JPH05103037A - Data transfer system - Google Patents

Abstract

PURPOSE:To improve the real data transfer speed in serial data transfer sent/ received in the unit of frames. CONSTITUTION:A host device 1 and a subordinate device 2 are connected with a couple of series interfaces 3, 4 formed with an optical cable. The host device 1 and subordinate device are respectively provided with frame header part replacement means 15 (17) which omits a frame header part of 2nd and succeeding frames at the transmission and sets transfer data instead to extend a data length of the data part when transfer data sent/received by two consecutive frames or over continue, and with consecutive frame discrimination means 16 (18) which discriminates it to be a same kind of consecutive frame sending/ receiving consecutive transfer data when transfer data are received as first effective data after final data in one frame discriminated from a maximum frame length of one frame at the reception.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer system, and more particularly to a data transfer system having a pair of serial interfaces composed of optical cables.

[0002]

2. Description of the Related Art In a conventional data transfer system between a pair of devices using a pair of serial interfaces consisting of optical cables, a frame header section, a data section (consisting of control information and transfer data in a narrow sense), a check code Control information and transfer data are serially transmitted / received in units of frames including parts.

Here, the frame header portion is an identification code indicating the type of frame, and the check code portion is, for example, CRC (C) for verifying the validity of data.
cyclic Redundancy check co
This is data for checking such as de).

In addition, the maximum frame length of the frame is limited, and when transmitting / receiving continuous transfer data exceeding the maximum data amount that can be transferred in one frame,
Data is transmitted and received by being divided into a plurality of frames.

FIG. 4 is a diagram for explaining this conventional serial data transfer. FIG. 4A shows a NOP (No operation) between frames even when transmitting and receiving continuous transfer data when the actual transfer rate is low. Data is inserted, and (b) shows that when the actual transfer rate is high, frames are continuously transmitted and received without inserting NOP data between frames.

[0006]

In the above-mentioned conventional serial data transfer system, when the actual data transfer rate is high, the data is continuously transmitted and received. There is a waste of retransmitting the frame header part, which is the same identification code as the second and subsequent frames, and there is a problem that the actual data transfer rate of the serial interface composed of the optical cable cannot be fully utilized.

An object of the present invention is to provide a data transfer system capable of increasing the actual data transfer rate in serial data transfer transmitted / received in frame units.

[0008]

According to the data transfer system of the present invention, a frame header section, a data section, and a check section are provided between opposite devices using a pair of serial interfaces.
In a data transfer system in which control information and transfer data are serially transmitted / received in units of frames including a code part, transfer data transmitted / received in consecutive two or more frames is continuous in a data transfer system in which the maximum frame length of one frame is limited. In this case, during transmission, the frame header part of the second and subsequent frames is omitted and the transfer data is mounted instead to extend the data length of the data part.
When the transfer data is received as the first valid data after the last data of one frame which is determined from the maximum frame length of one frame at the time of reception, the header portion replacement means and the continuous transfer data are transferred. And a continuous frame determining means for determining that the frames are the same type of continuous frames to be transmitted and received.

Further, the data transfer system of the present invention omits the check code part except for the last frame when the transfer data transmitted and received in two or more continuous frames are continuous, and instead, It is characterized in that it comprises check code part replacement means for mounting transfer data to further extend the data length of the data part, and mounting a check code only in the final frame during continuous transmission / reception of transfer data.

[0010]

In the serial data transfer in which the maximum frame length of one frame is limited, when the transfer data transmitted / received in two or more continuous frames are continuous, the frame header part of the second and subsequent frames Is omitted and the transfer data is mounted instead to improve the mounting efficiency of the transfer data.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a data transfer system of the present invention, FIGS. 2 (a), 2 (b) and 3
(A) And (b) is a figure for demonstrating serial data transfer which concerns on a present Example, respectively.

In the data transfer system of the present embodiment, the upper device 1 and the lower device 2 are maintained by a pair of serial interfaces 3 and 4 which are optical cables.

Data transmission / reception on the interface is serially performed in frame units including a frame header section, a data section, a check code section and the like. Controlling the frame transfer on these serial interfaces 3 and 4 is
Frame conversion control units 5 and 10, parallel / serial conversion units (described as P / S conversion units in the figure) 6 and 14,
Serial / parallel converter (described as S / P converter in the figure) 8 and 12 and electric / optical converter (E in the figure)
/ O conversion unit) 7 and 13, and an optical / electrical conversion unit (described as O / E conversion unit in the figure) 9 and 11.

When the transfer data transmitted / received in two or more continuous frames are continuous, the upper device 1 and the lower device 2 respectively transmit the frame header of the second and subsequent frames at the time of transmission. It is provided with frame / header replacing means 15 and 17 for omitting a part and mounting the transfer data instead to expand the data length of the data part, and at the time of reception, it is judged from the maximum frame length of one frame. When the transfer data is received as the first valid data instead of the frame header portion or NOP data after the final data of one frame, it is determined that the continuous frames are the same type of continuous transmission / reception data. The continuous frame determination means 16 and 18 are provided.

In the present embodiment, as shown in FIGS. 2 (a) and 2 (b), in the case of continuous transfer data, unlike the above-described conventional serial data transfer, the frames of the second and subsequent frames are transferred. The header part is omitted, and the transfer data is mounted instead and the transfer is performed. Here, also in this embodiment, 1
The maximum frame length of the frame is the same as the conventional serial data transfer described above.

Further, during the above-mentioned continuous frame transfer, the check code part is omitted except for the last frame,
Instead, by providing the check code portion replacing means 19 and 20 for mounting the transfer data to extend the data length of the data portion, as shown in FIGS. 3A and 3B, only the last frame is checked.・ Achieve a transfer with a code. Here, the check code is not only the check code for the final frame but for all the consecutive frames of the transfer process. Also in this case, 1
The maximum frame length of the frame is the same as described above.

[0018]

As described above, according to the present invention, in serial data transfer in which the maximum frame length of one frame is limited, the actual data transfer rate can be increased by increasing the loading efficiency of the transfer data. There is.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a data transfer system of the present invention.

2A and 2B are diagrams for explaining serial data transfer according to the present embodiment.

3A and 3B are diagrams for explaining serial data transfer according to the present embodiment.

4A and 4B are diagrams for explaining conventional serial data transfer, respectively.

[Explanation of symbols]

 1 Upper device 2 Lower device 3,4 Serial interface 5,10 Frame conversion control unit 6,14 P / S conversion unit 7,13 E / O conversion unit 8,12 S / P conversion unit 9,11 O / E conversion unit 15, 17 Frame / header part replacement means 16, 18 Continuous frame determination means 19, 20 Check code part replacement means

Claims (3)

[Claims] 1. A maximum of one frame in which control information and transfer data are serially transmitted / received in frame units consisting of a frame header section, a data section and a check code section by using a pair of serial interfaces between opposing devices. In a data transfer system with a limited frame length, when the transfer data transmitted / received in two or more consecutive frames is continuous, the frame header part of the second and subsequent frames is omitted during transmission. Instead, frame / header replacement means for mounting transfer data to extend the data length of the data part, and at the time of reception, after the last data of one frame determined from the maximum frame length of one frame. , When the transfer data is received as the first valid data, the continuous frame of the same type that transmits / receives continuous transfer data is received. Data transfer system is characterized in that a continuous frame determination means for determining that the beam. 2. When the transfer data transmitted / received in two or more continuous frames are continuous, the check code part is omitted except for the last frame, and the transfer data is mounted instead to check the data part. 2. The data transfer system according to claim 1, further comprising a check code part replacement means for further expanding the data length of the check code part, and mounting the check code only in the last frame when transmitting / receiving the transfer data continuously. 3. The data transfer system according to claim 1, wherein the pair of serial interfaces used between the opposed devices are optical cables.