DE102021120381A1 - Device and method for managing a memory - Google Patents

Abstract

A memory device and a method of managing a memory device for use in an automobile. The storage device comprises a storage medium comprising at least a first storage partition and a second storage partition; and at least one controller configured to: enable access to the first storage partition for a plurality of user applications, prevent access to the second storage partition for the plurality of user applications, manage access to the first and second storage partitions, wherein at least one Controller is configured to allocate a higher number of program/erase, P/E, cycles to the first memory partition than to the second memory partition.

Description

The invention relates to methods and devices for managing a memory, in particular a memory with a separate memory partition with a high "Terra Bytes Written", TBW, limit for user applications, for example for use in an automobile.

User and system applications in automobiles, especially in "connected cars", are constantly being further developed. In order to meet the emerging new requirements, faster and better storage media are required for use in automobiles. In particular, new storage technologies based on "floating gates" and SSD, as well as 3D TLC NAND instead of 2D MLV NAND memory are used. Adapted storage management is required to implement such new storage media in automotive applications.

One approach to improved management of new storage media is the use of local media management (“managed NAND”) in addition to conventional host-based system management. Local storage management solutions include, for example, integrated controllers for eMMC, UFS, and NVMs SSD devices, which include functionalities such as wear leveling, automatic updates, error detection and recovery, indications for TBW and endurance estimation, and others.

Such local media management is efficient, but affects the so-called "End of Life", EOL, management of the medium, including specifically the "Terra Bytes Written", TBW, management. TBW describes the number of program/erase (“program/erase”), P/E, cycles on a storage medium. The TBW limit describes the maximum number of P/E cycles that a storage medium can perform before its end of life, EOL, is reached. The number of P/E cycles performed depends on the user profile, the internal system architecture of the storage medium and the firmware efficiency. When the TBW limit is reached, the storage medium must be replaced, which is resource-intensive, expensive, and user-unfriendly. Therefore, estimating the required P/E cycles during the anticipated lifetime of the system and adapting the system architecture accordingly is mandatory.

Developments show that manufacturers of storage devices for the automotive sector are releasing the storage media for user applications, e.g. from third parties or for infotainment or cockpit camera systems. Many such user applications generate large amounts of data. In this case, it is not possible to estimate the number of additional writes and P/E cycles to the storage medium. This can lead to the TBW limit being reached prematurely, i.e. the EOL being reached prematurely.

The present invention is therefore based on the object of improving the management of storage devices in such a way that a TBW limit of a storage medium is not reached prematurely despite the storage medium being released for user applications.

• ein Speichermedium umfassend mindestens eine erste Speicherpartition und eine zweite Speicherpartition; und
• mindestens einen Controller, konfiguriert für:
  • Freigeben des Zugangs zu der ersten Speicherpartition für eine Vielzahl von Nutzeranwendungen,
  • Verhindern des Zugangs zu der zweiten Speicherpartition für die Vielzahl von Nutzeranwendungen,
  • Verwalten des Zugangs zu der ersten und zweiten Speicherpartition,
  • wobei mindestens ein Controller konfiguriert ist, der ersten Speicherpartition eine höhere Anzahl von Programmier-/Lösch-, P/E, Zyklen zuzuweisen als der zweiten Speicherpartition.

The solution to this problem consists in the memory device for use in an automobile, in particular in that the memory device comprises:

• a storage medium comprising at least a first storage partition and a second storage partition; and
• at least one controller configured for:
  • enabling access to the first memory partition for a variety of user applications,
  • preventing access to the second memory partition for the plurality of user applications,
  • managing access to the first and second storage partition,
  • wherein at least one controller is configured to allocate a higher number of program/erase, P/E, cycles to the first memory partition than to the second memory partition.

The storage device allows improved management of storage media and a prediction of the service life, ie the EOL, of the storage despite shared use of the storage device by user applications. The first memory partition is only released for user applications, such as third-party applications, infotainment applications or cockpit sensor applications. This first memory partition is assigned a larger number of P/E cycles, ie a higher TBW limit, than the second memory partition. For example, the high TBW limit can be achieved by reducing the data retention time. In addition, a wear leveling method that supports a higher TBW limit can be implemented on the first memory partition. The service life of the first storage partition can thus be extended. Reaching the TBW limit of the first storage partition depends on the usage profile. The access of user applications to the second memory partition is prevented, ie the second memory partition is before write processes by user protected. The separation of the first memory partition from the second memory partition thus means that the TBW limit of the storage medium is prevented from being reached prematurely due to uncontrollable and unforeseeable writing by user applications. The second memory partition is only released for system applications that ensure the operability of the memory device. The number of P/E cycles by system applications over the useful life of the storage device can be predicted. This can prevent the second memory partition from reaching the EOL prematurely.

In one embodiment, the storage medium is 3D TLC NAND memory. This combination of "triple level cell flash" memory cells and three-dimensional NAND memory offers a particularly high storage density.

In one embodiment, the plurality of user applications includes one or more third party applications, infotainment applications, or cockpit sensor applications. These applications are not systemically relevant, i.e. the functionality of the storage device for use in an automobile does not depend on these applications. The user applications may have high TBW consumption. The number of required P/E cycles of these applications depends on the intensity of use and is therefore not predictable over the useful life of the storage device. It is therefore advantageous to save the data of the user applications in a separate memory partition, i.e. to separate their storage location from the storage location of system applications.

In one embodiment, the at least one controller includes a first controller that is an internal controller of the storage medium and a second controller that is a host controller of the storage medium. The first controller is, for example, an internal eMMC or UFS controller or firmware. The internal controller is configured, for example, to grant read-only access to a memory partition when the TBW limit of the memory partition is reached. The internal controller can also manage the wear leveling process of a memory partition. The second controller can be an external host controller. For example, this second controller can control which applications write data to which memory partition. The second controller can control that large amounts of data are preferably stored on the first memory partition, for example.

According to one embodiment, the first controller either enables read/write access to the first and second memory partitions when the number of P/E cycles of the memory partition is less than a predetermined threshold; or the first controller enables read-only access to the first and second memory partitions when the number of P/E cycles of the memory partition is greater than a predetermined limit. This has the advantage that, for example, system applications can continue to have read/write access to the second memory partition, although the TBW limit of the first memory partition has been reached by user applications, i.e. the EOL of the first memory partition has been reached.

In one embodiment, the second controller enables applications to access either the first or the second memory partition. In other words, the second controller controls which applications have access to the first memory partition and which applications have access to the second memory partition. This allows the writing areas of user and system applications to be separated from each other.

According to one embodiment, the data retention time in the first memory partition is shorter than the data retention time in the second memory partition. The data retention time is related to the number of P/E cycles. A shorter data retention time on the first memory partition allows a larger number of P/E cycles, i.e. an increased TBW limit. Larger amounts of data can thus be written to the first memory partition than to the second memory partition. This is particularly advantageous for writing by user applications, such as infotainment applications, where large amounts of data are involved, where long data retention time is not required.

In one embodiment, a first wear leveling method is implemented on the first memory partition and a second wear leveling method is implemented on the second memory partition. This allows the wear leveling process to be optimized for each memory partition without affecting the wear leveling process on the other memory partition.

In another embodiment, at least one controller is configured to enable access to the second storage partition for system applications such as boot code, operating system, and/or file system. As a result, system-relevant data, ie data that ensure the functionality of the memory device for use in an automobile, is separated from system-irrelevant data from user applications. In contrast to the memory consumption, ie expect th P/E cycles, of user applications, the memory consumption of system applications can be predicted during the anticipated useful life of the storage device. This allows the TBW limit of the second memory partition to be adjusted in such a way that the EOL of the memory is not reached prematurely. The second storage partition may be configured to retain data for longer times than the first storage partition.

According to one embodiment, at least one controller is configured to enable read-only access to the storage medium when a predetermined TBW limit of the second storage partition is exceeded. This means that the storage medium is only released for read-only access when the EOL of the second storage partition, i.e. the storage partition for system applications, has been reached. In other words, read/write access to the storage medium is enabled until the EOL of the system-relevant second storage partition is reached.

• Erhalten einer Zugriffsanfrage zu der Speichervorrichtung durch eine Nutzeranwendung;
• Freigeben des Zugangs zu der ersten Speicherpartition der Speichervorrichtung für eine Vielzahl von Nutzeranwendungen,
• Verhindern des Zugangs zu der zweiten Speicherpartition der Speichervorrichtung für die Vielzahl von Nutzeranwendungen,
• Zuweisen einer höheren Anzahl von Programmier-/Lösch-, P/E, Zyklen zu der ersten Speicherpartition als der zweiten Speicherpartition,
• Verwalten des Zugangs zu der ersten und zweiten Speicherpartition.

As a further possibly independent aspect, the solution to the task mentioned at the outset consists in a method for managing a memory device for use in an automobile. The procedure includes:

• receiving, by a user application, an access request to the storage device;
• enabling access to the first memory partition of the memory device for a large number of user applications,
• preventing access to the second memory partition of the memory device for the plurality of user applications,
• allocating a higher number of program/erase, P/E, cycles to the first memory partition than to the second memory partition,
• Managing access to the first and second storage partitions.

The method makes it possible to release a first memory partition for user applications and to block a second memory partition for these user applications. This means that the second memory partition remains free of user application data and is available for access by system applications, for example. This can prevent the EOL of the storage device from being reached before the end of the anticipated useful life. Here, by allocating a higher number of P/E cycles to the first memory partition, a higher TBW limit can be allowed, i.e. larger amounts of data can be stored at the expense of a shorter data retention time. This can be advantageous in particular for storing data from user applications such as infotainment applications with a high data volume.

In one embodiment of the method, the plurality of user applications includes one or more third-party applications, infotainment applications, or cockpit sensor applications. Such user applications often consume a large number of P/E cycles, but do not require long data retention time. Therefore, it is advantageous to store data of such user applications on a storage partition with high TBW limit and short data retention time.

• Auslesen der Anzahl der P/E-Zyklen der Speicherpartition;
• Freigabe eines Schreib-/Lesezugriff auf die erste und zweite Speicherpartition, wenn die Anzahl der P/E-Zyklen der Speicherpartition niedriger ist als ein vorbestimmter Grenzwert; und
• Freigabe eines Nur-Lesezugriffs auf die erste und zweite Speicherpartition freigibt, wenn die Anzahl der P/E-Zyklen der Speicherpartition höher ist als ein vorbestimmter Grenzwert.

In another embodiment, managing access to the first and second storage partitions includes:

• reading the number of P/E cycles of the memory partition;
• enabling read/write access to the first and second memory partitions when the number of P/E cycles of the memory partition is less than a predetermined limit; and
• enabling read-only access to the first and second memory partitions when the number of P/E cycles of the memory partition is greater than a predetermined limit.

This has the advantage that, for example, system applications continue to have read/write access to the second memory partition, although the TBW limit of the first memory partition has been reached by user applications, i.e. the EOL of the first memory partition has been reached.

In one embodiment, read-only access to the storage medium is enabled when a predetermined TBW limit of the second storage partition is exceeded. This means that the storage medium is only released for read-only access when the EOL of the second storage partition, i.e. the storage partition for system applications, has been reached. In other words, read/write access to the storage medium is enabled until the EOL of the system-relevant second storage partition is reached.

The invention is described in more detail below on the basis of several preferred exemplary embodiments.

• 1 ein Blockdiagramm beschreibend eine Ausführungsform einer Speichervorrichtung zur Nutzung in einem Automobil;
• 2 ein Flussdiagramm beschreibend eine Ausführungsform eines Verfahrens zur Verwaltung einer Speichervorrichtung zur Nutzung in einem Automobil;
• 3 ein Flussdiagramm beischreibend eine weitere Ausführungsform eines Verfahrens zur Verwaltung einer Speichervorrichtung zur Nutzung in einem Automobil.

It shows:

• 1 12 is a block diagram describing an embodiment of a memory device for use in an automobile;
• 2 a flowchart describing an embodiment of a method for managing development of a memory device for use in an automobile;
• 3 FIG. 14 is a flowchart describing another embodiment of a method for managing a storage device for use in an automobile.

1 FIG. 1 shows a memory device 100 comprising a memory 102 with a first memory partition 104 and a second memory partition 106, and a controller 108. In a preferred embodiment, the memory 102 is a TLC-3D-NAND memory. In a preferred embodiment, the memory device 100 is used in an automobile.

The first memory partition 104 is configured to allow a large number of P/E cycles compared to the second memory partition 106 . For example, the first memory partition 104 may have a TBW limit of 300,000 P/E cycles or 500,000 P/E cycles. Such a high TBW limit can be achieved, for example, by reducing the data retention time of the first memory partition 104, for example to a few months. In a preferred embodiment, an automatic refresh function can update the memory partition and optimize data retention. The first memory partition 104 is thus particularly suitable for storing data from high-volume applications without the need for long-term data storage. In a preferred embodiment, the second memory partition 106 is configured to allow a low number of P/E cycles with high data retention compared to the first memory partition 104 . For example, the second storage partition 106 may have a TBW limit of 3,000 P/E cycles with a data retention time of several years, e.g., 5 years.

In a preferred embodiment, the controller 108 may comprise a first and a second controller. The first controller can be an internal controller and control access to the memory partitions depending on the number of P/E cycles. This is explained below with the help of 2 described in more detail. In a preferred embodiment, the first controller can also control the wear leveling of the memory partitions. A suitable wear leveling method is assigned to each memory partition. The wear leveling method can be static or dynamic. The wear leveling of one memory partition can differ from the wear leveling of the other memory partition. The second controller can be a host controller and allocate access of an application to either the first or the second memory partition. This is based on 3 described in more detail below.

In a preferred embodiment, user applications include third party applications, infotainment applications, and cockpit sensor applications. Third-party applications and infotainment applications are, for example, gaming applications, music applications, streaming, internet browsing or downloads. Cockpit sensor applications include dash cam applications, in which image data is recorded while an automobile is in motion, or surround-view camera applications, in which multiple image sensors enable an all-round view of the automobile, for example for use in parking assistance systems. Such applications generate large amounts of data at high writing speeds, with the actual amount of data to be written by such applications essentially depending on the behavior of the user. Therefore, the expected P/E cycles through these user applications cannot be predicted.

2 FIG. 2 shows a preferred embodiment 200 of a method for managing a memory device for use in an automobile. The method includes reading the number of P/E cycles of a memory partition in step 202. If the number of P/E cycles is less than a predefined limit x (step 204), then in step 206 a read/write access is granted of the storage partition freed. If the number of P/E cycles is greater than a predefined limit x (step 208), then in step 210 read-only access to the memory partition is enabled. In a preferred embodiment, this method is controlled by the first controller, ie an internal controller.

3 FIG. 3 shows a preferred embodiment 300 of a method for managing a memory device for use in an automobile. In step 302, the device receives a request for access to a memory partition from an application. If the application is a user application 304, then in step 306 access to the first memory partition is granted. If the application is a system application 308, then in step 310 access to the second memory partition is granted. Access to the second memory partition by user applications is denied in step 312. In a preferred embodiment, this method is controlled by the second controller, ie a host controller.

Reference List

100

Storage device 100 for use in an automobile

102

Storage

104

Storage partition 1

106

storage partition 2

108

controllers

200

Method 200 for managing a memory device for use in an automobile

202-210

Steps of the procedure 200

300

Method 300 for managing the memory partitions of a memory

302-312

Steps of Procedure 300

Claims (15)

A memory device for use in an automobile, the memory device comprising: a storage medium comprising at least a first storage partition and a second storage partition; and at least one controller configured for: enabling access to the first memory partition for a variety of user applications, preventing access to the second memory partition for the plurality of user applications, managing access to the first and second storage partition, wherein at least one controller is configured to allocate a higher number of program/erase, P/E, cycles to the first memory partition than to the second memory partition. The storage device after claim 1 , wherein the storage medium is a 3D TLC NAND memory. The storage device of any preceding claim, wherein the plurality of user applications includes one or more third party applications, infotainment applications, or cockpit sensor applications. The storage device of any preceding claim, wherein the at least one controller comprises a first controller that is an internal controller of the storage medium and a second controller that is a host controller of the storage medium. The storage device after claim 4 wherein the first controller either enables read/write access to the first and second memory partitions when the number of P/E cycles of the memory partition is less than a predetermined limit; or enabling read-only access to the first and second memory partitions when the number of P/E cycles of the memory partition is greater than a predetermined limit. The storage device after claim 4 , where the second controller grants access to applications for either the first or the second memory partition. The storage device of any preceding claim, wherein the data retention time of the first memory partition is shorter than the data retention time of the second memory partition. The memory device according to any one of the preceding claims, wherein a first wear leveling method is implemented on the first memory partition and a second wear leveling method is implemented on the second memory partition. The storage device of any preceding claim, wherein at least one controller is configured to enable access to the second storage partition for system applications such as boot code, operating system and/or file system. The storage device of any preceding claim, wherein at least one controller is configured to enable read-only access to the storage medium when a predetermined terra bytes written, TBL, limit of the second storage partition is exceeded. A method for managing a memory device for use in an automobile, the method comprising: receiving, by a user application, an access request to the storage device; enabling access to the first memory partition of the memory device for a large number of user applications, preventing access to the second memory partition of the memory device for the plurality of user applications, allocating a higher number of program/erase, P/E, cycles to the first memory partition than to the second memory partition, Managing access to the first and second storage partitions. The procedure after claim 11 , where the variety of user applications one or more third-party applications, infotainment appli cations or cockpit sensor applications. The procedure according to one of the Claims 11 and 12 wherein managing access to the first and second memory partitions comprises: reading the number of P/E cycles of the memory partition; enabling read/write access to the first and second memory partitions when the number of P/E cycles of the memory partition is less than a predetermined limit; and enabling read-only access to the first and second memory partitions when the number of P/E cycles of the memory partition is greater than a predetermined limit. The procedure according to one of the Claims 11 - 13 wherein access to the second storage partition is enabled for system applications such as boot code, operating system and/or file system. The procedure according to one of the Claims 11 - 14 wherein read-only access to the storage medium is enabled when a predetermined terra bytes written, TBL, limit of the second storage partition is exceeded.

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