Magnetic tape recording device including cartridge memory having a plurality of memory banks

The present disclosure relates to a cartridge memory, a tape cartridge, and a recording and reproducing system.

Magnetic recording media are widely used for storage of electronic data. In particular, magnetic tapes having low cost per data unit capacity have regained attention and are utilized in data centers and the like together with hard disk drives (HDDs) as recording media used in cloud storage services.

Magnetic tapes conforming to the Linier Tape Open (LTO) Ultrium standard are in widespread use as the magnetic tapes. A non-contact non-volatile memory using RF wireless communication called a cartridge memory (CM) is embedded in a tape cartridge conforming to the LTO Ultium standard (see, for example, Patent Document 1). Information such as manufacturing information, drive usage history, and vendor-specific management information are written to the cartridge memory, for example. The usage of the cartridge and the like can be checked in a short time by loading the cartridge into a drive and then the drive reading the above information from the cartridge memory.

As the storage capacity of the magnetic tape conforming to the LTO standard increases, the storage capacity of the cartridge memory needs to be increased. This is because the amount of information written to the cartridge memory increases in accordance with the storage capacity of the magnetic tape.

Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-109353

Problems to be Solved by the Invention

However, the Liner Tape Open Generation 8 (LTO-8) or IBM 3592 standard specifies the storage capacity of the cartridge memory to be 16 KB. Thus, if the storage capacity of the cartridge memory is increased to exceed 16 KB in accordance with the increase in the information written to the cartridge memory, there is a possibility that compatibility with the above existing standards is lost.

An object of the present disclosure is to provide a cartridge memory, a tape cartridge, and a recording and reproducing system that can improve the storage capacity while maintaining compatibility with an existing standard.

Solutions to Problems

In order to solve the above problem, a first disclosure is

a cartridge memory used for a tape cartridge, including: a communication unit that communicates with a recording and reproducing device using a wireless communication method defined by an ISO 14443-2 standard which is a wireless communication standard; a non-volatile memory with a storage capacity exceeding 16 KB; and a control unit that writes or reads data to or from the non-volatile memory on a word-by-word basis (2 bytes at a time) or on a block-by-block basis (32 bytes at a time), in which the non-volatile memory includes a plurality of memory banks each having a storage capacity of 128 KB or less, the control unit writes or reads data defined by a magnetic tape standard to or from one or two or more first memory banks among the plurality of the memory banks, and additional data is written or read to or from one or two or more second memory banks other than the first memory bank.

A second disclosure is

a cartridge memory used for a tape cartridge, including: a communication unit that communicates with a recording and reproducing device using a wireless communication method defined by an ISO 14443-2 standard which is a wireless communication standard; a non-volatile memory with a storage capacity exceeding 16 KB; and a control unit that writes or reads data to or from the non-volatile memory on a block-by-block basis (32 bytes at a time), in which the non-volatile memory includes a plurality of memory banks each having a storage capacity of 2 MB or less, the control unit writes or reads data defined by a magnetic tape standard to or from one or two or more first memory banks among the plurality of the memory banks, and additional data is written or read to or from one or two or more second memory banks other than the first memory bank.

Effects of the Invention

According to the present disclosure, the storage capacity can be improved while maintaining compatibility with an existing standard. Note that the present disclosure may have an effect not necessarily limited to the one described herein but any effect described in the present disclosure or an effect different therefrom.

FIG. 1 is a schematic diagram of a recording and reproducing system according to a first embodiment of the present disclosure.

FIG. 2 is an exploded perspective view of a tape cartridge.

FIG. 3 is a block diagram of a cartridge memory.

FIG. 4 is a block diagram of a non-volatile memory.

FIG. 5 is a flowchart for explaining an example of the operation of the recording and reproducing system according to the first embodiment of the present disclosure.

FIG. 6 is a flowchart for explaining an example of the operation of a recording and reproducing system according to a second embodiment of the present disclosure.

FIG. 7 is a flowchart for explaining an example of the operation of a recording and reproducing system according to a third embodiment of the present disclosure.

FIG. 8 is a flowchart for explaining an example of the operation of a recording and reproducing system according to a fourth embodiment of the present disclosure.

FIG. 9 is a block diagram of a variation of a non-volatile memory.

FIG. 10 is a block diagram of a variation of a non-volatile memory.

Embodiments of the present disclosure will be described in the following order. Note that in all the drawings of the following embodiments, parts that are identical or correspond to each other will be assigned the same reference numeral.

1 First embodiment (example of recording and reproducing system) 2 Second embodiment (example of recording and reproducing system) 3 Third embodiment (example of recording and reproducing system) 4 Fourth embodiment (example of recording and reproducing system) 5 Variation

1 First Embodiment

[Configuration of Recording and Reproducing System]

As illustrated in FIG. 1 , a recording and reproducing system 100 according to a first embodiment of the present disclosure includes a tape cartridge 10 having a magnetic tape MT and a cartridge memory 11 , and a recording and reproducing device (drive) 20 that can load and unload the tape cartridge 10 .

(Recording and Reproducing Device)

The recording and reproducing device 20 includes a reader/writer 21 as a communication unit, a recording and reproducing unit 22 , a system controller 23 as a control unit, and an interface 24 . The recording and reproducing device 20 is connected to an external computer 200 via the interface 25 .

The reader/writer 21 communicates with the cartridge memory 11 using a wireless communication method defined by the ISO 14443-2 standard which is a wireless communication standard. The recording and reproducing unit 22 includes a drive unit (not shown) for running the magnetic tape MT, a head unit (not shown), and the like, and performs recording and reproducing of data on the magnetic tape MT.

The system controller 23 controls each unit of the recording and reproducing device 20 such as the reader/writer 21 , and the recording and reproducing unit 22 . The system controller 23 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like not shown.

The interface 24 is connected to the recording and reproducing unit 22 and the external computer 200 . A signal read from the magnetic tape MT by the recording and reproducing unit 22 is output to the external computer 200 via the interface 24 . On the other hand, a signal to be recorded on the magnetic tape MT by the recording and reproducing unit 22 is supplied from the external computer 200 via the interface 24 .

The interface 24 may be connected to the reader/writer 21 . In this case, the reader/writer 21 can be controlled by an operation input from the external computer 200 connected to the interface 24 .

(Tape Cartridge)

The tape cartridge 10 is a tape cartridge conforming to the so-called LTO standard or IBM standard and as illustrated in FIG. 2 includes, inside a cartridge case 12 including a lower shell 12 A and an upper shell 12 B, a reel 13 around which the magnetic tape MT is wound, a reel lock 14 and a reel spring 15 for locking the rotation of the reel 13 , a spider 16 for unlocking the reel 13 , a slide door 17 for opening and closing a tape outlet 12 C provided in the cartridge case 12 across the lower shell 12 A and the upper shell 12 B, a door spring 18 for urging the slide door 17 to a closed position of the tape outlet 12 C, a write protection 19 for preventing accidental erasure, and the cartridge memory 11 . The reel 13 has a substantially disk shape with an opening at the center, and includes a reel hub 13 A and a flange 13 B made from hard material such as plastic.

The cartridge memory 11 used in the tape cartridge 10 includes, as illustrated in FIG. 3 , an antenna coil 31 , a rectifier power supply circuit 32 that generates power supply by generating and rectifying power using induced electromotive force from radio waves received by the antenna coil 31 , a clock circuit 33 that generates a clock by also using the induced electromotive force from radio waves received by the antenna coil 31 , a detector/modulator circuit 34 that detects radio waves received by the antenna coil 31 and modulates a signal to be transmitted by the antenna coil 31 , a controller 35 that includes a logic circuit or the like for determining a command and data from a digital signal extracted from the detector/modulator circuit 34 and processing the command and data, and a non-volatile memory (NVM) 36 .

The non-volatile memory 36 has a storage capacity exceeding 16 KB which is larger than the storage capacity defined by the LTO-8 or IBM 3592 magnetic tape standard. An electrically erasable programmable read-only memory (EEPROM) is typically used as the non-volatile memory 36 , but a magnetoresistive random access memory (MRAM), a resistive random access memory (ReRAM), or the like may be used as well.

The cartridge memory 11 is configured such that the antenna coil 31 and detection/modulation conform to the ISO 14443-2 standard in the radio frequency (RF) band, and the command system conforms to the LTO 8 or IBM 3592 standard. According to these standards, the non-volatile memory 36 provided in the cartridge memory 11 can be accessed on a word-by-word basis (2 bytes at a time) or on a block-by-block basis (32 bytes at a time), where addressing can be performed using a 12-bit address in the word-by-word access or a 16-bit address in the block-by-block access. The usable memory capacity is 128 KB at the maximum in a case where an access is made on a word-by-word basis (2 bytes at a time), or is 2 MB at the maximum in a case where an access is made on a block-by-block basis (32 bytes at a time). These are the limitations on the capacity that can be realized in terms of specifications.

The cartridge memory 11 includes four banks BK 0 to BK 3 , a bank switch register 41 , and a multiplexer 42 as illustrated in FIG. 4 . Although the four banks BK 0 to BK 3 are configured by four 16 KB memories in an example described herein, the number of banks is not limited to that of this example but can be selected at will as long as there are two or more banks irrespective of being an even number of banks or an odd number of banks.

The bank switch register 41 is for switching the banks BK 0 to BK 3 such that a bank to/from which data is to be written or read is any one of the banks BK 0 to BK 3 . The bit length of the bank switch register 41 varies depending on the number of banks but needs only be 2 bits minimum in the case of four banks. In other words, it is sufficient if the switching can be controlled in the number of ways equal to a square of two (2 2 ), that is, in four ways, as a combination. For performing write to the bank switch register 41 , for example, one word (2 bytes) being a minimum access unit is reserved, where 2 bits of the one word are allocated for bank switching. The one word for performing write to the bank switch register 41 is preferably allocated in a reserved area which is unused according to the LTO standard, for example, but may be allocated in any write protected area in the cartridge memory 11 . The multiplexer 42 sets any of the banks BK 0 to BK 4 as a destination to which data is written in accordance with an input signal from the bank switch register 41 .

Each of the banks BK 0 to BK 3 has a storage capacity of 128 KB or less, preferably 16 KB or more and 128 KB or less. The bank (first memory bank) BK 0 corresponds to a storage area of an existing cartridge memory conforming to the LTO-8 or IBM 3592 standard. Normal data is written to the bank BK 0 . Here, the “normal data” means data defined in the LTO-8 or IBM 3592 standard.

The banks (second memory banks) BK 1 to BK 3 correspond to extended storage areas for the storage area of the existing cartridge memory described above. Additional data is written to the banks BK 1 to BK 3 . Here, the additional data means data not defined in the LTO-8 or IBM 3592 standard. Examples of the additional data include management ledger data, a copy of the normal data written to the bank BK 0 , an error correction code of the normal data written to the bank BK 0 , index information, and the like but are not limited to these pieces of data.

The system controller 23 of the recording and reproducing device 20 requests the cartridge memory 11 to write or read the normal data. Specifically, the system controller 23 requests the controller 35 to switch the destination to/from which data is written or read from the bank BK 1 , the bank BK 2 , or the bank BK 3 to the bank BK 0 , and then supplies the controller 35 with write or read of the normal data.

The system controller 23 of the recording and reproducing device 20 requests the cartridge memory 11 to write or read the additional data. Specifically, the system controller 23 requests the controller 35 to switch the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 , the bank BK 2 , or the bank BK 3 , and then supplies the controller 35 with write or read of the additional data.

In response to the request from the system controller 23 to change the bank to/from which data is to be written or read, the controller 35 of the cartridge memory 11 switches the destination to/from which data is written or read from the bank BK 1 , the bank BK 2 , or the bank BK 3 to the bank BK 0 . Alternatively, the destination to/from which data is written or read is switched from the bank BK 0 to the bank BK 1 , the bank BK 2 , or the bank BK 3 .

In response to the request from the system controller 23 to write or read the normal data, the controller 35 of the cartridge memory 11 writes the normal data to the bank BK 0 or reads the normal data from the bank BK 0 . Furthermore, in response to the request from the system controller 23 to write or read the additional data, the additional data is written to the bank BK 1 , the bank BK 2 , or the bank BK 3 or is read from the bank BK 1 , the bank BK 2 , or the bank BK 3 . Note that in writing the normal data and the additional data, the normal data and the additional data are supplied from the system controller 23 to the controller 35 .

The system controller 23 and the controller 35 write or read data to/from the non-volatile memory on a word-by-word basis (2 bytes at a time) or on a block-by-block basis (32 bytes at a time).

[Operation of Recording and Reproducing System]

An example of the operation of the recording and reproducing system 100 according to the first embodiment of the present disclosure will be described below with reference to FIG. 5 .

First, when the tape cartridge is loaded into the recording and reproducing device 20 , for example, in step S 11 , the system controller 23 of the recording and reproducing device 20 inquires of the cartridge memory of the tape cartridge being loaded whether or not the cartridge memory has an extended storage area.

In a case where a response that the cartridge memory has the extended storage area is not returned from the cartridge memory in response to the inquiry of step S 11 , the system controller 23 determines that the cartridge memory is a general cartridge memory not having the extended storage area. On the other hand, in a case where a response that the cartridge memory has the extended storage area is returned from the cartridge memory, the system controller 23 determines that the cartridge memory is the cartridge memory 11 of the first embodiment having the extended storage area.

In the present specification, the “general cartridge memory” means a conventional cartridge memory conforming to the LTO-8 or IBM 3592 standard, that is, a cartridge memory having a storage capacity of 16 kB without an extended storage area. Furthermore, the extended storage area means a storage area exceeding 16 kB defined in the LTO-8 or IBM 3592 standard, that is, the memory space of the banks BK 1 to BK 3 .

In a case where it is determined in step S 11 that the tape cartridge has the general cartridge memory, the following write or read processing of the normal data is performed. That is, if the system controller 23 requests write or read of the normal data to a controller of the general cartridge memory, in step S 22 , the controller of the general cartridge memory writes the normal data supplied from the system controller 23 to the non-volatile memory or reads the normal data from the non-volatile memory and supplies the data to the system controller 23 .

In a case where it is determined in step S 11 that the cartridge memory is the cartridge memory 11 , the following write or read processing of the normal data and additional data is performed. That is, in step S 13 , the system controller 23 first determines whether or not write or read processing of the additional data has been performed. In a case where it is determined in step S 13 that the write or read processing of the additional data has been performed, the system controller 23 requests the controller 35 to change the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 in step S 14 . The controller 35 having received this request changes the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 .

Next, in step S 15 , the system controller 23 requests the controller 35 to write or read the additional data. The controller 35 having received this request writes the additional data to the bank BK 1 or reads the additional data from the bank BK 1 and supplies the additional data read to the system controller 23 .

Next, in step S 16 , the system controller 23 requests the controller 35 to change the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 . The controller 35 having received this request changes the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 .

In a case where it is determined in step S 13 that the write or read processing of the additional data has not been performed but a request to write or read the normal data has been made, the controller 35 writes the normal data to the bank BK 0 or reads the normal data from the bank BK 0 and supplies the normal data read to the system controller 23 in step S 17 .

The normal data and the additional data are read when, for example, the tape cartridge 10 is loaded into the recording and reproducing device 20 . On the other hand, the normal data and the additional data are written when, for example, the tape cartridge 10 is unloaded from the recording and reproducing device 20 or data is recorded on the magnetic tape MT.

Although the above operation describes the example in which the additional data is written to the bank BK 1 , the additional data may be written to the bank BK 2 or bank BK 3 which is the extended storage area other than the bank BK 1 . Furthermore, in a case where the additional data is so large that the storage capacity of the bank BK 1 is insufficient, the additional data may be written across the banks BK 1 and BK 2 , or across the banks BK 1 , BK 2 , and BK 3 .

[Effect]

In the recording and reproducing system 100 according to the first embodiment, the controller 35 performs the write or read processing of the normal data on the bank BK 0 among the plurality of banks BK 0 to BK 3 , and performs the write or read processing of the additional data on the bank BK 1 among the plurality of banks BK 0 to BK 3 . Therefore, the storage capacity can be improved while maintaining compatibility with the LTO-8 or IBM 3592 standard.

2 Second Embodiment

A second embodiment describes an example of writing, as the additional data, a copy of the normal data written in the bank BK 0 or an error correction code of the normal data written in the bank BK 0 to the extended storage area.

[Configuration of Recording and Reproducing Tape System]

A copy of the normal data written in the bank BK 0 (additional data) or an error correction code of the normal data written in the bank BK 0 (additional data) is written to the bank BK 1 which is the extended storage area.

After the normal data is written to the bank BK 0 , the system controller 23 requests the controller 35 to write a copy of the normal data or an error correction code of the normal data to the bank BK 1 , the bank BK 2 , or the bank BK 3 . In response to this request, the controller 35 writes the copy of the normal data or the error correction code of the normal data to the bank BK 1 , the bank BK 2 , or the bank BK 3 .

In a case where the normal data is read from the bank BK 0 and supplied from the cartridge memory 11 to the system controller 23 , the system controller 23 determines whether or not the normal data supplied is broken. The determination as to whether or not the data read from the bank BK 0 is broken is made by using, for example, an error detecting code included in the normal data supplied from the cartridge memory 11 . Note that the LTO standard defines that a cyclic redundancy check (CRC) is used as the error detecting code.

In a case where the system controller 23 determines that the normal data is not broken, the system controller supplies the normal data to the external computer 200 , for example. On the other hand, in a case where the system controller 23 determines that the normal data is broken, the system controller requests the cartridge memory 11 to read the copy of the normal data or the error correction code of the normal data written in the bank BK 1 , the bank BK 2 , or the bank BK 3 . In response to this request, the controller 35 reads the copy of the normal data or the error correction code of the normal data from the bank BK 1 , the bank BK 2 , or the bank BK 3 , and makes a request to the system controller 23 .

[Operation of Recording and Reproducing Tape System]

An example of the operation of the recording and reproducing system 100 according to the second embodiment of the present disclosure will be described below with reference to FIG. 6 . Note that a step similar to that in the operation of the recording and reproducing system 100 of the first embodiment is indicated by the same reference numeral as that in the operation of the first embodiment and will not be described.

In a case where it is determined in step S 11 that the cartridge memory is the cartridge memory 11 according to the second embodiment, the following write processing of the normal data and additional data is performed. That is, in step S 23 , the system controller 23 first supplies the normal data to the controller 35 . The controller 35 writes the normal data supplied from the system controller 23 to the bank BK 0 .

Next, in step S 24 , the system controller 23 requests the controller 35 to switch the destination to which data is written from the bank BK 0 corresponding to the storage area of an existing cartridge memory to the bank BK 1 corresponding to the extended storage area. In response to this request, the controller 35 switches the destination to which data is written from the bank BK 0 to the bank BK 1 .

Next, in step S 25 , the system controller 23 supplies the controller 35 with a copy of the normal data written to the bank BK 0 in step S 23 or an error correction code of the normal data written to the bank BK 0 in step S 23 . The controller 35 writes the copy of the normal data or the error correction code of the normal data supplied from the system controller 23 to the bank BK 1 .

Next, in step S 26 , the system controller 23 requests the controller 35 to switch the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 . In response to this request, the controller 35 switches the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 . The destination to/from which data is written or read is switched to the bank BK 0 as described herein so that, in a case where the tape cartridge 10 is loaded into a general recording and reproducing device, the general recording and reproducing device can perform write or read processing of normal data on the tape cartridge 10 as it does on a general cartridge.

Here, the “general recording and reproducing device” means a conventional recording and reproducing device that can write or read data to/from the storage area of an existing cartridge memory (that is, the 16 kB storage area (bank BK 0 ) defined by the LTO-8 or IBM 3592 standard) but cannot write or read data to/from the extended storage area (banks BK 1 to BK 3 ).

Although the above operation describes the example in which the copy of the normal data or the error correction code of the normal data is written to the bank BK 1 , the copy of the normal data or the error correction code thereof may be written to the bank BK 2 or the bank BK 3 .

[Effect]

In the recording and reproducing system 100 according to the second embodiment, the system controller 23 of the recording and reproducing device 20 writes the copy of the normal data or the error correction code of the normal data written in the bank BK 0 to the bank BK 1 which is the extended storage area. Thus, in a case where the normal data read from the bank BK 0 is found to be broken, the system controller 23 can read the copy of the normal data or the error correction code of the normal data from the bank BK 1 . As a result, the broken normal data can be restored so that the reliability of the write data can be improved.

3 Third Embodiment

A third embodiment describes an example of writing management ledger data to the extended storage area or reading management ledger data from the extended storage area.

[Configuration of Recording and Reproducing Tape System]

Management ledger data (additional data) defined in JIS Z-6019 is written to the bank BK 1 which is the extended storage area. Although an example of writing the management ledger data to the bank BK 1 is described herein, the management ledger data may be written to the bank BK 2 or the bank BK 3 which is the extended storage area other than the bank BK 1 . Furthermore, in a case where the management ledger data is so large that the storage capacity of the bank BK 1 is insufficient, the management ledger data may be written across the banks BK 1 and BK 2 , or across the banks BK 1 , BK 2 , and BK 3 .

The system controller 23 of the recording and reproducing device 20 requests the cartridge memory 11 to write or read the management ledger data. Specifically, the system controller 23 requests the controller 35 to switch the destination to/from which data is to be written or read from the bank BK 0 to the bank BK 1 , and then requests the controller 35 to write or read the management ledger data. The management ledger data is written when, for example, the tape cartridge 10 is unloaded from the recording and reproducing device 20 or the like. The management ledger data is read when, for example, the tape cartridge 10 is loaded into the recording and reproducing device 20 or the like.

In response to the request from the system controller 23 , the controller 35 of the cartridge memory 11 switches the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 . Furthermore, in response to the request from the system controller 23 , the management ledger data is written to the bank BK 1 or is read from the bank BK 1 and supplied to the system controller 23 .

[Operation of Recording and Reproducing Tape System]

An example of the operation of the recording and reproducing system 100 according to the third embodiment will be described below with reference to FIG. 7 . Note that a step similar to that in the operation of the recording and reproducing system 100 of the first embodiment is indicated by the same reference numeral as that in the operation of the first embodiment and will not be described.

In a case where it is determined in step S 11 that the cartridge memory is the cartridge memory 11 according to the third embodiment, the following write or read processing of data is performed.

First, in step S 31 , the system controller 23 determines whether or not write or read processing of a deposit ledger has been performed. In a case where it is determined in step S 31 that the write or read processing of the deposit ledger has been performed, the system controller 23 requests the controller 35 to change the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 in step S 32 . The controller 35 having received this request changes the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 .

Next, in step S 33 , the system controller 23 requests the controller 35 to write or read the management ledger data. The controller 35 having received this request writes the management ledger data to the bank BK 1 or reads the management ledger data from the bank BK 1 .

Next, in step S 34 , the system controller 23 requests the controller 35 to change the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 . The controller 35 having received this request changes the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 .

In a case where it is determined in step S 31 that the write or read processing of the deposit ledger has not been performed but normal read or write processing has been requested, the controller 35 writes the normal data to the bank BK 0 or reads the normal data from the bank BK 0 in step S 35 .

[Effect]

The recording and reproducing system 100 according to the third embodiment can switch the bank switch register 41 and write the management ledger data to the bank BK 1 or the like which is the extended storage area. Therefore, a search of the management ledger data can be sped up compared to a case where the management ledger data is written on the magnetic tape MT.

On the other hand, in a case where the management ledger data is not to be written, the normal data can be written to the bank BK 0 or read from the bank BK 0 . Therefore, the bank BK 0 can be treated as a non-volatile memory of a normal cartridge memory.

The JIS Z-6019 defines that the management ledger data is to be written in a storage for file management, where the management ledger data is required for each file to be managed. As the capacity of the magnetic tape increases, the number of files that can be written also increases so that the storage capacity of 16 KB established by LTO-8 is insufficient. Thus, a conventional recording and reproducing system needs to record the management ledger data on the magnetic tape simultaneously with a file, and also needs to access the magnetic tape each time the management ledger data is to be accessed. Therefore, a search for necessary information is performed after all information stored on the magnetic tape is read, whereby the magnetic tape that reads data not electrically but physically has a problem that the search takes time.

4 Fourth Embodiment

A fourth embodiment describes an example of writing index information to the extended storage area or reading index information from the extended storage area.

[Configuration of Recording and Reproducing Tape System]

Index information is written to the bank BK 1 which is the extended storage area. The index information is a management table (additional data) for managing a file system. The file system is a Liner Tape File System (LTFS), for example.

Although an example of writing the index information to the bank BK 1 is described herein, the index information may be written to the bank BK 2 or BK 3 which is the extended storage area other than the bank BK 1 . Furthermore, in a case where the index information is so large that the storage capacity of the bank BK 1 is insufficient, the index information may be written across the banks BK 1 and BK 2 , or across the banks BK 1 , BK 2 , and BK 3 .

The system controller 23 of the recording and reproducing device 20 requests the cartridge memory 11 to write or read the index information. Specifically, the system controller 23 requests the controller 35 to switch the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 , and then requests the controller 35 to write or read the index information. The index information is read when, for example, the tape cartridge 10 is loaded into the recording and reproducing device 20 or the like. The index information is written when, for example, data is recorded on the magnetic tape MT or the like.

In response to the request from the system controller 23 , the controller 35 of the cartridge memory 11 switches the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 . Furthermore, in response to the request from the system controller 23 , the index information is written to the bank BK 1 or read from the bank BK 1 .

[Operation of Recording and Reproducing Tape System]

An example of the operation of the recording and reproducing system 100 according to the fourth embodiment will be described below with reference to FIG. 8 . Note that a step similar to that in the operation of the recording and reproducing system 100 of the first embodiment is indicated by the same reference numeral as that in the operation of the first embodiment and will not be described.

In a case where it is determined in step S 11 that the cartridge memory is the cartridge memory 11 according to the fourth embodiment, the following write or read processing of data is performed.

First, in step S 41 , the system controller 23 determines whether or not write or read processing of the index information has been performed. In a case where it is determined in step S 41 that the write or read processing of the index information has been performed, the system controller 23 requests the controller 35 to change the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 in step S 42 . The controller 35 having received this request changes the destination to/from which data is written or read from the bank BK 0 to the bank BK 1 .

Next, in step S 43 , the system controller 23 requests the controller 35 to write or read the index information. The controller 35 having received this request writes the index information to the bank BK 1 or reads the index information from the bank BK 1 .

Next, in step S 44 , the system controller 23 requests the controller 35 to change the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 . The controller 35 having received this request changes the destination to/from which data is written or read from the bank BK 1 to the bank BK 0 .

In a case where it is determined in step S 41 that the write or read processing of the index information has not been performed but a request to write or read the normal data has been made, the controller 35 writes the normal data to the bank BK 0 or reads the normal data from the bank BK 0 in step S 45 .

[Effect]

In the LTFS specification, the magnetic tape is divided into partitions so that about 4% of the capacity of the magnetic tape is reserved for writing LTFS index information. The magnetic tape, by its nature, is suitable for sequential access but not for random access. Data is written additionally even in a case where a file is updated, and the file before the update is not deleted but only invalidated. The accompanying LTFS index information is also added repeatedly on an LTFS index partition. Therefore, in order to access a certain file, it is necessary to search the LTFS index partition and look for the latest index information on the magnetic tape. Due to this operation, a conventional recording and reproducing system has a problem that the speed of the tape system using LTFS is slow. Furthermore, in order to achieve some speed-up, a tape library vendor recommends an option that achieves speed-up by causing the cartridge memory to store the location on the tape with the latest LTFS index information within the limitation of the capacity of the cartridge memory (16 KB for LTO8).

The recording and reproducing system 100 according to the fourth embodiment is configured to write the index information only to the cartridge memory 11 suitable for random access, not to the magnetic tape MT. Therefore, more data can be written to the magnetic tape MT since the partition of about 4% thereof described above become unnecessary. Furthermore, in updating the index information, it is only required to overwrite existing index information without the need for additional write, so that the latest index information can always be accessed at high speed and that the recording and reproducing system 100 can be sped up.

<5 Variation>

Although the first to fourth embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above first to fourth embodiments but can be modified in various ways based on the technical ideas of the present disclosure.

For example, the configurations, methods, steps, numerical values, and the like described in the first to fourth embodiments above are merely examples, and configurations, methods, steps, numerical values, and the like different therefrom may be used as necessary.

Furthermore, the configurations, methods, steps, numerical values, and the like of the first to fourth embodiments above can be combined with one another without departing from the spirit of the present disclosure.

Although the first to fourth embodiments above describe the example of configuring the bank memory with the four banks BK 0 to BK 3 using four 16 KB memories, the configuration of the bank memory is not limited thereto.

For example, as illustrated in FIG. 9 , an apparent four-bank memory may be configured by using a memory 51 with the storage capacity of 64 KB and dividing the 64 KB memory into four using, for example, upper two address bits of each word. Alternatively, although not shown in the drawing, an apparent four-bank memory may be configured by using two memories each with the storage capacity of 32 KB and similarly dividing each 32 KB memory into two. Also, the bank switch address is not limited to the upper two bits but may be allocated anywhere.

Furthermore, as illustrated in FIG. 10 , a two-bank memory with each bank having 128 KB may be configured by using a memory 52 with the storage capacity of 256 KB. In the ISO 14443-2 standard, two access methods being word-by-word access and block-by block access can be selected, where addressing is performed with the address width of 12 bits for the word-by-word access and 16 bits for the block-by-block access. The 12-bit address width becomes a constraint for enabling access both on a word-by-word basis and a block-by-block basis so that only the capacity of 128 KB can be realized, but the present variation can extend the capacity up to 256 KB for use.

The first to fourth embodiments above describe the case where the system controller 23 and the controller 35 write or read data to/from the non-volatile memory 36 on a word-by-word basis (2 bytes at a time) or on a block-by-block basis (32 bytes at a time), but the system controller 23 and the controller 35 may write or read data to/from the non-volatile memory 36 on a block-by-block basis (32 bytes at a time). In this case, each of the banks BK 0 to BK 3 has the storage capacity of 2 MB or less, preferably 16 KB or more and 2 MB or less.

The first to fourth embodiments above describe the case where each of the plurality of banks included in the non-volatile memory 36 has the storage capacity of 16 KB or more than or equal to 16 KB, but each of the plurality of banks included in the non-volatile memory 36 may have the storage capacity of less than 16 KB. Specifically, each of the plurality of banks included in the non-volatile memory 36 may have the storage capacity of (16/n) KB (where “n” is a positive integer), for example, 8 KB. In this case, the normal data is written across a plurality of banks (first memory banks) with the storage capacity of 16 KB in total. For example, in a case where each of the plurality of banks included in the non-volatile memory 36 has the storage capacity of 8 KB, the normal data is written across two banks (first memory banks).

Although the first to fourth embodiments above describe the case where the present disclosure is applied to the recording and reproducing device, the present disclosure is not limited thereto but may be applied to a library apparatus, a storage system, or the like.

Furthermore, the present disclosure can also adopt the following configurations.

(1)

A cartridge memory used for a tape cartridge, including:

a communication unit that communicates with a recording and reproducing device using a wireless communication method defined by an ISO 14443-2 standard which is a wireless communication standard; a non-volatile memory with a storage capacity exceeding 16 KB; and a control unit that writes or reads data to or from the non-volatile memory on a word-by-word basis (2 bytes at a time) or on a block-by-block basis (32 bytes at a time), in which the non-volatile memory includes a plurality of memory banks each having a storage capacity of 128 KB or less, the control unit writes or reads data defined by a magnetic tape standard to or from one or two or more first memory banks among the plurality of the memory banks, and additional data is written or read to or from one or two or more second memory banks other than the first memory bank.

(2)

A cartridge memory used for a tape cartridge, including:

a communication unit that communicates with a recording and reproducing device using a wireless communication method defined by an ISO 14443-2 standard which is a wireless communication standard; a non-volatile memory with a storage capacity exceeding 16 KB; and a control unit that writes or reads data to or from the non-volatile memory on a block-by-block basis (32 bytes at a time), in which the non-volatile memory includes a plurality of memory banks each having a storage capacity of 2 MB or less, the control unit writes or reads data defined by a magnetic tape standard to or from one or two or more first memory banks among the plurality of the memory banks, and additional data is written or read to or from one or two or more second memory banks other than the first memory bank.

(3)

The cartridge memory according to (1), in which the memory bank has a storage capacity of 16 KB or more and 128 KB or less.

(4)

The cartridge memory according to (2), in which the memory bank has a storage capacity of 16 KB or more and 2 MB or less.

(5)

The cartridge memory according to any one of (1) to (4), in which the additional data is management ledger data defined in JIS 26019.

(6)

The cartridge memory according to any one of (1) to (4), in which the additional data is a management table for managing a file system.

(7)

The cartridge memory according to (6), in which the file system is a linear tape file system.

(8)

The cartridge memory according to any one of (1) to (4), in which the additional data is a copy or an error correction code of data written to the first memory bank.

(9)

The cartridge memory according to any one of (1) to (8), in which the non-volatile memory further includes a memory bank switch register for switching the plurality of the memory banks.

(10)

A tape cartridge including the cartridge memory according to any one of (1) to (9).

(11)

A recording and reproducing system including:

a tape cartridge including the cartridge memory according to any one of (1) to (9); and a recording and reproducing device that can load or unload the tape cartridge.

10 Tape cartridge

11 Cartridge memory

20 Recording and reproducing device

21 Reader/writer

22 Recording and reproducing unit

23 System controller

24 Interface

31 Antenna coil

32 Rectifier power supply circuit

33 Clock circuit

34 Detector/modulator circuit

35 Controller

36 Non-volatile memory

41 Bank switch register

42 Multiplexer

100 Recording and reproducing system

200 External computer

BK 0 Bank (first memory bank)

BK 1 to BK 3 Bank (second memory bank)

MT Magnetic tape