JPH0445870B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a program for controlling data communication between a central processing unit and a data communication line, or between another communication control processing device and a data communication line, using a dedicated communication control program. The present invention relates to a built-in communication control processing device.

Recently, in the field of computer systems, with the spread of distributed processing, multiple central processing units (hereinafter referred to as
(abbreviated as CPU), it has become common to connect a large number of terminals via communication lines to form a computer network. In such computer networks, a communication control program (hereinafter referred to as
Communication control processing unit (abbreviated as NCP)
(abbreviated as CCP). CCPs with built-in programs are becoming popular.

Conventional CCPs with built-in programs of this type
Now let's talk about the central control unit (hereinafter referred to as CCU) that processes NCP.
(hereinafter abbreviated as MMU), a storage device that stores NCP and transfer data (hereinafter abbreviated as MMU),
A channel connection device (hereinafter abbreviated as CAU) that controls the channel data transfer of the CPU, and a line connection device (hereinafter abbreviated as LIU) that controls the data transfer of the communication line are radially connected.
LIU etc. are all controlled by the CCU reading out machine language instructions from the MMU and executing them.

Conventionally, in this type of CCP, CAU, LIU
Finally, CCU command execution is required to control the
CPU channel, MMU, data communication line and
Since the CCU's leadware operates to transfer data to and from the MMU, execution of the NCP is obstructed and processing performance is reduced. Also, because the CAU and LIU have different wiring logics, several different types of hardware must be prepared to connect them to channels and communication lines that use different electrical interfaces and control procedures.
Furthermore, it is impossible to connect devices for new purposes such as magnetic disk devices, and it lacks expandability and flexibility. Furthermore, since control is concentrated in the CCU, it is impossible to continue system operation in the event of a CCU failure, and the CAU, LIU
It has the disadvantage that it is disconnected even when the system fails, and the control of its degenerate operation is extremely complicated.

On the other hand, in recent CCPs, with the increase in data communication speed, it is desired to improve the processing capacity of CCPs.
There is also a demand for connection of auxiliary storage devices such as magnetic disks for data communication using store-and-forward methods. Also, CCP
Failure of the CCP will lead to the online computer system going down and develop into a major social problem.
The requirements for reliability and availability are extremely high.

This invention was made to eliminate the above-mentioned drawbacks of the conventional technology.CCU, CAU, LIU,
Controls the operating status of MMU and each of these devices
The CCU can
The purpose of the present invention is to provide a communication control processing device that can continue system operation even in the event of a failure of the CAU or LIU, and that can easily disconnect the CAU or LIU and control degenerate operation in the event of a failure.

An embodiment of the invention shown in FIG. 1 will be described below. FIG. 1 is a block diagram showing one embodiment of this invention, in which 1 is a CPU, 2 is a channel control device (hereinafter referred to as
(abbreviated as CH), 3 is channel, 4 is CCP, 5
is a data communication line, 6 is a terminal, and 7 is a communication control processing unit (hereinafter abbreviated as RCP) without CAU, which is a modification of the present invention.

Next, the operation will be explained. CH2 is CPU1
During CCP4, the data sent from the CPU is converted to channel transfer data and sent via channel 3.
It sends it to CCP4, and also converts the transfer data from CCP4 via channel 3 into received data and sends it to CPU1.

CCP4 is connected to CH2 via channel 3 and to multiple terminals 6 and RCP7 via data communication line 5, operates under the control of NCP, and transmits the transmission data sent from CH2 using control means specific to each data communication line. Reassemble according to the speed, terminal 6 or
Send to RCP7, conversely to multiple terminals 6 and RCP7
The received data sent from the controller is reassembled into transfer data on channel 3 and sent back to the CPU 1 via CH2. On the other hand, the RCP 7 is connected to a plurality of terminals 6 and the CCP 4 via the data communication line 5, operates under the control of the NCP, and performs specific control procedures, communication speed conversion, etc. for each data communication line.
RCP7 just doesn't have CAU, and its operation is
Since it is included in CCP4, only the differences will be explained below.

Figure 2 is a block diagram showing an example of the internal connections of CCP4 and RCP7 shown in Figure 1.
1 is common bus, 12 is CCU, 13 is MMU, 14
is CAU, 15 is LIU, 16 is SCU, and RCP
7 does not have CAU14.

The common bus 11 includes a data bus (hereinafter abbreviated as SDB) 17 used for data transfer between the above devices;
An address bus (hereinafter abbreviated as SAB) 18 that transfers the address of the MMU 13 and a device identification address specified for each of the above devices, a control bus (hereinafter abbreviated as SAB) 18 that specifies the control code, direction, etc. of data transfer between the above devices. (abbreviated as SCB) consists of 19 components.

Also CCU12, CAU14, LIU15, SCU1
6 are independent microprograms, namely central controller microprograms (hereinafter referred to as
(abbreviated as CCUM) 20, channel connection device microprogram (hereinafter abbreviated as CAUM) 2
1. Line connection device microprogram (hereinafter
It has a system management unit microprogram (hereinafter abbreviated as SCUM) 22 (abbreviated as LIUM) 23.

During normal operation, CCU12 stores machine language instructions in SAB18 under the control of CCUM20.
Load the address of MMU13 and send the command read control code to SCB19, via SDB17
Instructions read from the MMU 13 are processed by a central controller arithmetic unit (hereinafter abbreviated as ALU) 24.

On the other hand, CAU14 operates independently of CCU12,
When a data transmission request is received from CH2, CAUM
21, communicates with CH2 and transfers the data to the channel connection device data buffer (hereinafter referred to as
(abbreviated as CABF) 25, removes the control code for channel data transfer, returns the necessary status code to CH2, and places the data storage area address on the MMU 13 specified in advance by the CCU 12 on the SAB 18. Sends the data write control code to the SCB 19 and writes the data sent via the SDB 17 to the MMU 13. Conversely, when a data transmission request is received from the CCU 12, the CCU 12
It only initiates transfer to CAU14,
After that, CAUM21 specifies the data storage area address specified in advance via SAB18, and the SDB
The received data read from the MMU 13 via No. 17 is temporarily stored in the CABF 25, and sent to CH2 after adding necessary control codes and status codes.

The specification of the data storage area address on the MMU 13 from the CCU 12, the activation of data transfer of the CAU 14, etc. are all carried out with the CCUM 20 via the common bus 11.
This was realized through the questions and answers of CAUM21, and CCUM20
Enter the device identification address of CAU14 on SAB18,
Put the data storage area address on SDB17,
Addressing or activation control code SCB19
and notify CAUM21.

Here, the CAUM 21 may be composed of a plurality of types of microprograms, and the operating microprogram can be switched according to control instructions from the SCU 16. In general, a normal computer system may have multiple types of channels due to differences in connected devices and data transfer speeds, but this is mainly due to differences in data transfer timing and control codes. In a preferred embodiment of the present invention, this can be realized by configuring the control memory that stores the CAUM 21 with a rewritable memory element and rewriting this from the SCU 16. Note that the operation of the CAU 14 described above is not included in the RCP 7. Similarly, LIU15 is
It operates independently of the CCU 12, and under the control of the LIUM 22, the transfer data sent from the data communication line 5 according to various control procedures is temporarily stored in the line connection device data buffer (hereinafter abbreviated as LUBF) 26 and various control procedures. Processes the unique control code, reassembles it into received data and sends it to SAB1 via SDB17.
Write to the data storage area on the MMU 13 specified by 8. Conversely, when a data transfer request is received from the CCU 12, the LIUM 22 reads out the transmission data stored in the MMU 13, adds a control code according to various control procedures, and sends it to the data communication line 5.

Processing of control procedures for this data communication line includes not only parallel/serial conversion of data, but also complex processing such as determination, insertion, and deletion of special characters, NRZI processing of HDLC procedures, and flag detection. For this reason
The LIUM 22 is composed of multiple types of microprograms, and is specified to the LIU 15 by the SCU 16. Selected based on configuration control information indicating attributes of the data communication line.

As mentioned above, CCU12 and CAU1 in the present invention
Control devices such as 4, LIU 15, and SCU 16 are equally connected to the common bus 11 and can operate independently. Similarly, by adding other control devices that have dedicated microprograms and can operate independently to the common bus 11, new purposes such as magnetic disks can be created without changing the existing control device and common bus. It is possible to connect peripheral devices for CCP4 or RCP7.

Next, the operation when a failure occurs in each device in the CCP 4 and RCP 7 will be explained. Normal operation
The SCU 16 constantly monitors the operating status of each device in the CCP4RCP7 and the common bus 11, and
When a failure is detected in the CAU 14, the operation of the above device is temporarily stopped, the failure location is determined under the control of the SCUM 23, and a recovery operation is initiated.

SCUM2 if a failure is discovered in channel 3
3 is a channel connection switching mechanism (hereinafter abbreviated as TCSW) 27 of the CAU 14 via the common bus 11.
A switching instruction is sent to change the connection to another channel 28. Further, if a failure is discovered in the CAU 14 itself, the SCUM 23 instructs the CAU 14 to disconnect and activates the standby CAU 29. For this reason, the CAUs 14 and 29 include operation and standby control flags, and functions for setting and resetting the flags by the CAUM 21.

In other general CCPs, if a failure is discovered in the CCU, it is impossible to continue the system operation, but in one embodiment of the present invention that requires high reliability, a standby CCU 30 is provided. It is possible to do so.

Further, it is desirable that the MMU 13 has an automatic error correction mechanism, but in an embodiment that requires even higher reliability, it is possible to have a standby MMU 31.

On the other hand, the data communication line control procedure includes a retransmission procedure for transferred data in order to ensure the transmission quality of the line. Therefore, in the event of a failure of the LIU 15, the data communication line connection switching mechanism (hereinafter abbreviated as LSSW) 3 installed outside the LIU 15
2, line connection switching signal 3 from SCU16
LIU for sending out 3 and waiting for data communication line connection
34, and then switch LIUs 15 and 34 between operation and standby as in the case of CAUs 14 and 29, and then execute the above retransmission procedure to eliminate failures without stopping system operation.
LIU15 can be disconnected.

As described above, according to the present invention, the channel connection device, central control device, and line connection device necessary as a program-embedded communication control processing device are controlled by a dedicated microprogram, and detailed operations of various channels and data communication line processing are performed. By absorbing the differences in each microprogram, it is possible to standardize the hardware, and by connecting each of the above devices to a common bus along with a storage device and a control device for other purposes, it is possible to operate independently of each other. By making this possible, the load on the central control device can be distributed, and a communication control processing device with high scalability and flexibility with a high price/performance ratio can be realized. In addition, since the system management device monitors and controls the operation of each of the above-mentioned devices in the communication control processing device using a common bus, any failure can be dealt with promptly and availability is improved. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a block diagram showing details of the communication control processing device shown in FIG. In the figure, 11 is a common bus, 12 is a central control unit, 13 is a storage device, 14 is a channel connection device, 15 is a line connection device, 16 is a system management device, 20 is a central control device microprogram, 2
1 is a channel connection device microprogram, 22
23 is a line connection device microprogram, and 23 is a system management microprogram. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. Between the central processing unit and a data communication line that requires various communication control procedures, connected to a channel of the central processing unit, and capable of data communication with the central processing unit using a dedicated communication control program. A communication control processing device that controls the transmission and reception of data between lines includes a channel connection device that controls channel data transfer, a central control device that processes a communication control program, and a memory that stores the communication control program and transfer data. A device and a line connection device for controlling a data communication line are provided, and each of these devices is connected by a common bus, and the channel connection device, the central control device, and the line connection device are each controlled by independent microprograms. and further comprising a system management device having an independent microprogram and connected to the common bus to monitor and control the operating states of the channel connection device, central control device, storage device, and line connection device. Communication control processing device.