JPH01180056A - Input and output controlling system - Google Patents

Abstract

PURPOSE:To shorten the access time of a channel device by executing the control of the channel device based on the information of a channel information holding means. CONSTITUTION:The information to show whether a channel device 111 is just used or not are supplied to a channel information holding means 121 by a channel information setting means 131 and held. A channel control means 141 controls the device 111 based on the information to be held in the means 121. As a result, the time to be needed for the exclusive control of the channel device 111 can be shortened.

Description

[Detailed Description of the Invention] (Summary) An input/output control method in which data is input/output using a channel device and a channel processing device.The purpose of this invention is to shorten the time required for exclusive control of a channel device. a channel device that controls data input/output to and from the channel device; a channel information holding unit that holds information as to whether the channel device is in use; and a channel information holding unit that holds information on whether or not the channel device is in use; channel information setting means for setting information to be used; and channel control means for controlling the channel device based on the information held in the channel information holding means.

[Industrial application field]

The present invention relates to an input/output control system, and particularly to an input/output control system in which data is input/output using a channel device and a channel processing device.

[Conventional technology]

In a computer system, the central processing unit (CPU
), a channel device is widely used to efficiently input and output data between a main storage unit (MSU) and an input/output device.

FIG. 4 shows the overall configuration of a general computer system. The computer system shown in the figure includes a CPU 431 that performs overall control and data processing;
MS that stores data and programs that are directly processed by
The CPU 433 includes four channel devices 411, 413, 415, and 417 that perform data input/output processing between the CPU 431 or MSU 433 and an input/output device, and a channel processing device 441 that controls the channel devices. An input/output device 421 and an input/output device 423 are connected to the channel device 411 (input/output devices connected to other channel devices are omitted).

The CPU 431 and MSU 433 are the channel processing device 44
1, and data exchange with the input/output device is performed via the channel processing device 441 and each channel device.

FIG. 5 shows detailed configurations of the channel processing device 441 and channel device 411 shown in FIG. 4.

In order to explain the conventional input/output control method, attention will be paid to the transmission and reception of control signals between the channel processing device 441 and the channel device 411. For example, consider a case where an instruction is sent from the channel processing device 441 to the channel device 411 in order to access the input/output device 421 from the CPU 431.

In the figure, the channel processing device 441 includes a microprocessor unit (MPU) 541 that controls the entire channel processing device 441.
1 executes the microprogram 543 to perform processing. Similarly, the channel device 411
It is equipped with an MPU511 that performs overall control of the MP
U511 executes the microprogram 513 to perform processing.

When the channel processing device 441 sends an instruction to the channel device 411, the MPU 541 first sends a request signal “1” from the output port 545 to the input port 515 of the channel device 411.
Send ゛′. The MPU 511 monitors the state of the input port 515 and accepts the request signal "1°" sent from the channel processing device 441. At this time, if the channel device 411 is in a usable state (input Output device 42
1 etc.), the MPU 511 connects the input port of the channel processing device 441 from the output port 517).
The enable signal "1" is sent back to 547.

When the MPU 541 receives the enable signal from the channel device 411 via the input port 547, it starts accessing the channel device 411 from then on.

FIG. 6 shows an operation procedure for exclusive control of the channel device 411 when focusing on the MPU 541 described above.

First, the MPU 541 sends out a request signal (step 611). Then, after sufficient time has elapsed for channel device 411 to service the request (step 612), a determination is made as to whether an enable signal has been received (step 613).

When the usable signal is received, an affirmative judgment is made and the channel device 411 is activated (step 614), and when the use of the channel device 411 is finished, the process is terminated.

When no available signal is received (channel device 4
11 is in use and the usable signal is not sent back), the MPU 541 makes a negative determination in step 613, suspends activation of the channel device 411 (step 615), and ends the process. Note that while waiting for a sufficient amount of time to elapse in step 612, the channel device 441 can also perform other processing.

[Problem that the invention seeks to solve]

By the way, in the conventional method described above, when the channel processing device 441 performs exclusive control over the channel device 411, the channel processing device 441 does not control the channel device ff411 until the usable signal corresponding to the request signal sent from the MPU 541 is sent back. Therefore, there was a problem in that exclusive control of the channel device took time.

In particular, the MPU 541 of the channel device 411 detects a request signal from the channel processing device 441 and returns a usable signal in parallel with the normal operation, and these processes are time-consuming and constant due to program processing. I will not do it.

The present invention was created in view of these points, and an object of the present invention is to provide an input/output control method that reduces the time required for exclusive control of channel devices.

[Means for solving problems]

FIG. 1 is a principle block diagram of the input/output control method of the present invention.

In the figure, a channel device 111 controls data input/output to/from input/output devices.

Channel information holding means 121 holds information as to whether or not channel device 111 is in use.

The channel information setting means 131 sets the information held in the channel information holding means 121 according to the usage status of the channel device 111.

Channel control means 141 includes channel information holding means 12
The channel device 111 is controlled based on the information held in the channel device 111.

Therefore, the overall structure is such that the channel device 111 is controlled based on the information in the channel information holding means 121.

[For production]

The channel information setting means 131 sends information as to whether the channel device 111 is in use to the channel information holding means 12.
1, and the channel information holding means 121 holds the information. The channel control means 141 controls the channel device 1 based on the information held in the channel information holding means 121.
11.

In the present invention, information on whether or not the channel device 111 is in use is held in the channel information holding means 121, and based on the information in the channel information holding means 121, the channel control means 141 controls the channel device. By controlling the channel device 111, the time required for exclusive control of the channel device 111 can be shortened.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows the configuration of an embodiment to which the input/output control method of the present invention is applied.

1.1 and 1'' - Here, the correspondence between the embodiment of the present invention and FIG. 1 will be shown.

Channel device 111 corresponds to channel device 210.

Channel information holding means 121 corresponds to latch 221.

The channel information setting means 131 corresponds to the MPU 211 microprogram 213.

The channel control means 141 includes MPU241. This corresponds to the microprogram 243.

Examples of the present invention will be described below assuming that the correspondence relationship as described above exists.

■-Fusi 5q Question Base In FIG. 2, data input and output between the CPU 251 and the input/output device 261, or between the MPU 241 and the input/output device 261, is performed via the channel processing device 240 and the channel device 210. .

The channel processing device 240 includes an MPU 241 that controls the entire channel processing device 240, and a channel processing device 2.
40 to the channel device 210 and a latch 221 for storing information regarding the usage status of the channel device 210. The MPU 241 operates by executing a microprogram 243.

Further, the channel device 210 includes an MPU 211, and the MPU 211 operates by executing a microprogram 213.

The MPU 241 of the channel processing device 240 executes a microprogram 243. Latch 221 and external CPU 251
．． MPU211. MPU 211 in the channel device 210
is connected to. In addition, the MPU of the channel device 210
211 is connected to the microprogram 213 and the latch 221 in the channel processing device 240.

Next, the operation of the input/output control system according to the embodiment of the present invention described above will be explained.

FIG. 3 shows the exclusive control procedure of the embodiment. (a) shows the operation of the channel device 210, and (b) shows the operation of the channel processing device 2.
40 MPU 241 is shown.

In the latch 221, the reserved bit 225 is set to "1" when there is an access request from the channel processing device 240 to the channel device 210, and the in-use bit 223 is set to 1' when the channel device 210 is in use. shall be taken as a thing.

For example, channel processing device 240 may
As an example of exclusive control, consider a case where the CPU 251 issues an input/output early release command to the channel processing device 240. The channel processing device 240 receives and receives a channel address word (CAW) and a channel address, and if the corresponding channel device 210 is available, returns a condition code CC=O to the CPU 251, releases the CPU 251, and uses the channel device 210. Start 210. If the channel device 210 is in use, the CPU
251 instruction execution is temporarily suppressed, and the channel device 21
The channel device 210 is accessed again in response to a processing request from 0 or cancellation of the usage state of the channel device 210.

Hereinafter, with reference to FIGS. 2 and 3, the channel equipment ff210. The detailed operation in channel processing bag=240 will be explained.

1 channel device First, the operation of channel device 210 will be explained.

Prior to normal processing (for example, accessing the input/output device 261), the MPU 211 of the channel device 210 first
It is determined whether the reserved bit 225 of the latch 221 in the channel processing device 240 is "1" (step 311). When the reservation bit 225 is "1", an affirmative judgment is made, the normal processing is suspended (step 315), and the processing is ended. Thereafter, the channel processing device 240 refers to the fact that the in-use bit 223 of the latch 221 is “O”° (unless the MPU 211 of the channel device 210 changes it to “1′”, it is “O゛”) and processes the channel device 210. can be accessed.

When the reserved bit 225 of the latch 221 is “0” (
When there is no access request to the channel device 210 from the channel processing device 240), a negative determination is made in step 311, and then the MPU 211 sets the in-use bit 2 of the latch 221.
23 to “1°” (step 312). From now on, M
The PU211 performs the desired processing (Step 3),
When finished, the in-use bit 223 of the latch 221 is set to °“0.
(step 314), and the process ends.

Channel holder φ Next, the operation of the channel processing device 240 will be explained.

When accessing the channel device 210 from the MPU 241 of the channel processing device 240, the MPU 241 first sets the reserved bit 225 of the latch 221 to ``1'' (step 351). Next, the MPU 241 sets the in-use bit 223 of the latch 221 to is "1" (step 352). If the in-use bit 223 is not "1" (when the channel device 210 is unused), a negative determination is made, and then the MPU 241 selects the channel device. 210 is activated (used) (step 353), and when the desired processing is completed, the latch 221 of the latch 221 is changed to "0" (step 354), and the exclusive control processing is ended.

Also, the determination in step 352 (the in-use bit 223 is “
1"), the MPU 241 suspends activation of the channel device 210 (step 355),
Exclusive control processing ends.

Summary of U Thus, the channel device 210 stores bit data indicating that it is in use in the latch 221 in the channel processing device 240. At this time, the channel processing device 24
When there is an access request from 0 to the channel device 210, that access request is given priority.

The MPU 241 of the channel processing device 240 uses the latch 22
1, it is determined whether or not the channel device 210 is in use, and when the channel device 210 is not in use, the channel device 21
Access 0.

Therefore, the MPU 241 of the channel processing device 240 can know the usage status of the channel device 210 by checking the latch 221, and can shorten the time required for exclusive control of the channel device 210.

In addition, since higher-ranking devices can usually perform faster processing, the time required to search the latch 221 by the MPU 241 is longer than the processing time in the MPU 211 of the channel device 210 (the time until the usable signal is sent in the conventional system). It is short and fixed.

Note that in the embodiment of the present invention described above, the relationship between the channel processing device 240 and the channel device 210 was considered, but the present invention is also applicable to the channel processing device 240 and other channel devices. can do.

In addition, in the embodiment, from the MPU 241 to the channel device 21
0 was considered, but on the other hand, when the channel processing device 240 is accessed from the channel device 210, the bit data representing the access request from the channel device 210 is stored in the latch 221 in the channel processing device 240. You can think of it in the same way.

Furthermore, in "■, Correspondence between Examples and FIG. 1",
Although the correspondence between the present invention and the embodiments has been described, those skilled in the art will easily assume that the present invention is not limited to this and that there are various modifications.

〔Effect of the invention〕

As described above, according to the present invention, information on whether or not a channel device is in use is held in the channel information holding means, and the channel control means controls the channel device based on the information in the channel information holding means. This control is extremely useful in practice, since it is possible to shorten the access time of the channel device.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram of the input/output control method of the present invention, Fig. 2 is a configuration diagram of an embodiment to which the input/output control method of the present invention is applied, Fig. 3 is an explanatory diagram of the operation of the embodiment, and Fig. 4 FIG. 5 is an overall configuration diagram of a computer system, FIG. 5 is a configuration diagram of a conventional example, and FIG. 6 is an explanatory diagram of the operation of the conventional example. In the figure, 111 is a channel device, 121 is a channel information holding means, 131 is a channel information setting means, 141 is a channel control means, 210.411, 413, 415, 417 is a channel device, 211.241, 511, 541 is an MPU . 213.243, 513, 543 are microprograms, 221 is a latch, 223 is a used bit, 225 is a reserved bit, 240.441 is a channel processing unit, and 251.431 is a CPU. 253,433 is MSU. 261.421,423 are input/output devices, 515.547
is the input boat, and 517.545 is the output boat.

Claims (1)

[Claims] A channel device (111) that controls input/output of data to/from an input/output device, and channel information holding means that holds information as to whether or not the channel device (111) is in use. (121); channel information setting means (131) for setting information to be held in the channel information holding means (121) according to the usage status of the channel device (111); and the channel information holding means (121). An input/output control system characterized in that it is configured to include a channel control means (141) that controls the channel device (111) based on information held in the channel device (111).