JPS6339065A - Data transfer device - Google Patents

Abstract

PURPOSE:To avoid danger of the system breakdown caused by a channel error by increasing the number of channels set in a data transfer device compared with the number of buses of an actual input/output device for redundancy. CONSTITUTION:It is supposed that a channel 2n is idle with no port. Then a channel 22 has a trouble during transfer of data between a memory device and a device and an error detecting circuit 212 detects an error. Under such conditions, the channel 22 interrupts the transfer of data and gives an interruption of the error information to a program control part 1 via an interruption circuit 222 and a connection path 702. The interrupted microprogram collects the error information on the channel 22 and cuts off the channel 22 to give the second connection between the channel 22 and an input/output device. Here the contents of a path selection table 3 are read out and a channel 2n is used in place of the channel 22 since the channel 2n is idle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to error processing in a channel within a data transfer device of an information processing system, and particularly to a data transfer device designed to improve the reliability of the entire system.

[Conventional technology]

Conventionally, this type of data transfer device, as shown in Figure 3,
Connections between input/output devices and channels were fixed at one-to-one.

[Problem that the invention seeks to solve]

In the case of such a data transfer device, in the case of a failure in a single channel, either the microprogram control section scans and extracts the channel error at a certain timing, or the channel sends an interrupt to the microprogram control section. Then, the channel error is handled. The microprogram that enters the channel error processing disconnects the error channel, collects error information, reports it to the central processing unit, and passes it on to O8. The O8 that is notified of the channel error performs channel recovery processing, but in the case of a fixed failure,
A channel error will occur again, so send a message to alert the maintenance personnel. At this time, if a so-called alternative path is configured that can be connected to either channel 21 or channel 22, such as the magnetic disk devices under channels 21 and 22 in the figure, O8 can Job execution can continue using channel 11, but if this channel fails, the magnetic tape device under channel 23 cannot be accessed because there is no alternative path. There is a risk that the entire system will go down, and the system designer must configure alternative paths as much as possible, which has the disadvantage of increasing the system scale.

[Means for solving problems]

According to the present invention, in a data transfer device comprising a plurality of channels greater than the number of input/output devices and a microprogram control section that controls the channels according to the input/output devices, the microprogram control section A path selection table in which the connection relationship between the channel and the input/output device is written in accordance with the specified or input error information, and an input/output path selection table in which the connection between the channel and the input/output device is selected based on the values of the table. A data transfer device is obtained which comprises a network and in each channel error detection means for the channel and interrupt means for sending error information to the microprogram control unit in accordance with the error information of the channel. [Example] Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and shows a microprogram control section 1. Channels 21 to 2n, path selection table 3. Path selection network 4. Channel error detection circuit 2
11-21n, channel interrupt circuits 221-22n, connection paths 501-503.601-60n, 701-70n
, 801-80n, and 901-90m.

FIGS. 2A and 2B are conceptual diagrams showing the path selection table 3 of the data transfer device of the present invention, where the boat # corresponds to paths 901 to 90m from the input device, and CH# corresponds to channels 20 to 90m. 2n. According to this table, the path selection network 4 connects input/output devices and channels.

When the microprogram is loaded into the microprogram control unit 1, the data transfer device becomes executable.

When an input/output command is issued from a central processing unit (not shown), the microprogram connects the input/output devices of the channel. FIG. 2(A) shows a path selection table after connection is performed according to a predetermined algorithm, and the relationship between the number of paths m and the number of channels n of input/output devices is here n=m+1. As long as n>m, the difference between n and m may be any number, and is determined by the number of channels and the reliability of the system. Figure 2 (
The channels of CH#1 to CH#m in A) are connected to the paths of boats #1 to m, and the constant "FFFF" indicates that the channel of CH$n is empty with no boats.

After this connection is made, the microprogram control unit 1 continues input/output processing, decoding input/output instructions, starting channels, accepting termination interrupts, creating status, etc., and confirms that the input/output operation is completed. Notify the central processing unit using an input/output interrupt.

When a failure occurs in the channel 22 during data transfer between the memory device and the device, and the error detection circuit 212 detects an error, the channel 22 interrupts the transfer between the device and the memory device, and interrupts the interrupt circuit 222 and the connection bus. 702 is used to send error information to the microprogram control unit 1 and interrupt it.

The interrupted microprogram collects error information on the channel 22, disconnects the channel 22, and reconnects the channel to the input/output device. Here, the contents of path selection table 3 (Fig. 2 (A)) are read out from CH9.
Since channel 2n of channel n is empty, CH9n is made to correspond to boat #2 instead of CH#2 of channel 22, which has failed, and CH#2 has "ooooo" indicating that it is failed.
" is set as shown in FIG. 2(B).Then, the microprogram control unit 1 reports the error in the channel 22 to the O8 of the central processing unit, and re-executes the job. After loading, channel 2n becomes channel 2.
It becomes visible as 2. Therefore, as described above, if the number of channels is extremely large and there is a probability that some channels will fail at the same time, the number of hot standby channels can be increased. Furthermore, if no more failures occur, there is no need to replace the failed channel, and the time it takes to stop the system can be reduced.

〔Effect of the invention〕

As explained above, the present invention suppresses the risk of system failure due to channel errors by increasing the number of channels in the data transfer device than the actual input/output device paths to create redundancy, and also provides alternative paths. The effect is that there is no need to install many.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a data transfer device of the present invention.
1. Microprogram control unit, 21 to 2n, channels, 211 to 21n, channel error detection circuit, 3. Path selection table, 221-22n, channel interrupt circuit, 4
．． Path selection network, 501-503, 601-60n, 70
1-70n. 801 to 80n and 901 to 90m are connection paths. FIGS. 2A and 2B are conceptual diagrams of the bus selection table shown in FIG. 1 and 3. FIG. 3 is a block diagram showing a conventional data transfer device and input/output device. 21 to 26. Channel. ・111g5g 1 roasted 5 [,)7ri 1 roasted 3141 figure c Anda 2 figure

Claims (1)

[Claims] In a data transfer device consisting of a plurality of channels greater than the number of input/output devices and a microprogram control unit that controls the channels according to the input/output devices, the microprogram control unit a path selection table in which connection relationships between the channels and input/output devices are written and read according to error information;
an input/output path selection network that selects connections between input and output devices of a channel according to values in the table;
A data transfer device comprising channel error detection means and interrupt means for sending error information to the microprogram control unit in accordance with the channel error information.