JP2007207277A - Semiconductor information processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonvolatile memory capable of nonvolatile software write protection, in an information processing apparatus and a memory card using the non-volatile memory without a write protect function, and a system technology using the same. <P>SOLUTION: A flash memory card 1 utilizes a rewritable non-volatile memory, which is rewritable and not provided with a function for the software write protection. The flash memory card 1 comprises a flash memory 2 being electrically collectively erasable and rewritable; a reset IC 3 generating a power-on reset signal when power is supplied through a power source; and a card controller 4 for controlling these devices and memory card interfaces. In the flash memory 2, a register 5 for holding the write protection, for writing an area address for write protection, is set in an attribute area, and a protection range is set by the system. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a nonvolatile memory and a system technology using the nonvolatile memory, and more particularly, a system using a rewritable nonvolatile memory without a nonvolatile software write protection function, for example, an information processing device in general and a memory card in general, and further nonvolatile The present invention relates to a nonvolatile memory that enables nonvolatile software write protection in a memory device, a memory card using the nonvolatile memory, an information processing apparatus, and a technology effective when applied to a software write protection control method for a nonvolatile memory.

  For example, Intel's Series 2+ has been commercialized as a flash memory card using a flash memory (flash EEPROM) as a nonvolatile memory and having a nonvolatile software write protection function. This uses Intel's Flash memory, and the Flash memory itself has a write protection function in units of erase blocks.

  The software write protect function is a word for the hardware write protect function such as a write prohibit switch, and means that the user (system) can arbitrarily set the write protect area in the flash memory area. Performing write protection by this software can be defined as software write protection.

  By the way, in the flash memory card as described above, since the flash memory itself has a write protect function, software write protect is possible. For example, a flash memory having no write protect function in an arbitrary area is provided. In the used memory card, rewritable nonvolatile software write protection of the write protect area is impossible.

  Accordingly, an object of the present invention is to provide a non-volatile software write protect by setting a write protect storage register in a non-volatile memory in a memory card and an information processing apparatus using a non-volatile memory such as a flash memory without a write protect function. And a memory card using the nonvolatile memory, an information processing apparatus, and a software write protection control method for the nonvolatile memory.

  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 this application, the outline of typical ones will be briefly described as follows.

  That is, the non-volatile memory of the present invention is applied to a rewritable non-volatile memory without a non-volatile software write protect function, and in order to enable a non-volatile software write protect control, a predetermined amount is included in the non-volatile memory. A write protect storage register for writing an address of an arbitrary write protect area in an erasing unit is set.

  In this case, it is possible to change the setting of the write protect area from the beginning of the nonvolatile memory to the arbitrary, from the last to the arbitrary, or from the arbitrary to the arbitrary erasing unit. This can be changed in units of blocks, and is applied to, for example, a flash memory.

  The memory card of the present invention uses the nonvolatile memory, and is composed of the nonvolatile memory and a card controller that controls at least between the nonvolatile memory and the memory card interface.

  Furthermore, an information processing apparatus according to the present invention uses the nonvolatile memory, and includes the nonvolatile memory, at least a central processing unit, and its peripheral devices.

  In the nonvolatile memory software write protection control method according to the present invention, the address of an arbitrary write protection area is written in the write protection storage register in the nonvolatile memory, and the address accessed from the user side using the address is written. It is determined whether or not it is within the protected area, and nonvolatile software write protection control is performed.

(Function)
According to the non-volatile memory, the memory card using the same, the information processing apparatus, and the non-volatile memory software write protection control method, for example, the final address of the flash memory capable of batch electrical erasing and writing can be write-protected. Set in the attribute area as a register, and write the address of the area to be write-protected to this write-protect storage register.

  In this case, the write protect area corresponds to the functional specification of the flash memory, and 512 bytes (4096 bits) of a data unit such as one sector increment from the first sector, the last sector or an arbitrary sector of the flash memory. ) Or a block unit from a block unit of a device representing a collection of data of several sectors, or a block unit from an arbitrary block to an arbitrary block can be set by the variable area protection method. .

  In addition, the write data written to the write-protect storage register can be entered into the card controller by putting a hardware reset by input from the system side, a software reset by register write from the system side, or a power-on reset by power-on to the card controller. Transfer to the write protect register in the controller.

  Thereafter, the card controller determines whether the address accessed from the user side is within the write protect area. As a result, if the address is within the write protect area, write protection is possible. Software write protection control can be performed in units of erase, making write protection impossible.

  As a result, the write protect information is non-volatile, and write protection in an arbitrary area is possible, and a memory card and information processing apparatus using a rewritable non-volatile memory such as a flash memory having no software write protect function In this system, the maintainability of the write protect information and the data in the write protect area can be improved.

  In addition, since write protection in any area is possible, the protected area in the area where writing is prohibited by software write protection in the memory and the work area in the area other than this area where writing is not prohibited are matched to the system. This makes it possible to make effective use of the nonvolatile memory.

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

  (1) By setting a write protect storage register that writes an address of an arbitrary write protect area in a predetermined erase unit in the nonvolatile memory, it is determined whether the address accessed from the user side is within the write protect area. In the write protect area, write protection can be performed. On the other hand, in the case outside the write protect area, write protection cannot be performed. Therefore, software write protection control in units of erasure can be performed.

  (2) In the above (1), the setting of the write protect area can be changed in the erase unit from the beginning of the nonvolatile memory to any, from the last to any, or from any to any, or the erase unit can be set. By making the change possible in sector units or device block units, good software write protection control corresponding to the functional specifications of the nonvolatile memory becomes possible.

  (3) When applied to the flash memory in (1) above, batch electrical erasure and writing can be performed.

  (4) According to the above (1) to (3), the write protect information is made non-volatile, and write protection in an arbitrary area is possible. Therefore, a rewritable non-volatile memory having no software write protect function is used. In systems such as memory cards and information processing apparatuses, it is possible to improve the maintainability of write protect information and data in the write protect area.

  (5) According to the above (1) to (3), write protection can be performed in an arbitrary area, and the protection area and work area of the nonvolatile memory can be set according to the system. It can be used.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a configuration diagram showing a memory card using a nonvolatile memory according to an embodiment of the present invention, FIG. 2 is a flowchart of software write protection setting in the present embodiment, and FIG. 3 is a time chart of write protection information transfer. 4 is a block diagram for explaining write protect information transfer, FIG. 5 is an explanatory diagram showing an address map of a memory card, FIG. 6 is a flowchart of write protect control, FIG. 7 is a block diagram showing a write protect determination circuit, and FIG. Is a time chart of the write protect control, FIG. 9 is a block diagram for explaining the write protect control, and FIG. 10 is a system configuration diagram using the memory card of the present embodiment.

  First, the configuration of a memory card using the nonvolatile memory of the present embodiment will be described with reference to FIG.

  The memory card of the present embodiment is, for example, a flash memory card 1 using a rewritable nonvolatile memory without a nonvolatile software write protection function, and a flash memory (nonvolatile memory) capable of batch electrical erasing and writing. 2, a reset IC 3 that generates a power-on reset signal when the power is turned on, and a card controller 4 that controls between these devices and the memory card interface.

  In the present embodiment, the flash memory 2 mounted on the flash memory card 1 includes, for example, a final chip of a common flash area that means a memory space of the flash memory 2 and a final sector that is a data unit (512 bytes). A write protect storage register (WP storage Reg) 5 for writing an address of an area to be write protected is set in the attribute area, and a protection range (protect end sector) can be set from the system.

  The attribute area represents a memory area for storing identification information of the Flash memory card 1 and configuration information indicating a hardware configuration and where the Flash memory card 1 is allocated in the system address space.

  The write protect range by the write protect storage register 5 is set by the variable protect method, for example, as an arbitrary sector from the first (0) sector to the (last -1) sector of the common flash area. This is because the erase unit is sector unit (512 bytes). This erasing unit is set in accordance with the functional specifications of the flash memory 2.

  In the card controller 4, a power-on reset that is performed when the power is turned on, a hardware reset by a reset signal from the system side that uses the Flash memory card 1, and a system side writes in a soft reset register set in the card controller 4. By performing a software reset, a write protect register (WPReg) 6 for storing write data transferred from the write protect storage register 5 of the flash memory 2 is set.

  Next, the operation of the present embodiment will be described with reference to FIG. 1 based on FIG. The control of the write protect setting, and the control of transfer of write protect information, which will be described later, and the write protect control, are performed by a logic circuit including logic elements constituting the card controller 4.

  First, the last chip and the last sector of the flash memory 2 mounted on the flash memory card 1 are set as the write protect storage register 5. This register 5 belongs to the attribute area, and the write protect end address is written to this register 5 to set the write protect range (step 201).

  Since the write protect storage register 5 of the last chip and the last sector of the flash memory 2 is in the flash memory 2, this information is rewritten or held as non-volatile information except for the destruction of the flash memory 2. be able to.

  Further, in order to transfer the information written in the write protect storage register 5, a power-on reset at power-on, a hardware reset by input from the system side, or a software reset by register write from the system side is entered (step 202-204).

  As a result, the written information is transferred to the write protect register 6 set in the card controller 4 to complete the software write protect setting (steps 205 and 206).

  After the write protect information is transferred to the write protect register 6, the address accessed from the system side is compared with the write protect end address written in the write protect register 6, and the write protect control is performed according to the comparison result. It can be performed.

  Next, the transfer of the write protect information will be described with reference to FIG. 4 based on the time chart of FIG.

  First, as shown in FIG. 4, in addition to the write protect register 6, the card controller 4 uses a reset pulse by a power-on reset, a hardware reset, and a software reset as a write protect information transfer function. A reset unit 7 that generates a signal, an address control unit 8 that generates an address when writing to and reading from the flash memory 2, a flash memory control signal generating unit 9 that generates a chip enable signal and an output enable signal, and a card controller 4 is provided with a software reset register 10 for generating a reset pulse by a software reset and a register control unit 11 for controlling the register.

  First, after writing the write protect end address to the write protect storage register 5 in the flash memory 2, for example, at the time of hardware reset, the reset pulse input to the reset unit 7 from the system side is used. The following transfer signals are generated in FIG.

  That is, in the card controller 4, the address control unit 8 generates an address signal (Adr) of the write protect storage register 5 based on the signal from the reset unit 7. The flash memory control signal generation unit 9 generates (low level) a chip enable signal (/ CE) and an output enable signal (/ OE) based on the signal from the reset unit 7.

  A latch signal for latching the read write protect information in the write protect register 6 in the card controller 4 in accordance with the generated address signal, chip enable signal and output enable signal of the write protect storage register. generate.

  Thereby, at the time of hardware reset, the write protect information read from the write protect storage register 5 of the flash memory 2 can be transferred to the write protect register 6 in the card controller 4 and latched.

  At the time of software reset, the write signal generated from the register control unit 11 in the card controller 4 is input to the software reset register 10 using the address control signal in the register write from the system side, and “1” is written. After that, “0” is written to generate a software reset pulse.

  Then, the software reset pulse is input to the reset unit 7 and a signal for transfer is generated in the card controller 4 in the same manner as at the time of hardware reset, and the write protect register 5 writes to the write protect register 6. Information can be transferred.

  Further, at the time of power-on reset, when the power of the flash memory card 1 is turned on, a power-on reset pulse is generated by the reset IC 3 and is input to the reset unit 7. Similarly, a transfer signal can be generated to enable transfer of write protect information from the write protect storage register 5 to the write protect register 6.

  Next, the write protect control will be described with reference to FIGS. 5 and 7 to 9 based on the flow of FIG.

  First, the flash memory card 1 has an address mapping as shown in FIG. 5, and the write protect storage register 5 is set in the last chip and the last sector of the common flash area. Therefore, the common flash area cannot be accessed.

  As shown in FIG. 9, the card controller 4 has a write protect control function for determining whether an address accessed by the system side to the flash memory card 1 is within the write protect area, as shown in FIG. A data control unit 13 for controlling write data to the flash memory 2 is provided. The write protect area determination unit 12 compares the sector address with the protect end sector address, and performs write protect control on the data control unit 13. A protect signal is transferred.

  That is, as shown in FIG. 7, the write protect area determination unit 12 includes a write protect upper register (WPUReg) that stores a sector address, upper 8 bits of the sector address, and a write protect low register (WPLReg) that stores lower 8 bits. ) And a protect end sector address stored in the write protect register 6 are provided, and a protect signal is generated.

  First, after setting the software write protection, when a write access (/ CE, / WE) from the system side to the common flash area is generated for the flash memory card 1, the write protect area determination unit in the card controller 4 12, the protect end address of the write protect register 6 is compared with the sector address accessed from the system side (steps 601 and 602).

  As a result, for example, if (sector address at the time of writing in the flash memory 2) ≦ (protect end sector address of the write protect register 6), it is determined that it is within the write protect range, and the write protect signal is sent from the write protect area determination unit 12 It is generated and input to the data control unit 13, and the data control unit 13 sets the write data to the flash memory 2 as a reset command or an invalid command and writes it to the flash memory 2 (steps 603 and 604).

  The reset command is a command for resetting the write setup state, and the invalid command is a command other than a command set in advance, and these commands are used in the write protection.

  On the other hand, if (sector address at the time of writing in the flash memory 2)> (protect end sector address of the write protect register 6), it is determined that it is out of the write protect range, and the write data is written to the flash memory 2 as it is as a normal write. (Steps 603 and 605).

  As a result, it is determined whether or not the address accessed during writing is within the write protection range. If it is within the write protection range, write protection is possible. If it is outside the write protection range, write protection is impossible. Normal light can be enabled.

  The flash memory card 1 configured as described above is applied to a system such as an information processing apparatus as shown in FIG. 10, for example. In addition to the flash memory card 1 having the flash memory 2 mounted thereon, The CPU 16, the RAM 17, the ROM 18, the printer 19, the hard disk 20, and the floppy (registered trademark) disk 21 are connected via the card interface 15.

  In this system, the RAM 17, the ROM 18 and the flash memory card 1 belong to the memory area, and the printer 19, the hard disk 20 and the floppy disk 21 belong to the I / O area. Thus, software write protection control as a system can be performed by determining whether the address is within the write protection range.

  Therefore, according to the flash memory card 1 of the present embodiment, the write protect storage register 5 is set in the flash memory 2, and the end sector address of the write protect range is stored in the write protect storage register 5. It is determined whether the address accessed from the side is within the write protection range. If it is within the write protection range, write protection is possible. If it is outside the write protection range, write protection is impossible. Write protect control can be performed in an arbitrary area.

  In particular, the present invention can be applied to a system such as a flash memory card 1 that uses a flash memory 2 that does not have a software write protect function and an information processing apparatus, and can improve the maintainability of write protect information and data in the write protect area. In addition, the write protect range can be set to an arbitrary area, and the protect area of the write prohibited area and the work area of the other area can be set in accordance with the system for effective use of the flash memory 2.

(Embodiment 2)
FIG. 11 is a block diagram showing a memory card using a nonvolatile memory according to another embodiment of the present invention.

  The memory card of the present embodiment is a flash memory card 1a using a rewritable flash memory (nonvolatile memory) 2a having no non-volatile software write protection function as in the first embodiment. 1 is that the write protect range of the flash memory 2a is defined from the (final-1) sector.

  That is, the write protect range (protect start sector) set in the write protect storage register 5a of the flash memory 2a can be set from the (final-1) sector to an arbitrary sector in the common flash area.

  Therefore, also in this embodiment, the non-volatile software write protection of the flash memory card 1a using the flash memory 2a without the software write protection function is controlled by the card controller 4a in which the write protect register (WPReg) 6a is set. Control can be enabled in any region from the (final-1) sector.

(Embodiment 3)
FIG. 12 is a block diagram showing a memory card using a nonvolatile memory according to still another embodiment of the present invention.

  The memory card according to the present embodiment is a flash memory card 1b using a rewritable flash memory (nonvolatile memory) 2b having no nonvolatile software write protection function as in the first and second embodiments. The difference from Embodiments 1 and 2 is that the write protect range of the flash memory 2b is defined by a variable method using a start address and an end address.

  That is, the write protect range (protect start and end sector) set in the write protect storage register 5b of the flash memory 2b can be set from any sector to any sector in the common flash area.

  Therefore, also in this embodiment, the flash memory 2b having no software write protect function is controlled by the card controller 4b in which the write protect register 6b of the write protect start register (WPSReg) and the write protect end register (WPEReg) is set. The non-volatile software write protection control of the used flash memory card 1b can be performed in any desired area.

(Embodiment 4)
FIG. 13 is a block diagram showing a memory card using a nonvolatile memory according to still another embodiment of the present invention.

  The memory card according to the present embodiment is a flash memory card 1c using a rewritable flash memory (nonvolatile memory) 2c having no non-volatile software write protection function as in the first to third embodiments. The difference from the first to third embodiments is that the write protect unit of the flash memory 2c is set to two sector units.

  In other words, the write protect range (protect end sector) of the write protect storage register 5c set to (final-1) and the last sector of the flash memory 2c can be set in units of two sectors in the common flash area.

  Therefore, also in this embodiment, the non-volatile software write protection of the flash memory card 1c using the flash memory 2c having no software write protection function is controlled by the card controller 4c in which the write protect register (WPReg) 6c is set. Control can be performed in an area of two sectors.

(Embodiment 5)
FIG. 14 is a block diagram showing a memory card using a nonvolatile memory according to still another embodiment of the present invention.

  The memory card according to the present embodiment is a flash memory card 1d using a rewritable flash memory (nonvolatile memory) 2d having no nonvolatile software write protection function as in the first to fourth embodiments. The difference from Embodiments 1 to 4 is that the write protect unit of the flash memory 2d is not limited to a sector unit, and the device erase unit is a block unit representing a collection of a plurality of data such as several sectors.

  That is, the write protect range (protect end block) of the write protect storage register 5d set in the last block of the flash memory 2d can be set in the common flash area in units of device blocks.

  Therefore, also in this embodiment, the nonvolatile software write protection of the flash memory card 1d using the flash memory 2d without the software write protection function is controlled by the card controller 4d in which the write protect register (WPReg) 6d is set. Control can be made possible in the area of the block unit of the device.

(Embodiment 6)
FIG. 15 is a flowchart of write protection control in a memory card using a nonvolatile memory according to still another embodiment of the present invention, and FIG. 16 is a time chart of write protection control.

  The memory card of the present embodiment is configured in the same manner as in the first embodiment (2 to 5), and a flash memory using a rewritable flash memory (nonvolatile memory) 2 having no nonvolatile software write protection function. The card 1 is different from the first to fifth embodiments in that the write protect control is performed not by the write data but by the control signal to the flash memory 2.

  That is, in the present embodiment, after setting the software write protection, when a write access from the system side to the common flash area is generated for the flash memory card 1, the protect end address of the write protect register 6 and the system The sector address accessed from the side is compared (steps 1501 and 1502).

  As a result, for example, if (sector address at the time of writing in the flash memory 2) ≦ (protect end sector address of the write protect register 6), it is determined that it is in the write protect range, and the write enable signal (/ WE) for writing or Write protection is performed while the control signal of the chip enable signal (/ CE) is negated (high level) (steps 1503 and 1504).

  On the other hand, if (sector address at the time of writing in the flash memory 2)> (protect end sector address of the write protect register 6), it is determined that it is out of the write protect range, and the write data is written to the flash memory 2 as it is as a normal write. (Steps 1503, 1505).

  Therefore, also in this embodiment, it is determined whether or not the address accessed from the user side is within the write protect range, and if it is within the write protect range, the write control signal is negated to enable write protection, On the other hand, when it is out of the write protect range, the write protect cannot be performed, and the non-volatile software write protect control can be performed in an arbitrary area.

(Embodiment 7)
FIG. 17 is a block diagram showing a semiconductor memory using a nonvolatile memory according to still another embodiment of the present invention.

  Unlike the first to sixth embodiments, the present embodiment has a write protect register 23 in the nonvolatile memory 22 itself, and a write protect area determination unit 24 that determines whether an address accessed by the system side is within the write protect area. And a semiconductor memory 26 provided with a write control unit 25 for controlling a write signal and write data to the nonvolatile memory 22, and the write data or the write signal is received using the protect signal from the write protect area determination unit 24. Thus, write protection control of the nonvolatile memory 22 is possible.

  That is, in the present embodiment, for example, the write protect function is realized as a single semiconductor memory 26 such as a flash memory, and if the result of the write protect area determination unit 24 is within the write protect area, the write protect area determination unit 24 A write protect signal is generated and input to the write control unit 25, and a write signal (/ CE, / WE) to the nonvolatile memory 22 is set to a high level, or write data is set to a reset command or an invalid command. .

  Therefore, in the present embodiment, the protection address set in the write protection register 23 of the nonvolatile memory 22 is compared with the address of access to the nonvolatile memory 22, and if it is within the write protection range, write protection is possible. On the other hand, if the write protection register 23 is included in the nonvolatile memory 22 itself, the nonvolatile software write protection control can be performed when the write protection register 23 is included in the nonvolatile memory 22 itself.

  The invention made by the present inventor has been specifically described based on the first to seventh embodiments. 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 flash memory in the embodiment, the case where the write protect storage register is set in the last chip and the last sector of the common flash area has been described. However, the present invention is not limited to the embodiment. In addition, the present invention can be applied to the case of setting in the top chip and the top sector of the common flash area.

  Further, it goes without saying that the write protect range and the erase unit are set as appropriate in accordance with the function specifications of the flash memory, together with the setting of the write protect storage register.

  In addition to the flash memory, the nonvolatile memory in the present embodiment can be applied to other nonvolatile memories such as an EEPROM that can be electrically erased and written for each bit, and a system using the nonvolatile memory. For example, the present invention can be widely applied to, for example, information processing apparatuses in general and memory cards in general, and non-volatile memory devices.

It is a block diagram which shows the memory card using the non-volatile memory which is Embodiment 1 of this invention. 3 is a flowchart of software write protect setting in the first embodiment. 3 is a time chart of write protect information transfer in the first embodiment. 4 is a block diagram for explaining write protect information transfer in Embodiment 1. FIG. 3 is an explanatory diagram showing an address map of a memory card in Embodiment 1. FIG. 4 is a flowchart of write protect control in the first embodiment. FIG. 3 is a configuration diagram illustrating a write protect determination circuit according to the first embodiment. 3 is a time chart of write protect control in the first embodiment. 4 is a block diagram for explaining write protect control in Embodiment 1. FIG. 1 is a system configuration diagram using a memory card in Embodiment 1. FIG. It is a block diagram which shows the memory card using the non-volatile memory which is Embodiment 2 of this invention. It is a block diagram which shows the memory card using the non-volatile memory which is Embodiment 3 of this invention. It is a block diagram which shows the memory card using the non-volatile memory which is Embodiment 4 of this invention. It is a block diagram which shows the memory card using the non-volatile memory which is Embodiment 5 of this invention. It is a flowchart of the write protection control in the memory card using the non-volatile memory which is Embodiment 6 of this invention. 18 is a time chart of write protect control in the sixth embodiment. It is a block diagram which shows the semiconductor memory using the non-volatile memory which is Embodiment 7 of this invention.

Explanation of symbols

1,1a-1d Flash memory card 2,2a-2d Flash memory (nonvolatile memory)
3 Reset IC
4, 4a to 4d Card controller 5, 5a to 5d Write protect storage register 6, 6a to 6d Write protect register 7 Reset unit 8 Address control unit 9 Flash memory control signal generation unit 10 Software reset register 11 Register control unit 12 Write protect area Determination unit 13 Data control unit 14 Size discrimination circuit 15 Card interface 16 CPU
17 RAM
18 ROM
19 Printer 20 Hard disk 21 Floppy (registered trademark) disk 22 Non-volatile memory 23 Write protect register 24 Write protect area determination unit 25 Write control unit 26 Semiconductor memory

Claims (2)

A flash memory card having a write protect storage register indicating a write protect address is mounted, and based on the data of the write protect holding register, a flash memory card that determines whether an address input from the outside is within a write protect range;
A card interface connected to the flash memory card;
A central processing unit connected via the card interface,
A semiconductor information processing apparatus.   The semiconductor information processing apparatus according to claim 1, wherein the flash memory does not have a software write protect function.

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