JPS6345635A - Access system for rom file - Google Patents

Abstract

PURPOSE:To realize the simple correction of the data on a ROM file by comparing this data with the data on the ROM file stored in a buffer RAM and storing the data, the address and the ID of a different part of both data into the RAM as the correction information. CONSTITUTION:It is first checked whether the correction information can be stored or not in a RAM 4 before the information is actually stored. In other words, a counter K for corrected data is initialized together with an additional character (n) for work. Then the comparing step for data between a buffer RAM 1 and a ROM file 6 is repeated together with the addition step of the counter K carried out when data are different by the frequency equal to the number C of data. Thus the number of corrected data is set to the counter K. Then a counter L for correction information on an empty ID of the RAM 4 and the character (n) are initialized repetitively until the reference given to the correction information. Thus the storage enable number L of the correction information is set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ROM file access method in a computer system that uses replaceable ROM devices as seven isles.

[Conventional technology]

Conventionally, this type of ROM file has been comprised of a ROM device equipped only with reading means.

[Problem that the invention seeks to solve]

The conventional ROM file described above has only a reading means and cannot be written to. Therefore, when modifying the file contents, there is a problem in that the ROM file must be recreated.

[Means for solving problems]

The ROM file access means of the present invention compares ROM data prepared in a buffer RAM with ROM data, and stores different portions of data, addresses, and rD as modification information in the RAM. .

[Effect]

Does this invention make 7 isles of ROM like 7 isles of RAM? It can be treated as a readable file and RO
M file data can be easily modified.

〔Example〕

FIG. 1 is a circuit block diagram for implementing an embodiment of the ROM 7 isle access method according to the present invention.

In the figure, 1 is used for reading and writing data, for example address B. 2 is a firmware ROM in which 7 armware programs are stored; 3 is a central processing unit that reads and executes the firmware program stored in this firmware ROM 2; 4 is as shown in FIG. , ID.

R where correction information consisting of address and data is stored
AM, 5 is a battery that is supplied to RAM 4 and retains the contents of RAM 4 even if the system power is cut off; 6 is a battery in which data is written; for example, address R;
, %R, and 7 is a path through which control information and data flow.

Note that this R is in the address R9 of the ROM file 6.
A unique ID is stored in the OM file.

In the RAM 4 shown in FIG. 2, for example, address PO~
Equipped with P9, each address has an ID and an address.

Although data is stored as a set, the address and data are invalid when XD is empty. In addition, in the flowchart showing the read processing shown in FIG. 3, Ri is the processing start address of the ROM file 6, Bj is the processing start address of the buffer RAM 1 that stores the read data, C is the number of data to be processed, and n is the work It is a subscript for In addition, in the flowchart showing the write processing shown in FIG. 4, Bj is the start address of the modified data stored in the buffer RAM 1, R1 is the processing start address of the ROM file 6, C is the number of data to be processed, and m is the modified data. L is a counter for the number of empty IDs in RAM4, m and n
is a working subscript.

Next, the operation of the ROM file access method with the above configuration, that is, from the ROM file 6 to the buffer RAM.
The operation of reading data to 1 will be explained. First, in step S1, the number C of data is included from the read start address R1 of the ROM file Jv6, including erroneous data.
Data is transferred to processing start address Bj of buffer RAM 1. Then, in step S2, a subscript n for referring to the modification information in the RAM 4 is initialized. This subscript n is updated in step S6, and in step S7 it is determined whether all the correction information in the RAM 4 has been referenced, and steps S3 to S6 are repeated until all the correction information has been referenced. Next, in step S3, the data transferred in step S1 is transferred to the IDpn of RAM 4 and the stored ID of RsK of ROM file 6.
Match with 8. Then, in step S4, when the address in the ROM file 6 stored in the Arashi address Pa is greater than or equal to the processing start address R1 and smaller than the processing end address calculated by R1+C, step S5 is executed. In this step S5, the data Pn is transferred to the buffer RA.
Transfer to address Bj+(address Pn)-1 of M1,
The read process can be finished.

Next, the modified data in buffer RAM 1 is transferred to RAM
4 and handle the ROM file 6 as a writable file like a RAM file will be described with reference to FIG.

First, in steps S8 to S21, before storing the modification information in the RAM 4, it is checked whether the modification information can be stored. That is, in step S8, a working subscript n is initialized for the counter of the corrected data. Then, in step 811 and step SH, the data in the buffer RAM1 and the ROM are
Step S9 of comparing the data of the seven aisles 6 and step S810 of incrementing the counter K when the data are different are repeated. In this way, in the processing from step 88 to step 812, the corrected data number is set in the counter K.

Then, in step SI3, a correction information counter L with an empty ID in the RAM 4 and a work subscript n are initialized. Then, steps 819 and S20 are repeated until all the correction information from steps 314 to 818 is referenced. That is, in step SI4, when IDpn is empty, in step 815, IDpn and IDe (Re) of the ROM file 6 match, and in step 81
In step 11, when address Pn is within the range of the data to be written, IDpn is changed to an empty state in step SI7, and counter L of empty correction information is incremented in step 8111. In this way, from step 813 to step SH
The number of correction information that can be stored is set at I. and,
In step S21, the corrected data count obtained earlier is compared with the storable count, and if it is possible, the process goes to the next process, and if it is not possible, it is determined as an error. And step 822
- In step 32g, the correction information is stored in the RAM 4.

That is, in step 822, working subscripts n and m are initialized, and in steps 827 and 828, steps 823 to SZ6 are executed for the number of data to be written.
repeat. That is, in step S23, the buffer R
When the data in AM 1 and the data in ROM buffer 6 are different, in step 824 and step S25, the RAM
4 is searched for, and in step S28, ID8, the address of the data of ROM file 6, and the buffer RAM are searched for.
1 can be stored in the RAM 4, and modification information can be stored in the RAM 4.

〔Effect of the invention〕

As explained in detail above, according to the ROM file access method according to the present invention, the ROM file data prepared in the buffer RAM is compared with the ROM file data, and the data, address, and ID of the different parts are corrected. By storing information in RAM, ROM
Since the file can be handled as a writable file like a RAM file, there is an advantage that data in the ROM file can be easily modified.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the ROM file access method according to the present invention, and FIG. 2 is a block diagram of the RAM shown in FIG. 1.
3 is a flow chart showing the read processing of FIG. 1, and FIG. 4 is a flow chart showing the write processing of FIG. 1. 1.Fist: Buffer RAM, 2..φ tourmuraev 10M, 3”..Central processing unit, 4..
・RAM, 5... battery, 6・φ・-ROM
File, T...φψ Babas Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a computer system that uses replaceable ROMs as files, a ROM having an ID for identifying a plurality of ROMs with different contents, an ID of this ROM,
A RAM that stores ROM modification information including addresses and data, a buffer RAM that is used for reading and writing data in the ROM, and a buffer RAM that stores the data modified in the ROM according to the modification information in the RAM. A reading means compares the data in the ROM prepared in the buffer RAM with the data in the ROM, and reads the data, address, and ID of the different portions as correction information to the RA.
1. A ROM file access method characterized by comprising: means for storing data in a ROM file.