JPS6226948A - Method and equipment for transmitting and receiving retransmission data - Google Patents

Abstract

PURPOSE:To reduce the time from error detection to the arrival of a retransmission data to the reception side by sending a retransmission data after buffer memories of the transmission side and the reception side are cleared when an error is detected in the reception data. CONSTITUTION:When an error detection circuit ED detects an error in the reception data, a read inhibition signal (INH) is given to a reception side control circuit RC, the circuit RC turns off the 4th switch SW4 to inhibit data read from reception side buffer memories BM4-BM6 to a data reception section DR. When the circuit RC receives the read inhibition signal (INH) from the error detection circuit ED, the content of the reception side buffer memories BM4-BM6 is cleared. When a transmission side control circuit SC receives an initializing instruction signal (INC 2), after all transmission side buffer memories BM1-BM3 are cleared immediately, the 1st switch SW1 is controlled so as to write the retransmission data from the initializing circuit INI to, e.g., the transmission side buffer memory BM1. A transmission side control circuit SC controls the 2nd switch SW2 to write the retransmission data in the memory BM1, then the data is sent immediately and sent to a transmission line L.

Description

[Detailed Description of the Invention] [Summary] In the U-Overnight Transmission/Reception System 1, when an error in received data is detected on the receiving side, reading of the receiving side buffer memory is prohibited and the contents of the receiving side buffer memory are Clear the transmitting side buffer memory and write the retransmitted data, and after storing the 11 data in the receiving side buffer memo, cancel the prohibition of 11 and send the reproduced data to the receiving side. The retransmission data transmission and reception system is designed to reduce the arrival time of data.

[Industrial application field]

The present invention provides a retransmission data transmission/reception method and apparatus in a data transmission/reception system (t, two coefficients ν), special a. This article relates to a complete memory control system designed to save time.

[Prior art] Generally, high-speed data such as image data is transmitted and received at a predetermined rate.
It is done in the do position, e.g. C, tono l/-1, and the honor rank. For this purpose, buffer memories for storing predetermined data 17 are provided on the transmitting side and the receiving side. Data is usually sent from the transmitting side to the receiving side by encoding differential data such as +;I: D 11 CM. Uke (18
The side receives the difference data at the specified 111th position and combines it with the already received data.1. 1-J to convert the difference data back to the original data.

In addition, the receiving side receives more data (11
Since the data is differential data 11', if there is even a single bit error in the transmission path in the received data, the difference will be added to the error in subsequent repeat data, and the error in the reproduced data will gradually propagate.

If an error is detected in the received data, the receiving fM section sends a data retransmission instruction to the transmitting section, and the transmitting section receives this and does not use the previous screen. , - data is retransmitted via the sending buffer memory.

In the conventional data transmission/reception system, when correct data is written into the transmitting side buffer memory at t7 in response to a data retransmission instruction, the data is received in the same way as normal transmission data.

In other words, while writing transmission data to the transmission side buffer memory or reading transmission data from the transmission side buffer memory, the retransmission data write date is set.
After the writing or reading of the transmitted data is completed, the retransmitted data is written to the transmitting side buffer memory. Then, on the receiving side, reading of the data received from the sending of the data retransmission instruction until the retransmission instruction data included in the retransmission data is detected is prohibited, and after the retransmission instruction data is detected, the data is received again, decoded, and reproduced. Was.

[Problems to be solved by the invention]

As mentioned above, conventionally, the writing of retransmission data on the sending side was performed after receiving a 1Til transmission instruction from the receiving side, and then writing or reading the normal sending data that was being written or read. Since the retransmission is carried out after the completion of the retransmission, there is a problem that the time required from issuing the retransmission instruction until the retransmission data reaches the receiving side is not long. especially,
A transmitting buffer memory each storing one frame's worth of data? In a multi-buffer memory configuration in which M number of buffer memories are arranged in parallel to eliminate waiting time in reading transmission data, multiple frames 1,
If the transmission data is sent out, the problem described in (1)-- becomes even more serious.

[Means for solving problems]

In order to solve the above two problems, the present invention provides a data transmission/reception system in which, when an error is detected in received data on the receiving side, reading of the receiving side buffer memory is prohibited, and the buffer memory on the sending side and the receiving side is 111 on the receiving side, and after storing the transmitted data in the receiving side buffer memory, the retransmitted data is prevented from being read from the receiving side buffer memory by canceling the read prohibition 11. A retransmission data transmission/reception method is provided.

[Function] In response to the detection of an error in the received data, the transmitting side and the receiving side
By clearing the side sofa memory, retransmission data can be written immediately, so data can be retransmitted in a short time.

〔Example] Hereinafter, the present invention will be described in detail based on the accompanying drawings.

In one embodiment of the present invention shown in the figure, a data transmitting/receiving system J consists of a transmitting side S and a receiving side R. The sending side S includes a data generating unit r)G, a first switch in total, and three sending side memories BM], BM2 and 8.
M3, a second SW2, and a transmitting side control circuit SC. Receiver R has switch SW3 and -3 receiver buffers Memo 1+MiBM5
and 8M6, a fourth switch heel 4, a data receiving side DR, and a receiving side control [01 path RC. The second switch SW2 on the sending side S and the third switch pot 3 on the receiving side R are connected through a transmission path I7. The data receiving section DR includes an error detection circuit ED, and the data generating section 11G includes an initialization circuit INI.

When the error detection circuit ED does not detect an error in the received data, the data generation section DG detects the error in the data reception section r'J.
The difference data from the screen data previously reproduced in R is written to any one of the transmitting side buffer memories BMI, BM2, and 8M3 via the first switch SKI. The transmission side control circuit SC controls the timing of writing or reading in the sending (third side IMI, RM2, and FIM3), and also controls the timing of writing or reading in the first and second
Controls the SWI and trace 2 of the transmitting side buffer memory 11M1. R) While writing the transmission data to any one of IIM3 and IIM3, the transmission data that has already been written is not read from one of the remaining transmission buffer memories to the transmission line L. ing.

On the receiving side, under the control of the receiving side control circuit RC, the transmission line I
5 is transmitted through the third switch SW3 to the receiving side buffer memories BM4 and 8M5.

Write to either 8M6 and 8M4.8M5, B
Data receiving unit D sequentially from i12 via switch SW4
Not read to R. The data receiving unit DR decodes the received data.
to play the screen data.

The operation when the error detection circuit ED detects an error in received data will be described next.

When the error detection circuit ED detects an error in the received data, it sends a read prohibition lL: signal (INI) to the reception side control circuit RC.
+), thereby causing the receiving side control circuit RC to
Turn off the switch SW4 of the receiving side buffer memory B.
M4. Prohibits reading of data from BM5 and 8M6 to data receiving section I)R. The error detection circuit I/D also sends a data retransmission request signal (DI?EQ) to the initialization circuit INI in the data generator DC in response to error detection. When the receiving side control circuit RC also receives a read inhibit signal (!Nl+) from the error detection circuit 1MID, it clears the contents of the receiving side buffer memo I (M4, 1E5, and 8M6).

When the initialization circuit IN+ receives the data retransmission request signal (111?EO) from the error detection circuits F and I,
While creating retransmission data, an initialization instruction signal (INIC2) is given to the transmitting side control circuit SO. The retransmission data is correct data for one frame, not difference data from data that has already been transmitted, and includes one retransmission instruction bit that does not indicate that it is retransmission data.

The transmission side control circuit SC receives the initialization instruction signal (INIC).
2) When receiving the data, the sending side buffer memory BMI, BM
After immediately clearing all of 2 and 8M3, the first switch SWI is controlled to write retransmission data from the initialization circuit INI to, for example, the sending buffer memory BMI. The transmission side control circuit SC also controls the second switch 2 to immediately read out the retransmission data from the BMI after writing it to the BMI, and send it to the transmission line (1).

On the receiving side R, a retransmission instruction detector Ii! When 8D detects the retransmission instruction bit in the retransmission data, it gives a retransmission instruction detection signal (I) to the receiving side control circuit RC, and thereby the receiving side control circuit RC controls the third switch SW3 to open the transmission line
The retransmitted data from BM4 is immediately written to, for example, the receiving side buffer memory BM4. The receiving side control circuit RC is FIM4
After writing the retransmission data to the retransmission data, it notifies the data receiving unit r)R of the completion of retransmission data preparation by a signal (INIC1),
The fourth switch SW4 is controlled to release the read prohibition 1, and the retransmitted data from 8M4 is not read to the data receiving section r)R.

According to the second embodiment, as soon as the receiving unit detects an error in the received data, both the transmitting side buffer memory and the receiving side buffer memory are cleared, so that the operation of the buffer memory during reading or writing is easily controlled. Retransmission data can be written and read immediately without the need to wait for completion.

Note that the present invention is not limited to the above-described embodiments; for example, the number of buffer memories can be determined by both the transmitting side and the receiving side.
The number of a is sufficient.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in a data transmission/reception system, when an error is detected in received data, retransmission data is sent after clearing the buffer memories of the transmitting side and the receiving side. As a result, the time from error detection to the time when retransmitted data reaches the receiving side is shortened, and in particular, the time during which a screen containing an error is displayed during image data transmission can be shortened.

[Brief explanation of drawings]

The drawings in Appendices I-J are block diagrams for explaining a retransmission data transmission/reception system according to an embodiment of the present invention. S...Sending side, I≧...Receiving side, DG・
...Data starting part 17, IN+...Initialization circuit,
RMI-8M3...Sending side buffer memory, SC...
・Transmission side control circuit, r)R...data reception section, ED・
...Error detection circuit, BM4 to l'1M6...Reception side buffer memory, RC
...Reception side buffer memory, D...Retransmission instruction detection circuit.

Claims (1)

[Claims] 1. In a data transmission/reception system, when an error is detected in the received data on the receiving side, reading of the receiving side buffer memory is prohibited, and the buffer memories on the sending side and the receiving side are cleared and the data is stored in the sending side buffer memory. The retransmission data is characterized in that the retransmission data is read from the reception side buffer memory by writing the retransmission data into the reception side buffer memory at the reception side, and after storing the retransmission data in the reception side buffer memory, canceling the read prohibition. How to send and receive. 2. The transmitting side is equipped with a data generating means, a transmitting side memory for storing transmission data from the data generating means, and a transmitting side control means for controlling writing/reading of data to and from the transmitting side memory, and the receiving side , a receiving side memory for storing data from the sending side memory, a data receiving means for receiving data from the receiving side memory, and a receiving side control means for controlling writing/reading of data to/from the receiving side memory. In the data transmitting/receiving system, the data receiving means includes an error detecting means, and when the error detecting means detects an error in the received data, the receiving side memory receives the data under the control of the receiving side control means. The data generation means is provided with an initialization means, and the data generation means is provided with an initialization means, and the data generation means is provided with an initialization means, and the data generation means is provided with an initialization means, and a data retransmission request signal is sent to the data generation means. The means creates retransmission data including retransmission instruction detection data in response to the data retransmission request signal, and clears the transmitting side memory under the control of the transmitting side control means in response to the data retransmission request signal. After that, the retransmission data is written into the transmitting side memory, and the receiving side is equipped with retransmission instruction detection means for detecting the retransmission instruction detection data from the retransmission data sent from the transmitting side memory. The retransmission instruction detection means writes the retransmission data into the reception side memory and then writes the retransmission data from the reception side memory under the control of the reception side control means in response to the detection of the retransmission instruction detection data. What is claimed is: 1. A retransmission data transmitting/receiving device, characterized in that the retransmission data transmitting/receiving device is capable of canceling a read prohibition of data.