JPH03192451A - Input/output controller - Google Patents

Abstract

PURPOSE:To improve the total transfer ability of data by executing a transfer processing at first for transfer data in the data buffer of a channel controller with the next higher priority order when there are not transfer data in the data buffer of the channel controller with the highest priority order. CONSTITUTION:A data buffer 11 can temporarily store the input/output data peculiarly for respective channel controllers 41, 42,... When the data transfer requests of the channel controller 4M with the lower priority order compete order compete and there are no effective data in a data buffer 11(N) of the channel controller 4N with the high priority order, a data transfer control part 14 returns a block signal 80 without waiting for the return of the signal until the effective data re stored in the data buffer 11(N) and when there are the effective data in the data buffer 11(N) of the channel controller 4N with the next higher priority order, the data transfer processing is executed at first for these data. Thus, the speed of data transfer can be accelerated as a whole.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an input/output control device that controls data transfer, and in particular, data to be transferred is prefetched from a main storage device into a data buffer. The present invention relates to an input/output control device that processes data transfer requests according to the state of data.

[Conventional technology]

This type of conventional input/output control device is known as a device that transfers data from a main storage device to a channel control device according to the priority of data transfer requests from each channel control device.

This input/output control device includes a data transfer request control unit that collectively manages data transfer requests from each channel control device, and a data transfer request control unit that processes data transfer requests from this data transfer request control unit and controls data transfer requests. The control unit includes a control unit, a data buffer that is assigned to each channel control device and temporarily stores input/output data to the main memory, and a prefetch control unit that prefetches data from the main memory and stores it in the data buffer.

In such an input/output control device, data transfer requests from each channel control device are manually input to a data transfer request control section. The data transfer request control unit selects one data transfer request according to the priority of the request and sends it to the data transfer control unit, and sends an acceptance signal indicating that the data transfer request transferred to the data transfer control unit has been accepted. Wait until you can receive it.

In addition, the preemption control unit, before starting data transfer,
Preemption control is executed to store part of the data to be transferred from the main storage device to the data buffer.

Upon receiving the data transfer request, the data transfer control unit returns an acceptance signal to the data transfer request control unit if valid data exists in the data buffer corresponding to the requesting channel control device, and also sends an acceptance signal to the data transfer request control unit. Transfer data to channel controller.

On the other hand, when the data transfer control unit receives a data transfer request, if there is no valid data in the data buffer corresponding to the requesting channel control device, the data transfer control unit does not return an acceptance signal and sends the data buffer to the main memory. Waited until valid data was stored.

[Problem to be solved by the invention]

In the conventional input/output control device as described above, when the data transfer request selected by the data transfer request control section is sent to the data transfer control section, if there is no valid data for the channel control device in the data buffer, , the following inconveniences occurred.

In other words, when the prefetch control unit has not prefetched data into the data buffer, the data transfer control unit cannot send an acceptance signal to the data transfer request control unit, and valid data is not stored in the data buffer. I waited until In other words, a data transfer request is also issued from a channel control device with a lower priority than the channel control device processing the data transfer request, and the data buffer of the lower priority channel control device is valid. Even though there is such data, the data is not transferred, causing the inconvenience of having to wait for the data transfer. Therefore, since the input/output control device operates in this manner, there is a drawback that the data transfer speed as a whole becomes slow.

SUMMARY OF THE INVENTION An object of the present invention is to provide an input/output control device that eliminates the above-mentioned drawbacks and increases the data transfer speed as a whole.

[Means to solve the problem]

The input/output control device of the present invention is an input/output system that controls data transfer between a main storage device and a channel control device. II device, a data buffer that temporarily stores input/output data specific to each channel control device; a data buffer management unit that determines whether valid data is stored in the data buffer corresponding to each channel control device; A data transfer request control unit that outputs the priorities of data transfer requests from a plurality of channel control devices, and a data buffer management unit that processes data transfer requests of channel control devices output from the data transfer request control unit. , a data transfer control unit that returns an acceptance signal if data transfer is possible, and a block signal if data transfer is impossible to the corresponding channel control device via a data transfer request control unit, and data to be transferred next. a data prefetch control unit that performs prefetch processing to store the data from the main memory to the data buffer in advance; This configuration is configured to process requests.

The present invention provides a method for when there is no valid data in the data buffer of the higher priority channel control device when there is a conflict between data transfer requests between a channel control device with a higher priority and a channel control device with a lower priority. , without waiting until valid data is stored in the data buffer, if there is valid data in the data buffer of the channel controller with the next priority, it is processed for data transfer first, improving overall data transfer efficiency. This is what I did.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an input/output control device of the present invention.

The input/output control device 1 shown in FIG. 1 is connected to a sound control device 3 via a system 2, and data can be transferred to a main storage device (not shown) through the main storage control device 3. It has become. Further, the input/output control device 1 is connected to a plurality of channel control devices 442, . . . and is configured to perform data transfer control.

The configuration of the input/output control device 1 described above will be further explained. The input/output control device l includes a data buffer 11, a data buffer management section 12, a data transfer request control section 13, a data transfer control section 14, a prefetch control section 15, and a system hash control section 16. It is structured as follows.

That is, the data buffer 11 is connected to each channel control device 4. , 4. , . . . uniquely capable of temporarily storing input/output data. The data buffer management unit 12 includes each channel control device 41, 42, . . .
It can be determined whether valid data is stored in the data buffer 11 corresponding to .

The data transfer request control unit 13 includes a plurality of channel control devices 4. , 42. The priority order of the data transfer requests from . . . is given to the data transfer control unit 14 as selected data transfer requests 50.

The data transfer control unit 14 processes the selected data transfer requests 50 and 60 from the data transfer request control unit 13 based on the judgment from the data buffer management unit 12, and sends an acceptance signal 70 if the data transfer is possible, and an acceptance signal 70 if the data transfer is not possible. If possible, the blocking signal 80 can be sent back to the corresponding channel control device 4 via the data transfer request control section 13. The data transfer control unit 14 also controls a channel control unit 4N with a high priority and a channel control unit @4 with a lower priority.
In the data buffer 11 when there is no valid data in the data buffer 1lnn of the channel control device 4N with a high priority when a data transfer request conflicts with M. The blocking signal 80 is returned without waiting until valid data is stored in the channel control device 4, and if there is valid data in the data buffer 11° It is configured to do this.

The prefetch control B15 executes a prefetch process in which data to be transferred next is stored in advance from the main storage device to the data buffer 11.

The system bus control unit 16 manages and controls the system bus 2. In addition, 90 is a person category, 9
5 is output data.

Next, the operation of the embodiment of the present invention will be explained.

From the main storage control device 3 to the channel control device 442,...
When output is transferred to ..., the preemption system i is sent before the data starts.
A part of the data to be transferred next is stored in the data buffer 11 in advance according to instructions from the wholesaler 15, and when data transfer is started, a data transfer request is sent from the corresponding channel control device 4, and the data is transferred. Transfer begins. Here, the data prefetched in the data buffer 11 is transferred in fixed length data in units of several bytes in accordance with the transfer request, and when there is no valid data in the data buffer 11, the prefetch control unit 15 instructs a prefetch operation.

However, when a data transfer request is made from the channel control devices 41.4□, .
The transfer request was made to wait until it was stored in 1. In contrast, in this embodiment, even in such a state, the data transfer control unit 14 sends a blocking signal 80 indicating that the transfer request cannot be accepted because the prefetch has not been completed. Channel control device 48 via section 13
and block the data transfer request. As a result, the data transfer control unit 14 selects the data transfer request of the channel control device 414 with the next priority, and processes the data transfer of the next channel control device 4@.

Furthermore, when writing from the channel control device 4 to the main storage device via the input/output control device 1, data transferred from the channel control device 4 is stored once in the data buffer 11, and when the data buffer 11 becomes full, The data in the data buffer 11 is written to the main storage control device 3 at once.

However, if a data transfer request is sent when the data buffer 11 is full, the request is made to wait until the data in the data buffer 11 is transferred to the main storage device, as in the case of data output, but a blocking signal 80 is output. By doing so, the processing of other channel control devices 4 can now be executed.

That is, the data buffer management unit 12 manages the amount of effective data in the data buffer 11, and blocks the data transfer request from the channel control device 4 when it cannot be accepted due to the data buffer. This allows data transmission requests from other channel control devices to be processed, eliminating waiting time.

〔Effect of the invention〕

As explained above, in the present invention, when data transfer requests conflict between a channel control device with a high priority and a channel control device with a lower priority, the data is transferred to the data buffer of the channel control device with a higher priority. When there is no data, if there is transfer data in the data buffer of the channel control device with the next priority, the data transfer process is performed on this data first, and there is an effect that the overall data transfer capability can be improved as a whole.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1...Input/output control device, 2...System bus, 3...Main memory control device, 42.4□...Channel control device, 11...・
...Data buffer, 12...Data buffer management section, 13...
...Data transfer request control unit, 14...Data transfer control unit, 15...Preemption control unit. Atsushi 1 diagram

Claims (1)

[Claims] In an input/output control device that controls data transfer between the main storage device and a channel control device, there is a data buffer that temporarily stores input/output data specific to each channel control device, and a data buffer corresponding to each channel control device. a data buffer management unit that determines whether valid data is stored in the data buffer management unit; a data transfer request control unit that outputs priorities of data transfer requests from a plurality of channel control devices; Processes the data transfer request from the channel control device based on the judgment from the data buffer management unit, and sends an acceptance signal if the data transfer is possible, or a blockage signal if the data transfer is not possible, via the data transfer request control unit. and a data prefetch control unit that executes prefetch processing to store data to be transferred next from the main storage device to the data buffer in advance, the data transfer control unit The input/output control device is characterized in that the input/output control device is configured to process a data transfer request of a channel control device with the next priority level when a blocking signal is returned.