JP3163124B2 - Electronic still camera device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE invention, the light of the subject taken
Convert the academic image into digital image data and record it on a memory card
Recording electronic still camera device, especially memory card
EEPROM (Electricity) as semiconductor memory
Eraseable and programmable read-out
Memory) .

[0002]

2. Description of the Related Art As is well known, an electronic still which converts an optical image of a photographed subject into an electric image signal using a solid-state image sensor, converts the image signal into digital image data, and records the digital image data in a semiconductor memory. Camera devices have been developed.
In this type of electronic still camera device, a memory card in which a semiconductor memory is built in a card-like case is configured to be detachable from a camera body, so that a film in an ordinary camera can be obtained. Equivalent handling is provided.

[0003] Here, the memory card of the electronic still camera device is currently being standardized, and the built-in semiconductor memory is required to have a large storage capacity for recording a plurality of digital image data. For example, SR
AM (static random access memory),
Mask ROMs and electrically erasable EEPROMs and the like have been considered, and memory cards using SRAMs have already been commercialized.

[0004] A memory card using an SRAM can cope with a data structure of any format and has an advantage that data writing speed and reading speed are fast, but it holds written data. Backup battery must be stored in the memory card, so that the storage capacity is reduced by the amount of the battery storage space and the SR
There is a problem that the cost of the AM itself is high and causes economic disadvantage.

Therefore, at present, in order to solve the problems of the SRAM, an EEPROM has been attracting attention as a semiconductor memory used for a memory card. This EEP
ROMs are attracting attention as a recording medium that replaces magnetic disks, and they do not require a backup battery for data storage and can reduce the cost of the chip itself. Therefore, development for use as a memory card has been actively conducted.

FIG. 5 shows a comparison between a memory card using an SRAM (SRAM card) and a memory card using an EEPROM (EEPROM card). First, as for the backup batteries and costs of the comparison items 1 and 2, as described above, the SRAM card has a problem that the backup battery is necessary and the cost is high, whereas the EEPROM card does not require the backup battery and the cost is high. Also has the advantage that it can be reduced.

Next, with regard to the write speed and read speed of the comparison items 3 and 4, data is written and read to and from a byte or a bit arbitrarily designated by an address. By designating a mode and a page composed of a plurality of consecutive bytes (several hundred bytes), it is possible to divide the mode into a page mode unique to an EEPROM in which data is written and read in a page unit at a time.

In the random access mode,
The SRAM has a high writing speed and a high reading speed, and the EEPROM has a low writing speed and a low reading speed. Also, EEPROM
In the page mode, a large amount of data for one page is simultaneously written and read in the page mode, so that the data write speed and the data read speed are faster than in the random access mode.

Further, the erase (erase) mode of the comparison item 5 is a mode peculiar to the EEPROM.
This mode does not exist in. That is, the EEPROM
When writing new data to an area in which data has already been written, new data cannot be written unless the previously written data is erased once. Is to be executed.

The write verify of the comparison item 6 is also a mode peculiar to the EEPROM, and is a mode not existing in the SRAM. That is, the EEPROM is
In the case of performing data write, usually, complete write is not performed by one write operation. For this reason, EEP
Each time a write operation is performed on the ROM, EEP
It is necessary to read out the written contents of the ROM and check whether or not the data has been correctly written. This is the write verify.

Specifically, data to be written to the EEPROM is recorded in a buffer memory, and after the data is transferred from the buffer memory to the EEPROM and written,
The written contents of the EEPROM are read and compared with the contents of the buffer memory to determine whether they match. If it is determined that there is a mismatch (error) as a result of the write verification, the operation of writing the contents of the buffer memory to the EEPROM again is repeated.

As is apparent from the above comparison results, EE
PROMs have unique advantages not found in SRAMs, such as the need for a backup battery, low cost, and the ability to write and read data in page units. There are disadvantages that the writing speed and the reading speed are slow, and that a mode not provided in the SRAM such as an erase mode or a write verify is required.

Therefore, as a semiconductor memory used for a memory card, EE is used instead of the SRAM currently used.
Considering the use of a PROM, the problem of data write speed and data read speed, and the problem of requiring an erase mode and write verify, etc. can be solved, and a handling equivalent to a memory card having a built-in SRAM can be performed. Thus, it is important to make various improvements in detail so that it can be used for SRAM card-like.

In this case, a particular problem is the EEP.
In the ROM, when the number of times of data rewriting exceeds a certain number, the memory cells are rapidly deteriorated, and data writing failure is likely to occur. That is, since the EEPROM is developed for recording program data and is intended to be able to rewrite data when a program is upgraded, it is possible to cope with data rewriting many times. Because it is not designed. However, when an EEPROM is used as a substitute for the SRAM, it is natural that the EEPROM is used in such a manner that data is frequently rewritten, so that it is inevitable that the occurrence rate of write failures will increase drastically.

Conventionally, regarding this write failure, it is determined that a write failure has occurred when the above-described write verify process has not been correctly performed even after being repeated a predetermined number of times. However, conventionally, EEPRO
Even if a write failure occurs in a part of M, the EEP
Since the entire memory card having a built-in ROM is handled as a defective product, there is a problem in that the efficiency is extremely low and the operation is economically disadvantageous.

[0016]

As described above, the EEP
A conventional memory card having a built-in ROM has a problem that it is extremely inefficient and economically disadvantageous because the entire memory card including the EEPROM in which writing failure has occurred is treated as a defective product.

Therefore, the present invention has been made in consideration of the above circumstances, and data which could not be written due to a writing error has been made.
Remedy, some write failures occur.
The generated EEPROM can be used continuously.
EEPRO as the semiconductor memory of the memory card
The use of M is economically advantageous and practical.
It is another object of the present invention to provide a very good electronic still camera device .

[0018]

SUMMARY OF THE INVENTION An electronic still camera apparatus according to the present invention is intended for converting an optical image of a photographed subject into digital image data and recording the digital image data on a memory card. And the memory card is an electronic still camera
An EEPROM having a data area and a rescue area , each of which is configured to be detachable from the camera body and each of which is constituted by a plurality of blocks of a predetermined capacity, and an electronic still camera body.
In a state where a memory card is inserted and a write failure is detected in any block of the EEPROM data area, data to be written to the defective block is searched for and written in a free area of the relief area, and the relief area is full. Further, in a state where it is detected that a writing failure has occurred in any of the blocks in the data area, control means for writing data to be written to the bad block by searching for a block having a free space in the data area is provided. It was done.

[0019]

According to the above arrangement, when a write failure occurs in some of the blocks in the data area, the data that could not be written in the defective block is searched for a block having a free area in the rescue area, and the block is searched. And write to
The rescue area is full and any of the data areas
When a write failure has occurred in a block,
The data to be written to the lock is
Block is searched and written, so that the EEPROM in which a writing failure has occurred partially can be used as it is, and the semiconductor memory of the memory card can be used.
Also it becomes suitable for economically advantageous and practical using EEPROM with.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electronic still camera device will be described below in detail with reference to the drawings. In FIG. 1, reference numeral 11 denotes a memory card main body, which is connected to an electronic still camera main body (not shown) via a connector 12 provided at one end thereof. The connector 12 is supplied with data to be written to the memory card main body 11, address data indicating a writing location, and the like from the electronic still camera main body side.

The data supplied to the connector 12 is taken into the data input / output control circuit 14 via the bus line 13. This data input / output control circuit 14
Has a built-in buffer memory (not shown) capable of high-speed writing and reading of data, and temporarily records the fetched data in the buffer memory. Thereafter, the data input / output control circuit 14 transmits the data recorded in the buffer memory to a plurality (4 in the illustrated case) through the bus line 15.
) At a timing corresponding to the write cycle of the EEPROM 16 and is recorded in the EEPROM 16.

In this case, the data input / output control circuit 14
Each time data is written to the EEPROM 16, the EEPROM
The data written from the ROM 16 is read, and a write verify is performed to determine whether the data matches the data recorded in the buffer memory. If the data read from the EEPROM 16 does not match the data recorded in the buffer memory, the data input / output control circuit 14 re-reads the data from the buffer memory.
The data is transferred to the PROM 16 for writing,
While this operation is repeated a predetermined number of times, the EEPROM 1
When the data read from the buffer memory 6 completely matches the data recorded in the buffer memory, the data writing is completed.

Next, when reading data from the EEPROM 16 to the outside of the memory card main body 11, an address designating data to be read from the electronic still camera main body via the connector 12 is stored in the data input / output control circuit 1.
4 is supplied. Then, the data input / output control circuit 14
Reads data from the EEPROM 16 based on the input address and temporarily records the data in the buffer memory.
Thereafter, the data input / output control circuit 14 derives the data recorded in the buffer memory to the outside via the read connector 12, and the data is read there.

Therefore, according to the above configuration,
Since data transfer between the electronic still camera main body and the memory card main body 11 is always performed via the buffer memory, the data write speed and the data read speed can be improved.
6 is also performed using the buffer memory, so that the memory card 11
Can be used for SRAM card-like at all.

As shown in FIG. 2, the EEPROM 16 has a storage area consisting of addresses 0000 to XXXX. This storage area is composed of a plurality of storage units each having a fixed capacity, which is the minimum unit for handling data. It is divided into blocks 1 to M (one block is several kilobytes). Of these blocks, blocks 1 to N are data areas for recording normal data, and by repeatedly specifying and writing addresses from the outside, data writing and reading in page units each consisting of several hundred bytes can be freely performed in block units. Can be written and read.

Blocks N + 1 to M serve as a relief area for writing data that could not be written to the data area due to a write failure. The rescue area is prohibited from being directly accessed from the outside, and data writing and reading are performed by the data input / output control circuit 14.
It is performed according to the instruction.

FIG. 3 shows a management table of the relief area provided in the EEPROM 16. That is,
The block numbers N + 1 to M of the rescue area and the head address of the block in which the writing failure has occurred in the data area have a one-to-one correspondence, and are set to 0000 before the head address is written. . The example shown in FIG. 3 shows a state in which blocks N + 1 to Y-1 have already been used for remedy of a write failure, and the head addresses AAAA to AAAA of the block where the write failure has occurred in the data area.
DDDD is recorded.

Here, a case where a write failure occurs when data is written to the block X in the data area will be described. That is, the data input / output control circuit 14 determines that the block X is defective in writing if no match is obtained even after performing the write verify process on the block X a predetermined number of times. Then, the data input / output control circuit 14 searches the management table shown in FIG.
Search for a free block in the rescue area.

In this case, since there is a vacancy in the block number Y, the data input / output control circuit 14 selects the block Y in the rescue area, writes the data that could not be written to the block X in the block Y, and performs a write verify process. When the writing is established, the head address YYYY of the block X is written in the block number Y of the management table, and the rescue procedure is completed.

For reading data from the EEPROM 16, the data input / output control circuit 14 sets the start address of the block in the data area requested to be read by an address from the outside, and all the start addresses written in the management table. And if they match, control is performed so that data is read from the block in the relief area corresponding to the matching start address.

In erasing the data in the EEPROM 16, similarly to the data reading, the start address of the block in the data area requested to be erased by an external address and all the start addresses written in the management table are read. The data is collated, and if they match, control is performed so that data is erased from the block in the relief area corresponding to the matching start address.

Therefore, according to the configuration of the above-described embodiment, when a write failure occurs in some blocks of the data area, the data that could not be written to the defective block is cleared from the management table with a free space in the rescue area. Since I searched for a block and written to that block,
The EEPROM 16 in which a writing failure has occurred partially can be used as it is, and is economically advantageous and suitable for practical use.

The above-mentioned rescue area is also stored in the EEPROM 16
, Writing failure may occur in the blocks N + 1 to M as well. In such a case, the data input / output control circuit 14 records a use prohibition flag in place of the head address in the portion of the management table where the write failure has occurred. As the use prohibition flag, for example, 1111 or the like is selected as an address that does not exist in the data area. Then, if the empty block Y in the found rescue area is defective in writing, the data input / output control circuit 14 operates to search the next empty block Y + 1 from the management table and write data.

Furthermore, even if the rescue area is full, if a write failure occurs in a block in the data area, an empty block in the data area can be used for rescue. In this case, as shown in FIG. 4, the management table has a one-to-one correspondence between all the block numbers 1 to M including the data area and the rescue area and the head address of the block where the writing failure has occurred in the data area. In the data area, 1111 is recorded as a use prohibition flag in the part of the block number already used for normal data recording in the data area, and the block number in which no data is recorded yet in the data area. "0000" is recorded in the part.

Here, a case will be described in which the rescue area is full and a write failure occurs when data is to be written to the block X in the data area. That is, when the data input / output control circuit 14 determines that the block X has a writing failure, the data input / output control circuit 14 searches the management table and searches for free blocks N + 1 to M in the rescue area. And
If it is determined that there is no empty block in the rescue area, the data input / output control circuit 14 searches for empty blocks 1 to N in the data area of the management table.

In this case, since there is a free space in the block N-1, the data input / output control circuit 14
If the data that could not be written to the block X is written to the block X, and the writing is verified by the write verify process, the head address YYYY of the block X is written to the block number N-1 in the management table, and the rescue procedure is completed here. . It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the scope of the invention.

[0037]

As described in detail above, according to the present invention,
Remedy data that could not be written due to write error
EEPR in which writing failure occurred partially
OM can be used continuously and memory
Even if you use EEPROM as the semiconductor memory of the card
Very good economical and practical
An electronic still camera device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a storage area of the EEPROM in the embodiment.

FIG. 3 is an exemplary view showing details of a management table in the embodiment.

FIG. 4 is a view showing a modification of the embodiment.

FIG. 5 is a diagram showing a comparison between the lengths of an SRAM and an EEPROM.

[Explanation of symbols]

11: memory card body, 12: connector, 13: bus line, 14: data input / output control circuit, 15: bus line, 16: EEPROM.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Konishi 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Media & Media Research Laboratories Co., Ltd. (72) Koji Maruyama 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Stock (72) Inventor Seto Terazaki 1-9-2 Hara-cho, Fukaya-shi, Saitama Prefecture In-house Toshiba Fukaya Factory (72) Inventor Tomoaki Sato 3-3-1 Shimbashi, Minato-ku, Tokyo No. 9, in Toshiba EBU Corporation (56) References JP-A-2-28855 (JP, A) JP-A-63-305444 (JP, A) JP-A-1-106152 (JP, A) JP-A-1-305490 (JP, A) JP-A-1-258091 (JP, A)

Claims (1)

(57) [Claims] 1. A electronic still camera apparatus for recording an optical image of the subject photographed in the memory card into digital image data, the memory card, electronic still
Detachably configured with respect to the camera body, and EEPROM each having a data area and a repair region including a plurality of blocks of a predetermined volume, the electronic still camera
The memory card is mounted on the main body and the EEPROM
In a state where a write failure is detected in any block of the data area, data to be written to the defective block is searched for and written in an empty block of the rescue area, and the rescue area is full, and Control means for writing data to be written to the defective block in a state where it has been detected that a writing failure has occurred in any of the blocks by searching for a block having a free space in the data area. Electronic still camera device.