MEMORY MANAGEMENT APPARATUS

• US 20090037780A1
• Filed: 08/04/2008
• Published: 02/05/2009
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nakagaki, Yoshio, Suganuma, Takeshi
• Granted Patent: US 8,166,353 B2
• Time in Patent Office: Days
• US Class Current: 714/48
• CPC Class Codes: G06F 11/0739 in a data processing system embedded in automotive or aircraft systems
• CPC Class Codes: G06F 11/0787 Storage of error reports, e.g. persistent data storage, storage using memory protection
• CPC Class Codes: G06F 11/1402 Saving, restoring, recovering or retrying
• CPC Class Codes: G06F 11/183 by voting, the voting not being performed by the redundant components

Abstract

A fault code memory management apparatus stores a permanent fault code in different places of a non-volatile memory, and restore the fault code when an error is detected in the fault code stored in the different places in a manner that, in case that discrepancy between the fault codes in different places is found, the fault code matching with data in a code table stored in a read-only memory is determined to be correct. If two fault codes have matching data in the code table, the fault code is compared with data in a standby random access memory that stores an original fault code data. Further, the data in the random access memory and the data in the code table are compared if the comparison between the code and the data in the random access memory is not sufficient.

Claims

1. A fault code memory management apparatus comprising:

a memory management unit capable of storing a same fault code of a detection object in a vehicle respectively at different memory areas of a non-volatile memory, wherein the fault code of the detection object represents a detected fault of the detection object, and wherein information in the non-volatile memory is both readable and writable;

an error detection unit capable of detecting an error of the fault code in the non-volatile memory upon detecting discrepancy of at least one of the same fault codes stored at respective different memory areas through performing a mutual matching of the fault code;

an information table memory capable of storing a fault code table to be stored in the non-volatile memory, wherein the fault code table is an information table that includes the fault codes; and

an authentication unit capable of authenticating the fault code as a genuine fault code by comparing each of the fault codes stored in the respectively different memory areas of the non-volatile memory and the fault code included in the fault code table when the error detection unit at least detects the error of the fault code in the non-volatile memory, wherein the fault code is determined as the genuine fault code when the authentication unit recognizes that the fault code is included in the fault code table.

2. The fault code memory management apparatus of claim 1, wherein

the memory management unit stores the same fault codes at two respectively different areas of the non-volatile memory.

3. The fault code memory management apparatus of claim 1, wherein

the memory management unit stores the same fault codes at three respectively different areas of the non-volatile memory.

4. The fault code memory management apparatus of claim 3, wherein

the authentication unit authenticates the fault code as the genuine fault code when a majority of matching fault codes stored at the respectively different areas is determined to be in the fault code table.

5. The fault code memory management apparatus of claim 1, wherein

the information table memory is a read-only memory (ROM).

6. The fault code memory management apparatus of claim 1 further comprising:

a rewrite unit capable of storing the fault code at the respectively different memory areas of the non-volatile memory, wherein the rewrite unit stores the genuine fault code at the memory area where the error of the fault code is detected.

7. The fault code memory management apparatus of claim 1, wherein

a standby random-access memory (SRAM) that maintains information while supply of an electronic voltage lasts is included in the fault code memory management apparatus,

the memory management unit stores the fault code in the non-volatile memory after storing the same fault code in the SRAM, and

when any of the fault codes in the non-volatile memory is not determined to be included in the fault code table by the authentication unit, the authentication unit authenticates the fault code in the SRAM as the genuine fault code on a condition that the authentication unit recognizes that the fault code in the SRAM is included in the fault code table.

8. The fault code memory management apparatus of claim 1, wherein

a standby random-access memory (SRAM) that maintains information while supply of an electronic voltage lasts is included in the fault code memory management apparatus,

the memory management unit stores the fault code in the non-volatile memory after storing the same fault code in the SRAM, and

when the error of the fault code is detected at least by the error detection unit, the authentication unit recognizes the fault code that matches with the fault code stored in the SRAM as the genuine fault code in a prioritized manner based on an examination whether each of the fault codes stored in the non-volatile memory matches the fault code stored in the SRAM.

9. The fault code memory management apparatus of claim 1 further comprising:

a trip term operation control unit capable of operating the error detection unit and the authentication unit in a trip term that is defined at least as one of a period between a turning-on of an ignition switch of the vehicle and a subsequent turning-on of the ignition switch, and a period between a turning-on and a turning-off of the ignition switch of the vehicle.

10. The fault code memory management apparatus of claim 1, wherein

the fault code memory management apparatus is configured to be connectable to an external diagnosis device for a diagnosis of a condition of the detection object, and

the fault code memory management apparatus further comprises a code request operation control unit capable of operating the error detection unit and the authentication unit upon receiving a request for the fault code at least from the external diagnosis device.

11. A fault code memory management apparatus comprising

a fault code memory capable of storing an information table that at least serves as a fault code table by including a fault code;

a memory management unit capable of storing same fault codes at respectively different plural areas in a non-volatile memory that stores information in a readable and writable manner, wherein storage of the same fault codes is performed when a diagnosis of a subject vehicular device being diagnosed leads to a detection of an error that is represented by a fault code included in the fault code table; and

an authentication unit capable of recognizing that a fault code is a genuine fault code based on a condition that the fault code stored in the non-volatile memory matches the fault code included in the fault code table after comparing each of the fault codes stored in the respectively different plural areas of the non-volatile memory and the fault code included in the fault code table, wherein, an authentication of the fault code is performed by the authentication unit when a discrepancy of at least one of the fault codes is found after the fault codes are retrieved from the respectively different plural areas for an examination of mutual matching.

12. A memory management apparatus comprising:

a memory control unit capable of storing same data at respectively different areas of the non-volatile memory that stores information in a readable and writable manner;

an error detection unit capable of detecting an error of the data in the non-volatile memory upon detecting discrepancy among at least one of the same data stored at respectively different areas through performing a mutual matching of the data;

a data table memory capable of storing a data table to be stored in the non-volatile memory, wherein the data table is a table that includes the data; and

an authentication unit capable of authenticating the data as a genuine data by comparing each of the data stored in the non-volatile memory and the data included in the data table when the error detection unit detects the error of the data in the non-volatile memory, wherein the data is determined as the genuine data when the authentication unit recognizes that the data is included in the data table.