JPH033029A - Electronic disk subsystem - Google Patents

Abstract

PURPOSE:To judge whether a command outputted from an EDC has been executed or not by adding an END signal form an EDU subsystem in a double writing constitution to check the execution of the command. CONSTITUTION:In a system example constituted of an electric disk controller (EDC) and four electric disk control units (EDUs), the EDU(A) 2 and EDU(B) 3 are used for double writing and the EDU(C) 4 and EDU(D) 5 are used for single writing. When the EDC 1 generates a command to both the specified EDU(A) 2, EDU(B) 3, both the EDUs (A), (B) 2, 3 are driven quite the same, and after ending the execution of the command, respectively apply an END(1) signal 11 and an END(2) signal 12. If either one of the END signals is not applied, the EDC 1 judges the abnormality of the EDU. In the case of a command individually generated to the EDU(A) 2 or the EDU(B) 3, the EDC 1 checks only an END signal corresponding to the command. Consequently, whether operation commanded by the EDC 1 is normally ended or not can be judged.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic disk subsystem, in particular:
This relates to checking the sub-system (2-system) dynamic 1st layer of an ECU with dual writing configuration.

Conventional technology Conventionally, this type of electronic disk subsystem has only one END signal on the interface signal line, and the EDLIs of the dual writing set must use the same END signal. Since it is logical, one EDIJ outputs the END signal on behalf of the other, while the other EDIJ does not output the END signal and only performs internal processing.

Problems to be Solved by the Invention In the conventional electronic disk subsystem described above, since the subsystem does not output an END signal during dual write access, the EDC
Did the commanded operation complete normally, or was there no reception at all and no action was taken, or did the read/write operation end before the designated number of transfers, or did the designated number of transfers be transferred? However, there is a drawback that it is impossible to determine whether or not the state will be terminated.

The present invention has been made in view of the above-mentioned conventional situation,
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a novel electronic disk subsystem which makes it possible to overcome the above-mentioned drawbacks inherent in the prior art.

Means for Solving the Problems In order to achieve the above object, an electronic disk subsystem according to the present invention includes one or more sets of dual-write configuration EDUs and ELICs that control a plurality of EDLIs connected in a daisy chain connection. In an electronic disk subsystem that has an interface, two EDLs with dual writing from IEIIc
Each of the two white EDUs in the double writing system has two END signals connected in a daisy chain to individually notify the EDC of the completion of the commands issued simultaneously to I.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a block configuration diagram showing one embodiment of the present invention, and is an example of the configuration of an electronic disk control device (EDC) 1 and an electronic disk unit (ECU) 4.

Referring to Figure 1, here ECU (A) 2 and EDt
J(B)3 is double written, EDU(C)4, EDU(
D) 5 is a single book. Also, double-written ECU (A)
2 is called the 1st system, and El)Ll(II>3 is called the 2nd system.

END (1) signal 11 is the ECU (A
) 2.
END signal used by LI(D)5 for EDC1,
END(2>Signal 12 is EDu(C
) 3 is the END signal used for EDC1. In addition, the common interface signal group 13 is from EDC1 to ED
This is an interface signal between the EDC and EDU, which includes command signals and data lines for each U, as well as control signals. Furthermore, although the END signal is actually included in the interface signal group, it has been extracted for the sake of clarity.

Next, the operation of the present invention will be explained.

From EDC1, EDU(A)2, I which is in dual writing mode
Commands can be issued to EDU (B) 3 by specifying both ECUs or individually.

When EDC1 issues a command to EDU(A>2 and ECU(B)3 specifying both EDUs, EDU(Δ)2
and ECU(B)3 operate in exactly the same way. When the command is executed and finished, the END (1) signal 11
．． END (2) Raise signal 12. EDLI(Δ)2
and EDU (B) 3 do not raise their END signals at exactly the same timing, so there will be a time lag, but if the lag is within the specified time, EDC 1 will process the commands issued by both EDUs. Decide that it is finished.

Further, if either one of the END signals does not rise, the EDC 1 determines that the EDU is abnormal.

Furthermore, in a read/write command, if the ECU (B) 3 raises the END (2) signal 12 while the specified number of transfers has not been completed, or if the ECU (B) 3 raises the END (2) signal 12 even though the specified number of transfers has been transferred. When the END(2) signal 12 is not raised, the EDCl determines that the EDU(B) 3 is abnormal.

In addition, EDCl is EDU(A) 2 and EDU(B
) For commands issued individually such as reading the error status for 3, only the corresponding END signal is checked.

Single book-T--to (7) EDU (C) 4, EDLI
(D) For 5, only the END (1) signal 11 is checked. In addition, EDLI (C) 4 and EDU (D) 5 may be a set of double writing, and in this case, EDU (A)
2, ECU (B) Same as 3, EDU (D)
5 will use the END(2) signal 12.

As described in the detailed description of the invention, according to the present invention, an ED having a double book configuration
By adding and checking the END signal of the υ subsystem (system 2), it is possible to determine whether the command (instruction) issued from the EDC has been executed, thereby providing the effect of guaranteeing the operation of the subsystem.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. 1... Electronic disk control device (EDC), 2... Electronic disk device A (EDU (A)), 3... Electronic disk unit 'IIB (ECU (B)), 4... Electronic disk device C (EDLI(C)), 5...Electronic disk device D (ECU(D)), 11...E
ND (1) signal, 12...END (2) signal, 13.
...Common interface signal group patent applicant NEC Corporation Representative Patent attorney Yutabe Kumagai

Claims (1)

[Claims] One or more sets of electronic disk devices with dual write configuration (hereinafter referred to as EDU)
In an electronic disk subsystem having an interface in which an electronic disk control device (hereinafter referred to as EDC) is connected in a daisy chain connection with an electronic disk control device (hereinafter referred to as EDC) that controls a plurality of EDUs, an electronic disk control device (hereinafter referred to as EDC) that controls a plurality of EDUs is connected in a daisy chain connection. The electronic disk sub has two END signals in a daisy chain connection for each of the two EDUs of the dual writing to individually notify the EDC of the completion of operations of commands issued at the same time. system.