JPS60167054A - Common use control system - Google Patents

Abstract

PURPOSE:To simplify a power supply system by bringing a shared memory under the control of some input/output controller, and supplying electric power to the shared memory from the power unit for the input/output controller. CONSTITUTION:The shared memory M belongs to the input/output controller C0 including the power supply system. This input/output controller C0 and shared memory M are supplied with electric power from the power unit P0 through a power supply line L0, and the input/output controller C1, on the other hand, is supplied with electric power through a power supply line L1. Voltage detecting circuit V0 and V1 detect power supply states respectively. When the power unit P0 is on, the shared memory M and internal memory M0 are usable and when a power unit P1 is on, the internal memory M1 is usable. Further, when the power units P0 and P1 are both on, the shared memory M and internal memories M0 and M1 are usable. When only an input/output controller supplied with an input/ output command is in a power supply state during exclusive control, only its internal memory is used to perform the exclusive control.

Description

DETAILED DESCRIPTION OF THE INVENTION A0 Technical details of the invention The present invention relates to a shared control system, particularly a case where a plurality of input/output control devices that share a plurality of input/output devices are shared by a plurality of upper channels, If an input/output device consisting of a higher-level channel is reserved, and an I/O request is made to the input/output device by another higher-level channel,
This invention relates to a shared control method that rejects this input/output request.

B. Prior art and its problems Multiple input/output control devices that share multiple input/output devices,
In a shared control method in which I/O devices are shared by Il number of upper channels, if an I/O device is reserved by a channel and an I/O request is made to that I/O device from another channel, this I/O device is It is necessary to perform exclusive control to deny output requests.

As shown in FIG. 1, as a shared control method that performs exclusive control, r>+1 input/output devices Do, Di...On
For example, if the input/output controllers are shared by two input/output controllers Co and Cx, and these input/output controllers are shared by the host systems So and Sl equipped with host computers, the input/output controllers from both Co and C1 There is a method that has an accessible shared memory M and performs exclusive control based on the recorded contents of this memory.

In such a shared control method, the information for identifying the upper system is system ■]) (IdeF&tificatio) for each channel of each upper system.
n) wo, command ° set system ID”K!, D.

Channel baud of input/output control devices Co and Cz) Set to A and B and held for each channel route of the input/output control device. That is, the ID of the system So is set in the channel port A of the input/output control device Co and the channel port A of the input/output control device Cz, and on the other hand, the ID of the system So is set in the channel port A of the input/output control device Co and the channel port A of the input/output control device Cz.
The ID of system S1 is set in channel port B of .

For example, when a reserve command for input/output device Do is given from system So to input/output control device Co, the system ID held in channel port A is
Write to the address assigned to the input/output device Do on the shared memory M. Figure 2 shows the system ID at the address assigned to the input/output device Do on the shared memory IJM.
Indicates the state in which is written.

With the input/output device Do reserved by the system So, the input/output device Do is reserved by the system S1.

When an input/output command is given to the channel port B of the input/output control device c9, the system ID held in that channel port and the address of the shared memory M corresponding to the input/output device Do that requested one person to appear are Compare the system ID written in the . In this case, since these system IDs do not match, the input/output device Do is deemed unusable and the input/output command is rejected. This exclusive control is performed not only between systems as described above, but also between channel routes (between A and B).

In the conventional shared control method that performs such exclusive control, in order to share the shared memo 'JM between the input/output control devices CO and CI, the shared memo 'IJM' is shared even when either input/output control device is in the power supply state. It is necessary to activate it. For this reason, the power supply system in the conventional shared control system, as shown in FIG.
O and the power supply Pl on the input/output control device C1 side must be connected to the shared memory IJM via the common power supply line 3 through the backflow prevention diodes 1 and 2, respectively.

As described above, since power must be supplied to the shared memory from two power supply devices, the power supply system becomes complicated.

C8 Object and Structure of the Invention An object of the invention is to provide a shared control system that can simplify the power supply system.

Therefore, the present invention provides a plurality of input/output control devices shared by a plurality of upper channels, and a plurality of input/output devices shared by these input/output control devices.

The shared control method includes a shared memory that can be accessed from each of the plurality of input/output control devices, and performs exclusive control based on the recorded contents of the shared memory, the shared memory being connected to a power supply system. In addition, each of the input/output control devices is provided with an internal memory and a detection circuit for detecting the power supply status of the other input/output control devices, and the input/output control device is assigned to one of the input/output control devices. When an input/output request is made to an output control device, based on the information from the detection circuit, if the other input/output control device is in a power supply state, the shared memory is used, and the other input/output control device The present invention is characterized in that when power is not supplied, exclusive control is performed using only the internal memory of the input/output control device that received the input/output request.

D0 Embodiments of the Invention In the following embodiments, for the sake of simplicity, a system including two input/output control devices will be described as an example.

FIG. 4 is a block diagram particularly for explaining the power supply system in one embodiment of the present invention.

The shared memo IJM, including the power supply system, is assigned to the input/output control device Co. This input/output control device C.

Power is supplied to the shared memo IJM through the power supply Pa and the stain source supply line Lo. On the other hand, the input/output control device C1 includes a power supply device P1 and a stain source supply line L.
Power is supplied via 1. Internal memo for each input/output control device! J Mo, Ml, and voltage detection circuit Vo.

vl. Voltage detection circuit V.

are connected to the power supply line L1, and the voltage detection circuit Vl is connected to the power supply line Lo to detect the power supply state, respectively.

In the power supply system as described above, when the power supply device Pa is on, the shared memory M and the internal memory MO are in a usable state, and when the power supply device Pz is on, the internal memory M1 is in a usable state. Maku, power supply device P
When o and Pa are both on, shared memory M and internal memories Mo and Ml are available for use.

For this reason, in the present invention, during exclusive control.

When only the input/output control device to which the input/output command is given is in a power supply state, exclusive control is performed using its internal memory, and the input/output control device to which the 9-person output command is given and other input/output control devices When the power supply is on, shared memory is used to perform exclusive control.

FIG. 5 is a block diagram showing an embodiment of the shared control system having the power supply system described in FIG. 4.

For example, upper systems So and Sl consisting of host computers share input/output control devices Co and Ccl, and these input/output control devices are connected to commonly connected input/output devices Do, Di...DB. It is assumed that they are shared. Channel port) A of input/output control device Co and channel port) A of input/output control device Cz are
o to each channel to form each channel route. Channel port B of the single-person output control device Co and channel port B of the input/output control device C1 are connected to each channel of the system S1 to form each channel route.

Each input/output control device is provided with internal memories Mo and Ml, respectively, as explained in FIG.
The shared memory M is assigned to the input/output control device Co. These internal memories No., Ml and shared memory IJ M
As shown in FIG.

It has addresses corresponding to the input/output devices Do, Di, . . . , Da, respectively. In addition, the shared memory M is a memory
It can be read from and written to by input/output controllers co and Cz via read/write interfaces (not shown), respectively.

Next, the operation of this embodiment will be explained. System ID for separating the systems for each upper channel path of each system So and Sz? Command “set system”
Set each channel route separately. That is, channel port A of input/output controller Co and channel port A of input/output controller C1 have system 5o (DID''').
X# is set.

On the other hand, the ID "Y" of the system Sl is set in the channel port B of the input/output control device Co and the channel port B of the input/output control device Cz.

For example, if a reserve command for the nine-person output device tDo is given to the channel port A of the input/output control device Co from the system so, the system ID "X" set in the channel port A of the one-person output control device Co will be
Input/output device Do of internal memory MO and shared memory M
is written to the address assigned to . Furthermore, when a reserve command is given from the system s1 to the input/output device D1 of the channel port B of the input/output control device co.

The system ID "Y#" held in the channel port (H) of the input/output control device Co is written to the address assigned to the input/output device DI of the internal memory Ml and the shared memory M.The input/output control device Cz No reserve command has been given to .

If the internal memory Mz is non-reserved, the shared memory M, internal memory Mo, internal memory Mx
The recorded contents are shown in Figures 6(a), (b), and (c), respectively. In the figure, the non-reserved address is shown as a blank space, but for example, a special ID (for example, all 0s) indicating that it is non-reserved, such as 9, can be written therein.

Exclusive control when an input/output command is given in such a state will be explained below. FIG. 7 is a flowchart showing the exclusive control operation. For example, assume that an input/output command for input/output device Do is sent from an upper channel of system So to channel port A of input/output control device Co. Further, at this time, it is assumed that the power supply Px on the side of the input/output control device C1 is turned off and the input/output control device C1 is in a state where power is not supplied.

The voltage detection circuit vO on the input/output control device Co side detects this and instructs to use the internal memory Mo. The input/output control device Co reads the contents of the address (assigned to the input/output device Dz) specified by the input/output command from the internal memory Mo.

Determine whether it is reserved. in this case.

The system ID ``''Y2 is reserved at that address, and it is determined whether this system ID ``Y'' is the same as the system ID set in the channel root currently being executed, that is, the channel boat. Ru. In this case, the running channel boat is the input/output controller Co.
Since the system ID set in channel port A is "X", it is determined that there is a mismatch. the result.

This input/output command will be rejected.

The above has explained an example of exclusive control between channel routes, but as shown in the flowchart in Figure 7, if the specified address is not reserved, the input/output command will be executed, and the reserved system ID If the input/output command matches the system ID set in the channel root being executed, the input/output command will be executed. The operation shown in FIG. 7 may be considered to be performed by, for example, a microprogram.

To help understand the operation of this embodiment, the operation of exclusive control between systems will be explained. When the recorded contents of the shared memory M, internal memories Mo and Ml are in the state shown in FIG. Suppose that the call was made to H. Also,
At this time, it is assumed that the power supply device 1iPo on the input/output control device CO side is turned on, and power is being supplied to the input/output control device Co. The voltage detection circuit v1 on the input/output control device Cz side detects this and instructs to use the shared memory UM. The input/output control device C1 receives the address (input/output device Do) specified by the input/output command.
The contents of the shared memory M are read from the shared memory M, and it is determined whether the contents are reserved. in this case,
The system ID "X" is reserved for that address, and this system ID "X" is the channel route currently being executed.

In other words, system I set on the channel boat
It is determined whether or not it is the same as D. In this case, the channel boat being executed is channel boat B of the input/output controller Cz, and the system ID set is #Y'.
Therefore, it is determined that there is a mismatch. As a result, this input/output command will be rejected.

That is, in the case of the embodiment, when power is supplied to both the input/output control device Co and the input/output control device C1, exclusive control is performed based on the contents of the shared memo IJM. When the contents of the shared memory M are updated, the updated contents are reflected in the internal memory MO or Ml belonging to the access route at that time. In addition, when power is not supplied to the input/output control device Co or C1 on one side, the input/output control device C1 or CO on the other side must at least consider exclusive control across the input/output control devices. Therefore, exclusive control is performed using its own internal memory without using the shared memory Mt.

E0 Effects of the Invention According to the shared control method of the present invention, the shared memory is assigned to the input/output control device, and the power supply to the shared memory is performed by the power supply device for this input/output control device, so that the power supply is reduced. The system becomes simple.

In order to adopt such a power supply system, each input/output control device must be equipped with an internal memory and voltage detection circuit, but since these components are inexpensive, the overall control system costs less than conventional systems. It has the advantage of being inexpensive.

[Brief explanation of drawings]

Figure 1 is a block diagram of the conventional shared control system, Figure 2 is a diagram showing the recorded contents of the shared memory, Figure 3 is a diagram showing the power supply system of the conventional shared control system, and Figure 4 is the shared control system of the present invention. The figure which shows the power supply system of a control method. FIG. 5 is a block diagram of an embodiment of the present invention, FIG. 6 is a diagram showing recorded contents of the shared memory and internal memory, and FIG. 7 is a flowchart 1 of exclusive control operation. In the figure, So and Sl are the system, A and B are the channel boats, Co and C1 are the input/output control device 9M is the shared memory,
Mo, Ml are internal memories, Do, Dl...
D is input/output device, Vo, vl is voltage detection circuit, Po
, Pl indicates a power supply device g, Lo and Lx indicate a power supply line, respectively. Patent applicant: Fujitsu Ltd. Representative Patent Attorney Mori 1) Hiroshi (1 other person), 2 years old, 3 years old, 3 years old

Claims (1)

[Claims] A plurality of input/output control devices shared by a plurality of upper channels, a plurality of input/output devices shared by these input/output control devices, and a shared memory accessible from each of the plurality of input/output control devices. The shared control method is configured to perform exclusive control based on the recorded contents of the shared memory, the shared memory being assigned to any of the input/output control devices including the power supply system, and the input/output control system Each of the control devices is provided with an internal memory and a detection circuit that detects the power supply state of other input/output control devices, and when an input/output request is received from the upper channel to the input/output control device, the vehicle inspection circuit Based on the information, if the other input/output control device is in the power supply state, the shared memory is used, and if the other input/output control device is not in the power supply state, the input/output request is performed. A shared control method characterized in that exclusive control is performed using only the internal memory of an output control device.