JPS58217035A - Input and output control system of computer system - Google Patents

Abstract

PURPOSE:To perform flexible input/output control, by storing a command string for input/output control in a main memory, and entering a command for instructing the writing, execution, etc., of the command string in a main program. CONSTITUTION:The main memory 2 is stored with commands in common conventionally and the command string 23 for input/output control consisting of commands characteristic to this invention such as a delay, a condition decision, and a repetition specifying command, and commands for indicating the writing, execution, etc., of said command string are added in the main program properly dispersedly. A central processing unit 1 sends said commands in the main program 21 to an input/output controller 3, which reads the command string 23 according to the input commands and executes the command string to control an input/output device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an input/output control method for a computer system.

In general, in computer systems, calling an input/output device from the central processing unit and operating it requires a complicated procedure, and the operation of the input/output device is extremely slow compared to the operation of the central processing unit. Therefore, the control method, that is, the software-related interface, has a large impact on software productivity (ease of creation) and system performance (throughput and response time). For this reason, the input/output control system must provide a unified and simple control means from a software perspective, and must also be able to reduce the load on the central processing unit.

Input/output devices include typewriters, line printers, card readers, displays, etc., as well as auxiliary storage devices such as magnetic disks and magnetic tapes, external storage devices, process input/output devices, communication control devices, and data ways. There are a wide variety of such things. In addition, control DMA (Direct M4mory) for these input/output devices
FIG. 2 is a configuration block diagram for explaining the Accept) method.

A central processing unit 1, a main memory 2, and an input/output control device 6 are connected to a bus 5, and an input/output device 4 is connected to the input/output control device 5. The central processing unit 1 has a main memory 2
The main program 21 stored in the main program 21 is read step by step, interpreted and executed. When the interpreted step indicates access of the input/output device 4, the central processing unit 1 executes the input/output control register group 3 in the input/output control device 6.
The contents of the status display register in 1 are read to check whether the input/output control device 3 is in a usable state. If it is available, the central processing unit 1 sets information necessary for access in the command register of the input/output control register group 61.

The main information required for access is the input/output command that specifies the type of operation (for example, REAv, rrRrrE), and the address of the area 22 in the main memory where data is exchanged when the input/output operation involves data transfer. , and the access target portion of the input/output device 4 (for example, if the input/output device 4 is a magnetic disk, the transfer start record number and the number of transferred data), etc. The information necessary to access these
It consists of an input/output command and various accompanying addresses, counters, flags, etc. When the input/output control device 3 is called a channel, a channel control word (Channel) is used.
el Control Word, CCV), etc., but in this specification, the above-mentioned input/output commands and various information accompanying them are collectively referred to as input/output commands.

When the central processing unit 1 finishes setting the input/output commands to the input/output control register group 61, it instructs the input/output control unit 3 to start input/output operations. Input/output control device 3
Based on the input/output command set in the register group 31, the control signal is sent to the controller section 41 of the input/output device 4 according to a predetermined procedure (3). The controller unit 41 controls the operation of the input/output device 4 based on the received control signal.

When an input/output command involves data transfer, data is exchanged between the area 22 on the main memory and the input/output device device section 42. If timing adjustment is necessary at this time, , input/output device 3 or controller section 4
The above data is exchanged via a backup memory installed in 1. When the input/output operation is completed in this way, the input/output control device 6 usually notifies the central processing unit 1 of the completion using an interrupt signal.

The above-mentioned input/output commands differ somewhat depending on the type of input/output device 4, but basically include a read command, a write command, and a sense command lt6. Each of these commands a single basic operation of the input/output device. Conventionally, these commands were combined in the main program to control the operation of the input/output device in a sequential order. . However, in such a conventional example, the input/output control procedure must be realized as program logic (4), and there is a drawback that it becomes troublesome to create the input/output program. Furthermore, each time the execution of one input/output command is completed, the central processing unit must be involved, sb, resulting in an excessive burden on the central processing unit.

The conventional method is command chaining, in which the input/output control unit reads and executes a series of commands in the main program continuously without going through the central processing unit. 4D does not have the flexibility to change the execution order of input/output commands depending on the status of the input/output device or the contents of the input/output data.

Therefore, an object of the present invention is to facilitate the creation of an input/output control program, improve system performance by reducing the burden on the central processing unit, and provide flexibility such as being able to change the execution order of input/output commands. The purpose of this invention is to provide an input/output control method with a wide range of functions.

The details of the present invention will be explained below with reference to Examples.

FIG. 2 is a block diagram of the configuration of an embodiment of the present invention, and in the figure, components denoted by the same reference numerals as in FIG. 1 are the same components as in FIG. 1.

In addition to the sense commands, read commands, write commands, etc. used in the conventional method, the main memory 2 contains delay commands and condition judgment commands (hereinafter collectively referred to as "first commands") specific to this embodiment. ) is stored separately from the main program 21. The types and contents of these first commands are as follows.

A. Common commands used in the conventional method (1)
Sense command; detects the status of the input/output control device 6 and input/output device 4.

(11) Read command; reading data from the input/output device 4 to the main memory 2.

(Ill) Write command; outputting data from the main memory 2 to the input/output device 4.

(1v) Control command; control of the input/output device 4 or an external medium attached to it, etc.

(V) Other commands; mask control of interrupt signals from input/output device 4, input/output control device 3, input/output device 4
diagnosis, etc.

B. Commands unique to this embodiment (1) Delay command: Setting an appropriate delay time for starting execution of the above-mentioned conventional commands.

(11) Condition determination command; changing the execution procedure of the above-mentioned conventional command based on the status of the input/output device 4 and the content of input/output data.

(Ill) Repetition specification command; execution of subsequent n commands m times.

A series of command strings 2 consisting of the first command above
3 may be composed of a plurality of dedicated groups depending on the type of input/output control, or may be composed of only one general-purpose group that includes a large number of commands related to condition determination, order change, etc.

A series of command strings 2 consisting of the first command above
5 to the input/output control device to start a series of input/output operations described by these command sequences are appropriately and discretely written in the main program 21. The second commands in this implementation (7) example are of the following three types.

(1) Nearman light and start; 1st
A command that reads a series of command strings 23 consisting of commands from the main memory 2 to the R, 4M area 63-2, and then instructs the input/output control device 3 to start executing the read command strings 23.

(11) Command write: Command string 26 is written to main memory 2
A command that instructs the input/output control device 3 to read from the RAM area 36-2.

(Ill) Command start; RAM area 6 already
A command that instructs the input/output control device 6 to start executing the command string 23 read out at 6-2.

Assume that a second command, for example, an instruction related to command write and start, is fetched to the central processing unit 1 as the main program 21 is executed by the central processing unit 1. Having decoded this, the central processing unit 1 sets the command string 25 in the input/output area 22 of the main memory 20, creates a second command (in this case, command write and start), and stores it in the input/output control register. Romance (8) of group 61 is transferred to the dress register, and finally a start command is sent to the processor unit 62 in the input/output control device 5. The processor unit 52 that received this start command stores the ROM
The software or firmware for executing the input/output control logic (hereinafter referred to as "input/output interpreter") is read from the section 66-1, and the second command register set in the command register of the input/output control register group 61 is read out. Decipher input/output commands. In this case, the second input/output command is the command write and start, so
The processor unit 32 reads out the command string 26 set in the input/output area 22 of the main memory 220 via the bus 5 to the RAM area 33-2 of its own memory 36. When the processor unit 32 completes reading the command string 26, it sequentially reads one command from the RAM section 63-2 according to the input/output interleater in the ROM section 66-1, decodes and executes these commands.

If the first command that has been decoded is a write command or a read command, the processor unit 62 specifies a command between the corresponding address area of the input/output area 22 of the main memory specified in the command and the input/output device 4. Perform a transfer of data of specified length. If the decoded first command is a delay command, the processor unit 32 waits to process the command for the time specified by the command. If the decoded first command is a condition determination command, the processor unit 62 monitors the status of the input/output device 4, or performs a specified check on the data to be transferred, and records the monitoring or check results. The first command to be processed next is taken out from the RAM section 36-2 in the order specified according to the command, decoded and executed. In this way, when the execution of the series of command strings 25 set in the RAM section 36-2 is completed, that is, when the second command (in this case, command write and start) is completed, the processor unit 26 This is notified to the central processing unit 1 by an interrupt signal.

Similarly, if the second command set in the command (11) register of the input/output control register group 61 is a command write, the input/output control device 6
6-2 only takes in the command group 26 and does not execute any input/output operations. When the import of command string 26 is completed,
This is notified by an interrupt from the input/output control device 6 to the central processing unit 1.

In addition, if the second command set in the command register is a command start, the input/output control device 3 has already loaded the new command string 23 into the RAM section 36-2 without loading it into the RAM section 36-2. Processing of the loaded command string 26 is started, and when the processing is completed, an interrupt is sent to the central processing unit 1 to notify that effect. in this way,
An interrupt signal from the input/output control device 6 to the central processing unit 1 is sent only when the processing of the series of command strings 23 is completed.

FIG. 3 is a block diagram of another embodiment of the present invention, sb,
In the same figure, components with the same reference numerals as in Figure 2 are shown in Figure 2.
The components are the same as those in the figure. In this embodiment, in addition to the six types of second commands (12) used in the embodiment shown in the second figure, the following six types of second commands are used.

(lv) Command write and start device.

(V) Command write device.

(vl) Command start device.

The processor unit 32 of the input/output control device 6 decodes the second command set in the command register of the control register group 61, and when it is a command write and start device, reads the command string 23. The data is transferred from the main memory 2 to the input/output device 4, and when the transfer is completed, a start command is issued to the input/output device 4. The controller section 41 of the input/output device 4 stores the transferred command string 26 in the RAM area 44-2 of the memory 44, and then stores it in the RAM area based on the start command received from the input/output control device 6. Processing of the command string 23 currently in progress is started.

This process is performed by the processor unit 43 and the memory 44.
This is performed based on the input/output interpreter stored in the M area 44-1.

When the second command set in the command register in the one-way output control device 6 is sent to the command write device, it is transferred from the main memory 2 to the RAM area 44-2 of the input/output device 4 via the input/output control device 6. The command string 26 is transferred to. Further, when the second command is a command start device, a start command is issued from the input/output control device 3 to the input/output device 4, and the controller section 41 of the input/output device 4 receives the start command, and the controller section 41 of the input/output device 4 stores the RAM area 44- Processing of the command string 23 already stored in 2 starts. The command processing in the input/output device 4 is terminated by the input/output control device 3.
The central processing unit 1 is notified as an interrupt signal via.

In the embodiment shown in FIG. 6, the delay command and condition determination command included in the command sequence 26 as the first command have particularly important significance. The delay command is originally a process specific to the input/output device, and the condition determination command is also used in combination with a buffer function for input/output data, thereby enabling independent processing in the input/output device. Therefore, primary processing of process input/output and dataway data, or checking of input data from man-machine equipment, etc., is independent not only from the central processing unit 1 but also from the input/output control unit 3. You can perform input/output processing using

In the embodiment shown in FIGS. 2 and 3, the input/output control device 6 and the controller section 41 of the input/output device 4 are equipped with a processor unit 52, 45 to process the command string 23, but they have the same control function. can also be realized using hardware logic.

However, this embodiment has the following advantages in that it is possible to use a microcomputer whose price is reduced and whose functions and performance are significantly advanced.
It is more suitable than hardware logic format.

In the embodiments shown in FIGS. 2 and 6, the input/output control device 3 has a command string 2 loaded into the RAM section 66-1 of the memory 63.
6 was executed based on an interpreter. However, the original command sequence 23 can include a machine language sequence (program) that can be directly executed by the general-purpose processor unit 62 without an interpreter (15). In this case, a first command is added to the command string 26 to indicate that the subsequent information is not a command but a machine language. Further, an operation mode instruction register for instructing whether command processing or program processing is to be performed is added to the input/output control device 3, and this register is controlled by an external switch or a control command.

When the input/output interpreter learns that the subsequent contents of the command string 23 loaded in the RAM section 63-2 are programs, it verifies the contents of the operation mode instruction register and then executes the program in the command string 25. is executed by calling it as a subroutine of the interpreter. Test rolls or diagnostic programs that require detailed control are particularly suitable as such programs. In such a configuration, test) 6 or the diagnostic program must be run in advance.
Compared to the case where it is incorporated into the OM section 36-1, it has the advantage that the load on the ROM section can be reduced and the program can be made more flexible.

(16) In the above embodiment, the configuration was explained in which the central processing unit 1 creates the second command from the instruction related to the second command fetched from the main program in the main memory 2. It is also possible to adopt a configuration in which the CPU 1 stores the second command in the main memory 2, and the central processing unit 1, which has decoded the instruction related to the second command, transfers the second command in the main memory 2 to the control device 6.

As explained in detail above, the input/output side instructions of the present invention are written in the main program, and the central processing unit that has fetched the instructions related to the second command sends the second command to the input/output control device, The input/output control device that received this
Since the configuration reads and executes the command sequence according to the command, it is easier to create input/output control programs that are more flexible than conventional methods, and the load on the central processing unit can be significantly reduced. There is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional system, and FIGS. 2 and 6 are block diagrams of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Central processing unit, 2... Main memory, 3... Input/output control device, 4... Input/output device, 5... Bus, 2
DESCRIPTION OF SYMBOLS 1... Main program, 26... Command sequence consisting of a first command, 31... Input/output control register group, 32, 43... Processor unit, 35.4
4... Mesori, 41... Controller section, 42...
・Device section. Patent applicant Fuji Electric Seizo Co., Ltd. (1 other person) Representative patent attorney Gobe Tamamushi (3 others)

Claims (1)

[Claims] In an input/output control method for a computer system including a central processing unit, a main memory, an input/output control device, and an input/output device, a plurality of types of first commands instruct the input/output control of the computer system. A series of command sequences consisting of the following are separated from the main program and stored in the main memory, and an instruction related to a second command that instructs the input/output control unit to write and execute the command sequence is sent to the main program in the main memory. The central processing unit reads the instructions related to the second command by executing the main program, sends the second command to the input/output control unit, and executes the input/output control unit that receives the second command. An input/output control method for a computer system, wherein the output control device performs input/output control that minimally includes reading the command string from the main memory or executing the read command string.