JPH06350673A - Protocol processor - Google Patents

Abstract

PURPOSE:To reduce the overhead of time-out processing in the protocol processing. CONSTITUTION:Timer parts 61 to 67 are provided correspondingly to buffers 51 to 57, and these timer parts 61 to 67 count down the set time-out values at each time of coming of a clock signal from a clock generating part 4. Zero detecting parts 71 to 77 detect the time-out of timer parts 61 to 67 to output time-out signals 81 to 87 to a protocol processing part 2 respectively. At the time of input of the time-out signal to the protocol processing part 2, this part 2 checks the buffer corresponding to the zero detecting part which outputs this time-out signal, and a transmission time-out processing routine is started to perform the time-out processing if data remains in this buffer, but a reception time-out processing routine is started to perform the time-out processing when data does not remain there.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protocol processing device for processing a protocol in a communication system.

[0002]

2. Description of the Related Art FDDI and BI are used as protocol processing devices.
High-speed protocol processing is required to connect a high-speed communication line such as SDN and to effectively use the bandwidth of the line for transmission / reception control.

In general, when performing protocol processing, it is usual to detect a time abnormality by a timer during transmission / reception to find an abnormality in the sequence. The following method is generally used as this method.

Each protocol processing module is configured on a multi-task OS, and a time-out system call is issued to create a queue waiting for each time. At the time-out, a time-out processing routine registered in advance is activated.

In this method, an interrupt occurs in system clock units within the multitasking OS, and each time the interrupt occurs, the timeout value of the time-waiting queue is decremented by one and the one that has become 0 is searched. Then, the found one is treated as a timeout occurs.

[0006]

The above-mentioned conventional method decrements the value of each time-waiting queue on the multitask OS by one each time an interrupt is generated by the system clock, and checks whether a time-out has occurred. If there is processing overhead and the system clock interrupts frequently, the overhead of interrupt processing significantly reduces the system performance, and the number of interrupts per unit time cannot be increased, resulting in good resolution. There was a drawback that the timer for timeout could not be configured.

It is an object of the present invention to provide a protocol processing device in which the overhead of timeout operation in protocol processing is small.

[0008]

A protocol processing device according to the present invention includes a line interface for receiving data on a communication line and sending data on the communication line, a plurality of buffers for holding protocol data, and a clock. A generation unit, a timer unit provided for each buffer and performing a down-count operation from a set timeout value each time a clock signal comes from the clock generation unit, and a protocol processing module is assigned to the plurality of buffers. A timer corresponding to the transmission buffer when a timeout value is set in the corresponding timer unit, the data stored in the transmission buffer is read, and the protocol processing is performed to start the operation of transmitting from the line interface to the line. When the time-out signal comes after starting the unit, the time-out signal was output. Examine the buffer corresponding to the timer unit,
If data remains in the buffer, the transmission timeout processing routine is started, and when the line interface receives the data on the line, performs protocol processing, and stores it in the reception buffer When the timer unit corresponding to the buffer is started and then the time-out signal comes, the buffer corresponding to the timer unit that has output the time-out signal is checked, and if no data is stored in the buffer, the reception time-out processing routine is started. And a protocol processing unit.

[0009]

According to the present invention, at the time of line reception, after the buffer for reception is assigned to the protocol processing module, the maximum time until the data is received is set in each timer section in the buffer. When the maximum time set in the timer section has elapsed, the value of the timer section in the buffer becomes 0,
A timeout signal is output from the buffer to the protocol processing unit. The protocol processing unit checks the inside of the buffer to which the time-out signal is output, and if the received data is not complete, activates the reception time-out processing routine.

At the time of transmission, after allocating a buffer for transmission to the protocol processing module, data is set in the buffer and the maximum time until the data is transmitted is set in each timer section in the buffer. . When the maximum time set in the timer unit has elapsed, the value of the timer unit in the buffer becomes 0, and the timeout signal is output from the buffer to the protocol processing unit. The protocol processing unit looks into the buffer where the time-out signal was output, and if data remains, it tries to send data from the line interface, but some error occurs on the line and the data is sent within a certain time. The transmission timeout processing routine is started as if it could not be done.

As described above, according to the present invention, since the timeout process is individually performed for each buffer, the overhead of the timeout process is extremely reduced.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram of a protocol processing device according to an embodiment of the present invention.

The protocol processing device of this embodiment uses the line I
Performs transmission / reception protocol processing with the line interface 1 having F
Run the protocol processing unit 2 and the application
An application processing unit 3, a clock generation unit 4,
Buffer that stores protocol headers and contents
5₁ , 5₂ ,,, 5₇ And buffer 5 respectively₁ , 5
₂ ,,, 5₇ Corresponding to the clock from the clock generator 4.
Each time a signal arrives, the timeout value set is
Timer unit 6 for counting down₁ , 6₂ , ..., 6
₇ And timer unit 6₁ , 6₂ , ..., 6₇ Is time
Timeout signal 8 when it is detected that₁ , 8
₂ , ..., 8₇ 0 detection unit for outputting the information to the protocol processing unit 2
7₁ , 7₂ , ..., 7₇ It is composed of.

When receiving a line, the protocol data on the line is received by the interface of the line interface 1 and the data is passed to the protocol processor 2. The protocol processing unit 2, while ensuring the area for reception buffer 5 _{1-5 7,} recommended protocol processing, the processing is completed, and passes the data to the application processing section 3. At the time of transmission, the data from the application processing unit 3 is transferred to the protocol processing unit 2
Are received by the buffer 5 ₁ as a buffer for transmission.
Protocol processing is performed while using the 5 ₇ areas.
Finally, the data is sent to the line via the line interface 1.

The buffer 5₁ ~ 5₇ Is normal RAM
Composed of. Timer unit 6₁ ~ 6₇Is a commonly used da
It can be configured with an uncounted timer component. O detection
Part 7 ₁ ~ 7₇ Is a circuit that detects the comparator and carry output
Easy to configure.

FIG. 2 is a flow chart of the timeout process performed by the protocol processing unit 2.

First, the protocol processing modules are assigned to the buffers 5 _{1 to} 5 ₇ (step 10). Next, a timeout value is set in the timer section (step 11). Next, the timer unit is activated (step 12). Next, it is checked whether a time-out signal is output (step 1
3). When the time-out signal is output, the buffer corresponding to the 0 detection unit that has output the time-out signal is checked (step 15). If the buffer is a transmission buffer, it is checked whether data remains in the buffer (steps 16 and 17). If data remains, it is determined that some abnormality has occurred, and the transmission timeout processing routine of the buffer is started (step 18).
As a result, re-transmission and error reporting to upper layers are performed. If the buffer is a receiving buffer, it is checked whether or not there is data in the buffer (step 1
6 and 19), if there is no data, it is considered that some abnormality has occurred, and the reception timeout processing routine of the buffer is started (step 20). As a result, a retransmission request to the other party and an error report to the upper layer are made.

FIG. 3 is a diagram showing an example of temporal changes in the contents of the buffers 5 _{1 to} 5 ₇ .

In the state of time 0, the buffers 5 ₁ and 5 ₂ are secured as transmission buffers, 100 bytes of transmission data are stored in each, and the timeout value is 5 bytes.
0 (ms) is set in the timer units 6 ₁ and 6 ₂ . At the same time, the buffers 5 ₃ and 5 ₄ are secured as receiving buffers, are in a reception waiting state, and a timeout value of 150 (ms) is set in the timer units 6 ₃ and 6 ₄ .

At time 50 (ms), the buffer 5 ₁
Since the timer portion ₆₁ and the timer section 6 _second buffer 5 ₂ is 0, that it is detected by the zero detection unit 7 ₁ and 7 _2, the timeout signal 8 ₁ and 8 ₂ protocol processing unit 2
Is output to. The protocol processing unit 2 has buffers 5 ₁ and 5 _2.
Find out. In this case, the data in buffer 5 ₂ has already been successfully transmitted, and buffer 5 ₂ is in the released state,
The transmission data remains in the buffer 5 ₁ due to some abnormality. Therefore, the protocol processing unit 2 activates the transmission timeout processing routine of the buffer 5 _1, processing such as error reporting to retransmit or higher is performed.

Next, when the time becomes 0.99 (ms), since the timer section 6 ₃ and 6 ₄ of the buffer 5 ₃ and 5 ₄ are set to 0, this fact is detected by the zero detection unit 7 ₃ and 7 ₄ , Timeout signals 8 ₃ and 8 ₄ are output to the protocol processing unit 2. Protocol processor 2 examines buffers 5 ₃ and 5 ₄ .
In this case, the buffer 5 ₄ has already received the data and has been successfully received, but the buffer 5 ₃ is in the waiting state for the received data due to some abnormality. Therefore, the protocol processing unit 2 activates the receive timeout processing routine of the buffer _3, processing such as error reporting to retransmission requests or the upper layer to the other side is performed.

As described above, since the timeout process performed in the protocol process is individually performed for each buffer in both transmission and reception, the overhead of the timeout process can be extremely reduced.

[0024]

As described above, according to the present invention, a timer unit is provided for each buffer, a time-out value is set in the timer unit, the timer unit decrements the time, and when the time-out time comes, the time-out signal is output. Is transmitted to the protocol processing unit and the protocol processing unit performs the time-out process, which has the effect of reducing the overhead of the time-out process.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a protocol processing device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a process of a protocol processing unit 2.

FIG. 3 is a diagram showing an example of temporal changes of data in buffers 5 _{1 to} 5 ₇ .

[Explanation of symbols]

1 line interface 2 protocol processor 3 application processor 4 clock generator 5 _{1 to} 5 ₇ buffer 6 _{1 to} 6 ₇ timer 7 _{1 to} 7 ₇ O detector 8 ₁ to 8 ₇ timeout signal 10 to 20 steps

Claims (1)

[Claims] 1. A line interface for receiving data on a communication line and transmitting data on the communication line, a plurality of buffers for holding protocol data, a clock generator, and a buffer for each buffer. A timer unit that performs a down-count operation from a time-out value that is set every time a clock signal comes from a clock generation unit, and a protocol processing module is assigned to the plurality of buffers, and a time-out value is set in the timer unit corresponding to these buffers. When the data stored in the transmission buffer is read and the protocol processing is performed to start the operation of transmitting from the line corresponding unit to the line, the timer unit corresponding to the transmission buffer is started, and then the timeout signal comes. And check the buffer corresponding to the timer unit that output the timeout signal, If data remains in the buffer, the transmission timeout processing routine is started, and when the data on the line is received by the line interface, protocol processing is performed and the operation for storing in the reception buffer is started. When the timer unit corresponding to the buffer is started and then the time-out signal comes, the buffer corresponding to the timer unit that has output the time-out signal is checked, and if no data is stored in the buffer, the reception time-out processing routine is started. A protocol processing device having a protocol processing unit.