JPS6162965A - Device switching apparatus - Google Patents

Abstract

PURPOSE:To perform easily exchange and arithmetic processing of exclusive control information by providing a memory for arithmetic and temporary storage where the exclusive control information is stored and a local memory for exclusive control independent of said memory and switching the address between exclusive control and normal control. CONSTITUTION:The exclusive control information is stored in a memories (local memories) 51 and 62 for the arithmetic and temporary storage to make it possible to perform the arithmetic processing of exclusive control information directly by a microprogram. Local memories 52 and 61 for exclusive control independent of normal local memories 51 and 62 are provided for the purpose of preventing the interference of the other part system sharing a device in the case other than exclusive control. Since the number of bits of address of local memories is limited, addresses in common to both local memories are used and are switched between te exclusive control and the normal control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a peripheral device for a computer system, and is particularly suitable for a magnetic disk subsystem.

The present invention relates to a device switching device.

[Background of the invention]

The present invention relates to a device cross call function that performs exclusive control of disk storage devices. The device cross-call function means that multiple control devices can
This is an interface switching function that allows multiple devices within a string (also called a string) to be controlled simultaneously. In the example of FIG. 1, the series (string) composed of devices 15 to 22 includes two sets of interfaces 27 and 2B,
The device switching device 13 is connected to the interface 271C, and the device switching device 14 is connected to the interface 28. In the following description, the device switching device will simply be referred to as a switching device. The switching devices are connected to control device 11 and control device 12 via interfaces 25 and 26, respectively.

- Furthermore, the switching device 13 and the switching device 14 are connected by a device sharing information interface.

In the example of FIG. 1, for example, the control device 13
While controlling the device 15 via the switching device B, the control device B can control the device 16 via the switching device B. This kind of function is called love vice cross call function.

Based on the device sharing information interface shown in Figure 1, conventional switching devices are generally logic devices that do not use microprograms, so three to four individual registers for exclusive control are required.
Bytes were provided, and constituted an interface that could be referred to by other switching devices.

In the conventional example shown in FIG. 2, each switching device has three ab-in registers.
1 or 32, hack change register 35i fcu
34. Each long connection register 35 or 36 is provided with 8 bits equal to the number of devices, and as necessary,
Refer to the register contents of the other party.

light, set, and reset.

Here, the contents of the assignment register 31 represent the device occupation state of the control device 13. For example, when bit 0 of the assignment register 31 is set, device 1
5 is occupied by the control device 11, and access to the device 15 by the control device 12 is prohibited. Back change register 33 holds specific interrupt information for the controller 11 of the Hachi vice. Long connection register 35
displays the connection status between the control device 11 and the device. For example, the set state of bit 0 of the long connection register 35 means that the control device 11 selects the device 15,
Indicates that an operation that requires a relatively long time (data transfer, etc.) is being executed.

As explained above, conventional equipment used a device sharing information interface as shown in Figure 2, but in recent years microprogram-controlled switching devices have come into use, and exclusive control interfaces as shown in Figure 2 have been used. Problems have arisen with providing individual registers.

One is that conventional logic sets or resets only the target bit of a register, but in a microprogram it is easier to change the contents of a register (8 bits). The second point is that configuring the exclusive control register as an external register of the microprocessor is
External register selection logic, etc., increases the amount of hardware, and the allocation of external register addresses becomes more difficult.

It is a matter of having a great influence.

[Purpose of the invention]

An object of the present invention is to enable exclusive control information to be easily exchanged and arithmetic processed by a microprogram, and to enable other systems to perform device control other than exclusive control.

To provide a device switching device with a small amount of hardware, in which a microprogram can run without being affected by the

[Summary of the invention]

In order to allow exclusive control information to be directly processed by a microprogram, the exclusive control information is stored in a memory for calculation and temporary storage, referred to as local memory, and when not under exclusive control, interference from the partner system that shares the device is prevented. In order to prevent this, we provided a normal local memory and a separate local memory for exclusive control. Furthermore, since the number of address bits in local memory is limited, the address is shared by both local memories, and is switched between exclusive control and normal control.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 6th
Figure LS (Local Eltorage) 51
teeth.

Memory circuit for normal calculations and temporary storage, L'''X.

52 is a memory circuit for exclusive control information of the Tepais cross call.

Both LB and LBX output 9 bits and address.

is 7 bits, LS takes a value of "Oo"-67, and L12 takes a value of "40" to "5F".

LSXRKADY LSXSBLF LSXOTH
The three lliR signals indicate the operation mode of the LSI and microprogram.

LBX (D7 de V, ;<> and input data (d T, B
The own system and the other system are connected by the XBWLIP and LSXOTH1ltR signals.

Switch. And the partner system's LSXSELF and L day X0
If TH]ilR is off, it is possible to refer to or rewrite I+SX, that is, exclusive example/control information of the other system, while the other system's microprogram is being executed.

FIG. 3 will be further explained. The upper half of FIG. 3 is mounted on the switching device t15, and the lower half is mounted on the switching device 14. Lf35i is a memory for calculation and temporary storage of the switching device 13, and is a static RAM of 9 bits x 128 words.The address lines of L851 are LSADR8Q to LSAD.
There are 7 R86s. The input data of LS51 is ALU
There are 9 lines of BUEIQ-ALUBUS 7 and ALUBUSF, which are the basic pass lines of the microprogram of switching device A. The write instruction line of L851 is L
This is the 8WR engineering Tl signal.

LSX52 is a pair of switching device 16 and switching device 14.

This is exclusive control information memory exclusively for device cross calls that can be accessed from anyone. The address line of LEIX52 is connected from selector 55VC to L8ADR of switching device 16.
8Q~6 and L8ADR8Q~6 of the switching device 14. The LSX520 input data is selected by the selector 54, ALUBUS of the switching device 13 and A of the switching device 14.
Switch between LUBUS and LUBUS. LB”ilR engineering Tl signal too.

Similarly, it is switched by the selector 55.

The selector 56 is LSDATA used in the switching device 13.
It is there to select Q to 7/P, and normally the output of LS51 is selected. When the switching device 13 refers to or changes the exclusive control information of its own system, the selector 56 selects the LSX5.
Select output 2. When referring to exclusive control information of another system, the selector 56 selects the 1,8X61 output of switching device [B].

LSXR] The 1f ADY signal is activated after the switching device is powered on.
After running the self-diagnosis program in the switching device, Micro 10
It is set in the gram and indicates that the LAK initial setting is complete. L8X81iiLF is set by a microprogram when the switching device refers to or changes its own LSI. LSXOTHFfR is set when the switching device refers to or changes LAX of another system. Furthermore, the above six signals outputted from other systems are made into logic circuits that can be referenced by a microprogram.

The above three numbers are used for input switching of the selector shown in FIG.

Ab-in register, back-change register in Figure 2,
The function of the long connection register is V in Figure 3.
r, LSADR8 is allocated as follows.

Address “46 &’ Assign register A “48 &’
Pack change register person “4B” Long connection register.

System “56” Assign register B “58” Hatch change register B “5B” Long connection register.

〔Effect of the invention〕

According to the present invention, even if there is a large amount of exclusive control information, a device cross call function can be realized with a small number of cues. In the case of the embodiment, the logic functions of approximately 90 integrated circuits are implemented by approximately 3
This was realized using 0 integrated circuits.

Further, the exclusive control information is stored in the calculation/temporary storage memory which is part of the microprocessor.

processing by microprograms is easy.

It is.

Appropriate operating mode indication as shown in the example.

? If added, interference from the other system can be almost eliminated. 1. Furthermore, the addition of exclusive control information, etc., can usually be realized without adding any hardware.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an example of a computer peripheral subsystem having a device cross call function, Fig. 2 is a schematic diagram of an exclusive control circuit of a conventional device control switching device, and Fig. 3 is a schematic diagram of an exclusive control circuit of a conventional device control switching device.
The figure is a block diagram showing one embodiment of the present invention. LS...Memory J (RAM) for calculation/1-time storage,
LBX...Additional memory for high speed cross call,
LsAnRso-s, , LS address line, ff1
LuBuso~7. P... A line that instructs to write data to the microprocessor's LB input data, LSWR, ..., LS.

Claims (1)

[Claims] An upper interface circuit and a lower interface circuit,
In a device switching device including a microprogram processor and a first calculation and temporary storage memory circuit, between the device switching device and another device switching device that shares a device such as a storage device connected to a lower-level interface,
It is characterized by comprising a second arithmetic and temporary storage memory circuit for exchanging control information, and switching and connecting address information lines, write data lines, etc. of the second memory circuit to other device switching devices. Device switching device.