JPH08161224A - Semiconductor file device - Google Patents

Abstract

PURPOSE: To eliminate the need of an elimination operation at the time of write by providing an elimination management means for managing the elimination part of two flash type EEPROMs and a simultaneous function execution means. CONSTITUTION: The flash type EEPROM 5 and the function selection circuit 15 of this semiconductor file device 1 for reading and writing data to/from the flash type EEPROM 5 by the control of a host controller 2 are duplexed and an elimination block management circuit 14 is provided. Then, an access control circuit 4 selects a read circuit 10 by using the function selection circuit 15(A), transfers a block provided with the data to be rewritten of the flash type EEPROM 5(A) to a work memory 7 by using the read circuit 10 and writes the contents of a data register 6 in a work area by referring to an address register 8. Then, an elimination circuit 11 and a write circuit 12 are selected, the contents of the work memory 7 are written in the flash type EEPROM 5(B) and simultaneously, the data of the block read from the flash type EEPROM 5(A) are eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor file device for reading / writing data from / to a flash type EEPROM, and more particularly to
Erasing and writing data in EEPROM.

[0002]

2. Description of the Related Art Since a semiconductor file device using a flash type EEPROM does not require a power source for holding data, it is a new semiconductor file device which mainly replaces a semiconductor file device using SRAM or DRAM such as a memory card or an IC card. It is used as a device.

A semiconductor file device using such a flash type EEPROM has a structure as shown in FIG. 2, for example.

When data is written to the flash type EEPROM 15 in the semiconductor file device 1 using the host controller 2, the data to be written is stored in the data register in the access control circuit 4, and the address to be written is stored in the access control circuit 4. Address register 8 of Next, the access control device 4 selects the read circuit 10 by using the function selection circuit 15.

The read circuit 10 stores the data of the block including the address indicated by the address register 8 in the work memory 7.
Read to. The access control device 4 writes the data in the data register 6 to the address indicated by the address register 8 in the work memory 7. Next, the access control device 4 selects the erasing circuit 11 using the function selecting circuit 15 and erases the block including the address indicated by the address register 8.

In order to shorten this erasing time, conventionally, a plurality of blocks can be selected and erased as described in Japanese Patent Laid-Open No. 6-131889. After the erasing is completed, the access control device 4 selects the writing circuit 12 by using the function selecting circuit 15. The writing circuit 12 uses the flash type EEPROM to store the block data in the work memory 7.
Write to OM5.

As described above, in the conventional semiconductor file device 1, when writing data to the flash type EEPROM 5, the block containing the data to be written is saved in the work memory 7, the data is written in the work memory, and then the block is erased. After that, the contents of the work memory 7 were written.

[0008]

By using the conventional technique, the erasing time can be shortened and the writing operation can be performed, but since the erasing operation is always accompanied by the writing, the speed cannot be further increased.

It is an object of the present invention to provide a semiconductor file device which does not require an erase operation during writing.

[0010]

In order to achieve the above object, the present invention is under the control of a host controller, and a flash EEPROM and data in the flash EEPROM under the control of the host controller. In a semiconductor file device composed of an access control circuit for reading and writing
Another flash type EEPROM with the same address as the above flash type EEPROM and two above flash type EE
In the access control circuit, an erase management means for managing the erased portion of the PROM and a simultaneous function execution means capable of simultaneously performing different functions on the two flash type EEPROMs based on the contents of the erase management means are provided. did.

[0011]

FIG. 3 is an explanatory view of the operation of the present invention. In FIG. 3, reference numerals 30 and 31 are flash type EEPROMs that are accessed using the same address. According to the present invention, the erase management means is a flash type EEPROM 30 and a flash type EEPROM.
The state of the erase block of the EEPROM 31 is managed. For example, when writing data in the block of the flash type EEPROM 30, the data in the block of the flash type EEPROM 31 is erased so that the flash type EEPROM 31 is reversely erased.
Flash type when writing data to the block
When the simultaneous function executing means is used to erase the data in the block of the EEPROM 30, it becomes as shown in FIG.

When writing data to the semiconductor file device in the state shown in FIG. 3, the data erased block always exists in either the flash type EEPROM 31 or the flash type EEPROM 30, so the data is written without erasing before writing. be able to.

[0013]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention, and FIG. 4 is a diagram explaining the operation of the first embodiment.

In FIG. 1, reference numeral 1 is a semiconductor file device of the present invention, 2 is a host controller for controlling the semiconductor file device 1, 3 is a control bus for connecting the host controller 2 and the semiconductor file 1, and 5 is for storing data. Flash type EEPRO
M and 4 are flash type EEPRO under the control of the host controller 2.
An access control circuit for reading / writing data from / to M5, 6 is a data register for storing data to be written from the higher-level controller 2 to the flash EEPROM 5 or data read from the flash EEPROM 5, and 7 is a flash EEPROM 5
A work memory that can store the data read from each block or the contents of the data register 6, and 8 is a flash type EE transferred from the host controller 2.
An address register for storing the address of the PROM 5, 10 is a read circuit for reading data from the flash type EEPROM 5 to the work memory 7, 11 is an erasing circuit for erasing the data of the flash type EEPROM 5, 12 is the content of the work memory 7 in the flash type EEPROM 5. Writing circuit for writing, 15
Read circuit 10, erase circuit 11, and write circuit 12
Function selector circuit for switching between, and 14 is a flash type EEPROM
5 is an erase block management circuit that manages 5 erase blocks.

In FIG. 4, reference numeral 40 is the state of the flash type EEPROM 5, work memory 7 and data register 6 when the host controller 2 sets rewriting data in the data register 6 in the access control circuit 4, and 41 is the flash type EEPROM.
The block containing the data to be rewritten in the OM5 (A) is read into the work memory 7 and rewritten data work memory 7
State of flash EEPROM 5, work memory 7 and data register 6 when written in
The state of the flash type EEPROM 5, the work memory 7 and the data register 6 when the data of the block read from the flash type EEPROM 5 (A) is erased at the same time the contents of is written in the flash type EEPROM 5 (B).

From the host controller 2 to the flash type EEPROM 5
When writing data to the host, the higher-level controller 2 uses the control bus 3
The address of the data to be written in the data register 6 in the access control device 4 is set in the address register 8 through the through, and a write command is issued to the access control device 4 (state 40).

The access control circuit 4 has a flash type EEPROM 5 having a block containing data to be rewritten from the contents of the address register 8 by using the erase block management circuit 14.
And the flash type EEPROM 5 having the data erased area are examined.

Next, the access control circuit 4 is the function selection circuit 1
5 (A) is used to select the read circuit 10, and the block containing the data to be rewritten in the flash type EEPROM 5 (A) is transferred to the work memory 7 using the read circuit 10.
The contents of the data register 6 are written into the work area with reference to the address register 8 (state 41).

Next, the access control circuit 4 uses the function selection circuit 15 (A) to select the erase circuit 11, and further uses the function selection circuit 15 (B) to select the write circuit 12.
At the same time as writing the contents of the work memory 7 to the flash type EEPROM 5 (B), the block data read from the flash type EEPROM 5 (A) is erased (state 42).

In this embodiment, the flash EEPROM 5 and the function selection circuit 15 of the semiconductor file device 1 for reading / writing data from / to the flash EEPROM 5 under the control of the host controller 2 are duplicated, and the erase block management circuit 14 is provided. Is characterized by.

[0021]

According to the present invention, when data is written to the flash type EEPROM 5 from the host controller 2, the states of the flash type EEPROM 5, the work memory 7 and the data register 6 are as follows: state 40, state 41, state 42. become,
Since there is a data erased block in either the flash type EEPROM 5 (A) or the flash type EEPROM 5 (B) before writing, data can be written without erasing before writing. Therefore, the time for writing data from the host controller 2 to the flash type EEPROM 5 can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment.

FIG. 2 is a block diagram showing a conventional technique.

FIG. 3 is an explanatory view of the operation of the present invention.

FIG. 4 is an explanatory diagram of the operation of the embodiment.

[Explanation of symbols]

1 ... Semiconductor file device, 2 ... Host control device, 3 ... Control bus, 4 ... Access control circuit, 5 ... Flash type EEPRO
M, 6 ... Data register, 7 ... Work memory, 8 ... Address register, 10 ... Read circuit, 11 ... Erase circuit,
12 ... Write circuit, 14 ... Erase block management circuit, 1
5 ... Function selection circuit.

Claims (1)

[Claims] 1. A semiconductor file device under the control of a higher-level control device, comprising a flash-type EEPROM and an access control circuit for reading / writing data from / to the flash-type EEPROM under the control of the higher-level control device. Flash EEPROM having the same address as the flash EEPROM, erase management means for managing the erased parts of the two flash EEPROMs, and two data based on the contents of the erase management means when writing data. A semiconductor file device characterized in that a memory selecting means for selecting one of the flash type EEPROM is provided in the access control circuit.