CN112397128A

CN112397128A - Control method and device for Flash memory

Info

Publication number: CN112397128A
Application number: CN202011302770.3A
Authority: CN
Inventors: 徐龙增; 郎学政; 张正阳; 李富民; 马彦
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2021-02-23

Abstract

The application provides a control method and a device of a Flash memory, which are applied to a vehicle-mounted electronic control unit, wherein the method comprises the following steps: and in the vehicle power-off stage, determining a storage block to be written according to the storable data amount of each storage block divided by Flash, writing data to be stored into the storage block to be written, setting the erasing flag bit of part of the storage blocks to be 1 if the storable data amount of each storage block does not meet the preset condition after writing, searching the storage block to be erased (the storage block with the erasing flag bit of 1) and executing data erasing operation on the storage block to be erased in the vehicle power-on stage, and re-determining the storage block to be erased after the vehicle is powered on again and continuing to execute the data erasing operation if the data erasing process is abnormally powered off in the erasing process. According to the scheme, data erasing and data writing operations are respectively executed in the power-on stage and the power-off stage, even if abnormal power failure occurs during power-on, erasing can be continued after power-on is performed again, data are prevented from being written in an unerased storage block in the power-off stage, and a Flash memory is prevented from being damaged.

Description

Control method and device for Flash memory

Technical Field

The invention relates to the technical field of vehicle automation, in particular to a method and a device for controlling a Flash memory.

Background

In consideration of reducing cost and system complexity, in an on-board Electronic Control Unit (ECU) ECU of a vehicle, a Flash memory is often used to simulate a charged Erasable Programmable read only memory (EEPROM) to implement power-off storage of data, and this function is generally called a fe function by using the Flash memory to simulate the EEPROM.

Due to the characteristics of the Flash memory, each storage block cannot be directly used for repeatedly storing data, and if a storage block full of data is used for storing new data, data erasing operation needs to be performed on the storage block first, and the storage block can be used for storing the new data only after the data erasing operation is finished, and if the new data is directly written in without erasing original data, the corresponding storage space in the Flash memory is damaged.

In the prior art, an ECU divides a Flash memory into a plurality of memory blocks, stores data to be stored into the memory blocks in a power-off stage of a vehicle, stores the data in another memory block that is not full after a previous memory block is full, and then performs a data erasing operation on the previous memory block to erase the previously written data.

However, the abnormal power-off is easy to occur in the power-off stage of the vehicle, the data erasing operation is immediately interrupted once the abnormal power-off occurs, and when the vehicle is restarted and enters the power-off stage again, the ECU directly writes new data into the previous memory block in which the data erasing is not completed, so that the memory block is damaged, and a write program failure is caused.

Disclosure of Invention

Based on the defects of the prior art, the application provides a control method and a control device of a Flash memory, so as to avoid the damage of the Flash memory of an ECU.

The first aspect of the present application provides a control method for a Flash memory, which is applied to a vehicle-mounted electronic control unit, wherein the Flash memory is divided into a plurality of memory blocks, and the control method includes:

in the power-off phase of the vehicle:

judging whether the storable data quantity of the current storage block is larger than the data quantity of the data to be stored; wherein the current memory block is a memory block to be written determined in a previous power-down phase of the vehicle;

if the storable data amount of the current storage block is not larger than the data amount of the data to be stored, determining the storage block with the storable data amount larger than the data amount of the data to be stored in the plurality of storage blocks as a storage block to be written in, and setting the current storage block to be in an erasable state;

if the storable data quantity of the current storage block is larger than the data quantity of the data to be stored, determining the current storage block as a storage block to be written;

writing the data to be stored into the storage block to be written;

judging whether a storage block with the data storage quantity larger than a data quantity threshold exists in the Flash memory or not; the data volume threshold is determined according to the data volume threshold of the data to be stored;

if the storage block with the data storage quantity larger than the data quantity threshold value does not exist in the Flash memory, selecting at least one storage block in an erasable state in the Flash memory, and setting an erasing flag bit of the selected storage block to be 1;

in a power-up phase of the vehicle:

searching a storage block to be erased in the plurality of storage blocks; the storage block to be erased refers to a storage block with a corresponding erase flag bit of 1;

if the memory blocks to be erased are found, setting the erasing success flag bit of each memory block to be erased to be 0;

executing data erasing operation to erase the data currently stored in each memory block to be erased;

if abnormal power failure occurs in the execution process of the data erasing operation, when the vehicle enters the power-on stage again, returning to the step of searching the storage blocks to be erased in the plurality of storage blocks;

after the data erasing operation is finished, setting the erasing flag bit of each storage block to be erased and the erasing success flag bit of the storage block to be erased to be 0 and 1, and setting the storage block to be erased to be in a writable state.

Optionally, the determining whether a storage block whose storable data amount is greater than the data amount threshold exists in the Flash memory includes:

calculating the product of the data volume of the data to be stored and a preset multiple to obtain a data volume threshold value;

comparing the storable data quantity of each storage block of the Flash memory with the data quantity threshold value;

if the storable data quantity of at least one storage block is larger than the data quantity threshold value, judging that the storage block with the storable data quantity larger than the data quantity threshold value exists in the Flash memory;

and if the storable data quantity of each storage block is not greater than the data quantity threshold value, judging that no storage block with the storable data quantity greater than the data quantity threshold value exists in the Flash memory.

Optionally, after the performing the data erasing operation to erase the data currently stored in each of the to-be-erased memory blocks, the method further includes:

if a lower electric signal is received in the execution process of the data erasing operation, recording the lower electric signal;

and after the data erasing operation is finished, responding to the power-off signal and entering a power-off stage.

Optionally, the selecting at least one storage block in an erasable state in the Flash memory includes:

selecting N storage blocks from small to large according to the storable data quantity from all the storage blocks in an erasable state of the Flash memory; and N is a positive integer less than the number of memory blocks of the Flash memory in an erasable state.

Optionally, the searching for a memory block to be erased in the plurality of memory blocks includes:

detecting the erasing flag bit corresponding to each storage block of the Flash memory one by one;

and for each storage block, if the erasure flag bit corresponding to the storage block is detected to be 1, determining the storage block as a storage block to be erased.

The second aspect of the present application provides a control device for a Flash memory, which is applied to a vehicle-mounted electronic control unit, wherein the Flash memory is divided into a plurality of memory blocks, and the control device includes:

the first judgment unit is used for judging whether the storable data quantity of the current storage block is larger than the data quantity of the data to be stored or not in the power-off stage of the vehicle; wherein the current memory block is a memory block to be written determined in a previous power-down phase of the vehicle;

a determination unit configured to:

the writing unit is used for writing the data to be stored into the storage block to be written;

the second judgment unit is used for judging whether a storage block with the storable data quantity larger than the data quantity threshold exists in the Flash memory; the data volume threshold is determined according to the data volume threshold of the data to be stored;

the selecting unit is used for selecting at least one storage block in an erasable state in the Flash memory and setting an erasing flag bit of the selected storage block to be 1 if the storage block which can store data with the data quantity larger than the data quantity threshold value does not exist in the Flash memory;

the searching unit is used for searching the storage blocks to be erased in the plurality of storage blocks in the power-on stage of the vehicle; the storage block to be erased refers to a storage block with a corresponding erase flag bit of 1;

the setting unit is used for setting the successful erasing flag bit of each storage block to be erased to 0 if the storage blocks to be erased are found;

the erasing unit is used for executing data erasing operation so as to erase the data currently stored in each memory block to be erased;

the searching unit is used for returning to the step of searching the storage blocks to be erased from the plurality of storage blocks when the vehicle enters the power-on stage again if the abnormal power failure occurs in the execution process of the data erasing operation;

the setting unit is configured to set the erasure flag bit of each to-be-erased storage block and the erasure success flag bit of the to-be-erased storage block to 0 and 1 after the data erasure operation is finished, and set the to-be-erased storage block to a writable state.

Optionally, when the second determining unit determines whether a storage block whose storable data amount is greater than the data amount threshold exists in the Flash memory, the second determining unit is specifically configured to:

Optionally, the control device further includes:

the recording unit is used for recording a lower electric signal if the lower electric signal is received in the execution process of the data erasing operation;

and the response unit is used for responding to the power-down signal and entering a power-down stage after the data erasing operation is finished.

Optionally, when the selecting unit selects at least one storage block in an erasable state in the Flash memory, the selecting unit is specifically configured to:

Optionally, when the search unit searches for a memory block to be erased in the plurality of memory blocks, the search unit is specifically configured to:

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flowchart of a method for controlling a Flash memory in a power-down phase of a vehicle according to an embodiment of the present disclosure;

FIG. 2 is a flowchart of a method for controlling a Flash memory in a power-on phase of a vehicle according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a control device of a Flash memory according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The control method of the Flash memory specifically comprises two processes, wherein one process is a data writing process executed in a power-off stage of a vehicle, and the other process is a data erasing process executed in a power-on stage of the vehicle and aiming at a memory block to be erased. The two processes are described below with reference to the corresponding drawings.

In this application, the power-off stage of the vehicle may be understood as a process in which a control system (generally, each electronic device and device including the vehicle-mounted ECU) of the vehicle is turned off one by one when the vehicle is turned off, and the power-on stage of the vehicle may be understood as a process in which the control system of the vehicle is turned on one by one when the user starts the vehicle. The vehicle-mounted ECU can be regarded as a central controller of the vehicle, and is used for uniformly controlling all electronic equipment and devices on the vehicle to work and controlling the running parameters of the vehicle through the electronic equipment and the devices.

Optionally, specifically, the power-on stage or the power-off stage is determined by a T15 signal in a control system of the vehicle, T15 is a switch input signal of the ECU, when a user stops or stops the vehicle, the T15 signal jumps from a high potential to a low potential, after the ECU detects a change of the T15 signal, it may be determined that the current vehicle enters the power-off stage, correspondingly, when the user starts the vehicle, the T15 signal jumps from the low potential to the high potential, and after the ECU detects a change of the T15 signal, it is determined that the current vehicle enters the power-on stage.

Referring to fig. 1, fig. 1 is a flowchart of a data writing process executed in a power-down phase according to an embodiment of the present disclosure, and as shown in fig. 1, a control method of a Flash memory according to an embodiment of the present disclosure may specifically include the following steps in the power-down phase of a vehicle:

s101, judging whether the storable data quantity of the current storage block is larger than the data quantity of the data to be stored.

If the storable data amount of the current storage block is not greater than (i.e., less than or equal to) the data amount of the data to be stored, step S102 is executed, and if the storable data amount of the current storage block is greater than the data amount of the data to be stored, step S103 is executed.

The data to be stored refers to data that needs to be saved during the power-down phase of the vehicle.

For example, the data amount of the current storage block is 100MB, that is, the current storage block can store up to 100MB of data, if the data amount of the data to be stored (denoted as record) is 60MB, it is determined that the data amount of the current storage block is larger than the data amount of the data to be stored, and if the data amount of the data to be stored is 100MB or 110MB, it is determined that the data amount of the current storage block is not larger than the data amount of the data to be stored.

It should be noted that the storable data amount here refers to a difference obtained by subtracting the already stored data amount of the memory block from the maximum stored data amount of the memory block, for example, a memory block can store at most 200MB of data, and the currently stored data amount of the memory block is 50MB if the memory block currently stores 150MB of data.

Wherein the current memory block is a memory block to be written determined in a previous power-down phase of the vehicle. Optionally, if there is no data to be stored in the previous power-down stage, so that the previous power-down stage does not specify a memory block to be written in, or the current power-down stage is the first power-down stage, then a memory block that is not currently in an erasable state may be arbitrarily specified as a memory block to be erased in the plurality of memory blocks of the Flash memory.

In the Flash memory, each divided storage block has a state flag, called a block head, for representing the current state of the storage block, and the state flag may be composed of a plurality of consecutive bytes.

For example, it can be specified that for any memory block, when the first 8 bytes of the status flag of the memory block are 0x5F5FFFFF, the memory block is currently in the writable state, and when the first 8 bytes of the status flag are 0x5a 0000, the memory block is currently in the erasable state.

S102, determining a storage block which can store data with the data size larger than that of the data to be stored in the plurality of storage blocks as a storage block to be written, and setting the current storage block to be in an erasable state.

Specifically, when step S102 is executed, the storable data amount of each storage block in the Flash memory except the current storage block may be obtained, and then whether each storable data amount is larger than the data amount of the to-be-stored data record is detected one by one.

And if a plurality of storage blocks of which the storable data amount is larger than the data amount of the data to be stored are detected, one storage block is arbitrarily selected from the storage blocks as the storage block to be written.

For example, assuming that two storage blocks are divided in the Flash memory, which are respectively denoted as block1 and block2, where block1 is the current storage block, when step S102 is executed, it is required to detect whether the storable data amount of block2 is greater than the data amount of the data to be stored, and if so, block2 is determined as the storage block to be written.

Further, if the Flash memory is divided into three storage blocks, which are sequentially recorded as block1 to block3, where block1 is the current storage block, when step S102 is executed, the storable data amount of block2 and the storable data amount of bolck3 may be detected, respectively, if only one storage block in which the storable data amount is greater than the data amount of the data to be stored is present, the storage block is determined as the storage block to be written, and if both the block2 and the block3 meet the condition that the storable data amount is greater than the data amount of the data to be stored, any one of the storage blocks is selected as the storage block to be written.

As can be understood from the description of the status flag of the memory block in step S101, in step S102, the current memory block is set to the erasable state, which is substantially to set the value of the corresponding byte (e.g. the first 8 bytes of the block head in the foregoing example) in the status flag of the current memory block, and set the value of the corresponding byte to the value representing the erasable state, e.g. 0x5a 0000 in the foregoing example, so as to set the status of the current memory block to the erasable state.

S103, determining the current storage block as a storage block to be written.

If the storable data amount of the current storage block is larger than the data amount of the data to be stored, the current storage block can completely store the data to be stored, and therefore the current storage block can be directly determined as the storage block to be written.

And S104, writing the data to be stored into the storage block to be written.

The specific writing process is prior art and will not be described in detail here.

And S105, judging whether a storage block with the data storage quantity larger than the data quantity threshold exists in the Flash memory.

If the storage block with the storable data quantity larger than the data quantity threshold value does not exist in the Flash memory, the step S106 is executed, and if the storage block with the storable data quantity larger than the data quantity threshold value exists in the Flash memory, the method is ended.

The data amount threshold is a threshold determined according to the data amount of the data to be stored, and specifically, N times of the data amount of the data to be stored may be used as the data amount threshold in step S105, where N is a preset positive integer. For example, if the data amount of the data to be stored is Tsize and N is set to 3, step S105 is equivalent to determining whether a storage block whose data amount can be stored is larger than 3 times the data amount of the data to be stored (i.e., 3 × Tsize) exists in the Flash memory.

Specifically, the execution process of step S105 is:

and calculating the product of the data volume of the data to be stored and a preset multiple to obtain a data volume threshold value. In the above example, the product of Tsize and the multiple N will be calculated to yield the data volume threshold.

And comparing the storable data quantity of each storage block of the Flash memory with a data quantity threshold value.

If the storable data quantity of at least one storage block is larger than the data quantity threshold value, judging that the storage block with the storable data quantity larger than the data quantity threshold value exists in the Flash memory.

If the storable data quantity of each storage block is not greater than the data quantity threshold value, judging that the Flash memory does not have the storage block with the storable data quantity greater than the data quantity threshold value.

The reason for executing step S105 is that the data amount of the data to be stored generated each time the power-down phase is entered is not fixed, in order to ensure that the Flash memory has enough space to store the data to be stored in the next power-down phase when the power-down phase is entered next time, it is necessary to ensure that at least one storage block whose storable data amount is greater than the data amount threshold in step S105 exists in the Flash memory, and if a storage block that meets the condition in step S105 (i.e., the stored data amount is greater than the data amount threshold) does not exist in the Flash memory, it is necessary to perform a data erasing operation on a part of the storage blocks in the power-up phase of the next vehicle by setting an erasing flag bit, that is, to empty the part of the storage blocks (or delete the data therein), so as to ensure that the data to be stored can be smoothly stored in the Flash memory when the power-down phase is entered again.

S106, selecting at least one storage block in an erasable state in the Flash memory, and setting the erasing flag bit of the selected storage block to be 1.

Each storage block in the Flash memory is configured with a corresponding erasure flag bit, the erasure flag may be a binary bit, and for any one storage block, if the value of the erasure flag bit of the storage block is 0, it indicates that the data erasure operation is not required to be performed on the storage block in the power-on stage, and if the value of the erasure flag bit of the storage block is 1, it indicates that the data erasure operation is required to be performed on the storage block in the power-on stage.

In step S106, the memory block to which the erase flag is set may be selected according to a variety of selection rules.

For example, N memory blocks may be selected from all memory blocks in an erasable state of the Flash memory from small to large according to the amount of storable data; wherein, N is a positive integer less than the number of memory blocks in an erasable state of the Flash memory.

Assuming that there are 10 memory blocks in an erasable state, 5 memory blocks in which the amount of storable data is small may be selected, and the erase flag bit of the 5 memory blocks is set to 1.

In addition, the selection can be performed according to the data stored in all the memory blocks in the erasable state. For example, if 5 of 10 memory blocks in an erasable state store data generated the previous day, and the other 5 memory blocks store data generated today, the 5 memory blocks in which the earlier data is stored may be selected, that is, the 5 memory blocks in which the data generated the previous day is stored may be selected to set the erasure flag.

Referring to fig. 2, fig. 2 is a flowchart of a data erasing process executed in a power-on phase according to an embodiment of the present disclosure, and as shown in fig. 2, the method for controlling a Flash memory according to the embodiment of the present disclosure may specifically include the following steps in the power-on phase of a vehicle:

s201, searching a storage block to be erased in the plurality of storage blocks.

The storage block to be erased refers to a storage block with an erase flag bit of 1.

If at least one memory block to be erased is found, step S202 is executed, and if the memory block to be erased is not found, the method is ended, and the subsequent operations to be executed in the power-on stage are normally executed.

That is, in step S201, it may be detected whether the erasure flag bit of each storage block of the Flash memory is 1 one by one, and finally, the detected storage block with the erasure flag bit of 1 is determined as the storage block to be erased.

S202, setting the erasing success flag bit of each memory block to be erased to be 0.

The erasure success flag (Flash1_ clearflag) is another flag corresponding to a memory block different from the aforementioned erasure flag, and each memory block corresponds to an erasure success flag, which indicates that the corresponding memory block is being erased when the erasure success flag is 0, and indicates that the erasure of data of the corresponding memory block has ended when the erasure success flag is 1, and the data originally stored in the data block has been erased.

When the erase success flag is 0, the corresponding memory block is not allowed to be used for writing data.

S203, executing data erasing operation to erase the data currently stored in each memory block to be erased.

It should be noted that it takes a certain time to erase data from each memory block, for example, it may take 1 second to complete the erasing of one memory block, and if there are 4 memory blocks to be erased, the data erasing operation in step S203 needs to last for at least 4 seconds.

In the process of continuously executing the data erasing operation, if abnormal power failure occurs, the currently executed data erasing operation is terminated. When the vehicle enters the power-on phase again after the abnormal power failure occurs, the ECU performs step S201 again, that is, searches the memory block to be erased again, and then continues to perform the data erasing operation terminated before.

After the data erasing operation is finished, step S204 is executed.

The data erasing operation is finished, that is, each memory block to be erased is erased.

S204, setting the erasing flag bit of each memory block to be erased and the erasing success flag bit of the memory block to be erased to 0 and 1, and setting the memory block to be erased to a writable state.

That is, after the data erasing operation of step S203 is finished, the erase flag of each to-be-erased memory block is changed from 1 to 0 before the data erasing operation is performed, and the erase success flag is changed from 0 to 1 before the data erasing operation is performed.

Setting the memory block to be erased into a writable state, which essentially changes the value of the block head corresponding to the memory block to be erased into a value representing the writable state.

The memory block in the writable state may be used as a memory block to be written for writing data to be stored in the power-down stage. That is, in step S102, it may be considered that, among the plurality of memory blocks, one memory block which can store a data amount larger than the data amount of the data to be stored and is currently in a writable state is determined as the memory block to be written.

Optionally, in the data erasing operation executing process of step S203:

if a lower electric signal is received in the execution process of the data erasing operation, recording the electric signal;

The lower signal, which is actually the T15 signal, transitions from high to low. That is, if the user stops and extinguishes the vehicle during the execution of the data erasing operation, and the T15 signal is triggered to jump from the high potential to the low potential, the ECU may record the jump without executing the operation to be executed in the power-down phase, and continue to execute the data erasing operation until the data erasing operation is finished, and then enter the power-down phase in response to the jump, and then start to execute the operation to be executed in the power-down phase, thereby avoiding frequent power-up and power-down operations in the power-up phase.

In the present application, the power-off signal is a signal triggered when a user closes a control system of a vehicle through normal operation, and the abnormal power failure may be triggered when the user forcibly closes the control system of the vehicle through abnormal operation, or may be triggered when a line in the control system of the vehicle is failed, and when the abnormal power failure occurs, all electronic devices and devices included in the control system of the vehicle may be immediately powered off.

The following Flash memory divided into two memory blocks (respectively denoted as block1 and block2) is taken as an example to illustrate the implementation process of the method provided by the present application.

After the vehicle enters a power-off stage, step S101 is executed, whether the storable data amount of the current block1 is greater than the data amount of the data to be stored is detected, after the storable data amount of block1 is detected to be smaller than the data amount of the data to be stored, step S102 is executed, block2 which is in a writable state and whose storable data amount is greater than the data amount of the data to be stored is determined as the block to be written, a block head (state flag) of block1 is set to an erasable state, and then the data to be stored is written into block 2.

After the writing is finished, step S105 is executed to detect that both the storable data amount of block2 and the storable data amount of block1 are smaller than the data amount threshold, that is, no storage block with the storable data amount larger than the data amount threshold exists in the Flash memory, and then step S106 is executed to set the erasure flag bit of only one storage block1 in an erasable state in the Flash memory to 1.

When the user starts the vehicle again, the vehicle enters a power-on stage, the ECU executes step S201, determines that the erasure flag bit of block1 is 1, determines block1 as a to-be-erased storage block, executes step S202, sets the erasure success flag bit of block1 to 0, and then starts to execute data erasure operation on block 1.

If abnormal power failure occurs in the process of erasing block1, after the ECU is powered on again, the ECU detects that the erasing flag bit of block1 is 1 again, and continues to perform data erasing operation on block 1.

After the data erasing operation for block1 is finished, the ECU executes step S204 to set the erase flag bit of block1 to 0, the erase success flag bit of block1 to 1, and the block head of block1 to a writable state.

From the above process, it can be found that even if the abnormal power failure occurs in the power-on stage to terminate the data erasing operation being executed, the ECU continues to execute the data erasing operation on the memory block to be erased after the power-on again, and before the data erasing operation on the memory block to be erased is finished, the ECU does not directly enter the power-off stage, and meanwhile, the erasing flag bit and the erasing success flag bit of the memory block to be erased do not change, so that the data to be stored cannot be written into the memory block to be erased, which has not finished the data erasing, and the damage of the Flash memory is effectively prevented.

A second aspect of the present application provides a control device for a Flash memory, which is applied to a vehicle-mounted electronic control unit, wherein the Flash memory is divided into a plurality of memory blocks, as shown in fig. 3, and the control device includes:

the first judging unit 301 is configured to judge whether the storable data amount of the current storage block is larger than the data amount of the data to be stored in the power-off phase of the vehicle.

Wherein the current memory block is a memory block to be written determined in a previous power-down phase of the vehicle.

A determining unit 302, configured to:

if the storable data quantity of the current storage block is not larger than the data quantity of the data to be stored, determining the storage block with the storable data quantity larger than the data quantity of the data to be stored in the plurality of storage blocks as a storage block to be written in, and setting the current storage block to be in an erasable state;

and if the storable data volume of the current storage block is larger than the data volume of the data to be stored, determining the current storage block as the storage block to be written.

The writing unit 303 is configured to write data to be stored into a storage block to be written.

The second determining unit 304 is configured to determine whether a storage block in which the storable data amount is greater than the data amount threshold exists in the Flash memory.

The data volume threshold is determined according to the data volume threshold of the data to be stored.

The selecting unit 305 is configured to select at least one storage block in an erasable state in the Flash memory and set an erasure flag bit of the selected storage block to 1 if the storage block in which the amount of data that can be stored is greater than the data amount threshold does not exist in the Flash memory.

The first determining unit 301 to the selecting unit 305 operate at the power-off stage of the vehicle.

The searching unit 306 is configured to search the memory blocks to be erased in the plurality of memory blocks during a power-on phase of the vehicle.

The setting unit 307 is configured to set the erase success flag bit of each to-be-erased storage block to 0 if the to-be-erased storage block is found.

The erasing unit 308 is configured to perform a data erasing operation to erase the data currently stored in each memory block to be erased.

The searching unit 306 is configured to, if an abnormal power failure occurs during the execution of the data erasing operation, return to the step of searching for the memory block to be erased from the plurality of memory blocks when the vehicle is powered on again.

The setting unit 307 is configured to, for each to-be-erased storage block, set the erase flag bit of the to-be-erased storage block and the erase success flag bit of the to-be-erased storage block to 0 and 1 in sequence after the data of the to-be-erased storage block is erased, and set the to-be-erased storage block to a writable state.

The lookup unit 306 to the erase unit 308 described above operate during the power-up phase of the vehicle.

And finishing the data erasing operation after the data of each memory block to be erased is erased.

comparing the storable data quantity of each storage block of the Flash memory with a data quantity threshold value;

Optionally, the control device further includes:

the recording unit is used for recording the electric signal if the lower electric signal is received in the execution process of the data erasing operation;

and the response unit is used for responding to the power-off signal and entering a power-off stage after the data erasing operation is finished.

selecting N storage blocks from small to large according to the storable data quantity from all the storage blocks in an erasable state of the Flash memory; wherein, N is a positive integer less than the number of memory blocks in an erasable state of the Flash memory.

detecting an erasing flag bit corresponding to each storage block of the Flash memory one by one;

The specific working principle of the control device for the Flash memory provided in this embodiment may refer to the control method for the Flash memory provided in any embodiment of the present application, and details are not described here.

The application provides a device of a Flash memory, in a vehicle power-off stage, determining a storage block to be written in according to the storable data quantity of each storage block divided by Flash, writing data to be stored in the storage block to be written in, after writing, setting the erasing flag bit of a part of the storage blocks to be 1 if the storable data quantity of each storage block does not accord with a preset condition, in a vehicle power-on stage, finding out the storage block to be erased (the storage block with the erasing flag bit of 1) and executing data erasing operation on the storage block to be erased, and in an erasing process, if abnormal power failure occurs, re-determining the storage block to be erased after the vehicle is powered on again and continuing to execute the data erasing operation. According to the scheme, data erasing and data writing operations are respectively executed in the power-on stage and the power-off stage, even if abnormal power failure occurs during power-on, erasing can be continued after power-on is performed again, data are prevented from being written in an unerased storage block in the power-off stage, and a Flash memory is prevented from being damaged.

The embodiment of the present application further provides a computer storage medium, which is used for storing a computer program, and when the stored computer program is executed, the computer storage medium is specifically used for implementing the method for controlling the Flash memory provided in any embodiment of the present application.

An electronic device is also provided in the embodiments of the present application, as shown in fig. 4, and includes a memory 401 and a processor 402.

The memory 401 is used for storing a computer program, among other things.

The processor 402 is used for executing a computer program, and is specifically used for implementing the control method of the Flash memory provided in any embodiment of the present application.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

It should be noted that the terms "first", "second", and the like in the present invention are only used for distinguishing different devices, modules or units, and are not used for limiting the order or interdependence relationship of the functions performed by the devices, modules or units.

Those skilled in the art can make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method of a Flash memory is characterized by being applied to a vehicle-mounted electronic control unit, wherein the Flash memory is divided into a plurality of memory blocks, and the control method comprises the following steps:

in the power-off phase of the vehicle:

writing the data to be stored into the storage block to be written;

in a power-up phase of the vehicle:

2. The control method according to claim 1, wherein the determining whether a storage block in which a storable data amount is greater than a data amount threshold exists in the Flash memory comprises:

3. The control method according to claim 1, wherein after the performing the data erasing operation to erase the data currently stored in each of the memory blocks to be erased, the method further comprises:

4. The method according to claim 1, wherein the selecting at least one memory block in an erasable state in the Flash memory comprises:

5. The method according to claim 1, wherein the searching for the memory block to be erased in the plurality of memory blocks comprises:

6. A control device of a Flash memory, which is applied to an on-board electronic control unit, wherein the Flash memory is divided into a plurality of memory blocks, the control device comprising:

a determination unit configured to:

7. The control apparatus according to claim 6, wherein the second determining unit is configured to, when determining whether a storage block whose storable data amount is greater than a data amount threshold exists in the Flash memory, specifically:

8. The control device according to claim 6, characterized by further comprising:

9. The control device according to claim 6, wherein when the selecting unit selects at least one storage block in an erasable state in the Flash memory, the selecting unit is specifically configured to:

10. The control device according to claim 6, wherein the search unit, when searching for the memory block to be erased from the plurality of memory blocks, is specifically configured to: