved in the storage device.

  According to a fourth aspect of the present invention, in the queue device according to the third aspect, when the execution right is transferred again to the process A, the packet data saved in the storage means before the execution of the process A is stored. The data storage device further comprises a data restoration means for transferring to the FIFO buffer.

  In the invention according to claim 5, the execution right is switched to another process B while the process A is writing the packet to the FIFO buffer, the storage means, and the FIFO buffer into which the packet is written by a plurality of processes. At this time, when the execution right of the process A is transferred again to the data saving means for taking out incomplete packet data written by the process A from the FIFO buffer and saving it to the storage means, before the execution of the process A is started. Data restoration means for transferring the packet data saved in the storage means to the FIFO buffer.

The principle of the present invention or related invention (hereinafter referred to as related invention) will be described below.
FIG. 1 is a diagram for explaining the principle of the first related invention.

  The present invention includes a FIFO buffer 1, a save buffer 2 in which data written to the FIFO buffer is saved, and a flag 3 indicating whether or not data is saved in the save buffer. Further, a first detection unit 4 and a data saving unit 5 are provided.

The first detection means 4 detects that the remaining capacity of the FIFO buffer 1 has become smaller than a predetermined first threshold value.
When the first detection unit 4 detects that the remaining capacity of the FIFO buffer 1 is less than the first threshold value, the data saving unit 5 saves the subsequent write data to the FIFO buffer 1. While saving to the buffer 2, the flag 3 is set, and while the flag is set, write data to the FIFO buffer 1 is written to the save buffer.

The second related invention has the following means in addition to the components of the first related invention described above.
The second detection means 6 detects that the remaining capacity of the FIFO buffer 1 is greater than a predetermined second threshold value when the flag 3 is set.

  When the second restoring means 6 detects that the remaining capacity of the FIFO buffer 1 is larger than the second threshold value, the data restoring means 7 stores the data saved in the saving buffer 2 as described above. When the data transferred to the FIFO buffer 1 and saved in the save buffer 2 is lost, the flag 3 is reset.

The third related invention includes the following third detection means 8 in addition to the constituent elements of the first related invention.
The third detection means 8 detects that the remaining capacity of the save buffer 2 has become smaller than a predetermined third threshold value, and generates a specific signal such as an interrupt signal at the time of the detection.

FIG. 2 is a diagram for explaining the principle of the fourth to seventh related inventions.
The fourth related invention includes a FIFO buffer 11 in which packets are stored, and a counting means 12 that counts the number of packets stored in the FIFO buffer 11.

  In the fifth related invention, in addition to the constituent elements of the fourth related invention, a save buffer 13 for saving packet data to be written to the FIFO buffer 11, and packet data is saved in the save buffer 13. A first flag indicating whether or not the remaining capacity of the FIFO buffer 11 is less than a predetermined first threshold, and the first detector 15 When it is detected that the remaining capacity of the FIFO buffer 11 is smaller than the first threshold value, the subsequent write data to the FIFO buffer 11 is saved in the save buffer 13 and the flag 14 is set. While the flag is set, write packet data to the FIFO buffer 11 Further comprising a packet data saving unit 16 for writing toward the saving buffer, a.

  For example, a bit in which information indicating whether or not the packet data is the last data of the packet may be added to each packet data stored in the FIFO buffer 11.

  According to a sixth related invention, in addition to the constituent elements of the fifth related invention, the count value of the counting means 12 is a predetermined second threshold value when the flag 14 is set. A second detecting means 17 for detecting that the number of packets is less than the second threshold, and detecting that the number of packets stored in the FIFO buffer 11 is less than the second threshold by the second detecting means 17. A data restoring means 18 for transferring the data saved in the save buffer 13 to the FIFO buffer 11 and resetting the flag 14 when there is no data saved in the save buffer 13; Is further provided.

  In the seventh related invention, in addition to the constituent elements of the fourth related invention, referring to the count value of the counting means 12, whether or not there is complete packet data in the FIFO buffer 11 Further, a packet completion detecting means 19 for detecting the above is further provided.

FIG. 3 is a diagram for explaining the principle of the eighth to tenth related inventions.
The eighth related invention is partly in common with the invention described in claim 1, and includes a FIFO buffer 21 in which a packet having data set with information indicating a packet size is stored, and the FIFO Counting means 22 for counting the number of packet data stored in the buffer 21; data in which the count value of the counting means 22 and the packet size information of the packet stored in the FIFO buffer 21 are set And packet completion detecting means 23 for detecting whether or not there is a completed packet in the FIFO buffer 21.

  In the ninth related invention, in addition to the constituent elements of the eighth related invention, a save buffer 23 for saving packet data to be written to the FIFO buffer 21, and packet data is saved in the save buffer 23. A first flag 24 indicating whether or not the remaining capacity of the FIFO buffer 21 is less than a predetermined first threshold, and the first detector 25. When it is detected that the remaining capacity of the FIFO buffer 21 is smaller than the first threshold value, the subsequent write data to the FIFO buffer 21 is saved in the save buffer 23 and the flag 24 is set. While the flag 24 is set, the write data to the FIFO buffer 21 is deleted. Further comprising a packet data saving unit 26 for writing towards the buffer, the.

  In a tenth related invention, in addition to the constituent elements of the ninth related invention, a second threshold value in which the count value of the counting means 22 is predetermined when the flag 24 is set. The second detection means 27 for detecting that the capacity is less than the second threshold, and when the second detection means 27 detects that the remaining capacity of the FIFO buffer 21 is less than the second threshold value, Data restoration means 28 is further provided for transferring the data saved in the save buffer 23 to the FIFO buffer 21 and resetting the flag 24 when there is no more data saved in the save buffer 23.

Next, FIG. 4 is a principle diagram for explaining the invention according to claim 5.
In the present invention, when the execution right is switched to another process B while the process A is writing a packet to the FIFO buffer 41, the FIFO buffer 41 into which packets are written by a plurality of processes, the storage means 42, and the process A. The data saving means 43 for taking out incomplete packet data written by the process A from the FIFO buffer 41 and saving it to the storage means 42; and when the execution right is transferred to the process A again, before the execution of the process A is started. And a data restore means 44 for transferring the packet data saved in the storage means 42 to the FIFO buffer.

Next, the operation of the above-described invention will be described.
In the first related invention, the first detecting means 4 detects that the remaining capacity of the FIFO buffer 1 has become smaller than a predetermined first threshold value. When there is a data write request to the FIFO buffer 1 after the detection, the data saving unit 5 writes the data to the saving buffer 2 and sets the flag 3. While the flag 3 is set, the data saving unit 5 writes the write data for the FIFO buffer 1 into the saving buffer 2.

  As a result, the data generation device that writes data to the FIFO buffer 1 can output data without waiting until the FIFO buffer 1 becomes full even when the FIFO buffer 1 is full, and the processing efficiency is improved. improves.

  In the second related invention, the second detection means 6 detects that the remaining capacity of the FIFO buffer 1 exceeds a predetermined threshold value in a state where the flag 3 is set. In response to this detection, the data restore means 7 transfers the data saved in the save buffer 2 to the FIFO buffer 1. Then, the flag 3 is reset when there is no save data in the save buffer 2.

  As a result, the data saved in the save buffer 2 is written into the FIFO buffer 1 in the correct order. When the flag 3 is reset, data is written again in the FIFO buffer 1 while the FIFO 1 is empty.

  In the third related invention, the third detecting means 8 detects a state where the remaining capacity of the save buffer is smaller than a predetermined third threshold value, and outputs a specific signal indicating the fact to the outside. To do.

Thereby, for example, it becomes possible to interrupt the processor or the like and expand the size of the save buffer 2.
In the fourth related invention, the number of packets stored in the FIFO buffer 11 is counted by the counting means 12. Therefore, the packets are stored in the FIFO buffer 11 by referring to the count value of the counting means 12. The packet processing apparatus 20 can continuously extract the packet data after the packet is completed in the FIFO buffer 11, and performs packet processing efficiently. be able to.

  In the fifth related invention, the save buffer 13, the flag 14, the first detection means 15, and the packet data save means 16 perform the same operation as that of the above-described invention according to claim 2 to the packet data for the FIFO buffer 11. This is done for writing. Therefore, the packet generation device 10 can output packet data without waiting until the FIFO buffer 11 becomes full even when the FIFO buffer 11 is full, and the processing efficiency is improved.

  In the sixth related invention, when the second detection means 17 is in a state in which the flag 14 is set, the count value of the counting means 12, that is, the number of stored packets in the FIFO buffer 11 is predetermined. Detect less than. In response to this detection, the data restorer 18 transfers the packet data saved in the save buffer 13 to the FIFO buffer 11. Then, when there is no save packet data in the save buffer 13, the flag 14 is reset.

  Therefore, the packet saved in the save buffer 13 is restored to the FIFO buffer 11 in the correct order and in the correct format, including the packet in which a part of the data is saved.

  In the seventh related invention, the packet completion detection means 19 refers to the count value of the counting means 12 and detects whether or not complete packet data exists in the FIFO buffer 11. Therefore, this detection can be used to prevent a situation in which uncompleted packet data is output from the FIFO buffer 11.

  If the value of a specific bit output together with the packet data from the FIFO buffer 11 is referred to, the packet processing device can easily determine whether or not the data read from the FIFO buffer 11 is the last data of the packet. It can be detected.

  In an eighth related invention that is partly in common with the invention described in claim 5, the number of packet data stored in the FIFO buffer 21 is counted by the counting means 22. The packet completion detecting means 23 inputs the count value and data in which the size information of the packet stored at the head of the FIFO buffer 21 is set, and compares them to complete the data in the FIFO buffer 21. Detect whether there is a packet that exists.

  Therefore, it is possible to avoid a state in which uncompleted packet data in the FIFO buffer 21 is output to the packet processing device 40 using the detection information of the packet completion means 23.

In the ninth related invention, operations similar to those of the fifth related invention described above are performed by the save buffer 23, the first detection means 25, and the packet data save means 26.
Therefore, the packet generation device 30 can output the generated packet even when there is no empty space in the FIFO buffer 21, so that the processing efficiency is improved.

In the tenth related invention, the same operation as in the sixth related invention is performed by the second detecting means 27 and the data restoring means 28.
Therefore, the packet saved in the save buffer 23 is restored to the FIFO buffer 11 in the correct order and in the correct format, including the packet in which a part of the data is saved.

  In the fifth aspect of the present invention, when the execution right is switched to another process B while the process A is writing a packet to the FIFO buffer 41, the data saving means 43 is incomplete that the process A has written. Packet data is taken out from the FIFO buffer 41 and saved in the storage means 42. When the execution right is transferred again to the process A, the data restoration unit 44 transfers the packet data saved in the storage unit before the execution of the process A to the FIFO buffer 41 to be restored.

  Therefore, even when the process A is in the middle of writing the packet data to the FIFO buffer 41, the newly activated process B can write the packet to the FIFO buffer 41. When the process B is restarted again, the process B writes the remaining packet data in the FIFO buffer 41, so that the packet can be correctly written in the FIFO buffer 41.

  According to the first to fourth aspects of the present invention, the number of packet data stored in the FIFO buffer is counted by the counting means, and the packet completion detecting means is configured to receive the count value and the packet data stored in the FIFO buffer. Based on the number of packets, it is detected whether or not there is a completed packet in the FIFO buffer, and the data saving means saves the data in the FIFO buffer determined to be incomplete in the storage means. Therefore, it is possible to avoid a state in which uncompleted packet data in the FIFO buffer is output to the packet processing device using the detection information of the packet completion detection means.

  According to the invention described in claim 5, even when the process A is in the middle of writing the packet data to the FIFO buffer, the newly started process B can write the packet to the FIFO buffer. When the process B is restarted again, the process B writes the remaining packet data in the FIFO buffer, so that the packet can be correctly written in the FIFO buffer. Therefore, it is possible to save and restore data of incomplete packets already stored in the FIFO buffer.

FIG. 5 is a block diagram showing the overall configuration of the queue device according to the embodiment of the present invention.
The FIFO buffer 110 is a first-in, first-out type memory capable of batch input / output of data in units of n bits, and is configured by one chip, for example. Then, a full flag signal full (hereinafter referred to as a full signal) indicating that the remaining capacity of the FIFO buffer 110 has become equal to or less than a predetermined first threshold, and the FIFO buffer 110 currently does not store any data. An empty flag signal empty (hereinafter referred to as an empty signal) indicating a state, a write enable signal W1 that is enabled when data is written to the FIFO buffer 110, and data are read from the FIFO buffer 110 An input terminal for a read enable signal R1 that is sometimes enabled is provided.

  Further, an n-bit data input line D1 and an n-bit data output line Q1 are provided. The FIFO buffer 110 outputs an Almost-Empty signal when the remaining capacity in the buffer becomes larger than a predetermined second threshold value.

  The FIFO buffer 110 is composed of, for example, an SRAM (Static Random Access Memory) array, and data is input to and output from the array. Further, an input pointer indicating a write address of the next input data to the SRAM and an output pointer indicating the address of data read next from the SRAM are incorporated. These pointers are composed of, for example, a ring counter. Further, a comparator that constantly monitors and compares the difference between the address values pointed to by the two pointers is built in, and the full signal, the empty signal, and the almost-empty signal are generated and output by the comparator.

Note that the FIFO buffer 110 may be configured by a shift register instead of the SRAM.
The save buffer 120 is composed of, for example, a DRAM (Dynamic Random Access Memory) or the like, and has a larger storage capacity than the FIFO buffer 110, for example. The save buffer 120 also includes a data input line D2 and a data output line Q2 each having an n-bit width, and a write enable signal W2 having a function equivalent to the write enable signal W1 included in the FIFO buffer 110. Output enable signal OE. In the save buffer 120, when the remaining capacity of the FIFO buffer 110 becomes smaller than the first threshold, that is, when a full signal is output from the FIFO buffer 110, the FIFO buffer 110 is controlled by the overflow control unit 130. Data for which a write request has been made is saved and stored.

  The overflow control unit 130 accepts a data input request to the FIFO buffer 110 by an enable input of the data write request signal “write”, and sends the input request data to the FIFO buffer 110 according to the state of the full signal input from the FIFO buffer 110. Alternatively, it is stored in one of the save buffers 120.

The overflow control unit 130 includes a write destination determination device 131, a flag 132, a write pointer 133, and a save buffer full detection device 134.
When the data write request signal “write” is enabled and added, the write destination determination device 131 checks whether or not the full signal input from the FIFO buffer 110 is active. Data D1 input from the apparatus is written into the FIFO buffer 110 by controlling the write enable signal W1.

  When the data input to the FIFO buffer 110 is performed at a higher speed than the data extraction from the FIFO buffer 110, the FIFO buffer 110 eventually becomes full, and the FIFO buffer 110 sets the full signal to “active”. If the data write request signal “write” is enabled and added while the full signal is “active”, the write destination determination device 131 is sent to the write pointer 133 after the signal “write” is enabled. The storage destination address on the save buffer 120 for the write data to the FIFO buffer 110 is set.

  The address value set in the write pointer 133 is sent to the save buffer 120 as an address signal and input. Then, when the write destination determining device 131 enables the write enable signal W2, the write request data D1 for the FIFO buffer 110 is the address on the save buffer 120 pointed to by the pointer value set in the write pointer 133 as the save data D2. Is temporarily saved. The write destination determination device 131 sets the flag 132 after writing data to the save buffer 120 in this way.

  Once the flag 132 is set, the write destination determination device 131 transfers the write data from the external device to the FIFO buffer 110 to the save buffer 120 for writing. During this time, the Almost-Empty signal output from the FIFO buffer 110 is monitored, and when the signal becomes “active”, that is, when “free” above the second threshold value occurs in the FIFO buffer 110, the save buffer 120. The saved data is transferred / returned to the FIFO buffer 110 via a data list device (not shown).

  On the other hand, before the Almost-Empty signal becomes “active”, the remaining capacity of the save buffer 120 may become smaller than a predetermined third threshold value. The save buffer full detection device 134 detects that the save buffer 120 is in such a state based on the pointer value input from the write pointer 133, that is, the storage destination address of the next data in the save buffer 120. At the time of detection, the buffer full detection signal buffer-full is output to the outside. This signal is used as an interrupt signal for a data generation device such as a processor.

  Next, FIG. 6 is a schematic diagram showing an embodiment in which the FIFO buffer 110 is used as a queue for storing “packets”, which are one or more data strings expressing commands and the like.

  The counter 140 counts the number of packets stored in the FIFO buffer 110 and outputs the count value value to a packet processing device that takes out the packets from the FIFO buffer 110 and processes them.

  The increment (+1) of the counter 140 is performed by a packet generation device that inputs a packet to the FIFO buffer 110 such as a processor, and the decrement (−1) is performed by a packet processing device that extracts the packet from the FIFO buffer 110. That is, the packet stored in the FIFO buffer 110 is incremented by incrementing the counter 140 at the end of input of the data input side packet to the FIFO buffer 110 and decrementing the counter 140 at the end of extraction of the data output side packet. Can be detected.

  In this way, by adding the counter 140 that counts the number of packets, the packet processing device can extract the data of the packets continuously after the packets are completed in the FIFO buffer 110 and process them efficiently. become.

  Next, in the embodiment shown in FIG. 7, in the configuration shown in FIG. 6 described above, 1-bit information indicating whether or not the data is the last data of the packet is included in each data of the packet stored in the FIFO buffer 110A ( end bit) is added. With such a configuration, the end of the packet can be easily detected on the output side of the FIFO buffer 110A by monitoring the end bit output terminal in the process of extracting data from the FIFO buffer 110A.

FIG. 8 is a block diagram showing an overall circuit configuration of a processor element to which the queue device 1000 according to the embodiment of the present invention is applied.
The processor 100 is formed of, for example, a RISC (Reduced Instruction Set Computer) type or CISC (Complex Instruction Set Computer) type microprocessor, and generates a packet including a command or the like.

  A memory 300 is connected to the processor 100 via a bus 200. The memory 300 is composed of, for example, a DRAM and the like, and an area for the save buffer 1020 is secured therein. The save buffer 1020 has the same function as the save buffer 120, and is used as a temporary save area for packets generated by the processor 100.

A portion of the queue device 1000 of the present embodiment excluding the save area 1020 is connected to the bus 200 via the bus interface 400.
Next, the configuration of the queue device 1000 other than the save area 1020 will be described.

  A FIFO buffer 1010 composed of two FIFO buffers (FIFO 1 and FIFO 2) is a FIFO memory that functions as a queue for storing packets to be written by the processor 100 via the bus interface 400. The processor 100 instructs which of the FIFOs 1 and 2 is to write data by controlling a write request signal W11 or W12 output to the overflow control unit 1030 via the bus interface 400.

A counter 1040 having counters C1 and C2 respectively corresponding to the FIFO buffers 1 and 2 is provided.
Counters C1 and C2 count the number of packets stored in FIFOs 1 and 2, respectively.

The overflow control unit 1030 is provided between the FIFOs 1 and 2 and the counters C1 and C2 and the bus interface 400.
The overflow control unit 1030 has a flag 1032 having two flags F1 and F2, a packet data latch circuit 1036 (hereinafter simply referred to as a latch circuit 1036), a write pointer 1033 for the save buffer 1020, and the size of the save buffer 1020. A limit register 1037 in which a limit value (final storage address) of the write pointer 1033 determined in response is set, a comparator 1038 for comparing the pointer 1033 and the limit register 1037, and the flags F1 and F2 and the counter C1 , C2 is provided with an interrupt generation unit 1039 for issuing an interrupt requesting data restoration to the processor 100.

  The flag F1 is “set” when the full1 signal input from the corresponding FIFO1 becomes “active”, that is, when the FIFO1 becomes full. Then, when all the data saved in the save buffer 1020 is input to the FIFO buffer 1, it is “cleared” (reset).

  The flag F2 performs the same operation as the flag F1 with respect to the FIFO2. The write destination pointer 1033 is initially set to the head address of the save buffer 1020. It is incremented every time write data to the FIFO buffer 1010 is stored. The value of the write destination pointer 1033 is supplied as an address signal (address) to the memory 300 via the bus interface 400 and the bus 200.

  The comparator 1038 adds an interrupt signal (Interrupt 1) to the processor 100 via the bus interface 400 and the bus 200 when the value of the write destination pointer 1033 exceeds the value of the limit register 1037. This interrupt notifies the processor 100 that there is no “empty” in the save buffer 1020.

  The latch circuit 1036 temporarily holds write data (data) to the FIFO buffer 1010 output from the processor 100 input via the bus interface 400 onto the bus 200. Further, when writing the last data of the packet, the processor 100 enables (“1”) the end bit signal line on the bus 200. The value of the end bit is also latched by the latch circuit 1036 via the bus interface 400.

  The counter control unit (not shown) in the overflow control unit 1030 detects that the end bit latched in the latch circuit 1036 is set to “1”, whereby the last data of the packet is stored in the latch circuit 1036. Detect that it was latched. Then, after writing the last data of the packet in FIFO1 or FIFO2, the counter C1 or C2 is incremented (+1).

  When the flag F1 or F2 is set and the value of the counter C1 or C2 corresponding to the set flag F1 or F2 is “0” or less than a predetermined threshold value, the interrupt generation unit 1039 sets an interrupt signal ( Interrupt 2) is generated to interrupt the processor 100 via the bus interface 400 and the bus 200. This interruption occurs when the data stored in the FIFO 1 or the FIFO 2 becomes “none” while the write data to the FIFO buffer 1010 is saved in the save buffer 1020.

FIGS. 9A and 9B are diagrams showing a circuit configuration example of the interrupt generating unit 1039. FIG.
In the interrupt generation unit 1039 shown in FIG. 5A, the flag F1 is set and the value of the counter C1 (the number of packets stored in the FIFO1) value 1 is “0” or the flag F2 is set. When the value of the counter C2 (number of FIFO2 stored packets) value2 is "0", a common interrupt signal Interrupt2 is generated.

  The comparator 1102 outputs an “H” signal to one input terminal of the AND gate 1104 when the value value 1 of the counter C1 is “0”. The AND gate 1104 inputs the value of the flag F1 (“H” when “1” (set state), “L” when “0” (clear state)) to the other input terminal. When the flag F1 is set and the value value 1 of the counter C1 is “0”, an “H” signal is output to the OR gate 1110. A circuit similar to the circuit for the output of the flag F1 and the counter C1 is also provided for the output of the flag F2 and the output of the counter C2 by the comparator 1106 and the AND gate 1108. The AND gate 1108 outputs an “H” signal to the OR gate 1110 when the flag F2 is set and the value 2 of the counter C2 is “0”.

  The OR gate 1110 outputs the interrupt signal Interrupt 2 to the bus interface 400 when either the AND gate 1104 or the AND gate 1108 becomes “H”.

  In this case, the processor 100 reads the values of the counters C1 and C2 via the overflow control unit 1030 and the bus interface 400, and detects the counter Ci (i = 1, 2,) whose value is “0”. Thus, it is determined which of the FIFO1 and the FIFO2 has the number of stored packets has become “0”.

  On the other hand, the circuit shown in FIG. 9B is obtained by omitting the OR gate 1110 from the circuit shown in FIG. 9A, and outputs of the AND gate 1104 and the AND gate 1108 are independent interrupt signals. Interrupt 2A and 2B are output to the bus interface 400. In this case, the processor 100 can recognize which one of the FIFO1 and the FIFO2 has the number of stored packets “0”.

  The arbiter 1050 monitors the values value 1 and 2 of the counters C1 and C2, and when the value of the counter value value 1 or 2 becomes larger than “0”, the appropriate one of the two FIFOs 1 and 2 is selected. Then, the enable signal r1 or r2 applied to the selected FIFO1 or 2 is set to “enable” to sequentially read out the packet data. These read packet data are input to the multiplexer 1060. The arbiter 1050 adds the input selection signal select to the multiplexer 1060 and causes the packet processing device 500 to input the packet data data read from the FIFO1 or FIFO2.

  The multiplexer 1060 is a data selector to which the packet data extracted from the FIFO 1 and the FIFO 2 by the arbiter 1050 is input, and the packet data output from either the FIFO 1 or the FIFO 2 in accordance with the input selection signal select applied from the arbiter 1050. Data is output to the packet processing device 500.

  The multiplexer 1070 receives the empty signals 1 and 2 from the FIFO 1 and FIFO 2, respectively, and receives the input selection signal select from the arbiter 1050 in the same manner as the multiplexer 1060. In response to the selection signal select, either one of the two empty signals 1 or 2 is selectively output to the packet processing device 500.

  The packet processing device 500 sends a packet read request signal read to the arbiter 1050 at the start of packet processing, and requests the arbiter 1050 to take out the packet stored in the FIFO buffer 1010. Upon receiving this signal read, the arbiter 1050 refers to the counters C1 and C2, and inputs the packet data stored in the FIFO1 or FIFO2 to the packet processing device 500 via the multiplexer 1060. When the packet processing apparatus 500 receives the last data of the packet via the multiplexer 1060, the packet processing apparatus 500 outputs a done signal indicating the end of the packet extraction to the arbiter 1050. When receiving the done signal, the arbiter 1050 decrements (-1) the counter Ci corresponding to the FIFOi (i = 1, 2) from which the packet is extracted. Since the empty signal is input to the packet processing device 500 through the multiplexer 1070 as described above, it can be known that the packet is stored in the FIFO buffer 1010 while the empty signal is inactive. it can.

FIG. 10 is a diagram illustrating a format of a packet stored in the FIFO buffer 1010 (FIFO1, FIFO2).
Information indicating the type of command is set at the head (first word) of the packet. From the second word onward, the necessary number of parameters associated with the command are set.

  FIG. 11 is a diagram showing a format of a packet saved in the save buffer 1020. In this packet, in addition to the packet data data, packet data corresponding to a queue number (for example, “1” in the case of FIFO1, “2” in the case of FIFO2) indicating the FIFO buffer to be input is included in the packet. An end-bit which is information indicating whether or not it is the last data is added. The end-bit is effective when it is “1”, for example. When the processor 100 returns the packet data saved in the save buffer 1020 to the corresponding FIFOi (i = 1, 2), the additional information is referred to.

Next, the operation of the processor element configured as described above will be described.
When the processor 100 generates a packet, the processor 100 divides the packet according to the data bus width of the bus 200, sets a corresponding value in the end bit data, and sequentially outputs it to the bus 200. Then, the write request signal W11 or W12 of the packet data data for FIFO1 or FIFO2 is enabled and output to the command bus on the bus 200 to the overflow control unit 1030.

  When the bus interface 400 detects the enable output of the write request signal Wi (i = 1, 2), it outputs this signal Wi to the overflow control unit 1030 and is output to the internal latch circuit 1036 on the bus 200. Packet data data and end bit are latched.

  In this way, the packet data latched in the latch circuit 1036 is sequentially written into the FIFOi requested to be written by the overflow control unit 1030. When the processor 100 outputs the end bit data set to “1” together with the last data of the packet onto the bus 200, the overflow control unit 1030 writes the last data of the packet into the corresponding FIFOi, and then responds. Counter Ci to be incremented (+1).

  As described above, the processor 100 writes packets into the FIFO buffer 1010 (FIFO1 or FIFO2), and the overflow control unit 1030 counts the number of packets written in the FIFOs 1 and 2 with the counters C1 and C2.

  The arbiter 1050 constantly monitors the values of the counters C1 and C2. When the value of the counter C1 or C2 becomes larger than “0”, the arbiter 1050 controls the multiplexer 1060 to select the appropriate one of the two FIFOs 1 and 2. Is selected as the queue from which packets are taken out. In addition, an inactive empty signal is applied from the multiplexer 1070 to the packet processing device 500 in accordance with the control. The inactive empty signal indicates that a packet is stored in the FIFO buffer 1010, that is, at least one of FIFO1 and FIFO2.

  When an inactive empty signal is added from the multiplexer 1070, the packet processing device 500 activates the signal read output to the arbiter 1050 and makes a packet reception request. In response to this request, the arbiter 1050 “enables” the read enable signal r1 or r2 to the appropriate one of the FIFO1 and the FIFO2, and outputs it from the FIFOi (i = 1, 2) that performed the enable output. Read the packet data sequentially. For example, when both the values of the counters C1 and C2 are larger than “0”, the arbiter 1050 preferentially selects the FIFO value having a larger counter value, that is, the number of stored packets. Then, the multiplexer 1060 is controlled to sequentially input packet data read from the selected FIFOi to the packet processing device 500.

  The packet processing device 500 sequentially takes in the packet data read from the FIFOi and starts packet processing. When the last data of the packet is captured, a done signal is transmitted to the arbiter 1050. In response to this, the arbiter 1050 decrements (-1) the value of the counter Ci corresponding to the FIFOi. That is, since the number of FIFOi stored packets has decreased by “1”, the value of the counter Ci is updated accordingly. For example, the packet processing device 500 stores the total length of various commands, and detects the end of the extraction of each packet based on the stored information.

  If the speed at which the processor 100 writes a packet to the FIFO 1 or the FIFO 2 is faster than the speed at which the packet processing device 500 fetches the packet from the FIFO 1 or the FIFO 2 and processes the packet, the FIFO 1 or the FIFO 2 may become full. .

  In such a case, when the overflow control unit 1030 receives a packet data write request for the FIFOi that is currently full from the processor 100, the overflow control unit 1030 stores the packet data for which the write request has been made in the save buffer 1020 in the format shown in FIG. Write to the address pointed to by the pointer 1033. Then, the corresponding flag Fi is set. As described above, once the flag Fi is set, the overflow control unit 1030 writes a packet for which a write request is made from the processor 100 to the FIFOi thereafter in the save buffer 1020 while updating the pointer 1033.

  While packets are being written to the save buffer 1020 in this way, packets are sequentially extracted by the packet processing device 500 from the FIFOi that has been full. Eventually, the number of packets stored in the FIFOi becomes “0”. That is, the value of the counter Ci corresponding to the FIFOi is “0”. As a result, the interrupt signal Interrupt 2 is applied from the interrupt generation unit 1039 to the processor 100 in the overflow control 1030.

  In response to this interrupt, the processor 100 executes the interrupt processing routine, reads the packet data to be input to the FIFOi from the save buffer 1020, and writes the packet data to the FIFOi. As a result, when there is no packet data to be input to FIFOi in the save buffer 1020, the corresponding flag Fi is cleared (reset). By clearing the flag Fi, the overflow control 1030 writes packet data for which a write request is made from the processor 100 to the FIFOi until the FIFOi becomes full again.

  On the other hand, in the restoration of data from the save buffer 1020 to the FIFOi, if the input packet data to the FIFOi still remains in the save buffer 1020, the flag Fi is not cleared. Therefore, in this case, the overflow control 1030 continues to write the input data for the FIFOi of the processor 100 into the save buffer 1020. That is, in this case, packet data to be input first into FIFOi remains in the save buffer 1020.

  By the way, there is a case where the FIFOi becomes full while data is being input into the FIFOi in a certain packet, and the subsequent data is stored in the save buffer 1020. In this case, since the counter Ci is not incremented (+1), it is considered that the packet is not stored in the FIFOi. Then, when all the remaining data saved in the save buffer 1020 is transferred to the FIFOi, the counter Ci is incremented (+1). Therefore, the packet processing device 500 can efficiently extract a packet from the FIFOi at all times when the packet is completed in the FIFOi.

  On the other hand, there may be a state where the save buffer 1020 overflows. In this case, the interrupt signal Interrupt 1 is applied to the processor 100 by the comparator 1038. When this interrupt is applied, the processor 100 performs a process of expanding the size of the save buffer 1020 on the memory 300, for example. Along with this, the value of the limit register 1037 is updated.

In the above-described embodiment, data restoration from the save buffer 1020 to the corresponding FIFOi is executed by software processing of the processor 100.
The embodiment described below is an example of a processor element in which a queue device that implements the data restoration processing is completely implemented by hardware.

  In this embodiment, as schematically shown in FIG. 12, in addition to the write pointer WP (corresponding to the pointer 1033 in FIG. 8) for the save buffer 1020, the storage address of the first packet data to be read from the save buffer 1020 A read pointer RP pointing to is prepared. As a result, the save buffer 1020 can be handled as a ring buffer. When it is detected that the FIFO buffer 1010 is empty, the data saved in the save buffer 1020 is read from the address indicated by the read pointer RP and transferred to the FIFO buffer 1010. If the save buffer 1020 becomes “empty” by this data transfer, the flag 1032 indicating that there is save data in the save buffer 1020 is reset (cleared). A series of these processes is realized by hardware.

FIG. 13 is a block diagram showing an overall configuration of a processor element in which the queue device 2000 that implements the data restoration processing is implemented by hardware.
In the figure, the same reference numerals are assigned to the same blocks as those in the embodiment shown in FIG. 8 described above, and detailed description thereof is omitted.

  In this embodiment, only one FIFO buffer 1010 is provided, and a counter 1040 for counting the number of stored packets in the FIFO buffer 1010 is provided correspondingly.

  The overflow control unit 2030 of this embodiment includes a flag 1032 indicating that packet data to be written to the FIFO buffer 1010 is saved in the latch circuit 1036 and the save buffer 1020, as in the embodiment shown in FIG. ing. In addition to these circuits, a write pointer WP and a read pointer RP, a pointer comparator 2031, a sequencer 2032, and two multiplexers 2033 and 2034 provided for the save buffer 1020 are provided.

  The pointer comparator 2031 inputs and compares the values of the two pointers WP and RP, and detects whether the save buffer 1020 is currently “empty” or “full”. If the save buffer 1020 is “empty”, the empty 3 signal is output to the sequencer 2032. If the save buffer 1020 is “full”, the full 3 signal is output to the sequencer 2032. Since the save buffer 1020 has a ring buffer configuration as described above, the values of the two pointers match when in the “empty” state, and the pointers are adjacent addresses on the ring buffer when full. Will point to.

  The sequencer 2032 controls the overflow control unit 2030 as a whole, and receives the packet data data from the processor 100 to the FIFO buffer 1010 and an end bit data write request signal W added thereto via the bus interface 400. Then, the latch circuit 1036 latches the packet data data and end bit data.

  The multiplexer 2033 outputs either the pointer WP or RP to the bus interface 400 as an address signal in accordance with the input selection signal select 1 added from the sequencer 2032. This address signal is sent to the memory 200 via the bus 200. That is, when the sequencer 2032 saves the input data to the FIFO buffer 1010 in the save buffer 1020, the data saved in the save buffer 1020 is output to the FIFO buffer 1010 so that the value of the write pointer WP is selectively output. When the data is restored, the multiplexer 2033 is controlled so that the value of the read pointer RP is selectively output.

  The multiplexer 2034 stores either the write data of the processor 100 latched in the latch circuit 1036 or the restore data read from the save buffer 1020 in the FIFO buffer 1010 in accordance with the input selection signal select2 applied from the sequencer 2032. Select output. That is, when the sequencer 2032 directly writes the packet data data requested to be written by the processor 100 to the FIFO buffer 1010, the sequencer 2032 selects the packet data data latched in the latch circuit 1036 from the save buffer 1020. When the read packet data data for restoration is written in the FIFO buffer 1010, the multiplexer 2034 is controlled so that the restoration packet data data input from the bus interface 400 is selectively output. Further, when the output packet data data from the multiplexer 2034 is written in the FIFO buffer 1010, the sequencer 2032 enables the write enable signal write 2 and adds it to the FIFO buffer 1010.

  When the last data data of the packet is latched in the latch circuit 1036, the sequencer 2032 latches the last data data of the packet in the latch circuit 1036 according to the end-bit value latched in the latch circuit 1036 together with the data data. Recognize that Then, after writing the last data data to the FIFO buffer 1010, the counter 1040 is incremented (+1).

  In this embodiment, since only one FIFO buffer 1010 is mounted, the format of the packet data stored in the save buffer 1020 is different from the above-described embodiment as shown in FIG. Will be added. When the sequencer 2032 reads the packet data data to be restored from the save buffer 1020 to the FIFO buffer 1010, the sequencer 2032 detects reading of the last data data of the packet based on the end-bit information. Then, after the last data data is restored to the FIFO buffer 1010, the counter 1040 is incremented (+1). The packet processing device 500 decrements (-1) the counter 1040 each time the last data of the packet is read from the FIFO buffer 1010.

The operation of the queue device 2000 in the embodiment having the above configuration will be described with reference to the flowchart of FIG.
The sequencer 2032 of the overflow control unit 2030 makes the following determinations (A) to (D).

  (A) When there is a write request for packet data data from the processor 100 to the queue, that is, the FIFO buffer 1010, it is checked whether or not the save buffer 1020 has “free”. This is determined by whether or not the full3 signal input from the pointer comparator 2031 is active. If inactive, the save buffer 1020 has “free”.

  (B) It is checked whether the overflow data is currently saved in the save buffer 1020 by referring to the flag information set in the overflow flag 1032 to determine whether the overflow flag 1032 is set. If there is saved data, the state of the full2 signal from the FIFO buffer 1010 is next checked to check whether the FIFO buffer 1010 currently has “free”.

  (C) If it is determined in the above determination (A) that the save buffer 1020 is currently “empty”, then whether the overflow flag 1032 is set or whether the FIFO buffer 1010 is full (full state). Investigate. As described above, the overflow flag 1032 being set means that save data currently exists in the save buffer 1020.

  (D) If it is determined in the determination (A) that the save buffer 1020 currently has “free”, it is checked whether the overflow flag 1032 is off and the FIFO buffer 1010 has “free”.

  The sequencer 2032 makes the above determinations (A) to (D), and writes the packet data requested to be written to the queue from the processor 100 in either the FIFO buffer 1010 or the save buffer 1020 according to the determination result. Further, the packet data saved in the save buffer 1020 is restored to the FIFO buffer 1010.

  That is, at the start of the operation of the system, it is recognized that the overflow flag 1032 is reset in the determination of (D) and that the FIFO buffer 1010 has “free”, and the write request data for the queue from the processor 100 is The data is sequentially written into the FIFO buffer 1010 (step S11). When the end-bit added to the packet data written to the FIFO buffer 1010 is “ON”, that is, when the last data of the packet is written to the FIFO buffer 1010, the counter 1040 is incremented ( +1) (step S12). As a result, the number of packets stored in the FIFO buffer 1010 is set in the counter 1040. Even after that, the write data to the queue of the microprocessor 100 is written to the FIFO buffer 1010 by the processing of steps S11 to S12.

  Then, when the FIFO buffer 1010 becomes full, the full2 signal output from the FIFO buffer 1010 becomes “active”. As a result, the sequencer 2032 detects that the FIFO buffer 1010 is full (full) in the determination (C), and writes write data data to the queue from the microprocessor 100 thereafter to the save buffer 1020. . At this time, as shown in FIG. 14, "end-bit" is added to the write data data (step S21). Then, after the data data is written, the write pointer WP is incremented (+1) (step S22). The overflow flag 1032 is set to “ON” (step S23). As described above, when the overflow flag is turned “ON”, the sequencer 2032 performs the processing of steps S21 to S23 each time there is a request for writing the packet data data from the microprocessor 100 to the queue, and stores it in the save buffer 1020. Write packet data data.

  Thereafter, when the packet processing device 500 extracts a packet from the FIFO buffer 1010 and “free” is generated in the FIFO buffer 1010, the full2 signal output from the FIFO buffer 1010 becomes inactive. Thereby, the sequencer 2032 detects that “free” has occurred in the FIFO buffer 1010 in the determination (B). Further, when the overflow flag 1032 is set, it is known that overflow data (saved data) is stored in the save buffer 1020.

  As a result, the sequencer 2032 reads the packet data data from the address pointed to by the read pointer RP of the save buffer 1020 and writes the data data to the FIFO buffer 1010 (step S31). Subsequently, the read pointer RP is incremented (+1) (step S32). If the end-bit added to the packet data data written to the FIFO buffer 1010 is set to “on”, the counter 1040 is incremented (+1). That is, the counter 1040 is incremented (+1) every time one packet is restored in the FIFO buffer 1010 (step S33). Thereafter, the state of the empty3 signal input from the pointer comparator 2031 is checked to check whether or not the save buffer 1020 has become “empty”. The overflow flag 1032 is cleared (reset) (step S34).

  The sequencer 2032 performs the processes of steps S31 to S34 as needed while there is no request for writing packet data data from the microprocessor 100 to the queue, for example. As a result, it is possible to restore data from the save buffer 1020 to the FIFO buffer 1010 without interfering with the operation of the microprocessor 100 while the microprocessor 100 is not using the bus 200.

  Next, FIG. 16 is a block diagram showing an overall configuration of a processor element in which a queue device 3000 according to still another embodiment of the present invention is mounted. In the figure, the same reference numerals are given to the same blocks as the blocks in the processor element shown in FIG. 8, and a detailed description thereof will be omitted.

  The FIFO buffer 3010 of this embodiment is composed of two FIFO memories 1 and 2 (hereinafter simply referred to as FIFOs 1 and 2), and each FIFO 1 and 2 has a ring buffer configuration. FIG. 17 shows the detailed configuration.

  The FIFOi (i = 1, 2,) includes a FIFO buffer 3110, a write pointer wpi indicating the next data write address to the buffer 3110, and a read pointer rpi indicating the next data read address. Then, by operating these two pointers wpi and rpi, it functions as an endless buffer.

  The format of a packet written to the FIFO buffer 3110 is shown in FIG. As shown in the figure, size information indicating the entire length of the packet is set at the head (first word) of the packet.

  A packet completion detection unit 3060 is provided corresponding to each of the FIFOs 1 and 2. The packet completion detection unit 3060 detects whether or not a completed packet is stored in the corresponding FIFO 1 or 2. If one or more completed packets are stored in the FIFO 1 or 2, an external output is performed. Set the packet complete 1 and 2 signals to “active”. The packet complete 1 and 2 signals are input to the arbiter 3050, and the arbiter 3050 controls the multiplexer 1060 and the multiplexer 1070 by the packet complete 1 and 2 signals. That is, the packet complete 1 and 2 signals function as an alternative to the counters C1 and C2 for the arbiter 3050. The arbiter 3050 updates the pointers rp1 and rp2 each time the packet data data is read from the FIFO1 and FIFO2. The write pointers wp1 and 2 are operated by a sequencer (not shown) in the overflow control unit 3030.

Next, an internal circuit configuration of the packet completion detection unit 3060 will be described with reference to FIG.
The packet decoder 3061 decodes the data of the first word of the packet stored in the FIFOs 1 and 2, and outputs a packet length indicating the entire size of the packet to the comparator 3063.

  The arithmetic unit 3062 receives the values of the two pointers rp and wp from the FIFOs 1 and 2, and the data length indicating the number of packet data (number of words) stored in the FIFOs 1 and 2 from both pointer values. Is output to the comparator 3063.

  The comparator 3063 compares the packet length input from the packet decoder 3061 with the data length input from the calculator 3062. If the data length is equal to or longer than the packet length, the packet complete signals 1 and 2 applied to the arbiter 3050 are set to “active” to indicate that the packet is completed in the FIFOs 1 and 2.

  The pointer comparator 3064 performs the same operation as the above-described pointer comparator 2031 shown in FIG. 13 and inputs the above two pointers rp (rp1,2) and wp (wp1,2) from the FIFOs 1,2. The two pointer values are compared, and a full flag 1 and 2 signal indicating that the FIFOs 1 and 2 are in “full state” and an empty flag 1 indicating that the FIFOs 1 and 2 are “empty”. , 2 signals are generated and output to the overflow control unit 3030.

The configuration of the interrupt generation unit 3039 in the overflow control unit 3030 in this embodiment is shown in FIG.
As shown in the figure, the interrupt generation unit 3039 has a configuration in which the comparators 1102 and 1106 are deleted from the interrupt generation unit 1039 described above. Empty flag 1 and 2 signals are input. Similarly to the interrupt generation unit 1039, when the FIFO Fi becomes “empty” when the flag Fi (i = 1, 2) is set, the interrupt signal Interrupt 2 is set to “active” to interrupt the processor 100. multiply.

  In the embodiment described above, the packet processing device 500 takes out the packet when the packet is completed in the FIFO buffer 1010. In other words, when a packet is incomplete in the FIFO buffer 1010, output of the packet data data from the FIFO buffer 1010 can be suppressed. As a result, a part of data data of an incomplete packet once input to the FIFO buffer 1010 is extracted from the FIFO buffer 1010 and temporarily provided in the memory 300 and saved in a save area (not shown) by software processing of the processor 100. It is possible to complete the packet in the FIFO buffer 1010 like other packets by returning the packet data data saved in the save area to the FIFO buffer 1010 again.

  Such a function is effective when the processor 100 supports multi-program processing. In this case, when a plurality of processes (here, a process is a running unit of one program) shares one FIFO buffer (FIFO1 or FIFO2) as a queue, a process writes a packet to the FIFO buffer. On the way, the execution right may be switched to another process, and this another process may write a packet to the FIFO buffer. In such a case, by using the above function, both processes can correctly write a packet to the FIFO buffer.

  20 and 21 are flowcharts for explaining the operation of the processor 100 and the queue devices 1000, 2000, or 3000 for realizing the above functions. The flowchart in FIG. 20 is a flowchart for explaining the operation when the processor 100 interrupts the execution of the process A during the execution of the process A and shifts to the execution of another process B.

  In this case, the processor 100 reads the value of the write pointer in the FIFO buffer 1010 via the overflow control unit 1030 (2030 or 3030) (step S101).

  Next, the data data at the address pointed to by the write pointer is read from the FIFO buffer 1010 via the overflow control unit 1030 (2030 or 3030) (step S102), and whether or not the data is the data data being written by the process A. It discriminate | determines (step S103). If the process A is data data being written (S103, YES), the data data is saved in a save area on the memory 300. Then, the write pointer of the FIFO buffer 1010 is corrected along with the saving of this data (step S104).

  The processes in steps S101 to S104 are repeated until all the data data being written by the process A is saved from the FIFO buffer 1010 to the save area of the memory 300, and the data of the packet being written by the process A in the FIFO buffer 1010 When there is no data (S103, NO), the process is terminated.

Through the above processing, an incomplete packet written in the FIFO buffer 1010 during the execution of the process A is saved in a specific area of the memory 300.
Next, FIG. 21 is a flowchart for explaining operations performed before the processor 100 finishes the execution of the process B and resumes the execution of the process A again.

The processor 100 checks the save area on the memory 300 and checks whether the save data data of the process A exists in the save area (step S201).
If the saved data data exists (S201, YES), it is transferred to the FIFO buffer 1010 via the overflow control unit 1030 (2030 or 3030). Then, the write pointer of the FIFO buffer 1010 is updated according to the transferred data length (S202).

  Through the above processing, the data buffer of the incomplete packet written before the process A is interrupted is stored in the FIFO buffer 1010 after the packet written by the process B. Thus, after the process A is resumed, the process A can write the remaining packet data data following the stored packet data data and write the completed packet in the FIFO buffer 1010.

Whether or not the data being written by the process A in step S103 of FIG. 20 exists in the FIFO buffer 1010 is determined by the following method, for example.
(1) As shown in FIG. 14, when adopting a configuration in which an end bit is added to each packet data stored in the FIFO buffer 1010, the end bit added to the packet data last written in the FIFO buffer 1010 Check the value of. If the end bit is set to “0” (information indicating that it is not the end data of the packet), it is determined that the data being written by the process A is in the FIFO buffer 1010. In this case, as shown in FIG. 22, the packet data stored immediately before the end data of the previous packet in which the end bit is set to “1” (information indicating the end data of the packet). (Data) is saved in a save area provided on the memory 300.

  (2) The bus interface 400 is provided with a counter that counts the number of data of packets written to the FIFO buffer 1010. This counter starts counting every time a packet writing operation to the FIFO buffer 1010 is started, and is reset to “0” when the last data writing of the packet to the FIFO buffer 1010 is completed, and the counting ends. . Therefore, when switching from the process A to the process B occurs, it is possible to determine whether or not the process A was in the middle of packet writing by examining the value of the counter. That is, if the value of the counter is “0”, the packet writing is finished. On the other hand, when the value of the counter is not “0”, it can be seen that there are as many pieces of data as process A is in the middle of writing. Therefore, the number of data equal to the counter value is saved in the save area on the memory 300 from the end of the FIFO buffer 1010 (data written last).

  (3) An input signal pause and an output signal stop are added to the arbiter 1050 or 3050 shown in FIG. 8 or 16, as shown in FIG. The input signal pause is a signal for instructing the arbiter 1050 or 3050 to “stop”, and the output signal stop is a signal indicating that the arbiter 1050 or 3050 has stopped outputting data from the FIFO buffer 1010 (stop state). It is.

  When the arbiter 1050 or 3050 is instructed to “stop” by the pause signal (FIG. 24A), the data in the middle of the output of the packet A is output from the FIFO buffer 1010 to the end, that is, the packet processing device 500. The data is output from the FIFO buffer 1010 until an active done signal is output from (FIGS. 24B and 24C). When the data of the packet A is output to the end, the data output from the FIFO buffer 1010 is stopped, and the stop signal indicating the “stop state” is activated. Therefore, when the stop signal is active, the head data of the FIFO buffer 1010 is always the head data of the packet.

  When the microprocessor 100 switches the execution process from the process A to the process B, for example, the microprocessor 100 adds an active pause signal to the arbiter 1050 or 3050 via the bus interface 400. When the stop signal is detected to change actively through the bus interface 400, data is sequentially read from the head of the FIFO buffer 1010, and the contents in the FIFO buffer 1010 are analyzed, thereby obtaining an incomplete packet, that is, a process. A can detect whether data of an incomplete packet being written is in the FIFO buffer 1010.

It is FIG. (1) explaining the principle of this invention. It is FIG. (2) explaining the principle of this invention. It is FIG. (3) explaining the principle of this invention. It is FIG. (4) explaining the principle of this invention. 1 is a block diagram illustrating an overall configuration of a queue device according to an embodiment of the present invention. It is a schematic diagram which shows one Example in the case of using a FIFO buffer as a queue which stores a packet. Embodiment in which 1-bit information (end bit) indicating whether or not the data is the last data of the packet is added to each data of the packet stored in the FIFO buffer having the configuration shown in FIG. FIG. It is a block diagram which shows the whole circuit structure of the processor element to which the cue apparatus of the Example of this invention is applied. (a), (b) is a figure which shows the circuit structural example of the interrupt generation part 1039 shown in the said FIG. It is a figure which shows the format of the packet stored in the FIFO buffer (FIFO1, FIFO2) shown in the said FIG. It is a figure which shows the format of the packet evacuated by the evacuation buffer 1020 shown in the said FIG. It is a figure which shows the structural example of the save buffer used with the processor element which mounted the queue apparatus which implement | achieves the data restore process from a save buffer to a FIFO buffer completely with hardware. It is a block diagram which shows the whole structure of the processor element which mounted the queue apparatus which implement | achieves the said data restoration process with hardware. It is a figure which shows the format of the packet data stored in the save buffer 1020 in the queue apparatus shown in FIG. It is a flowchart explaining operation | movement of the queue apparatus shown in the said FIG. It is a block diagram which shows the whole structure of the processor element which mounted the queue apparatus which is another Example of this invention. It is a figure explaining the structure of the FIFO buffer shown in the said FIG. It is a figure which shows the format of the packet written in the FIFO buffer shown in the said FIG. It is a figure which shows the structure of the interrupt generation part in the overflow control part shown in the said FIG. 10 is a flowchart for explaining an operation in a case where the processor interrupts execution of the process A during execution of the process A and shifts to execution of another process B sharing the same FIFO buffer as a queue. 12 is a flowchart for explaining an operation performed before a processor finishes the execution of the process B and resumes the execution of the process A again. FIG. 21 is a diagram illustrating an example in which the operation of adding an end bit to each packet data stored in the FIFO buffer described in FIG. 20 is adopted. FIG. 17 is a diagram illustrating a configuration in which an input signal pause and an output signal stop are added to the arbiter shown in FIG. 8 or FIG. 16. (a), (b) is a figure explaining operation | movement of the arbiter of the structure shown in the said FIG.

Explanation of symbols

1,11,21,41 FIFO buffer 2,13,23 save buffer 3,14,24 flag 4,15,25 first detection means 5,43 data save means 6,17,27 second detection means 7, 18, 28, 44 Data restoration means 8 Third detection means 12 Counting means 16, 26 Packet data saving means 19, 23 Packet completion detection means 42 Storage means

Claims (5)

A FIFO buffer in which packets are stored;
Storage means;
Counting means for counting the number of packet data stored in the FIFO buffer;
Packet completion detection means for detecting whether or not there is a completed packet in the FIFO buffer based on the count value of the counting means and the number of packets of packet data;
Data evacuation means for evacuating the data in the FIFO buffer determined to be incomplete by the packet completion means to the storage means;
A queue device comprising:   The packet completion detection means determines whether complete data exists in the FIFO buffer based on the count value of the counting means and the packet size information stored in the packet data packet stored in the FIFO. The queue device according to claim 1, wherein it is determined whether or not. The FIFO buffer is one in which packet data is written by a plurality of processes.
The packet completion means determines whether or not there is incompletely written data in the FIFO buffer when the execution right is switched to another process B while the process A is writing the packet to the FIFO buffer. Discriminate,
The data saving means saves the incomplete write data in the FIFO buffer to the storage device when the data packet completion means determines that there is incomplete write data in the FIFO buffer. The cue device according to claim 1 or 2, characterized in that:   And a data restoring means for transferring packet data saved in the storage means before the execution of the process A to the FIFO buffer when the execution right is transferred to the process A again. Item 4. The cue device according to item 3. A FIFO buffer into which packets are written by multiple processes;
Storage means;
When the execution right is switched to another process B while the process A is writing a packet to the FIFO buffer, the incomplete packet data written by the process A is taken out of the FIFO buffer and saved in the storage means. Data evacuation means;
Data restoration means for transferring the packet data saved in the storage means before the execution of the process A to the FIFO buffer when the execution right is transferred to the process A again;
A queue device comprising:

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