JPS6315625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an input/output control device for a data processing device. In particular, the present invention relates to an input/output device connection control method when a plurality of data processing devices (including channel devices; the same applies in this specification) and a plurality of input/output devices are cross-connected.

Conventionally, a method is known in which a data processing device is cross-connected to a plurality of input/output devices to perform input/output control. In this case, as a method for data processing devices to use input/output devices, each data processing device shares the input/output device, and when transferring data, the input/output device is used only for the minimum necessary time (for example, the time to transfer 1 byte). A method for exclusive use is known. However, with this method, if the input/output device used by a data processing device is accessed due to a failure in another data processing device or a software error, it will have a negative impact on the device that is exclusively using it. It has a wide range of drawbacks.

Furthermore, as another method of using an input/output device, a method is known in which when a data processing device uses an input/output device, it is monopolized and all use by other data processing devices is prohibited. However, this method has the disadvantage that the use prohibition means prevents the data processing devices belonging to the system from using the input/output devices at any time, resulting in a decrease in efficiency.

Therefore, if use by other data processing equipment is prohibited, and the data processing equipment that is currently using the input/output device exclusively has a failure, the exclusive use of the input/output device can be released and other data processing equipment can be used. Techniques that can also be used in data processing devices have been proposed (Japanese Unexamined Patent Publications Nos. 54-2635 and 58954-1988).

However, this technology is only configured to release the currently occupied data processing device when a failure occurs, so for example, if one input/output device is being used online, another data processing device However, the program cannot be debugged by the program, and such processing must be performed by software, so there is a problem in that it is not possible to use a separate data processing device with a simple configuration.

The present invention improves this point, and the input/output devices used by the data processing device are not adversely affected by failures in other data processing devices or software errors, and moreover, the input/output device used by the data processing device is It is an object of the present invention to provide an input/output device connection control device that allows a data processing device whose use of the input/output device is prohibited by a prohibition means to use an input/output device in an idle state.

The input/output control device of the data processing device of the present invention includes:
The data processing devices each include a use request signal line serving as a path for a corresponding input/output device use request signal and an input/output device use prohibition request signal. A first circuit is connected to a use prohibition request signal line that serves as a passage for the use prohibition request signal line, and one of the use prohibition request signal lines is input to the first circuit, and a switch circuit input for disabling the use prohibition state is commonly input. and a second AND gate, connected to a data processing device different from the data processing device to which the output of the first AND gate and the use prohibition request signal line input to the first AND gate are connected. a third AND gate whose input is a use request signal line, and an output of the second AND gate and a use prohibition request signal line input to the second AND gate are connected. a fourth AND gate circuit whose input is a use request signal line connected to a data processing device different from that of the third AND gate, whose input is the output of the third and fourth AND gates, and whose output is connected to an input/output device. It is characterized by having an or gate with a For input/output devices, it is possible to prevent the operation of the input/output device used in one data processing device from being adversely affected due to a failure in the other data processing device or a software error, and to prevent software errors in the other system. The feature is that the input/output device required for debugging etc. can be used.

This will be explained in detail based on the drawings. FIG. 1 is a configuration diagram of one embodiment of the present invention. In this example,
An example is shown in which two channel devices are cross-connected to two input/output control devices. Figure 1 1 and 2
is a channel device. Use request signal lines 3 and 4, which serve as paths for input/output device use request signals, are connected to the channel devices 1 and 2.
The use request signal lines 3 and 4 are branched and connected to input terminals of selectors 6 and 7, respectively.

Further, a usage prohibition request signal line 9 is connected to the channel device 1, which serves as a path for an input/output device usage prohibition request signal to the channel device 2. The channel device 2 includes a use prohibition request signal line 10 that serves as a path for the input/output device use prohibition request signal to the channel device 1.
is connected. The use prohibition request signal lines 9 and 10 are branched and connected to input terminals of selectors 6 and 7, respectively. This selector 6
The selector outputs of and 7 are connected to input/output devices 12 and 13, respectively. Switch circuits 14 and 15 are connected to the selectors 6 and 7, respectively. This switch circuit 14
Reference numeral 15 denotes a circuit manually operated from the panel, which is used to invalidate the above-mentioned prohibited state.

FIG. 2 is a diagram showing an example of the electric circuit of the selectors 6 and 7 in the above example. For ease of explanation, FIG. 2 shows the case of the selector 6 for connection to the outside. Use prohibition request signal lines 10 and 9 are connected to input terminals of AND gates 17 and 18, respectively. This and gate 17
The output of the switch circuit 14 is commonly connected to the invert input terminals 18 and 18. The outputs of AND gates 17 and 18 are connected to invert input terminals of AND gates 19 and 20, respectively. Use request signal lines 3 and 4 are connected to other input terminals of AND gates 19 and 20, respectively. The outputs of AND gates 19 and 20 are connected to the input terminal of OR gate 21. The output of this OR gate 21 is connected to the input/output device 12.

With such a configuration, a case will now be described in which a use prohibition request signal is sent from the channel device 1 to the selector 6 or 7 depending on the contents of the software, and the switch circuit 14 or 15 is also in the "OFF" state. In this state, the invert inputs of AND gates 17 and 18 in selectors 6 and 7 are at "H" level. Therefore, the AND gate 18 to which the use prohibition request signal is input is "H".
The AND gate 17 outputs an "L" level output signal.

This "L" level output signal is given as an invert input to AND gate 19. Therefore, depending on the content of the software, channel device 1
When a use request signal is applied to the AND gate 19, an "H" level is output from the selector 6 or 7, and the channel device 1 and the input/output device 12 or 13 are connected. On the other hand, and gate 20
An "H" level output signal is applied from the AND gate 18 to the invert input of the circuit. Therefore, AND gate 20 is closed, and even if a use request signal is applied to AND gate 20 from channel device 2, it is blocked. Therefore, channel device 1
is exclusively connected to the input/output device 12 or 13, and is not adversely affected by a failure in the channel device 2 or a software error.

Further, in the above state, the switch circuit 14 or 15 is turned on. In this state, "H" level signals are applied to the invert inputs of AND gates 17 and 18. Therefore, AND gates 17 and 18 output "L" level signals. If this "L" level signal is given as an invert input to the AND gates 19 and 20, and a use request signal is given to the AND gate 20 from the channel device 2, an "H" level signal is sent from the selector 6 (or 7). Sent out. Thereby, the channel device 2 can be connected to the input/output device 12 or 14.

Therefore, if the switch circuit 14 or 15 corresponding to the input/output device 12 or 13 that is not being used by the channel device 1 is turned on by operation, the channel device 2 will turn on the input/output device 12 or 13 that is not being used. or 13 can be used.

As explained above, when a data processing device (including a channel device) sends an input/output device use prohibition request signal to another data processing device, the input/output device usage signal of this other data processing device is In addition, switch circuits were provided for input/output devices not used by the data processing device so that they could be used by other data processing devices. Therefore, the online processing side is not adversely affected by the offline processing side due to data processing device failures, software mistakes, etc.
Moreover, on the offline processing side, software can be debugged and troubleshooting can be performed, and system safety can be improved.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the present invention. FIG. 2 is a configuration diagram of the selector in the above example. 1.2...Channel device, 3.4...Use request signal line, 6.7...Selector, 9.10...Use prohibition request signal line, 12.13...I/O device, 14.15...
Switch circuit, 17-20...And gate, 21
…orgate.

Claims (1)

[Scope of Claims] 1. First and second data processing devices and a plurality of input/output devices are provided, and each of the data processing devices has a usage request signal line that serves as a path for a corresponding input/output device usage request signal. A use prohibition request signal line that serves as a path for the input/output device use prohibition request signal is connected, one of the above use prohibition request signal lines is input, and a switch circuit input for disabling the use prohibited state is connected. A data processing device to which the first and second AND gates input in common, the output of the first AND gate, and the use prohibition request signal line input to the first AND gate are connected. a third AND gate whose input is a use request signal line connected to a different data processing device; an output of the second AND gate; and a use prohibition request signal line input to the second AND gate. a fourth AND gate circuit whose input is a use request signal line connected to a data processing device different from the connected data processing device; and whose input is the output of the third and fourth AND gates; An input/output control device for a data processing device, comprising: an OR gate having an output connected to an input/output device;