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| # | Item | User |
|---|---|---|
UC.BD.1 | Data protection in case of ACC-OFF or sudden power failure | Even when the driver presses the button for ACC-OFF or a sudden power failure occurs after changing the display settings of the navigation IVI system, the display settings are retained and the driver uses the information. |
UC.BD.2 | Utilize the persistent data | The driver searches for a destination using the search history stored in the navigation application. |
UC.BD.3 | Data attribute when the system battery is removed | Each OEM chooses whether to make each persistent data stored in the IVI volatile or non-volatile when the battery is removed, for handling the persistent data after the battery is removed. |
UC.BD.4 | Data Initialization | If a user reset the system, all data is deleted. |
Functional Requirements
This table includes the functional requirements of Persistent Data Management module. RQ.BD.1.1 and RQ.BD.1.2 are requirements realized by usual filesystem. Others are newly defined.
Table 2
| # | Item | Related Use Case | Description |
|---|---|---|---|
RQ.BD.1.1 | Backup Data store in case of sudden power off | UC.BD.1 | The Persistent Data Management module shall prevent “persistent” data loss if the power supply is stopped. |
RQ.BD.1.2 | Backup Data store of system lifecycle | UC.BD.1 | IVI system shall preserve any "persistent" data requested by IVI services/apps through system startup/shutdown lifecycle. |
RQ.BD.2.1 | Storage memory requirement | UC.BD.1 | The Persistent Data Management module shall minimize actual write operations to the storage device to make the lifetime as long as possible. |
RQ.BD.32.2 | Utilization of Persistent data | UC.BD.2 | The data which needs to be read shall be readable by request from IVI services/apps. |
RQ.BD.2.43 | Data backup to non-volatile areahandling when the battery is removed. | UC.BD.3 | The type of "persistent" data Data shall be configurable , i.e. it can be configured to be either volatile or non-volatile kept or not when the system battery is removed. |
RQ.BD.2.5Storage memory requirement4 | Data Verification | UC.BD.12 | The Persistent Data Management module shall minimize actual write operations to the storage device to make the lifetime as long as possibledetect the stored data corruption and provide alternative correct data. |
RQ.BD.2.5 | Data deletion | UC.BD.4 | The data shall be deleted by request from IVI services/apps. |
Persistent Data Management in Basesystem
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As shown in the following figure 273, for example when a driver uses an application application and a data backup request occurs, on receiving the request, Backup Manager writes the data to the specified storage with the specified offset and data size based on the timing defined in the Configuration(ⅰ). When reading the data, Backup manager reads the data from the specified storage and sends it back to the application side(ⅱ). The above two functions are the roles of Backup ManagerBackup Manager has responsible to provide those features. It will manage not only access to the persistent data for applications but also verify the underlying persistent data consistency in order to detect the data corruption so that alternative correct data can be provided. It also can delete part of the persistent data upon the requests from applications.
Figure 3
Backup manager
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