JP3016362B2 - Memory bank exchange method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method of exchanging memory banks in a computer system.

[0002]

2. Description of the Related Art Conventionally, in order to reduce the price of a small-scale computer, a standard memory is directly mounted on a substrate. The program could not start the hardware when the standard memory failed.
Further, since the initial diagnosis program cannot be executed, it takes time to diagnose the faulty memory.

For this reason, as shown in, for example, Japanese Patent Application Laid-Open No. 2-48755, a method is adopted in which the memory is duplicated to increase the redundancy and the memory bank is switched when a failure occurs.

[0004]

A problem with the conventional memory duplication method is that it is difficult to diagnose a faulty memory.

[0005] The reason is that in a duplex configuration in which memories are added in parallel, writing is performed to both banks,
This is because each bank cannot be accessed independently.

On the other hand, a small-sized computer cannot adopt a dual memory configuration which increases the price.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a memory bank replacement method that enables the operation of an initial diagnosis program even when a failure of a standard memory occurs.

[0008]

According to the method of the present invention, a standard memory directly mounted on a substrate, a memory slot prepared for an additional memory, a bank switch for replacing a memory in a bank unit, and an additional memory are provided. Means for notifying that the memory has been implemented, and an R storing an initial diagnosis program for performing hardware diagnosis using the standard memory as a work memory.
An OM and a processor for executing an initial diagnosis program are provided, and memory banks are replaced by hardware depending on the presence or absence of an additional memory.

[0009]

According to the present invention, even if a failure occurs in the memory directly mounted on the board, the initial diagnosis program using the standard memory on the board as a work memory cannot be operated, and the system cannot be started, By performing the expansion, the bank switch recognizes the expansion of the memory and exchanges the banks. Therefore, the normal diagnosis memory can be used as a work memory to operate the initial diagnosis program, and the system can be started.

[0010] Diagnosis of a fault in the memory can also be performed on the system.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

Referring to FIG. 1, an embodiment of the invention is:
A processor 1 and a read-only memory (hereinafter referred to as "ROM")
That. 2), a memory controller 3, a bank switch 4 for changing the allocation of each memory and each bank, a standard memory 5, and a plurality of additional memories 6, 7, and 10 mounted in additional memory slots. , An additional memory mounting notification signal line 8 and a bank control signal line 9.

First, in a system in which only the standard memory 5 directly attached to the board exists, the processor 1 executes an initial diagnosis program stored in the ROM 2 when the system is started. Under the control of the initial diagnosis program, the processor 1 accesses the standard memory 5 via the memory controller 3 and initializes the standard memory 5. Since only the standard memory 5 is mounted on the bank switch 4, the banks are not exchanged. Under the control of the initial diagnosis program, after initializing the standard memory, the processor 1 uses the standard memory 5 as a work area to diagnose other parts (not shown) connected to the system.

On the other hand, if a failure occurs in the standard memory 5, the initial diagnosis program does not operate normally as it is. In this case, an additional memory, for example, an additional memory 6 is mounted in one of the plurality of additional memory slots. When the additional memory 6 is mounted, an additional memory mounting notification signal for notifying the mounting of the additional memory 6 is supplied from the additional memory slot to the bank switch 4 via the signal line 8. The switch 4 switches connection of the bank control signal line 9 to exchange the bank control signal. As a result, the initial diagnosis program is stored in the standard memory 5
Instead of using the additional memory 6 as a work memory,
The faulty standard memory 5 can be diagnosed.

Similarly, when a failure occurs in the additional memory 6, the work memory of the initial diagnosis program is changed to the additional memory 7 by mounting the additional memory 7.

FIG. 2 is a diagram showing how the above-mentioned banks are exchanged. The initial diagnosis program always uses the memory allocated to the memory bank 0 as a work memory. State where only standard memory 5 is mounted ((a) of FIG. 2)
Then, the standard memory 5 is allocated to the bank 0. When a failure occurs in the standard memory 5 and the additional memory 6 is mounted,
The banks are switched by the bank switch 4, and the additional memory 6 is allocated to the bank 0 and the standard memory 5 is allocated to the bank 1 (FIG. 2B). Similarly, when the additional memory 7 is mounted, the additional memory 7 is allocated to the bank 0, the additional memory 6 is allocated to the bank 1, and the standard memory 5 is allocated to the bank 0 ((c) in FIG. 2).

[0018]

The first effect of the present invention is that even if a failure occurs in the standard memory directly attached to the board, the operation of the initial diagnosis program becomes possible only by mounting the additional memory, and the computer system is started. This makes it possible to easily diagnose the faulty memory.

The reason is that by treating the faulty memory as an additional memory, the memory used as the work memory can be transferred to the additional memory without changing the initial diagnostic program.

A second effect of the present invention is that a more inexpensive diagnosis method for a memory failure can be provided.

The reason is that the inexpensive configuration can be obtained by not performing the duplication, and the initial diagnosis program does not need to be changed by replacing the memory by hardware.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing how banks are exchanged according to the present invention.

[Description of Signs] 1 Processor 2 ROM 3 Memory Controller 4 Bank Switch 5 Standard Memory 6 Extension Memory a 7 Extension Memory b 8 Extension Memory Mounting Notification Signal Line 9 Bank Control Signal Line 10 Extension Memory Slot

Claims (1)

(57) [Claims] [1 claim] and the standard memory, and a memory slot that is prepared for extension, and the additional memory and the standard memory control as the memory banks, when said in the standard memory fails
When the additional memory is installed in the memory slot,
A memory controller for supplying a memory mounting notification signal, and the additional memory mounting notification signal from the memory controller.
When the signal is supplied, the memory is replaced with the standard memory.
Switch the additional memory installed in the slot to work memory.
A bank switch changing, the memory bank changing system which comprises an initial diagnostic program for diagnosing hardware using the work memory.