External storage device using non-volatile semiconductor memory
First Claim
1. An external storage device connectable to a host computer, comprising:
- a non-volatile semiconductor memory;
an interface to connect to the host computer; and
a controller to access the non-volatile semiconductor memory in response to a command and an address from the host computer;
wherein said non-volatile semiconductor memory is divided into plural areas;
wherein a first command for accessing a first area among said plural areas of the non-volatile semiconductor memory is different from a second command for accessing a second area among said plural areas of the non-volatile semiconductor memory;
wherein the controller determines whether the command from the host computer is the first command or the second command, wherein, when the command is the first command, the controller carries out first command processing to a sector of the first area in accordance with the address from the host computer; and
wherein, when the command is the second command, the controller carries out second command processing to a sector of the second area in accordance with the address from the host computer, further comprising information indicative of the plural areas of the non-volatile semiconductor memory, the external storage device dynamically changing the sizes of the first and second areas of the non-volatile semiconductor memory on the basis of an instruction of the host computer by a part which rewrites the information indicating of the plural areas of the non-volatile semiconductor memory.
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Accused Products
Abstract
The external storage device according to the present invention which uses a non-volatile semiconductor memory such as a flash memory is provided with plural areas which store user data, and restricts access to the user data from a host computer and also dynamically changes an area an access to which is to be restricted. Accordingly, the ease of use of the external storage device for the host computer is improved. Specifically, the interior of the flash memory is divided into a normal area not protected by a password or the like and a protected area protected by a password or the like. A microprocessor controls accesses to the normal area and the protected area in accordance with a command from the host computer. In addition, the host computer can access the protected area after passing through authentication using a password. Moreover, the host computer changes information indicative of the location of the protected area, thereby dynamically changing the protection area.
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Citations
21 Claims
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1. An external storage device connectable to a host computer, comprising:
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a non-volatile semiconductor memory;
an interface to connect to the host computer; and
a controller to access the non-volatile semiconductor memory in response to a command and an address from the host computer;
wherein said non-volatile semiconductor memory is divided into plural areas;
wherein a first command for accessing a first area among said plural areas of the non-volatile semiconductor memory is different from a second command for accessing a second area among said plural areas of the non-volatile semiconductor memory;
wherein the controller determines whether the command from the host computer is the first command or the second command, wherein, when the command is the first command, the controller carries out first command processing to a sector of the first area in accordance with the address from the host computer; and
wherein, when the command is the second command, the controller carries out second command processing to a sector of the second area in accordance with the address from the host computer, further comprising information indicative of the plural areas of the non-volatile semiconductor memory, the external storage device dynamically changing the sizes of the first and second areas of the non-volatile semiconductor memory on the basis of an instruction of the host computer by a part which rewrites the information indicating of the plural areas of the non-volatile semiconductor memory. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An external storage device connectable to a host computer, comprising:
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a non-volatile semiconductor memory;
an interface to connect to the host computer; and
a controller to access the non-volatile semiconductor memory in response to a command and an address from the host computer;
wherein said non-volatile semiconductor memory is divided into plural areas;
wherein a first command for accessing a first area among said plural areas of the non-volatile semiconductor memory is different from a second command for accessing a second area among said plural areas of the non-volatile semiconductor memory;
wherein the controller determines whether the command from the host computer is the first command or the second command, wherein, when the command is the first command, the controller carries out first command processing to a sector of the first area in accordance with the address from the host computer; and
wherein, when the command is the second command, the controller carries out second command processing to a sector of the second area in accordance with the address from the host computer, wherein the non-volatile semiconductor memory includes an area which stores data of the host computer and an area which stores information on the external storage device, wherein the area of the non-volatile semiconductor memory which stores the data of the host computer is made of a protected data area and a non-protected data area, wherein the area of the non-volatile semiconductor memory which stores the information on the external storage device stores location information on the protected data area, wherein the external storage device dynamically changes the protected data area of the non-volatile semiconductor memory on the basis of an instruction of the host computer by a part which rewrites the location information on the protected data area of the non-volatile semiconductor memory, wherein, when the host computer is to access the protected data area, the external storage device performs authentication through an authentication procedure for accessing to the protected data area, and wherein said first area is the non-protected data area and the second area is the protected data area.
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13. An external storage device connectable to a host computer, comprising:
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a non-volatile semiconductor memory;
an interface to connect to the host computer; and
a controller to access the non-volatile semiconductor memory in response to a command and an address from the host computer;
wherein said non-volatile semiconductor memory is divided into plural areas;
wherein a first command for accessing a first area among said plural areas of the non-volatile semiconductor memory is different from a second command for accessing a second area among said plural areas of the non-volatile semiconductor memory;
wherein the controller determines whether the command from the host computer is the first command or the second command, wherein, when the command is the first command, the controller carries out first command processing to a sector of the first area in accordance with the address from the host computer; and
wherein, when the command is the second command, the controller carries out second command processing to a sector of the second area in accordance with the address from the host computer, further comprising;
a register which stores the address of the second area of the non-volatile semiconductor memory;
wherein, when the command from the host computer is the first command, the controller determines whether a sector to be accessed by the host computer is within the second area or not by comparing the address from the host computer with the address of the second area stored in the register and carries out the first command processing to a sector in the first area if the sector to be accessed by the host computer does not exist in the second area.
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14. An external storage device connectable to a host computer, comprising:
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a non-volatile semiconductor memory;
an interface to connect to the host computer; and
a controller to access the non-volatile semiconductor memory in response to a command and an address from the host computer;
wherein said non-volatile semiconductor memory is adapted to be divided into plural areas;
wherein a first command for accessing a first area amond the plural areas of the non-volatile semiconductor memory is different form a second command for accessing a second area amond said plural areas of the non-volatile semiconductor memory;
wherein the controller determines whether a command from the host computer is the first command or the second command, wherein, when the command determined by the controller is the first command, the controller carries out first command processing to a sector of the first area in accordance wiht the address form the host computer; and
wherein, when the command determined by the controller is the second command, the controller carries out second command processing to a sector of the second area in accordance with the address from the host computer, wherein the non-volatile semiconductor memory stores area information associated with the plural areas of the non-volatile semiconductor memory, wherein the external storage device changes sizes of the first and second areas of the non-volatile semiconductor memory and a border between the first area and the second area in response to a third command from the host computer by updating the area information stored in the non-volatile semiconductor memory to a new area information, wherein the third command is different form the first and second commands. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. An external storage device connectable to a host computer, comprising:
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a non-volatile semiconductor memory;
an interface to connect to the host computer; and
a controller to access the non-volatile semiconductor memory in response to a command and an address from the host computer;
wherein said non-volatile semiconductor memory is adapted to be divided into plural areas;
wherein a first command for accessing a first area amond said plural areas of the non-volatile semiconductor memory is different from a semiconductor memory is different from a second command for accessing a second area among said plural areas of the non-volatile semiconductor memory;
wherein the controller determines whether a command form the host computer is the first command or the second command, wherein, when the command determined by the controller is the first command, the controller carries out first command processing to a sector of the first area in accordance with the address from the host computer; and
wherein, when the command determines by the controller is the second command, the controller carries out second command processing to a sector of the second area in accordance with the address from the host computer, wherein the first area is a non-protected data area, wherein the second area is a protected data area, wherein the non-volatile semiconductor memory stores information regarding the size and address of the proctected data area, wherein the controller changes the size and address of the protected data area of the non-volatile semiconductor memory in response to a third command from the host computer, wherein the third command is different from the first and second commands, and wherein, when the host computer accesses the protected data area, the external storage device performs an authentication procedure for accessing to the protected data area.
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Specification