JPS63263700A - Memory control device - Google Patents

Abstract

PURPOSE:To efficiently read out a memory by forming a memory control device for easily changing data without forming and replacing a read-only memory. CONSTITUTION:At the time of inputting an access request to a changed address area through a memory access interface 6, a memory access address converter 4 converts the access request to an access request to an address area in which changed data in a RAM 2 are written and read out and outputs the changed data. Since the system is provided with the RAM 2 writing the changed data, a device 3 for writing the changed data from a ROM 1 to be changed into the RAM 2 and the converter 4, the contents of the ROM 1 can be partially or totally changed by the converter 4 without preparing and changing the ROM changing its contents when an access request to an address area of the ROM 1 whose contents are to be changed is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a memory control device that allows data in a read-only memory to be changed in a pseudo manner.

[Prior Art] Conventionally, when changing data in a read-only memory, even if the change is only a part, a new read-only memory is created to store the changed data, and this and the other memory are I had to replace the memory that was inserted into the device.

[Problems to be solved] As mentioned above, conventionally, when changing data in a read-only memory, the read-only memory itself had to be replaced with a new one. This method is time-consuming, uneconomical, and lacks flexibility in use.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a memory control device that allows data to be easily changed without requiring the creation and replacement of read-only memory.

[Means for Solving Problems] In order to achieve the above object, the present invention includes a read-only memory, a random access memory, and a change data for writing change data corresponding to data to be changed in the read-only memory into the random access memory. a writing device;
The present invention includes a memory access address conversion device that accesses data written in a corresponding address area of the random access memory in response to a request for access to an address area to be changed in the read-only memory.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a memory control device according to this embodiment.

In the drawing, l is read-only memory (ROM).

This read-only memory 1 is generally composed of a memory element in which stored data cannot be changed (written) or requires a long time to be changed.

2 is a random access memory (RAM), which has both read and write functions.

3 is a changed data writing device, and 4 is a memory access address converting device. The change data writing device 3 uses the change content registration interface 5.

The address area of the read-only memory 1 whose data is to be changed (change address area) and the new data to be changed (change data) are input.

Further, the changed data writing device 3 is connected to the memory access address translation device 4 via a memory access interface 6 and an address translation registration interface 7. Then, write the changed data to the random access memory 2 via the memory access interface 6, and write the changed data to the changed address area of the read-only memory 1 where you want to change the data via the address conversion registration interface 7. The loaded address area of the random access memory 2 is output to the memory access address conversion device 4.

Memory access address converter! 4 sends an access request to the changed address area to the memory access interface 6.
When the access request is input via the random access memory 2, the access request is converted into an access request to the address area in which the changed data has been written in the random access memory 2, and the changed data is read and output.

In this way, by providing a random access memory for writing change data, a device for writing change data of a read-only memory to be changed into the random access memory, and a memory access address conversion device, a read-only memory whose contents are to be changed is provided. When there is a request to access an address area of memory, a read-only memory with changed contents is prepared and the contents of the read-only memory are partially or completely changed in a memory access address conversion device without replacing it. be able to.

[Effects of the Invention] As described above, the present invention has the advantage that read data can be easily changed without requiring the creation and replacement of a read-only memory.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a memory control device according to this embodiment. 1-Read-only memory 2: Random access memory 3: Change data writing device

Claims (1)

[Claims] A read-only memory, a random access memory, a change data writing device for writing change data corresponding to data to be changed in the read-only memory into the random access memory, and access to an address area to be changed in the read-only memory. A memory control device comprising: a memory access address translation device that accesses data written in a corresponding address area of the random access memory in response to a request.