JP2007334915A - Memory card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To additionally correct or modify a program by selecting a certain firmware-on-flash from a plurality of firmware-on-flashes. <P>SOLUTION: In a memory card 1, firmware-on-flashes FOF1-FOF3 serving as programs for adding, modifying or correcting functions such as batch programs are stored in a flash memory 2 independently of programs stored in a built-in ROM 6. Then, the firmware-on-flash to be enabled is set by means of a parameter sector or the like and loaded to an external RAM 7 and the CPU of control logic 4 executes a process. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a memory card, and more particularly to a technique effective when applied to multi-functionalization of a memory card using a nonvolatile memory.

  Memory cards are rapidly spreading as storage devices such as personal computers and multi-function terminals. With the recent demand for higher performance, as a semiconductor memory mounted on a memory card, for example, a non-volatile memory such as a flash memory that can be electrically erased and rewritten electrically and can hold a large amount of data. It is used.

  In such a memory card, a control program is stored in a ROM (Read Only Memory) provided in the memory card. In addition, firmware such as a patch program for the control program or an additional control program for expanding the function of the control program stored in the ROM may be stored in the flash memory.

  This firmware (hereinafter referred to as “firm on flash”) can be freely rewritten any number of times, and even if it is a product, it can be easily changed and added with functions.

  In some multimedia cards, the command and the data format are set to be valid / invalid by firmware (see, for example, Patent Document 1).

Furthermore, in the IC card, a command table is provided in a nonvolatile memory such as an EEPROM (Electrically Erasable and Programmable ROM) separately from the command table in the ROM, and the command table in the ROM is known to third parties. In some cases, a command table is used in the non-volatile memory when there is a risk of being read (see, for example, Patent Document 2).
JP 2003-085509 A Japanese Unexamined Patent Publication No. 7-44672

  However, the present inventors have found that the above memory card has the following problems.

  That is, the firmware on flash is expanded in a RAM (Random Access Memory) used as a CPU work area provided in the controller when the memory card is activated. Therefore, only one firmware on flash is provided.

  For this reason, additional functions and program corrections due to firmware-on-flash are also restricted, and the convenience of the memory card may be impaired.

  Further, in an IC card having a command table in a nonvolatile memory, the nonvolatile memory and the controller are formed in one semiconductor chip, and the EEPROM is usually capable of random access in byte units. However, in the memory card, the non-volatile memory and the controller are formed on different semiconductor chips, and the access unit to the non-volatile memory is also a sequential access such as a 512-byte unit.

  Therefore, in the case of a memory card, in the configuration in which the firmware on flash is stored in the non-volatile memory and the firmware on flash is read out by the controller, the operation speed with the controller is different, so the overhead of data reading and data transfer speed is increased. There is a problem that it gets bigger.

  An object of the present invention is to provide a memory card that has a plurality of firmware-on-flashes, and can arbitrarily add, modify, or change a program by arbitrarily selecting the firmware-on-flash.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  The present invention includes a non-volatile semiconductor memory having a plurality of non-volatile memory cells and capable of storing predetermined information, and a controller for instructing operation of the non-volatile semiconductor memory based on an externally issued command. The non-volatile semiconductor memory is a card that can store two or more firmware, and the controller includes a volatile semiconductor memory that stores the firmware, and the firmware is stored when the two or more firmware is stored. When there is a selection instruction, one arbitrary firmware is selected from two or more firmware stored in the volatile semiconductor memory and stored in the volatile semiconductor memory, and the controller accesses the volatile semiconductor memory and depends on the firmware. The process is executed.

  More specifically, a nonvolatile semiconductor memory having a plurality of nonvolatile memory cells and capable of storing data and data management information thereof, and operating instructions of the nonvolatile semiconductor memory based on an externally issued command A non-volatile semiconductor memory configured to store two or more firmware as data, the controller including a volatile semiconductor memory for storing firmware, and a firmware selection instruction When is enabled, any one firmware is selected from two or more firmware that can be stored in the volatile semiconductor memory, stored in the volatile semiconductor memory, accessed to the volatile semiconductor memory, and executed by the firmware. The controller is the firmware of the nonvolatile semiconductor memory It is to find the firmware to be stored in the volatile semiconductor memory using the chromatography data management information.

  According to the present invention, the firmware data management information comprises a firmware start address value stored in a nonvolatile semiconductor memory.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  (1) It is possible to realize a multi-functional memory card, etc., and it is possible to quickly cope with program correction and addition.

  (2) According to the above (1), it is possible to flexibly cope with market changes and to provide a low-cost memory card.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 is a block diagram of a memory card according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of an internal configuration of a flash memory provided in the memory card of FIG. 1, and FIG. FIG. 4 is a flow chart of the memory card when selecting the firmware on flash according to the parameters by the memory card of FIG. 1, and FIG. 5 is for firmware on flash selection by the memory card of FIG. FIG. 6 is a flowchart for selecting and loading a firmware on flash using a command, FIG. 6 is a flowchart for selecting a firmware on flash during program execution by the memory card of FIG. 1, and FIG. 7 is a memory card of FIG. Float to search for selected farm-on-flash using ID code Over DOO, FIG. 8 is a flowchart for search by specifying a search range farm on flash selected by the memory card of FIG.

  In the present embodiment, the memory card 1 is used as an external storage medium of the host device HT in a digital video camera, a mobile phone, a portable music player, a personal computer, or the like.

  As shown in FIG. 1, the memory card 1 includes a plurality of flash memories (nonvolatile semiconductor memories) 2 and a controller 3. The flash memory 2 is a nonvolatile semiconductor memory that can electrically rewrite and erase data. Here, a plurality of flash memories 2 are provided, but one or more flash memories 2 may be provided.

  In addition to the program stored in the built-in ROM 6, the flash memory 2 stores firmware on flash (firmware) FOF1 to FOF3, which are programs for adding, changing, and correcting functions such as a patch program.

  Here, it is assumed that three firmware on flashes FOF1 to FOF3 are stored in the flash memory 2, but the number of firmware on flashes stored in the flash memory 2 is three or more, or three or less. Any of these may be sufficient.

  The controller 3 is connected to the host device HT, controls the flash memory 2, reads out a program or data stored in the flash memory 2, and outputs it to the host device HT or is input from the host device HT. Instructs program and data write operations.

  The controller 3 includes a control logic 4, a built-in RAM (volatile semiconductor memory) 5, a built-in ROM 6, an external RAM 7, and the like. The control logic 4 manages all the controls in the controller 3.

  The built-in RAM 5 is a volatile memory such as SRAM (Static RAM), and is used as a work area of the CPU provided in the control logic 4. The built-in ROM 6 stores a control program for operating the control logic 4 and the like. The external RAM 7 is a memory in which any one of the firmware-on-flash FOF1 to FOF3 stored in the flash memory 2 is loaded.

  FIG. 2 is an explanatory diagram of the internal configuration of the flash memory 2.

  The flash memory 2 includes a user access area A1 and a user access impossible area A2.

  The user access area A1 includes a data block area R1 that can be used by the user, and a management area K1 in which data for managing the data block area is stored.

  The user inaccessible area A2 is an area that cannot be accessed by the user, and includes a data block substitution area R2, a FOF area R3, a CIS / ID / parameter area R4, and a substitution table area R5.

  The data block substitution area R2, the FOF area R3, the CIS / ID / parameter area R4, and the substitution table area R5 are provided with management areas K2 to K5, respectively.

  The data block replacement area R2 is an area that is replaced when a defect occurs in the data block area, and the management area K2 stores information for managing the data block replacement area R2.

  The FOF area R3 is an area in which the firmware on flashes FOF1 to FOF3 are stored, and the management area (firmware management area) K3 stores information for managing the FOF area R3.

  The CIS / ID / parameter area R4 stores a drive information ID (Identify Drive Information) of the memory card 1, information such as the name, type, and function of the memory card 1, a CIS (Card Information Structure), and various parameters. The management area K4 stores information for managing these CIS / ID / parameter areas R4. The substitution table area R5 is an area for storing area substitution area information, and the management area K5 stores information for managing the substitution table area R5.

  The configuration in the management area K3 will be described with reference to the configuration explanatory diagram of FIG.

  As shown in the figure, the management area K3 includes a good sector code, a firmware on flash No. , An identification code (firmware identification information), management ECC information, and the like are stored.

  The good sector code is a code indicating whether each sector in the FOF area R3 is normal or abnormal. Farm on flash No. Is a number assigned to each of the firmware-on-flash FOF1 to FOF3.

  The identification code is a code indicating that it is a block of each firmware-on-flash FOF1 to FOF3 (hereinafter referred to as FOF block) stored in the FOF area R3, and is used when searching for the FOF block. The management ECC information is ECC (Error Collecting Code) information used when performing data correction.

  Next, the operation of the memory card 1 of the present embodiment will be described.

  First, the operation of the memory card 1 when a firmware-on-flash FOF1 to FOF3 selection instruction (firmware selection instruction) is performed using parameters will be described with reference to the flowchart of FIG.

  In this case, a selection bit of firmware on flash FOF1 to FOF3 is provided in the parameter sector, and loading of the firmware on flash selected by the selection bit is performed in a reset sequence such as at power-on.

  First, in the reset sequence, the CPU of the controller 3 reads a necessary parameter sector from the CIS / ID / parameter region R4 of the flash memory 2 and stores it in the external RAM 7 (step S101).

  Thereafter, the selected firmware on flash No. is selected from the read parameter sector. Is acquired (step S102). Then, with reference to the identification code in the management area K3 of the flash memory 2, it is searched whether or not the flash memory 2 has the FOF area R3 (step S103).

  In the process of step S103, if the FOF area R3 exists, a process for searching for an FOF block in the FOF area R3 is performed (step S104).

  When the FOF area R3 does not exist, the CPU accesses the built-in ROM 6 and operates the memory card 1 based on a program stored in the built-in ROM 6.

  Next, the operation of the memory card 1 when a firmware on flash selection command is issued using the firmware on flash selection command will be described with reference to the flowchart of FIG.

  First, when receiving a firmware on flash selection command from the host device HT or the like, the CPU sets the firmware on flash selection command in the task file register provided in the control logic 4 (step S201). This task file register is a register for exchanging data with the host device HT in the same manner as a normal command.

  After that, the firmware on flash No. Is set in the task file register (step S202). Then, with reference to the identification code in the management area K3 of the flash memory 2, it is searched whether or not the FOF area R3 exists in the flash memory 2 (step S203).

  In the process of step S203, if the FOF area R3 exists, a process for searching for an FOF block in the FOF area R3 is performed (step S204). When the FOF area R3 does not exist, the CPU accesses the built-in ROM 6 and operates the memory card 1 based on the program stored in the built-in ROM 6.

  Next, the operation of the memory card 1 in the case of a selection instruction for selecting an arbitrary firmware-on-flash during program execution will be described using the flowchart of FIG.

  Here, for example, a case where the firmware-on-flash FOF2 is newly selected and executed during the processing of the firmware-on-flash FOF1 will be described. The same applies to the process of newly selecting and executing.

  When an arbitrary process is being executed based on the firmware of the firmware-on-flash FOF1 (step S301), the CPU determines which of the other firmware-on-flash FOF2, FOF3 that is not selected due to the occurrence of an interrupt process or an error process. It is determined whether or not such processing is necessary (step S302).

  When processing of any other firmware-on-flash FOF2 or FOF3 that is not selected is necessary, the firmware-on-flash No. to be selected is selected. Is set (step S303).

  Then, with reference to the identification code in the management area K3 of the flash memory 2, it is searched whether or not the flash memory 2 has the FOF area R3 (step S304).

  In the process of step S304, if the FOF area R3 exists, a process for searching for an FOF block in the FOF area R3 is performed (step S305).

  When the FOF area R3 does not exist, the CPU accesses the built-in ROM 6 and operates the memory card 1 based on a program stored in the built-in ROM 6.

  Next, the search process of the firmware on flash selected in FIGS. 4 to 6 will be described.

  First, processing for searching using the identification code in the management area K3 will be described with reference to the flowchart of FIG.

  First, the CPU reads the management area K3 from the head address of the FOF area R3 (step S401), and checks the identification code of the management area K3 (step S402). And it is discriminate | determined by an identification code whether it is a FOF block (step S403). In the process of step S403, if the checked identification code is a block code other than the FOF block, the process ends.

  In the case of the FOF block in the process of step S403, the firmware on flash No. in the management area K3 is displayed. (Step S404), the firmware on flash No. Based on the above, it is determined whether or not the FOF block in the process of step S403 is the corresponding firmware-on-flash (step S405).

  In step S405, if it is not the corresponding FOF block, the address of the FOF block is incremented (decremented when searching in reverse order) (step S406), and the processes of steps S402 to S405 are repeatedly executed.

  When the corresponding FOF block is searched in the process of step S405, the firmware of the firmware on flash is loaded into the built-in RAM 5 (step S407), and the process by the firmware is performed.

  As described above, the CPU can execute high-speed processing by loading the firmware-on-flash into the built-in RAM 5 that can be randomly accessed.

  Next, a case where the FOF block is searched by limiting the search range will be described with reference to the flowchart of FIG. In this case, an address value indicating the range of the FOF block (FOF area R3) is set in the parameter sector.

  First, the search range of the FOF block is acquired from the parameter sector in the CIS / ID / parameter region R4 (step S501).

  Then, it is determined whether or not the head address of the FOF area R3 is the search range acquired from the parameter sector (step S502). If it is not within the search range, the process ends.

  If it is within the search range, the management area K3 is read (step S503), and the firmware on flash No. of the management area K3 is read. Is checked (step S504).

  The checked farm-on-flash No. From this, it is determined whether or not the FOF block is the corresponding firmware-on-flash (step S505).

  In step S505, if it is not the corresponding FOF block, the address of the FOF block is incremented (decremented when searching in reverse order) (step S506), and the processes in steps S502 to S505 are repeatedly executed.

  When the corresponding FOF block is searched in the process of step S505, the firmware on flash firmware is loaded into the internal RAM 5 (step S507), and the process by the firmware is performed.

  Thereby, according to the present embodiment, by setting a plurality of firmware-on-flashes in the flash memory 2, it is possible to realize the multi-function of the memory card 1.

  Further, the plurality of firmware-on-flashes can easily modify, change, and add programs without changing the programs stored in the built-in ROM 6, and can flexibly deal with them.

  Furthermore, in the present embodiment, the firmware-on-flash FOF1 to FOF3 may be programs having an optional function such as a program having a secure function.

  As a result, the program in the built-in ROM 6 can be shared for any memory card 1 that requires or does not require a secure function, so that the cost of product management can be greatly reduced.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments of the invention. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, in the above embodiment, the memory card has a configuration in which a plurality of firmware-on-flashes are stored in the flash memory in advance. However, when the host device executes an updater program or the like, a new firmware-on-flash can be added. Rewriting or the like may be performed.

  When a new firmware-on-flash is added, for example, a spare area is provided in the FOF area in the flash memory, and the firmware-on-flash to be added to the spare area is stored, or in another area such as a data block replacement area. Stores the farm-on-flash to be added.

  Thereby, it is possible to deal with the correction, change, addition, etc. of the program more flexibly.

  The flash memory in the above embodiment may be a multi-value flash memory that sets a plurality of threshold values of a certain voltage level and stores data of 1 bit or more in one nonvolatile memory cell.

  The present invention is suitable for a memory card using a nonvolatile memory.

1 is a block diagram of a memory card according to an embodiment of the present invention. It is explanatory drawing of the internal structure in the flash memory provided in the memory card of FIG. FIG. 3 is an explanatory diagram of a configuration in a management area provided in the flash memory of FIG. 2. FIG. 2 is a flowchart of a memory card when firmware on flash is selected according to parameters by the memory card of FIG. 1. FIG. FIG. 3 is a flowchart for selecting and loading a firmware-on-flash using a firmware-on-flash selection command by the memory card of FIG. 1. FIG. FIG. 3 is a flowchart in the case of selecting firmware on flash during program execution by the memory card of FIG. 1. FIG. 2 is a flowchart for searching for a selected firmware-on-flash using the memory card of FIG. 1 using an identification code. 3 is a flowchart for searching for a selected firmware-on-flash using the memory card of FIG. 1 by specifying a search range.

Explanation of symbols

1 Memory card 2 Flash memory (nonvolatile semiconductor memory)
3 Controller 4 Control logic 5 Built-in RAM (volatile semiconductor memory)
6 Internal ROM
7 External RAM
FOF1 to FOF3 firmware on flash (firmware)
A1 User access area A2 User inaccessible area R1 Data block area R2 Data block substitution area R3 FOF area R4 CIS / ID / parameter area R5 substitution table area K1, K2 management area K3 management area (firmware management area)
K4, K5 management area HT Host device

Claims (2)

A nonvolatile semiconductor memory having a plurality of nonvolatile memory cells and capable of storing data and data management information thereof;
A memory card comprising a controller for instructing operation of the nonvolatile semiconductor memory based on a command issued from the outside,
The nonvolatile semiconductor memory is configured to be able to store two or more firmware as data,
The controller is
A volatile semiconductor memory for storing the firmware;
When the firmware selection instruction is enabled, any one of the firmware that can be stored in the volatile semiconductor memory is selected, stored in the volatile semiconductor memory, and accessed to the volatile semiconductor memory And execute the process by the firmware,
The memory card, wherein the controller searches for firmware stored in the volatile semiconductor memory using data management information of firmware of the nonvolatile semiconductor memory. The memory card according to claim 1,
The firmware data management information is:
A memory card having a firmware start address value stored in the nonvolatile semiconductor memory.

Images