JPH08228203A - Data transfer system - Google Patents

Abstract

PURPOSE: To improve an effective data transfer speed by executing data transfer processing between a data processing unit and a data input/output device in the data transfer system between the data processing unit and the data input/ output device. CONSTITUTION: A data input/output device 2 receives data from plural connected destinations through plural virtual channels on a physical channel, stores the data for each connected destination and transfers the data to a data processing unit 1 in the unit of frames. In this case, the data processing unit 1 informs a reception buffer area to the data input/output device 2 in advance. When the data input/output device 2 receives data frames, the data input/output device 2 transfers data to an area in the reception buffer area to be informed after an area of the reception data transferred precedingly to the data processing unit 1 and informs the reception of data frames at the end of the transfer.

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 between a data processing device and a data input / output device.

A data processing device performs a required data processing by performing an interrupt and a command issuance in accordance with a predetermined data transfer procedure and mutually transferring data with a data input / output device.

In the data transfer method in this case, it is necessary that the program processing time related to the interruption and the command issuance is short and the data transfer between the data processing device and the data input / output device can be performed efficiently. .

[0004]

2. Description of the Related Art FIG. 8 shows a configuration of a data processing device and a data input / output device, where 1 is a data processing device, 2 is a data input / output device, and 3 is a data processing device 1 and a data input device. It is a bus connecting to the output device 2. In the data processing device 1, PU is a processor that controls data processing, MM is a main memory that stores programs and data, and these are connected to each other via an internal bus of the data processing device. In the data input / output device 2, IOC is an input / output controller that controls the input / output of data to / from the data processing device 1, LM is a local memory that stores data during data input / output, and TRX is a line (transmission line). A transmission / reception unit that transmits / receives data to / from the outside via the, and these are mutually connected via an internal bus of the data input / output device.

The data input / output device 2 has a plurality of logical connections (channels) on one physical line. The data handled by the data processing device 1 consists of frames,
On the line, the frame is divided into a plurality of frames, and a tag indicating the connection destination (channel number) is added to each frame.
When receiving the data, the data input / output device 2 accumulates the data for each connection destination indicated by the tag, and when one frame is reconstructed, after notifying the data processing device of the reception of the data, Transfers data.

FIG. 9 shows a conventional data transfer procedure between a data processing device and a data input / output device. The data transfer procedure is performed by the following steps as shown in the figure. (1) The data input / output device receives data from the line,
When the reception of one frame is completed, the data processing device is notified of the reception of the frame by designating the channel number and the number of received bytes. Reception notification is generally given by interruption.

(2) In the data processing device, an interrupt process is performed to secure a reception buffer area, a channel number and a buffer address are designated to the data input / output device, and reception is instructed to transfer a frame. A data transfer command is issued by an interrupt.

(3) The data input / output device performs interrupt processing, prepares for DMA (Direct Memory Access), and transfers data from the memory in the data input / output device to the memory in the data processing device. Data transfer is generally performed by DMA processing.

(4) The data input / output device interrupts the data processing device by designating a channel number by interrupting the data processing device.

[0010]

In such data transfer processing, when the processing time until the reception data transfer command is issued in response to the reception notification and the processing time related to the interrupt are long, it is effective. Data transfer speed decreases. In particular, when a small frame is transmitted on a high speed line, the degree of deterioration of data transfer performance becomes large.

For example, ATM (Asynchronous Transfer)
Mode) In a 156 Mbps line in a transmission system, the average reception interval of 1024-byte frames is 5
It is 2.5 μsec, and if the data transfer process between the data processing device and the data input / output device is not completed within this time, the received data disappears or it is necessary to reduce the effective transfer rate. is there.

On the other hand, JP-A-61-250758
In the publication, after receiving data is once stored in a receiving buffer, the receiving data in the receiving buffer is collectively transferred to the main memory of the system by DMA in accordance with a receiving command of the processor of the system to interrupt the processor. It is described that the number of times is reduced and the communication speed is improved. This method is premised on the fact that there is one communication destination and the received data can be sequentially combined or decomposed, and when there are a plurality of communication destinations on one physical line as in the present invention. It cannot be applied to data transfer methods.

The present invention is intended to solve such a problem of the prior art, and in the data transfer processing between the data processing device and the data input / output device, a program processing time for issuing an interrupt or a command. By shortening, the data transfer between the data processing device and the data input / output device can be performed efficiently,
The purpose is to improve the effective data transfer time.

[0014]

[Means for Solving the Problems]

(1) The data input / output device 2 receives data from a plurality of connection destinations by a virtual circuit having a plurality of channels on a physical line, accumulates the data for each connection destination, and transfers the data to the data processing device 1 in frame units. In the data transfer method, the data processing device 1 notifies the data input / output device 2 of the reception buffer area in advance, and the data input / output device 2 notifies the data processing device 1 of the reception buffer area when receiving the frame. The data is immediately transferred to the area after the previously transferred received data in the area, and at the end of this transfer, the data reception notification of this frame is performed.

(2) In the case of (1), the data input / output device 2
Notifies the data processing device 1 by adding attribute information relating to the received data as a header to the received data and transferring it to the receiving buffer area.

(3) In the case of (1), the data input / output device 2
However, by adding the attribute information regarding the received data to the shared area for the data reception notification, the data processing device 1
To notify.

(4) In the case of (1), the data input / output device 2
When the data size of the received frame is larger than the remaining size of the reception buffer in the data processing device 1, the data processing device 1 requests the reception buffer region, and the data processing device 1 secures a new reception buffer region. Then, the information is notified to the data input / output device 2.

(5) The data input / output device 2 receives data from a plurality of connection destinations through a virtual line having a plurality of channels on a physical line, accumulates the data for each connection destination, and stores the data in frame units. When the data input / output device 2 notifies the data processing device 1 of the reception of a frame in the data transfer method of transferring data to the data processing device 1, the data processing device 1 secures the reception buffer area in response to the reception notification, and The reception data transfer command is issued to the data input / output device 2 by adding the information of the reception buffer area, and the data input / output device 2 receives the frames received by the reception of the reception data transfer command within the notified reception buffer size. Combine and transfer to this receive buffer area.

(6) In the case of (5), the data input / output device 2
However, the frames are combined in a format in which the attribute information of the received frame is added to the received data as a header, and the frames are transferred to the reception buffer area.

(7) In the case of (5), the data input / output device 2
However, the attribute information of each combined frame is added to the notification of transfer completion of the received data by the amount of the combined frame, and the data processing device 1 is notified.

(8) In the case of (5), the data input / output device 2
However, the frame is combined for each single connection destination, the attribute information of the combined frame is added to the transfer completion notification of the received data, and the data processing apparatus 1 is notified.

[0022]

FIG. 1 shows a principle configuration (1) of the present invention, and shows a procedure of a data transfer system conceptually showing a first solution to the above-mentioned problem. In this data transfer procedure, the received data transfer command is not issued every time data is received.

(1) Prior to data reception, the data processing device secures a large reception buffer area capable of storing a plurality of frames and notifies the data input / output device of the reception command. The reception command is notified by an interrupt, and at that time, the buffer (head) address indicating the area and the buffer size are notified to the data input / output device.

(2) When the data input / output device receives data from the line and completes the reception of one frame, the DMA
Is prepared, the data is immediately transferred to the previously notified buffer area of the data processing device, and when the transfer is completed, the reception of the received frame A is notified to the data processing device by an interrupt.

(3) When receiving the second and subsequent frames (received frame B, received frame C, ...), data for the continuous area in the buffer area calculated from the previous transfer start address and data size The transfer is performed, and each time the transfer is completed, the reception of the frame (received frame B, received frame C, ...) Is notified to the data processing device by an interrupt.

(4) When the remaining size of the buffer area in the data processing device becomes smaller than the received frame size, the data input / output device requests the data processing device to secure a new buffer area.

According to the procedure shown in FIG. 1, the reception notification in the conventional data transfer procedure shown in FIG. 9 and the processing of issuing the received data transfer command in response thereto can be omitted, and the data transfer While the processing device is processing the already transferred data in response to the reception notification shown in FIG. 1, the next received data is transferred from the data input / output device to the memory of the data processing device. Therefore, the data transfer processing time can be significantly reduced.

FIG. 2 shows a principle structure (2) of the present invention, and shows a procedure of a data transfer system conceptually showing a second solution to the above-mentioned problem. This data transfer procedure is characterized in that already received frames are combined with one data transfer command and transmitted to the data processing device.

(1) When the data input / output device receives data from the line and completes the reception of one frame (received frame A), it notifies the data processing device of the reception of the frame. Reception notification is generally performed by interruption, and at this time, the channel number and the number of received bytes are notified.

(2) The data processing device performs interrupt processing to secure a large buffer area of an allowable size and issues a received data transfer command to the data input / output device. Issuing the receive data transfer command
This is performed by an interrupt, and at this time, the channel number, buffer address, and buffer size are notified.

(3) The data input / output device, when receiving the received data transfer command, performs an interrupt process to perform DMA processing.
And prepare for and continue to the notified frame,
Another frame (received frame B, received frame C, ...)
Is received, combine the received frames,
Transfer to the memory of the data processing device.

(4) When the data transfer is completed, the data input / output device notifies the completion of the transfer (command). Transfer completion is notified by an interrupt, and at this time, information on the combined frame is added.

According to the procedure shown in FIG. 2, the notification interrupt at the time of frame reception and the transfer command of the received data can be degenerated to the one for the first frame even in the case of a plurality of frames. Moreover, since the DMA preparation process for data transfer can be reduced, the data transfer process time can be shortened.

[0034]

Embodiments of the present invention will be described below. In each of the following embodiments, the system configuration to which the present invention is applied is the same as that shown in FIG.

In the first embodiment of the present invention, data transfer is performed according to the communication procedure shown in FIG. Further, FIG. 3 shows a format of a reception command issued from the data processing device to the data input / output device.
FIG. 4 shows the format of a reception notification issued from the data input / output device to the data processing device.

When the data input / output device receives data from the line and one frame is formed, the data input / output device receives the data at the buffer (head) address given by the receive command shown in FIG. Transfer data. After the data transfer is completed, a reception notification is created in the format shown in FIG. 4, and the data processing device is notified of the reception. As shown in the figure, the reception channel number or the reception data size, which is the attribute information about the reception data, is notified to the data processing device by adding it to the shared area for the data reception notification in the reception notification block.

The command block and the reception notification block used for communication between the data processing device and the data input / output device are realized by a shared memory or a register of the data input / output device accessible from the data processing device.

At the time of receiving the second and subsequent frames, the previous transfer data size is added to the buffer start address at the time of the previous transfer, the buffer start address to be transferred is calculated, and the first frame is received. Similar data transfer and reception notification are performed.

When the data input / output device receives the frame,
When trying to transfer data to the data processing device, if the sum of the received data size transferred to the data processing device minus the buffer size given by the receive command is smaller than the received frame size, The input / output device sets the reception status code to “buffer request” and notifies the data processing device of the reception.

Upon receipt of the "buffer request" reception notification, the data processing device newly secures a buffer area and notifies the data input / output device of the buffer start address and the buffer size by a reception command.

In the second embodiment of the present invention, instead of notifying the channel number and data size of the received frame by the reception notification block in the first embodiment,
It is added and notified as a header of the data transferred to the data processing device. In this case, the reception notification block uses only the field of the reception status code.

FIG. 5 shows a format of transfer data from the data input / output device to the data processing device. In the second embodiment, as compared with the first embodiment, when the data processing device temporarily holds the processing of the received data and prioritizes another processing, a copy of the channel number or the data size is created. It has the advantage that it is not necessary.

In the third embodiment of the present invention, data transfer is performed according to the communication procedure shown in FIG. When the data input / output device receives the frame, it notifies the data processing device of the reception in the format shown in FIG. At this point, the data processing device secures a reception buffer having a size larger than the notified reception data size within the allowable range, and sends a reception command to the data input / output device in the format shown in FIG. To issue.

The data input / output device, within the frame received between the issuance of the reception notification and the reception of the reception command, sets the frame having the same channel number as that of the reception notification within the buffer size given by the reception command. The data is combined and transferred to the reception buffer of the data processing device.

FIG. 6 shows a format (1) of the transfer completion notification from the data input / output device to the data processing device. In the transfer completion notification block, in the variable length area following the completion status code, the transfer data size corresponding to the combined frame is listed following the transfer channel number. The end of this block is judged by the data size = 0. A part of the completion status code may be the number of combined frames.

In the fourth embodiment of the present invention, the frames to be combined are not limited to the frames of the same channel number in the third embodiment, but all the received frames are targeted.

FIG. 7 shows the format (2) of the transfer completion notification from the data input / output device to the data processing device. In the transfer completion notification block, in the variable length area following the status code, the transfer channel number corresponding to the combined frame and the transfer data size are paired,
They are listed as (a, b, c, ...). The end of the block is judged by the data size = 0. Note that a part of the completion status code may be the number of combined frames.

In the fifth embodiment of the present invention, the channel number and transfer data size in the fourth embodiment are
Instead of notifying by the transfer completion notification block, it is added as a header to the transferred data. As the format of transfer data, the format shown in FIG. 5 is used. The transfer completion notification block uses only the completion status code field.

[0049]

As described above, according to the data transfer method of the present invention, it is possible to reduce the program processing time for issuing an interrupt or a command when transferring data between the data processing device and the data input / output device. You can
Since the data transfer processing of the data processing device and the data input / output device can be efficiently executed, there is an effect that the effective data transfer speed can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration (1) of the present invention.

FIG. 2 is a diagram showing a principle configuration (2) of the present invention.

FIG. 3 is a diagram showing a format of a received command.

FIG. 4 is a diagram showing a format of a reception notification.

FIG. 5 is a diagram showing a format of transfer data.

FIG. 6 is a diagram showing a format (1) of a transfer completion notification.

FIG. 7 is a diagram showing a format (2) of a transfer completion notification.

FIG. 8 is a diagram showing a configuration of a data processing device and a data input / output device.

FIG. 9 is a diagram showing a conventional data transfer procedure.

[Explanation of symbols]

 1 data processor 2 data input / output device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiko Yuki 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Hiroyuki Kawahara, 1015, Kamikodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (8)

[Claims] 1. A data input / output device receives data from a plurality of connection destinations through a virtual circuit having a plurality of channels on a physical line, accumulates data for each connection destination, and transfers the data to the data processing device in frame units. In the data transfer method, the data processing device notifies the data input / output device of the reception buffer area in advance, and the data input / output device notifies the data processing device of the previous reception in the reception buffer area when receiving the frame. A data transfer method characterized in that data is immediately transferred to an area after the transferred received data and a data reception notification of the frame is given at the end of the transfer. 2. The data transfer method according to claim 1, wherein the data input / output device notifies the data processing device by adding attribute information relating to the received data as a header to the received data and transferring the header to the received buffer area. A data transfer method characterized by: 3. The data transfer method according to claim 1, wherein the data input / output device notifies the data processing device by adding attribute information regarding the received data to a shared area for data reception notification. And data transfer method. 4. The data transfer system according to claim 1, wherein the data input / output device receives the data from the data processing device when the data size of the received frame is larger than the remaining size of the reception buffer in the data processing device. A data transfer method characterized in that a data processing device reserves a new reception buffer region and notifies the data input / output device of the information by making a buffer region request. 5. A data input / output device receives data from a plurality of connection destinations by a virtual circuit having a plurality of channels on a physical line, accumulates data for each connection destination, and transfers the data to the data processing device in frame units. In the data transfer method, when the data input / output device notifies the data processing device of the reception of the frame, the data processing device secures the reception buffer area in response to the reception notification, and the information of the reception buffer area is received. The data input / output device additionally issues a receive data transfer command to the data input / output device, and the data input / output device combines the frames received until the reception of the received data transfer command within the notified receive buffer size and combines them into the receive buffer area. A data transfer method characterized by transferring. 6. The data transfer method according to claim 5, wherein the data input / output device combines the frames in a format in which attribute information of the received frames is added to the received data as a header and transfers the combined frames to the reception buffer area. A data transfer method characterized by: 7. The data transfer system according to claim 5, wherein the data input / output device adds the attribute information of each combined frame to the transfer completion notice of the received data for the combined frame. A data transfer method characterized by notifying the user. 8. The data transfer method according to claim 5, wherein the data input / output device combines the frames for each single connection destination, and the attribute information of the combined frame is used as a notification of completion of transfer of the received data. A data transfer method characterized by adding and notifying to a data processing device.