JPS6257345A - Frame check sequence system - Google Patents

Abstract

PURPOSE:To reduce the relay time by applying frame check sequence in the stage of the reception of an FCSO after a header in data relaying so as to complete the next sending preparation during the reception of the succeeding data. CONSTITUTION:Two FCS (FCSO and FCSI) are used. The FCSO applies the frame check sequence to the heater H and the FCSI applies the frame check sequence to all frames. Thus, at the relay station side, the frame check sequence is applied immediately when the FCSO is received to confirm the destination and sender. When the FCSO is received and the frame check sequence is finished (when a transmission D is received), the preparation of transmission to the next reception station is applied and when the reception of the data D and the frame check sequence by the FCSI are finished, the data is sent immediately.

Description

[Detailed Description of the Invention] [Summary] When performing data transmission, the communication control device has a function that is located between the character assembly/disassembly unit and the channel unit and performs a frame check on the first character string of a fixed length, and reports the result to the channel unit. An additional device for frame check sequence is added.

[Industrial application field]

The present invention relates to data transmission.

The conventional frame check sequence method has the disadvantage that it takes a long time to transmit data when relaying data, and there has been a strong demand for an improvement.

[Conventional technology]

FIG. 4 shows an example of a conventional transmission frame.

In the figure, F is a flag, H is a header, D is data, and Fe2 is a frame check sequence.

Flag F is a specific bit string representing the beginning or end of a transmission frame, and is composed of, for example, 8 bits. The header H stores the destination, source, etc., and usually has a fixed focus length. The frame check sequence FC'S is a series of bit strings used by the receiving station to detect transmission errors.
It has a 6-bit configuration. Data D is a telegram.

In the conventional frame check sequence method for data transmission, as shown in FIG. 4, all data strings sandwiched between fixed patterns are checked, that is, one transmission frame is checked.

[Problem that the invention seeks to solve]

Therefore, it is good to communicate between two points using a signal made up of the above transmission frame and check its normality, but when this signal is further relayed and sent to the next station, −
Unless the transmission frame is received and its check completed, it is not possible to proceed to the next transmission operation. Therefore, there is a drawback that the relay takes time.

An object of the present invention is to shorten this relay time and provide a frame check sequence system of the same level.

The configuration of a communication control device that uses frames with Fe2O added and adopts a frame check sequence method is as follows: character assembly/disassembly units 50 to 5N for each line, character assembly/disassembly units 50 to 5N, and character assembly/disassembly units 50 to 5N for each line.
5. A channel section 3 that controls the transfer of the received characters assembled in step 5 and the disassembled and transmitted characters between the memory 2 and the character assembly/disassembly sections 50 to 5N and the channel section 3.
A frame that is located between the frames and has a function of performing a frame check on the fixed-length first character string and reporting it to the channel unit 3, and a function of adding frame check data to the fixed-length first character string of the transmission data from the channel unit 3. This problem can be solved by providing the additional device 4 for check sequence.

[Effect]

According to the present invention, when relaying data, a frame check sequence is performed at the stage when Fe2O located after the header () is received, and preparation for the next shipment is completed while the following data is being received, so the relay time can be shortened. This effect is produced.

〔Example〕

FIG. 1 is a diagram showing an embodiment of a transmission frame according to the present invention.

In the conventional transmission frame, only one Fe2 was used, but in the present invention, two Fe2 (Fe2O and FC3L) are used.
use.

F and C5O perform a frame check sequence for header H, and FC3I performs a frame check sequence for all frames as in the conventional system.

Therefore, on the relay station side, upon receiving Fe2O, it can immediately perform a frame check sequence and confirm the destination and source. Therefore, when Fe2O is received and the frame check sequence is finished - when the transmission is being received - preparations for sending to the next receiving station are made, data D is received, and as soon as the frame check sequence by Fe21 is finished, sending is possible. , shorten relay time, -.

FIG. 2 shows the equipment configuration of a communication control device according to the present invention.

FIG. 3 shows an example of the configuration of Fe2-ADP according to the present invention.

In the figure, 1 is the processor (CPU), 2 is the memory (ME
M), 3 is a direct memory access control unit/data channel (DMAC/DCH), 4 is an additional device for frame check sequence (Fe2-ADP), 56-
5N is a character assembly/disassembly unit (UR
T), 4. is the arithmetic unit (ALU), 4□ is the line memory (LM), 43 is the channel control unit, and 44 is the pair U
This is an RT control section.

As shown in FIG. 2, the communication control device according to the present invention has a character assembly/disassembly section for each line. That is, a character assembly/disassembly section URT50 for line #0, a character assembly/disassembly section URT5N for line #N, etc. are provided.

Fe2-ADP4 is provided between DMAC/DCH3 and URT50 to URT5N. Fe2-ADP4 according to the present invention resets the built-in byte counter and starts counting at the same time as data transmission starts, and when a certain number of bytes is reached, Fe2 0 is added and transferred to the URT 511 of the designated line #N.

When Fe2-ADP4 finishes sending data D shown in FIG. 1, it instructs URT5N to finish sending data D.

Upon receiving this instruction, U RT 5 N adds FCSI and sends it to line #N.

Fe2-ADP4 resets its built-in byte counter and starts counting at the same time as it starts receiving data from URT5N of line #N, and when it reaches a certain number of bytes (Fe12 minutes)
, performs a frame check sequence using Fe2O,
Check the normality of header H. DMA if there is any abnormality
Notify this to C/DCH3.

Upon receiving further data, the URT5N notifies the Fe2-ADP4 of the check result for the entire frame. Fe
2-ADP4 notifies this notification to DMAC/DCH3, and DMAC/DCH3 further notifies processor 1.

The equipment configuration of Fe2-ADP4 according to the present invention is as shown in FIG.
4 The line memory serves as working memory for I, and has a memory area allocated to each line.
The ALU 41 is capable of time-division operation.

The channel control unit 43 serves as an interface for the DMAC/DCH3, and controls the URT? The t+ control section 44 operates as an ink face for the URT.

In the example of Fig. 2, Fe2O in Fe2-ADP4
However, Fe2-ADP4 is
It is also possible to merge functions into MAC/DCH3 and generate them in DMAC/DCH3.

〔Effect of the invention〕

As described above in detail, the present invention has the great effect of shortening the data relay time.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of a transmission frame according to the present invention. FIG. 2 shows the equipment configuration of a communication control device according to the present invention. FIG. 3 shows an example of the configuration of Fe2-ADP according to the present invention. FIG. 4 shows an example of a conventional transmission frame. In the figure, F is a flag, H is a header, D is data, Fe2.
Fe2O2 and FCSI are frame check sequences respectively, 1 is processor, 2 is memory, 3 is DMAC/D
CH,4 is Fe2-ADP. 50 to 5N are character assembling/disassembling units (URT), 4 is an arithmetic unit, 4□ is a line memory, 43 is a channel control unit, and 44 is a URT control unit. i♀Toso ears (two and four Buddhas? 茫-)shi-Otsu-no-￥::Xn
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＼Spring 2 Hosukero Kuni 14ru fcs-ADP/) - Lecture Example Kaya , 3 Figures are the seventh of the ice, Otsu, Me -! l Matter 4 Figure

Claims (1)

[Claims] In a communication control device that adopts a frame check sequence method, a character assembly/disassembly unit (5_0 to 5_N) for each line, and a character assembly/disassembly unit (5_0 to 5_N) that a channel unit (3) for controlling the transfer of received characters and characters to be disassembled and transmitted between the memory (2);
A function located between the decomposition unit (5_0 to 5_N) and the channel unit (3) to check the frame of the first character string of a fixed length and report it to the channel unit (3), and transmission from the channel unit (3). A frame check sequence method characterized by comprising a frame check sequence adding device (4) having a function of adding frame check data to a first character string of a fixed length of data.