Recording medium, host device, and data processing method

• US 20060050622A1
• Filed: 05/02/2005
• Published: 03/09/2006
• Est. Priority Date: 05/10/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Inoue, Shinji, Maeda, Takuji, So, Hirokazu
• Granted Patent: US 7,801,930 B2
• Time in Patent Office: Days
• US Class Current: 369/275.100
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G11B 20/12 Formatting, e.g. arrangement of data block or words on the record carriers within interface between computers and data recorders G06F3/06
• CPC Class Codes: G11B 2020/1823 wherein a flag is set when errors are detected or qualified

Abstract

A semiconductor recording medium holds an open flag showing presence or absence of consistency between content data stored in a data storage section and file system management information, in a system region not directly accessible from a host device. Upon receipt of a write request or erase request to the data storage section from the host device, the semiconductor recording medium automatically updates the open flag to “ON” (value showing possibility of inconsistency). When actual consistency is verified, the host device requests the recording medium to set the open flag to “OFF” (value showing presence of consistency). When mounting, the host device refers to the open flag with a special command to judge necessity for error check process.

Claims

1. A recording medium for storing data and accessible from a host device, comprising:

a data storage section that stores various data;

a host interface section that communicates with the host device; and

a controller that controls the recording medium,

wherein the data storage section includes a data region for storing content data, and a retrieval information storing region for storing management information used by the host device to acquire the content data, and the data storage section further stores an open flag showing possibility of inconsistency between information stored in the data region and information stored in the retrieval information storing region, and

the controller updates the value of the open flag automatically to a value showing that there is a possibility of inconsistency, when receiving a write request or erase request to the data storage section from the host device.

2. The recording medium according to claim 1, wherein the data storage section further includes a system region which is a region not directly accessible from the host device, and the open flag is stored in the system region.

3. The recording medium according to claim 1, wherein a special command is provided to be used by the host device for acquiring the value of the open flag.

4. The recording medium according to claim 1, wherein the controller, when executing initialization process, notifies the value of the open flag to the host device together with response information for the initialization process.

5. The recording medium according to claim 1, wherein even when the host device requests to change the value of the open flag to the value showing no inconsistency, the controller checks for inconsistency between the information stored in the data region and the information stored in the retrieval information storing region, and does not change the value of the open flag to the value showing no inconsistency when the checking result suggests inconsistency.

6. The recording medium according to claim 1, wherein the controller includes a function of initializing logically the retrieval information storing region, and automatically updates the open flag to the value showing consistency between the information stored in the data region and the information stored in the retrieval information storing region right after executing the logical initialization.

7. The recording medium according to claim 1, wherein the data region of the data storage section can selectively be set in one size out of plural region sizes, the data storage section manages the retrieval information storing region, the data region, and the open flag as one set in each size of data region, and further stores information showing one selected set, and

the controller refers to the information showing one selected set, and accesses the retrieval information storing region, the data region, and the open flag about the one selected set.

8. The recording medium according to claim 7, wherein on changeover of each set, the value of the open flag included in each set is not changed when the data region and retrieval information storing region before changeover process do not overlap with those after changeover process.

9. The recording medium according to claim 7, wherein the value of the open flag included in each set is updated upon receiving a write process request or erase process request for the first time after changeover process, when changeover process of each set occurs.

10. The recording medium according to claim 1, wherein the data storage section includes a nonvolatile memory.

11. A host device for accessing a recording medium, the recording medium including a data region for storing content data, and a retrieval information storing region for storing management information used for reading the content data, and further storing an open flag showing possibility of inconsistency between information stored in the data region and information stored in the retrieval information storing region, the host device comprising:

an access section that exchanges information with the recording medium, and

a data processing section that controls operation of the host device,

wherein the data processing section refers to the open flag, and when the value of the open flag shows possibility of inconsistency, the data processing section executes verification process of checking if inconsistency actually occurs between the information stored in the data region and the information stored in the retrieval information storing region of the recording medium, or when the value of the open flag does not show possibility of inconsistency, the verification process is omitted.

12. The host device of claim 11, wherein when judging inconsistency does not occur as a result of verification process, the data processing section issues, to the recording medium, a request for updating the value of the open flag to a value showing no possibility of inconsistency.

13. A data processing method being implemented between a host device and a recording medium, the recording medium including a data region for storing content data, and a retrieval information storing region for storing management information used for reading the content data, and storing an open flag showing possibility of inconsistency between the information stored in the data region and the information stored in the retrieval information storing region, the data processing method comprising:

updating the open flag automatically to a value showing possibility of inconsistency in the recording medium when write process or erase process occurs in the recording medium; and

transmitting a request for updating the value of the open flag to a value showing no possibility of inconsistency, from the host device to the recording medium, after completion of write process or erase process, only when inconsistency does not occur between the information stored in the data region in the recording medium and the information stored in the retrieval information storing region.

14. The data processing method according to claim 13, further comprising

referring to the value of the open flag to judge presence or absence of inconsistency-between the information stored in the data region in the recording medium and the information stored in the retrieval information storing region, and

determining, according to the judging result, whether it is required to execute a process of checking presence or absence of actual inconsistency between the information stored in the data region and the information stored in the retrieval information storing region in the recording medium.