JPH0361388B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] The present invention acquires and processes information such as processing requests for the next line to be scanned in advance in order to speed up line scanning processing in a communication control device. In a line scanning mechanism that receives instructions from a device and performs a control operation for a specific line separately from the line scanning process, it is possible to prevent logical contradictions from occurring due to conflict between the control operation and the preceding operation. Therefore, when the line for which the control operation is instructed is the line to be scanned next to the line currently being processed, the control operation is held on hold until the processing of the line is completed.

[Industrial application field]

The present invention relates to the control of a line scanning mechanism of a communication control device that is located between a plurality of data communication lines and a data processing device and controls data transfer therebetween, and particularly relates to the control of a line scanning mechanism of a communication control device that is located between a plurality of data communication lines and a data processing device and controls data transfer therebetween. A line scanning process in a line scanning mechanism that adopts a method of proactively acquiring state information etc. of the line to be scanned next, and an operation related to a line control instruction from a higher-level device that occurs asynchronously with the line scanning process. This relates to control to prevent logical contradictions from occurring when conflicts occur.

[Conventional technology]

A line scanning mechanism of a communication control device includes a line scanning process of scanning a plurality of communication lines connected to the communication control device to transfer data, etc.;
Processing related to control of a specific line based on instructions from a higher-level device, which occurs asynchronously, is performed.

These line-related processes perform operations such as reading line information, line processing, and setting line information. Examples of the latter control of a specific line based on instructions from a higher-level device include reception reset instructions and transmission. There are instructions to start.

Operations such as reading line information, line processing, and setting line information related to line scanning processing are conventionally performed.
This used to be done serially, but in recent years, in order to speed up the line scanning process, the line information of the line to be scanned next to the line currently being processed is read out in advance while the current line is being processed. Increasingly, a control system based on

[Problem that the invention seeks to solve]

If a control method is adopted in which the line information of the line to be scanned next is acquired in advance as described above, the line scanning process and the control operation based on instructions from the higher-level device that occur asynchronously with this are performed. If executed as is, a conflict may occur and a logical contradiction may occur.

To explain this logical contradiction, for example, when pre-reading line information including a character processing request for a certain line, an instruction from the host device is generated before this line information is used, and In some cases, a reset may have been executed, and in this case, in the next line scanning process, a character processing request is detected from the line that was supposed to have been reset, resulting in a logical contradiction.

Conventionally, in order to prevent the occurrence of such logical contradictions, even if an instruction is received from a higher-level device, the control operation is not performed immediately, but the control operation is executed when the next line is scanned, or when a series of lines are scanned. A method has been adopted in which the control operation is executed between the end of a scan and the start of the next line scan.

However, this method has a problem in that even if an instruction is received from a higher-level device, the corresponding control cannot be executed immediately.

In view of such conventional problems, in order to speed up the line scanning process, the present invention acquires line information of the line to be scanned next in advance, and also responds to instructions from the host device. It is an object of the present invention to provide a control system for a line scanning mechanism that can respond quickly and without causing logical contradictions.

[Means for solving problems]

According to the present invention, as described in the claims, the purpose is to perform a line scanning process in which a plurality of lines are sequentially scanned, a processing request from the line is detected, and the process is performed, and a request from a host device to a specific line. In a line scanning mechanism of a communication control device that, when a control operation is instructed, interrupts the line scanning process being executed at line-by-line divisions and performs the instructed control operation,
During line scanning processing, a means is provided for preemptively reading status information including a processing request for a line to be scanned next to the line currently being processed, and a control operation for a specific line from a host device is performed during execution of line scanning processing. When instructed, if the address of the line and the address of the line to be scanned next match, execution of the control operation in accordance with the instruction from the host device is suspended, and if the addresses do not match, the control operation is carried out. This is achieved by a line scanning mechanism control method characterized by implementation.

〔Example〕

FIG. 1 is a flowchart showing control of one embodiment of the present invention.

As shown in FIG. 1, in this embodiment, normally, as shown by symbol 1 in the figure, line processing of a certain line and information reading of the next line are performed in parallel, and then the line By setting the information, processing for one line related to line scanning is completed, and if there is no control instruction for a specific line from the host device during this time, the line address to be scanned is updated and the next line scanning process 1 is started. Running.

When a higher-level device instructs control of a specific line, if the line address is a line (line i in the figure) for which line information has been previously read in the previous line scanning process, the upper-level device will control the specified line. Do not immediately execute the line control process, but temporarily suspend it, perform the line scanning process (indicated by 2 in the diagram) for the line (i line), and then hold it until then. The line control processing (indicated by 3 in the figure) is executed. Thereafter, the scanning line address is updated and normal scanning processing is resumed. In this case, the value of j shown in line control processing 3 is equal to i, and the updated value of the scanning line address is i+1.

On the other hand, the line that is instructed to be controlled by the host device is
If the line is different from the line for which the line information was previously read in the previous scanning process, the line address for scanning is updated after immediately performing a control operation for the instructed line (line j). (In this case, the updated value is i) and the scanning process for the next line is started.

As shown in the figure, in the above-mentioned line control processing 3, line information reading, line processing, and line information setting operations are performed in three stages (preliminary operations are not performed).

In the present invention, when a control operation is instructed for a line whose line information has been read in advance in this way, the control operation according to the instruction from the host device is performed after completing the scanning process for the line. Since it is executed, no logical contradiction occurs.

FIG. 2 is a diagram showing an example of an apparatus for implementing the present invention.

In FIG. 2, control memory 4 stores microprograms that control the operation of the line scanning mechanism.
The microprocessor 5 reads a microprogram from the control memory 4 and executes it, thereby controlling the operation of the entire line scanning mechanism.

The common bus interface controller 6 controls data transfer between the line scanning mechanism and the common bus.
The working RAM 7 stores control information for each line and a portion of transmission/reception data. The scanning address creation unit 8 creates a line address for scanning N line adapters. The control address holding unit 9 holds a line address for performing line control processing instructed by a higher-level device. The adapter interface control unit 10 controls data transfer between the line adapters 14 ₁ to 14 _o according to instructions from the microprocessor 5. The pre-read control unit 11 pre-reads and holds information from the line adapter specified by the next line address according to instructions from the microprocessor. This information is used by the microprocessor during the next line scan process.

During line scanning processing, the address switching circuit 12 selects the next line address created by the scanning address creation unit when the advance readout control unit 11 performs advance readout, and selects the current line address in other cases to switch the line. Send to address bus. Also, during execution of line control processing, the line address held by the control address holding unit is selected.

The data switching circuit 13 is the advance read control section 11
When performing advance reading, the advance read control section 11 is connected to the line data bus 18, and in other cases, the adapter interface control section 10 is connected to the line data bus 18.

Line address bus 17 conveys a line address for designating one of the N line adapters. The line data bus 18 is a bidirectional bus for transferring data between the line adapter designated by the line address on the line address bus 17 and the line scanning mechanism. There are two types of data transfer directions via this bus: reading information from the line adapter and setting information to the line adapter.

The line adapters 14 ₁ to 14 _o have a character disassembly and assembly function for transmitting and receiving data in bit series for the line. When the character assembly of the received data from the line is completed, a received character processing request is generated to request processing from the line scanning mechanism. Furthermore, when the character decomposition of the transmission data to be sent to the line is completed, a transmission character processing request is generated to request the line scanning mechanism to perform the processing.

FIG. 3 is a time chart for explaining the temporal relationship of processing, and shows a case where an instruction to control line j is issued from a host device during time period A shown in the figure. In the figure, the upper row of the line data bus signals shows the signal from the line adapter to the line scanning mechanism, and the lower row shows the signal from the line scanning mechanism to the line adapter.

〔Effect of the invention〕

As explained in detail above, according to the method of the present invention, in a line scanning mechanism of a communication control device configured to obtain line information of a line to be scanned next in advance to speed up processing. , it is possible to quickly execute processing related to a line control processing instruction from a higher-level device that occurs asynchronously with line scanning processing, and line information is obtained in advance based on this instruction. Even if a line is specified, no logical contradiction will occur. Therefore, it is possible to easily realize a communication control device that is capable of high-speed line scanning processing and can quickly execute control operations for a specific line based on instructions from a host device, which is highly effective.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing control of one embodiment of the present invention, FIG. 2 is a diagram showing an example of an apparatus implementing the present invention, and FIG. 3 is a time chart. 1, 2...Line scanning processing, 3...Line control processing, 4...Control memory, 5...Microprocessor, 6...Common bus interface control unit, 7...
...Working RAM, 8...Scanning address creation section, 9
...Control address holding unit, 10...Adapter interface control unit, 11...Preliminary reading control unit,
12... Address switching circuit, 13... Data switching circuit, 14 ₁ to 14 _o ... Line adapter, 15
...Current line address, 16...Next line address,
17... Line address bus, 18... Line data bus.

Claims (1)

[Claims] 1 Line scanning processing that sequentially scans multiple lines to detect and process processing requests from the lines, and line scanning processing that is currently being executed when a control operation for a specific line is instructed from a higher-level device. In a line scanning mechanism of a communication control device that performs an instructed control operation by interrupting at a break, during line scanning processing, state information including a processing request for a line to be scanned next to the line currently being processed is read in advance. When a higher-level device instructs a control operation for a specific line during execution of line scanning processing, if the address of the line matches the address of the next line to be scanned, the instruction from the higher-level device 1. A line scanning mechanism control method, wherein execution of a control operation is suspended, and when the two addresses do not match, the control operation is executed.