JP3261715B2 - I / O data transfer processor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input / output data transfer processor, and more particularly to an input / output data transfer processor for controlling a data transfer request between an input / output processor and a channel device.

[0002]

2. Description of the Related Art In a conventional request arbitration system in an input / output processing device, a specific priority is assigned in advance to a plurality of channel devices, and the input / output processing device requests a data transfer request. Performs memory access to. When requests compete between channel devices, the requests are arbitrated according to a predetermined priority and memory access is performed.

[0003]

However, in the above-mentioned prior art, when the load increases or a channel device having a high priority occupies a memory access, the request waits due to a low priority. Such a channel device has a drawback that data transfer cannot be made in time and data overrun is likely to occur.
Further, when a data overrun occurs, the peripheral control device requests a restart of the data transfer, which causes a disadvantage that the performance of the input / output transfer system is reduced. On the other hand, if a method of receiving requests from a specific channel device in a time-sharing manner without performing request arbitration is adopted, there is an inconvenience that as the number of channel devices increases, the peak performance of data transfer per channel device decreases. Was.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to improve the disadvantages of the prior art, to prevent data overruns as much as possible, and to construct an efficient processing system independent of the system configuration and concentration of processing. to provide a high-performance input and output data transfer Okusho management apparatus, and an object.

[0005]

According to the present invention, an input / output processing device connected to a main storage device, a plurality of channel devices connected to the input / output processing device, and a peripheral connecting the plurality of input / output devices are provided. It has a control device and an input / output interface for connecting the channel device and the peripheral control device.
Then, the input and output data transfer processing device and a processing unit that performs data transfer between the main memory stores the the group Hazuki main memory to transfer command information to the input-output device,
The channel device has a buffer unit for filling a difference in transfer rate between the main storage device and the peripheral control device, and a buffer management unit that determines valid data or the number of free areas in the buffer according to a transfer direction, depending on the output of the buffer management means, typically a request for outputting the data transfer request of the request (usually request) to the input-output processor
When the occurrence of data overrun is expected based on the sending means, the data transfer rate between the peripheral control device and the channel device, and the output of the buffer management means, a request for a high priority data transfer request is sent to the input / output processing device. Emergency request sending means for outputting a request (emergency request) . Then, the input / output processing device includes a plurality of channels.
Receiving a data transfer request request from the
Arbitrate requests based on specific priorities,
And it includes a request arbitration means for performing the reactance Seth. So
Then, the request arbitration means sends an emergency request from the channel device.
Data transfer by urgent request when receiving quest
Memory access with priority to the channel device that requested
Means for performing the
Count the number of urgent requests and determine which channel device
Data that determines whether data overruns are likely to occur
Overrun analysis means and data overrun analysis means
Output, that is, the possibility of data overrun
Change the priority in request arbitration
Priority changing means. This aims to achieve the above-mentioned object.

[0006]

An embodiment of the present invention will be described below with reference to FIG. In the embodiment shown in FIG. 1, reference numeral 1 denotes an arithmetic processing device, reference numeral 2 denotes a main storage device, reference numeral 3 denotes a system bus, reference numeral 4 denotes an input / output processing device, and reference numeral 5 denotes data between the input / output processing device and the channel device. A bus (8 bytes wide in this embodiment), reference numeral 6 denotes a parameter bus between the input / output processing device and the channel device, reference numeral 7 denotes a channel device, reference numeral 8 denotes a peripheral control device, and reference numeral 9 denotes an input / output device. Also, reference numeral 4
Reference numeral 1 denotes an interface unit of the input / output processing device 4 with respect to the main storage device 2, reference numeral 42 denotes a data transfer control unit for controlling data transfer in the input / output processing device 4, and reference numeral 43 arbitrates request signals from a plurality of channel devices. Reference numeral 44 denotes an area for storing priority information to be given to the request arbitration unit 43, reference numeral 45 denotes an overrun analysis unit for determining a channel device likely to cause data overrun, and reference numeral 46 denotes an overrun analysis unit 45. This is a priority change unit that rewrites the priority information storage area 44 according to the output. Further, reference numeral 71 denotes a data buffer for temporarily storing transfer data, reference numeral 72 denotes an input / output control unit for controlling input / output transfer in the channel device 7, and reference numeral 73 denotes a buffer management unit for managing the amount of data in the data buffer 71. Reference numeral 74 denotes a transfer rate storage area for storing a data transfer rate between the channel device 7 and the peripheral control device 8, and reference numeral 75 denotes a data transfer request (normal request) to the input / output processing device 4 in accordance with the output of the buffer management unit 73. Reference numeral 76 denotes a normal request transmitting unit for transmitting, and reference numeral 76 denotes an emergency request transmitting unit for transmitting a high priority request from the output of the buffer management unit 73 and the transfer rate storage area 74.

Here, the operation of the above embodiment will be described. First, when the data transfer process is started based on the transfer command information stored in the main storage device 2 by the arithmetic processing device 1, the input / output processing device decodes the transfer command information and performs data transfer to the channel device 7. to start. The buffer management unit 73 of the channel device 7 that has started the data transfer determines the number of valid data and the number of free areas in the data buffer 71 according to the transfer direction, and outputs the result to the normal request transmission unit 75 and the emergency request transmission unit 76. To

The normal request sending section 75 sends a request for a data transfer request to the input / output processing device 4 based on the output result of the buffer management section 73. More specifically, in the present embodiment, since a maximum of 8 bytes of data can be input / output to the input / output processing device 4 by one data transfer request, the normal request sending unit 75 stores the valid data in the data buffer 71 in the input transfer. When there are 8 bytes or more in the data transfer 71 and when there is an empty area in the data buffer 71 in the output transfer of 8 bytes or more, the normal request 7
7 to the input / output processing device 4. The urgent request transmission unit 76 receives the output of the buffer management unit 73 and the output of the data transfer rate storage area 74, predicts the occurrence of a data overrun in advance, and sends a request to the input / output processing device 4 for a data transfer request. Send the request. More specifically, in the case of the output transfer, when the data buffer 71 may be in an empty state due to the relationship between the number of remaining valid data in the data buffer 71 and the transfer rate, and in the case of the input transfer, the number of empty areas of the data buffer 71 and the transfer rate An urgent request 78 is requested to the input / output processing device 4 when there is a possibility that the data buffer 71 will become full.

The request arbitration unit 43 of the input / output processing unit 4
Are the channel devices (channel devices 1 to
The data transfer request requested in n) is arbitrated in accordance with the priority information from the priority information area 44, and the processing is shifted to the data transfer control unit 42. Further, the request arbitration unit 43 performs processing with priority given to an urgent request over a normal request, so that it is possible to quickly transfer data to a channel device which is likely to cause a data overrun requesting the urgent request.

The overrun analyzer 45 counts urgent requests from each channel device and determines the likelihood of data overrun in each channel device.
The priority change unit 46 receives the output of the overrun analysis unit 45 and creates priority information used for request arbitration so as to give priority to processing of a channel device in which data overrun is likely to occur. Write to

[0011]

According to the present invention as described in the foregoing, divided data transfer request in the channel device to the normal request and emergency request output, preferentially process the urgent request by the request arbitration unit in the input-output processor By doing so, occurrence of data overrun can be relieved. Also, in the input / output processing device, the priority in request arbitration of a channel device in which data overrun is likely to occur is dynamically increased, so that it is possible to configure optimal priority information in which data overrun is unlikely to occur. As a result, it is possible to provide an unprecedented superior input / output data transfer processing device which can solve the problems associated with the system configuration and the concentration of processing and can realize a high performance of the input / output data transfer system.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 arithmetic processing device 2 main storage device 3 system bus 4 input / output processing device 5 data bus 6 parameter bus 7 channel device 8 peripheral control device 9 input / output device 41 memory interface unit 42 data transfer control unit 43 request arbitration unit 44 priority information Area 45 Overrun analysis unit 46 Prioritized priority unit 71 Data buffer 72 Input / output control unit 73 Buffer management unit 74 Transfer rate storage area 75 Normal request transmission unit 76 Urgent request transmission unit 77 Normal request 78 Urgent request

Claims (3)

(57) [Claims] 1. An input / output processing device connected to a main storage device.
And a plurality of channel devices connected to this input / output processing unit.
Devices, peripheral control devices that connect multiple input / output devices, and
I / O input to connect the channel device and peripheral controller
And a transfer stored in the main storage device.
Based on command informationFollowBetween the main storage device and the input / output device
Input / output data provided with an arithmetic processing unit for performing data transfer
In the transfer processing device, the channel deviceIs, The main storage device and the peripheral control device
It has a buffer to fill the difference in transfer rate between devices.
That is, if there is valid data in the buffer according to the transfer direction,
Buffer management means for determining the number of free areas;
The input / output processing device according to the output of the buffer management means
Request for data transfer request (normal request)
EmpowerNormal request transmissionMeans, and the peripheral control device;
A data transfer rate between channel devices and the buffer tube
Data overrun is expected based on the output of
if you did this,SaidPriority for I / O processor
High data transfer request (urgent request)
OutputEmergency request transmissionWith means, The input / output processing device receives data from the plurality of channel devices.
Receiving the data transfer request request and receiving the plurality of requests.
Arbitration based on a specific priority, and
Request arbitration means The request arbitration unit transmits an urgent request from the channel device.
Data transfer with urgent request when request is received
Memory access with priority to the channel device that
Means for performing the communication, and that issued by the plurality of channel devices.
Count the number of each urgent request, and which channel
Determine if equipment is prone to data overrun
Data overrun analysis means;
Of the data overrun
Depending on the simplicity, the above arbitration of request
And priority changing means for changing the priority. An input / output data transfer processing device, characterized in that: (2)The emergency request sending means includes an output switch.
In transmission, the number of remaining valid data in the buffer unit and the data
The buffer is empty due to the transfer rate
When there is a danger of
Based on the relationship between the number of empty areas and the data transfer rate,
When there is a danger that the buffer will become full,
Output a sudden request, The input / output data transfer processing device according to claim 1. (3)The normal request sending means includes a one-time
Maximum number of bytes that can be input / output in the data transfer request
Is m, the valid data is stored in the buffer
When there are more than m bytes of data,
When there are more than m bytes of free area in the
Output the normal request respectively, The input / output data transfer processing device according to claim 1.