JPH06222974A - Semiconductor storage device - Google Patents

Abstract

PURPOSE:To provide the semiconductor storage device which can easily handle digital information and analog information while mixing both of information even in a small scale system and can prevent the cost from being increased as well. CONSTITUTION:This device is provided with a main storage circuit (digital/ analog information) 1 for storing the digital information and the analog information while mixing both of information and a management information storage circuit 4 for storing the storage management information of the storage circuit, the digital information and the analog information can be stored while being mixed by controlling the respective storage circuits with a storage control circuit 2, and the efficient and economical storage system can be provided even in a small scale system. Further, since the analog information is stored as a previously set multilevel value, the management is more facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor memory device for storing information, and more particularly to a semiconductor memory device capable of storing data other than binary data.

[0002]

2. Description of the Related Art Conventionally, in a storage device using a semiconductor integrated circuit, in a system that handles digital information and analog information, for example, digital information is stored in a normal semiconductor memory, and analog information is converted into analog information. After converting it to information, store it in the same way as the above digital information,
A method of converting digital information stored at the time of output into analog information or a method of directly storing the analog information in an analog memory (US Patent No. 4989179 by IDS,
No. 4890259) was adopted.

[0003]

However, in the method of converting analog information into digital information, since the amount of stored information increases remarkably, the number of required storage elements becomes enormous and the above-mentioned separate storage elements are required. If two types of memory are prepared and each is controlled separately, the control becomes complicated and a dedicated memory is required for each type. However, it was difficult to achieve it due to cost.

The present invention has been made in view of the above problems of the prior art, and its main purpose is to easily handle digital information and analog information in a mixed manner even in a small-scale system. It is an object of the present invention to provide a semiconductor memory device which can be manufactured and whose cost does not soar.

[0005]

According to the present invention, there is provided a main memory circuit for storing digital information and analog information in a mixed manner, and a management information storage circuit for storing storage management information of the storage circuit. And a control circuit for controlling each of the storage circuits. In particular, the main memory circuit is
The analog information is stored as a preset multilevel value, and the management information stored in the management information storage circuit is
Including distinction between digital information and analog information of each address in the main memory circuit, the control circuit controls the address of each address in the main memory circuit based on the memory management information stored in the management information memory circuit. It is preferable to control discrimination between digital information and analog information, input / output of analog information values, and the like.

[0006]

With such a configuration, digital information and analog information can be mixedly stored in one addressable storage circuit, and the number of storage elements hardly increases. Even in a small system, an efficient and economical storage device can be realized. For example, when a storage device is configured by using a flash ROM capable of selectively setting a threshold value at a preset multi-value level as a main storage circuit, digital information is stored as arbitrary binary information among multi-values. For analog information such as audio and video, if a level corresponding to the quality of the information is selected and stored as multivalued analog information, each information can be stored in the main memory circuit at high density. In addition, the storage management information such as the address and the type of information is stored in the management information storage circuit,
If the control circuit writes / reads each address based on the management information, the control does not become complicated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a semiconductor memory device. The main memory circuit 1 is composed of a flash ROM capable of selectively setting a threshold value to a preset multi-valued level, capable of storing binary digital information and also capable of storing multi-valued analog information. It is like this. The main memory circuit 1 distinguishes between addresses for storing digital information and analog information in the main memory circuit 1, multi-valued levels of information,
It is connected to a storage control circuit 2 which receives a storage control signal from the outside and controls protection information and the like. The storage control circuit 2 is also connected to an input / output control circuit 3 for controlling the interface between the main storage circuit 1 and an input / output port (not shown), and a management information storage circuit 4 for storing the above-mentioned management information. Information stored in the main memory circuit 1 is managed by interacting with the management information memory circuit 4. still,
The above-mentioned protection information is information related to protection of each address of the main memory circuit 1, such as write prohibition for a write request and read prohibition for a read request.

The operating procedure of this embodiment will be described below. First, the storage control circuit 2 writes / reads from the outside.
A storage control signal such as a read request is received, and writing / reading to / from the main memory circuit 1 and control such as memory protection are performed based on the management information stored in the management information storage circuit 4. When making the request, the request source sends a write request, an address of the main storage circuit 1, storage information, a multi-valued level of storage information, protection information, etc. to the storage control circuit 2 as a storage control signal. The storage control circuit 2 instructs the input / output control circuit 3 from these information to input information and its multi-valued level, controls it, and writes it to the main storage circuit 1. Also,
At the same time, the address, the multi-valued level of the stored information, the management information such as the protection information, etc. are written to the address corresponding to the address of the main memory circuit 1 in the management information storage circuit 4.

Next, when reading from the main memory circuit 1, the request source sends the read request and the address of the main memory circuit 1 to the memory control circuit 2 as a memory control signal. The storage control circuit 2 thereby reads the data of the main storage circuit 1 and the management information from the address corresponding to the address of the main storage circuit 1 in the management information storage circuit 4, and reads the multivalued level of the read information and the protection information. Based on the I / O control circuit 3.

Here, if the information to be read is digital information, the multi-valued level is converted into binary digital information by the input / output control circuit, whereby high reliability with the external interface can be secured. Further, if the information to be read is multi-valued analog information, it can be interfaced with the outside with a small number of pins by directly outputting it as an analog value to the outside. In this embodiment, the storage control circuit 2 also controls the input / output level of the analog value.

With the above-mentioned structure, since digital information and analog information can be mixed in the same memory space and stored at an arbitrary ratio, an efficient and economical storage system can be realized.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the technical scope of the present invention. For example, in the above-described embodiment, the management information includes the distinction between the addresses for storing digital information and analog information, the multi-valued level of information, the protection information, and the like. You may add it. Further, although the storage information and the management information are stored in different storage circuits in this embodiment, they may be stored in the same storage circuit by address management.

[0014]

As is apparent from the above description, according to the semiconductor memory device of the present invention, the main memory circuit for storing digital information and analog information in a mixed manner and the memory management information for the memory circuit are stored. By having a management information storage circuit and controlling each storage circuit by the control circuit, digital information and analog information can be stored in a mixed manner, and even in a small-scale system, An economical storage system can be realized. Further, by storing the analog information as a preset multi-value level value, its management becomes easier.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a semiconductor memory device to which the present invention is applied.

[Explanation of symbols]

 1 main memory circuit 2 memory control circuit 3 input / output control circuit 4 management information memory circuit

Claims (3)

[Claims] 1. A main memory circuit for storing digital information and analog information in a mixed manner, a management information memory circuit for storing memory management information of the memory circuit, and a control circuit for controlling each memory circuit. A semiconductor memory device characterized by: 2. The semiconductor memory device according to claim 1, wherein the main memory circuit stores analog information as a preset multilevel value. 3. The management information stored in the management information storage circuit includes a distinction between digital information and analog information of each address in the main storage circuit, and the control circuit stores in the management information storage circuit. 3. The method according to claim 1, wherein the main memory circuit controls the digital information at each address and the analog information, and the input / output of the value of the analog information based on the stored storage management information. The semiconductor memory device described.