DE102015223834A1 - Electronic control apparatus, means of locomotion and method of using a writable storage means - Google Patents

Abstract

An electronic control device, a means of transportation, and a method of using a rewritable storage means are proposed. The method comprises the steps of: determining a predefined maximum number of permitted writes to the storage means, determining a number of previous writes to the storage means, determining that the number of allowed writes is equal to the number of completed writes, and thereby preventing another Write operation with respect to the storage means.

Description

The present invention relates to an electronic control apparatus, a traveling means, and a method of using a rewritable storage means. In particular, the present invention relates to avoiding overstressing of the memory means by an excessive number of write operations.

Storage means may be subject to wear from the repetitive execution of writes. An example of this are so-called flash memory devices. Flash memory can lose its life each time it is backed up and saved. Therefore, controllers equipped with flash memory should not be rewritten too often.

It is therefore an object of the present invention to improve a lifetime of a rewritable storage means. In particular, it is an object of the present invention to reduce or eliminate write operations, preferably unnecessary writes.

The above object is achieved by a method for using a rewritable storage means according to the invention. The rewritable storage means may comprise, for example, a flash memory. The storage means may be understood as a storage area which undergoes self-destructive wear by writes, and may thereby differ from other storage areas (other "storage means") in that the other storage means are not subject to wear in the same storage operations. In a first step, a predefined max. Number of allowed writes with respect to the storage means under consideration. In other words, a reference is created or read out by means of which it can be determined whether a predefined max. Number of write operations is reached. In addition, a number of actual writes already made with respect to the storage means are determined. This can be done by counting (eg by means of an incrementing circuit) successful write operations. Subsequently, a comparison is made, which shows that the number of allowed writes is equal to the number of successful writes. It is thus determined that a critical number of allowed writes has been achieved. Due to this result, another write operation with respect to the storage means is automatically prevented. For this purpose, it can first be determined that a resource wishes to execute a write operation with respect to the memory means and that the write operation is prevented on the basis of the above-described comparison result. In this way, a use of the storage means in response to a previous critical usage behavior can be limited and a (eg permanent) defect of the storage means can be prevented. In this way, the availability of the storage means for a predefined duration can be ensured. The duration may, for example, be the expected service life of a technical device comprising the storage means.

The dependent claims show preferred developments of the invention.

The max. Number of permitted write operations with respect to the storage means can be determined, for example, based on a previous total number of write operations since the start of a startup of the storage means. Alternatively or additionally, for a sub-period which, for example, is adjacent to a current time, the write operations carried out in the sub-period are summed up and stored with an associated reference value, i. H. a predefined max. Number of allowed writes to be compared. The partial period can be determined, for example, in hours, days, weeks, months or years. Alternatively or additionally, it may be determined whether, in view of an expected life span, an actual operating period, a number of possible write operations set for the expected lifetime, and a number of previous write operations, another write (eg, average) to above or above would cause excessive stress on the memory means and in response to the further write operation with respect to the storage means can be prevented. In this case, in particular a linear dependence between the numbers of permitted write operations and the associated service life periods of the storage means can be used. An offset (also "offset") can be superimposed on this dependence in order to allow above-average stress peaks in a predefined frame.

If a prevention according to the invention of a further writing operation with regard to the storage means is carried out, an output of a user query for confirming a cancellation of the prevention of the further writing process can take place. In other words, the user may first be asked to declare his agreement with a (temporary) overuse of the storage means and only be carried out in response to a confirmation of the further writing process. It may therefore, for example, the user decide whether he premature failure of the storage means in view of the circumstances at hand, or whether it can, for example, foresee that a claim of the storage means, which on average will not be objected to, will compensate for the current overuse by a less intensive future use of the storage means.

If the user has (temporarily) agreed to cancel the prevention of further writing, the output of another user query can be suspended. This can be done for a predefined period of time and / or for a second predefined number of writes by which the predefined max. Number of allowed writes is exceeded. In particular, it can be provided that the predefined time period or the predefined number of write processes cause a re-output of the user query, depending on which condition is fulfilled first.

Since different priorities can be assigned for write operations, the prevention of the further write operation or the suspension of the inhibition of the further write operation can each take place depending on the priority level of the further write operation. For example. For example, for a low priority level, an earlier write time or fewer writes already made can be prevented from further writing with respect to the memory means, whereas execution at a later time or at a higher number of completed writes can be prevented with respect to a write operation with a higher priority level another writing operation with respect to the storage means is prevented.

The predefined max. The number of permitted write operations with regard to the storage means can be defined, for example, in the form of an annotation and / or a label and / or a (debug) parameter / symbol in the binary program and / or a build parameter / argument.

For example, a label may be stored in a system-internal or external database, and criteria to be observed such as maximum number of writes, etc. Here, a label may be associated with one or more resources in the database. The resource then references again to another table in which, for example, concrete maximum values are stored. Example: label Resource Comment APP_ROM_ID1 Flash_1 max writes of Flash_1 = 5000 ROM_ID1 Flash_1 max writes of Flash_1 = 5000 ROM_ID2 Flash_2 max writes of Flash_2 = 20000 ROME Flash_1, Flash_2 max (max writes of Flash_1, max writes of Flash_2)

Depending on the application, preventing further writing of the storage means may include automatically skipping an update of a software version and / or build and / or compilation operation.

Alternatively or additionally, an automatic change of a writing area to be used for the further writing operation may result in the storage means in question being spared to the disadvantage of another writing area.

According to a second aspect of the present invention, an electronic control device for automotive use is proposed, which has a storage means and an evaluation unit. The storage means may be that which is to be described by the method according to the first aspect of the invention. The evaluation unit is set up to carry out the steps of such a method, the preferred embodiments of which can also be transferred analogously to the electronic control unit.

According to a third aspect of the present invention, there is proposed a traveling means having an electronic control apparatus according to the second aspect of the invention.

The features, feature combinations and resulting from these advantages of the second and third aspects of the invention will become apparent in accordance with those of the first-mentioned aspect of the invention that reference is made to avoid repetition of the above statements.

It is a core idea of the present invention to have labels / annotations interpreted by a build and test mechanism such that the mechanism only builds and loads into a flash memory, as long as the total balance (ie the number of flash operations per day / per week / per month / per year) is not considered harmful to the storage resource used (eg a control device). The overall balance depends on the flash memory used. For example, a max. Number of ten flash operations per day. The mechanism stores the number of "sensitive" transactions. Over a certain period of time then a threshold is not or only slightly exceeded in order to keep the overall balance on balance. If 15 Flash operations have already occurred in one day, a corresponding message is output and the build strategy is changed so that the total balance of the future Flash operations is compensated again. For example. 15 Flash operations can be performed on a Monday, and then only 5 Flash operations on Tuesday, resulting in an average balance of 10 flash operations per day of the week. If possible, then later (for example, on the basis of a confirmation by the user), it will now be transmitted despite an increased number of flash operations. In this case, the user is thus informed, for example, that a certain quota of write operations has already been exhausted. If necessary, in the knowledge of this situation, the user confirms the writing process anyway, so that a flash operation can nevertheless be transmitted. This option has already been mentioned above.

Preferably, a property can be deposited in the manner of an annotation, which results in "not being rebuilt" and a corresponding writing process being prevented. Moreover, a priority can be defined by means of a label. Depending on the priority value, this will then be processed in a queue (English: "Queue"). This snake is unique and duplicate entries are not provided. If a command is triggered a second time, it will be eliminated in the queue. The prioritization is e.g. either maintained or set higher using a different approach. It is also conceivable that with a certain number of build commands the prioritization is increased. According to the invention, the resources can also be influenced. For example. For example, a build method may be adapted such that, with multiple resources in parallel, the lowest resource is coupled to the least prioritized instruction. If a resource has been used for a long time, the build mechanism is so intelligent that a data transfer including a check is performed later. In this way, a resource-saving use of a storage means and thus a longer life and more efficient use is made possible.

The invention is particularly easy to implement. In addition, a "starvation" can be avoided in parallel processes. Moreover, the process of prioritizing becomes more efficient.

Further details, features and advantages of the invention will become apparent from the following description and the figures. Show it:

1 a schematic representation of an embodiment of an inventively designed means of transport or inventively designed working machine;

2 a schematic detail view of components of an embodiment of a control device according to the invention;

3 a diagram illustrating a linear progression of a number of allowed writes over time;

4 a first embodiment of a method according to the invention; and

5 A second embodiment of a method according to the invention.

1 shows a car 10 as an embodiment of a means of transport. The car 10 has a plow blade 9 on, by means of which the passenger car 10 is also designed as a working machine. An evaluation unit 1 is information technology connected to a flash memory as storage means.

In addition, the evaluation unit has 1 via an information technology connection to a touchscreen 3 as user interface.

2 shows a detailed view of an electronic control unit 8th which has a touch screen 3 is connected as a user interface information technology. Inside the control unit 8th is an evaluation unit 1 Information technology with a flash memory 2 which has four memory areas or write areas 4 . 5 . 6 . 7 having. Each of the writing areas 4 . 5 . 6 . 7 may be understood as claiming memory means, since a write operation with respect to each of the write areas 4 . 5 . 6 . 7 has no influence on the wear of the other writing areas.

3 shows a possible linear course of a number of allowed writes S (t) over time t. A linear relationship results for a considered write area of a considered memory means in that the maximum allowed number of write operations Smax may be executed until time Tmax. For partial life-time ranges, correspondingly linearly reduced permissible numbers of write operations result. A number of write operations Sa arranged above the graph exceeds the allowable number of write times with respect to the corresponding lifetime of the memory means under consideration, thus leading, on the one hand, to preventing further writing to the memory means under consideration and, on the other hand, to outputting a user query to confirm that the memory has been disabled further writing. A second number of executed write operations Sb is below the linear graph and therefore does not cause any expected impairment of the usable useful life of the memory means.

4 shows steps of a first embodiment of a method according to the invention for using a rewritable storage means. In step 100 is a predefined max. Number of allowed writes with respect to the storage means under consideration. This can, for example, based on the in 3 illustrated context. In step 200 Subsequently, a number of already performed write operations with respect to the storage means is determined. This may involve the use of a counter, which is incremented at each write. Of course, for each independently usable write area in the memory means, a respective counter can be implemented. In step 300 it is determined that the number of allowed writes is equal to the number of allowed writes for a corresponding period of time. Because of that, in step 400 prevents another, announced by a resource writing with respect to the storage means. In order to ensure a needs-based use of the storage medium, in step 500 determines a priority level of the further write operation. In response to another write of a first priority level, in step 600 the prevention of further writing automatically suspended in order to perform the writing process of a particularly high importance to the detriment of the life of the memory means nevertheless can.

5 shows steps of a second embodiment of a method according to the invention for the use of a rewritable storage means. The steps 100 to 400 similar to those associated with 4 have been discussed. In contrast to 4 the procedure continues in step 700 with the output of a user query confirming a cancellation of the prevention of the further writing process. The output of the user query can, for example, a display of a corresponding button on a touch screen (see. 1 and 2 ) respectively. In step 800 In response to the receipt of the confirmation by the user, further writing is performed. In order not to bother the user unnecessarily with further queries and to increase the user acceptance of the method according to the invention, in step 900 an output of another user query for confirming a suspension of the prevention of further writing for a predefined period or for a second predefined number of write operations by which the predefined maximum number of allowed writes is exceeded suspended. In this way, it is left to the user to decide on a case-by-case basis whether a predefined or (for example via a settings menu) predefinable number of further write operations should be allowed in order to allow a particularly flexible use of the storage means.

LIST OF REFERENCE NUMBERS

1

evaluation

2

Flash memory

3

touchscreen

4, 5, 6, 7

Write areas within the flash memory 2

8th

control unit

9

dozer blade

10

car

100-900

steps

Sa, Sb

Number of writes

S (t)

Max. allowed number of writes over time.

Smax.

 Max. Total number of allowed writes to a storage device

t

Time

Tmax.

Life of the component containing the storage medium 2 contains.

Claims (10)

Method for using a rewritable storage medium ( 2 ) comprising the steps of: - determining ( 100 ) a predefined maximum number of allowed writes to the storage means ( 2 ), - Determine ( 200 ) a number of previous writes to the storage medium ( 2 ), - Determine ( 300 ), that the number of allowed writes is equal to the number of successful writes and due to this - preventing ( 400 ) of a further write operation with respect to the storage means ( 2 ). Method according to claim 1, wherein the storage means ( 2 ) comprises a flash memory. Method according to claim 1 or 2, wherein the maximum number of permitted write operations (Smax) with respect to the memory means ( 2 ) on the basis of: - a previous total number and / or - a maximum number of write operations made in an immediately preceding predefined sub-period and / or - a mean expected life of the storage medium ( 2 ), an empirical value for a number of possible writes to the storage medium ( 2 ) and a number of already done write operations. Method according to one of the preceding claims further comprising - issuing ( 700 ) of a user query confirming a cancellation of the prevention of further writing and in response to a receipt of the confirmation - performing ( 800 ) of the further writing process. The method of claim 4 further comprising - suspending ( 900 ) an output of another user query for confirming a cancellation of the further writing process - for a predefined period of time and / or - for a second predefined number of write operations by which the predefined maximum number of permitted write processes is exceeded. Method according to one of the preceding claims further comprising - determining ( 500 ) of a priority level of the further write and in response to a first priority level - suspend ( 600 ) preventing the further writing operation and in response to a second priority level which is lower than the first priority level, - preventing ( 400 ) of the further writing process. Method according to one of the preceding claims, wherein the predefined maximum number of permitted write operations (Smax) with respect to the memory means ( 2 ) in the form of - an annotation and / or - a label and / or - a debug comment and / or - a build target is predefined. A method according to any one of the preceding claims, wherein said preventing ( 400 ) of a further write operation with respect to the storage means ( 2 ) includes: - automatic skipping - updating a software version and / or - a build and / or A compilation process and / or an automatic change of a writing area to be used for the further writing process. Electronic control unit ( 8th ) for automotive use comprising - a storage means ( 2 ), and - an evaluation unit ( 1 ), whereby the evaluation unit ( 1 ) is adapted to carry out the steps of a method according to one of the preceding claims. Means of transportation ( 10 ) comprising an electronic control unit ( 8th ) according to claim 9.

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