JPS62145600A - Memory device - Google Patents

Abstract

PURPOSE:To automatically judge the exchange time of a nonvolatile memory (NVRAM) by writing the value of number of times of stores in which a restriction to record a data normally is provided at a prescribed area, adding one on the value of number of times of stores at every data store on the second memory having a nonvolatile function in the nonvolatile memory, reading the value of number of times of stores in a recall operation time, comparing it with a restriction value stored in advance, and issuing an alarm when it exceeds the restriction value. CONSTITUTION:A number of times of writes area 1d is provided within an area 1c for a data M especially, out of areas 1a, 1b and 1c in a nonvolatile memory 1. The number of times of writes area 1d adds one on the value at every store of the data from the area 1b on a memory function part to the area 1a on the memory function part. The value of number of times of stores is read out simultaneously with the data in the recall operation time for the data M, and is compared with the restriction value stored in advance within a monitor area, and by issuing the alarm to a host device when it exceeds the restriction value, the exchange time of the nonvolatile memory can be judged automatically.

Description

[Detailed Description of the Invention] [Summary] A storage device equipped with a non-volatile memory (NVRAM), in which a store count value, which is limited in order to record data normally, is written in a predetermined area, and the non-volatile memory (
Each time data is stored in a second memory unit (EEPROM) having a non-volatile function in NVRAM), the store count value is incremented by 1, and the store count value is read out during a recall operation.
Non-volatile memory (NVRAM)
It becomes possible to automatically determine when to replace the

[Industrial application field]

The present invention relates to a storage device in which the number of times data can be stored in a second memory section (EEPROM) having a non-volatile function in a non-volatile memory (NVRAM) is limited, and in particular, it is concerned with This invention relates to a storage device that automatically displays images.

Currently, with the development of digital integrated circuit technology, semiconductor memories have been developed for various uses and are widely used.

One type of semi-solid memory is non-volatile memory, which is formed by combining volatile memory (RAM), which allows data to be pasted/written at will, and non-volatile memory (EE) (RO11). A memory memo IJ (NVRAM) has been developed.

On the other hand, manufacturing data (hereinafter referred to as M data) such as device name, serial number, device version number, etc. is usually added to products, but in order to clearly indicate these, conventionally, labels etc. are attached. was.

However, as the automation of equipment manufacturing, modification, testing, etc. advances, a method has been adopted in which these M data are written to and read from semiconductor memory through an interface from higher-level equipment such as test equipment. Non-volatile memory (NVRAM) has become popular as a semiconductor memory.
) is used.

However, this non-volatile memory (NVl?AM) has a limit on the number of times it can be stored, and if the limit is exceeded, it must be replaced. The practical application of a method for automatically notifying such exchange is awaited.

[Prior art and problems to be solved by the invention] FIG. 4 is a block diagram illustrating a conventional example, and FIG. 5 is a diagram illustrating the configuration of a memory.

Figure 4 is a block diagram showing conventional examples of storage devices, including a memory (RAM) with a data rewriting function and a memory (EEPROM) with a non-volatile function for storing recorded data.
Non-volatile memory (N~'RAM) formed by combining
) 1, a microprocessor (hereinafter referred to as MPU) 2 that programmably controls the non-volatile memory (NVl?AM) 1, and a non-volatile memory (NVRAM) 1 to detect abnormalities in data read/written to the memory (NVRAM) 1. Controls the interface between the error detection circuit 3, which detects and sends an error signal to a host device (not shown), and the host device (not shown)? [
It is composed of an interface control section 4 that performs II.

The non-volatile memory (NVRAM) 1 includes a monitor area la for storing data for monitoring internal conditions;
A calculation work area 1b that stores work data for data processing, and a non-volatile memory (NVRAM) l.
The area 10 for M data stores M data.

FIG. 5 is a diagram showing an outline of the configuration of the non-volatile memory (NVI?AM) 1, in which a data bus ■ which outputs data to each area 1a = 1c and other control signals (address ■, write enable signal ■, chip select signal ■, etc.) are connected.

For example, memory (RA) that does not have non-volatile performance even after power is turned off.
M) In order to leave the data in area lb on
Migrate all data to a. This is called a store operation.

Furthermore, the operation of transferring all data stored in area 1a on the memory (EEPROM) to area 1b on the memory (RAM) when the power is turned on is called a recall operation.

Normally, reading/writing data to the nonvolatile memory (NVRAM) 1 is performed on the memory (RAM) functional part. Therefore, non-volatile memory (NVl?AM)
1 as a component, when recording M data such as the device name of the product, serial number 1 version number, etc., for example, the memory (RAM ) is written in area lb on the functional part and stored in area lc on the memory (E[PI?OM) functional part.

In general, there is a limit to the number of times a non-volatile memory (NVRAM) can be stored, and when that number of times is exceeded, the non-volatile memory (NVRAM) must be replaced.

However, in the past, there was no function to accurately monitor and notify the number of stores (therefore, the number of stores was estimated and replaced when the number of stores approached the limit).

[Means for solving problems]

FIG. 1 shows a block diagram illustrating the invention in detail.

FIG. 1 shows a hardware configuration similar to that explained in FIG.
A write count area ld is provided within the area.

This write count area 1d increments its value by 1 every time data is stored from area 1b on the memory (RAM) functional part to area 1a on the memory (ccpl?oM) functional part, and when recalled, it is added together with the stored data. Gono 4
n is read.

[Effect]

Write the write count value, which is limited in order to record normal data, to the write count area in the M data area,
The number of times is incremented by 1 each time data is stored from the area on the memory (RAM) functional part to the area on the memory (EEPROM) functional part.

This store count value is read at the same time as the data when the M data is recalled, for example, and compared with the store limit value stored in advance in the monitor area.If it exceeds the store limit value, an alarm is issued to the host device. To automatically and accurately determine whether it is time to replace nonvolatile memory (NVRAM).

〔Example〕

The gist of the present invention will be specifically explained below with reference to embodiments shown in FIGS. 1 to 3.

FIG. 2 is a diagram illustrating a memory address map in an embodiment of the present invention, and FIG. 3 is a diagram illustrating an operation flow in an embodiment of the present invention. Note that the same reference numerals refer to the same objects throughout the plan.

Figure 2 shows the non-volatile memory (NVRAM) in this embodiment.
) An example of the configuration of the address map on i is shown, and it is assumed that this is configured in the following order: calculation work area lb, M data area 1c, write count area ld, and monitor area 1a.

Next, the state of checking the store count value will be explained using the operational flow of this embodiment shown in FIG. In addition, the code 100 to 10
7 displays operation steps. Also, set the store count value to “X”.
It is assumed that the store count limit value -'Y'' is stored in advance in the area la.

When the power is turned on, the storage device 10 becomes a non-volatile memory (NVR).
AM) Data stored in area 1a in area 1 is transferred from area la to area lb by a recall operation (steps 100 and 101).

The MPU 2 reads the data transferred to the area 1b, and instructs the error detection circuit 3 to select the store count value -X from the data as the pre-stored store count limit value = "
Y” (area 1b when recalling from area 1a)
It is checked whether X" ≧ "Y", and if "no", the next operation is waited (step 102).

Next, for example, for some reason, non-volatile memory (NVRA)
If the storage device 10 configured with M) 1 is modified and the M data is modified, the M data is changed in area 1b, and at the same time the value in write count area 1d is incremented by 1, and the data is stored. In operation, data is transferred from area 1b to area 1a and the power is turned off.

(Steps 103-106).

Next, when the power is turned on, the steps 100 to 1 described above are performed.
02 is repeated, and when the store count values are compared in step 102, if “Xo ≧ Y”, the error detection circuit 3
Then, a predetermined error signal is sent to a host device (not shown). As a result, the host device (not shown) treats the non-volatile memory (NVRAM) 1 as abnormal, and displays that the non-volatile memory (NVRAM) 1 needs to be replaced. (Step 107).

〔Effect of the invention〕

According to the present invention as described above, non-volatile memory (NVR)
This has the effect of automatically and accurately determining when to replace the AM).

[Brief explanation of drawings]

FIG. 1 is a block diagram explaining the present invention in detail, FIG. 2 is a diagram explaining an address map in an embodiment of the present invention, FIG. 3 is a diagram explaining the uJ production flow in an embodiment of the present invention, FIG. 4 is a block diagram illustrating a conventional example, and FIG. 5 is a diagram illustrating a memory configuration. In the figure, ■ is non-volatile memory (NVRA1), 2 is liver U,
3 is an error detection circuit, 4 is an interface control unit, la is a monitor area, 1b is a calculation work area, 1c is an area for M data, 1d is a write count area, and 10 is a storage device. 5th hearing

Claims (1)

[Scope of Claims] A non-volatile memory unit formed by combining a first memory unit (RAM) with a data rewritable function and a second memory unit (EEPROM) with a non-volatile function of storing recorded data. A storage device comprising a non-volatile memory (NVRAM), the predetermined area (1c) of the non-volatile memory (NVRAM)
A store count area (1d) for recording the number of stores to the second memory section (EEPROM) is provided in the memory section, and the data written in the first memory section (RAM) is stored in the second memory section (RAM). (EEPROM), the store count value in the store count area (1d) is checked, and the store count value is transferred to the microprocessor (2).
A storage device characterized in that the value is compared with a pre-stored value, and if the value exceeds the pre-stored value, a device abnormality is reported to a host device through an error detection circuit (3).