JPH06309241A - Hard ram device - Google Patents

Abstract

PURPOSE:To enable a hard RAM device to allocate checksum without using uselessly a memory and with high reliability. CONSTITUTION:A part of an extended memory connected to a system is used as a hard RAM 14, this hard RAM 14 is managed by dividing it into fixed blocks for an access and a checksum calculation, and the checksum is calculated at every fixed block. Therefore, a CPU 11 checks the capacity of the hard RAM 14 at the time of initialization of the system in accordance with a BIOS program of a ROM 12, decides the quantity of a necessary checksum area in accordance with its result, and allocates the necessary checksum area to the hard RAM inside 14, by which an appropriate check sum management system corresponding to the capacity is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard RAM device capable of handling a part of memory in the same manner as a hard disk.

[0002]

2. Description of the Related Art In the field of personal computers, laptop type computers, which are small and lightweight and convenient for carrying, have become widespread in place of the conventional disc type computers. Due to the characteristics of this type of personal computer, the miniaturization, lightness, shortness and miniaturization are the most important design items. A part of that is a hard RAM that can handle a part of the memory in the same way as a hard disk, and it is an indispensable function for this kind of personal computer.

A hard RAM can be accessed at a higher speed than a hard disk. However, since the memory for realizing the hard RAM is expensive and difficult to miniaturize,
At present, there is almost no large-capacity hard RAM. From the viewpoint of safety and reliability of data stored in the hard RAM, it is necessary to allocate a memory area as a checksum more than ever before in order to support a large capacity hard RAM. Also, if the checksum is calculated for each fixed block and the fixed part of the disk is set to the place for storing the checksum, the place for storing the checksum is limited, so that place for large capacity hard RAM. There was also a problem that it was difficult to pay the checksum.

[0004]

As described above, in the conventional method of calculating the checksum for each fixed block of the hard RAM and storing it in the fixed location of the hard RAM,
Data reliability cannot be guaranteed or hard RA
There was a problem such as not being able to obtain the checksum for the entire capacity of M.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hard RAM device which can allocate checksums with high reliability without wasting memory.

[0006]

The present invention provides a hard RAM capable of handling a part of the memory as a disk device.
In an information processing device that supports, at the time of system initialization, the amount of hard RAM set in the system is checked, and the number of blocks required for checksum is calculated,
A means for allocating a memory block for storing the checksum, and a capacity adjustment of the available hard RAM so that the allocated block is not used as a data area,
A means for storing information for associating a data block with a checksum block in a predetermined area in the memory and a checksum according to the memory capacity when using the hard RAM, and storing the checksum in the predetermined area in the memory. Means for storing the checksum in each checksum block according to the stored information.

[0007]

The present invention uses a part of the extended memory connected to the system as the hard RAM, and the hard RAM
Is managed by dividing it into fixed blocks for access and checksum calculation, and a checksum is calculated for each fixed block. For this purpose, the CPU checks the capacity of the hard RAM at the time of system initialization according to the BIOS program, determines the amount of the necessary checksum area according to the result, and allocates the necessary checksum area inside the hard RAM. This realizes an appropriate checksum management method according to the capacity.

When the capacity of the hard RAM is small, the area used for the checksum is reduced to improve the usage efficiency of the hard RAM, and even if the capacity is large, the functions of calculating the checksum for all the areas can be compatible and the reliability is high. You can build a personal computer with the characteristics.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 11 is a microprocessor (C
PU), which is the control center of the system. Reference numeral 12 is a system ROM which stores a BIOS (basic input / output control system) program which controls the initialization of the system and the control of peripheral devices connected to the system. Reference numeral 13 is a system RAM, which stores various application programs such as an OS, word processor, and spreadsheet, and is also allocated as a work area.

Reference numeral 14 is treated as a disk device,
It is a hard RAM composed of a memory element such as a semiconductor memory chip. Specifically, expansion memory is added,
Part of it is used as a hard RAM. The hard RAM 14 is controlled via the memory controller 15.

Reference numeral 16 is a CPU peripheral circuit such as an interrupt controller (PIC), a DMA controller (DMAC), and a timer (PIT), which is a CPU peripheral LSI. Reference numerals 17 (1) to 17 (n) are peripheral device controllers for controlling the peripheral devices, respectively, such as a keyboard (KB), a display (CRT), a floppy disk drive (FDD), and other peripheral devices connected to the system. This is a control LSI.

The functional blocks 11 to 17 described above are commonly connected to each other via a system bus 18 having a plurality of lines for address, data and control.

2 and 3 are views for explaining the operation of the embodiment of the present invention, FIG. 3 is a flow chart showing the operation of the embodiment of the present invention, and FIG. 4 is the relationship between the hard RAM and the checksum. FIG.

In FIG. 3, FIG. 3A shows a first memory configuration, which is a small capacity hard RAM configuration including one checksum block. FIG. 2B shows a second memory configuration, which is a medium capacity hard RAM configuration including two checksum blocks. FIG. 3C shows a third memory configuration, which is a large-capacity hard RAM configuration including four checksum blocks. In the figure, reference numeral 21 is a checksum 1.
The checksum storage area for the small-capacity hard RAM, reference numeral 22 is the checksum 2, and the checksum storage area for the medium-capacity hard RAM, reference numerals 23 and 24.
Is a checksum 3, which is a checksum storage area for the large capacity hard RAM.

The operation of the embodiment of the present invention will be described below. As shown in FIG. 3, the system can have a variable configuration according to the capacity of the hard RAM.
It is the data storage area and the checksum storage area that configure the hard RAM 14 that change according to the capacity. That is, the system checks the capacity of the hard RAM 14 at the time of initialization and controls as follows according to the capacity of the memory.

First, when the capacity of the hard RAM is small, the area for storing the checksum is arranged in the highest one block of the memory blocks constituting the hard RAM 14. This corresponds to the checksum storage area 21 of the first memory configuration shown in FIG.

When the capacity of the hard RAM is medium, the area for storing the checksum is not enough for one memory block. Therefore, in addition to the checksum storage area 21, the checksum storage area 22 is arranged at the highest position. . This corresponds to the second memory configuration shown in FIG.

When the hard RAM has a large capacity,
In addition to the checksum storage areas 21 and 22, the blocks 23 and 24 are used as areas for storing checksums.
Is placed at the highest tail. This corresponds to the third memory configuration shown in FIG.

In order to realize the above-mentioned function, according to the BIOS program stored in the system ROM 12,
This is done by performing the following processing shown in FIG. First, the microprocessor (CPU) 11 is the system R
Read the BIOS program stored in OM12,
RT (initialization processing routine) is started. Specifically, in the initialization processing routine, processing for determining the capacity of the hard RAM at system startup, processing for securing a checksum block (securing a checksum area), initialization processing, etc. are performed.

Next, a checksum is calculated and checked according to the memory capacity of the hard RAM being used. That is,
In the initialization process, the capacity of the hard RAM 14 set in the system is checked and the number of blocks required for the checksum is calculated. As a result, the usable capacity of the hard RAM 14 is adjusted so that the reserved block is not used as a data area, and the data block accessed when the hard RAM 14 is used and the checksum block that stores the checksum for the data block are associated with each other. The information for is stored in the work area in the system RAM 13.

In the checksum calculation / inspection routine, the checksum block is changed by the actual use of the hard RAM 14, so that the data block obtained as described above and the checksum block are associated with each other. The checksum is stored in each checksum block by using the information for In this way, an appropriate checksum is stored according to the memory configuration according to the capacity (that is, the first to third memory configurations in the embodiment), and as a result, data is guaranteed and a highly reliable system can be obtained.

[0022]

As described above, according to the present invention, when the capacity of the hard RAM is small, the checksum usage area is reduced to improve the usage efficiency of the hard RAM, and even when the capacity is large, all The functions that can calculate the checksum for the area can be compatible. As a result, a highly reliable system can be constructed with a personal computer that supports hard RAM.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing an operation processing procedure of the above embodiment.

FIG. 3 is a hardware R for explaining the operation of the above embodiment.
The figure which shows the relationship between AM and checksum.

[Explanation of symbols]

11 ... Microprocessor (CPU), 12 ... System ROM, 13 ... System RAM, 14 ... Hard RAM,
15 ... Memory controller, 16 ... CPU peripheral circuit, 1
7 ... Peripheral device controller 21, 22, ... 24 ... Checksum storage area (checksum storage block).

Claims (2)

[Claims] 1. In an information processing device that supports a hard RAM capable of handling a part of the memory as a disk device, at the time of system initialization, the capacity of the hard RAM set in the system is checked to make a checksum. A means for calculating the number of blocks required to secure a memory block for storing the checksum, and a hardware R that can be used so that the secured block is not used as a data area.
A means for adjusting the capacity of the AM and storing information for associating the data block with the checksum block in the memory, and a checksum corresponding to the memory capacity when the hard RAM is used and stored in the memory. And a means for storing the checksum in each checksum block according to the information. 2. The hard RAM device according to claim 1, wherein the hard RAM is constituted by an extended memory, and information for associating a data block and a checksum block is stored in the system memory.