CN116225467A - OTP (one time programmable) burning method and microcontroller - Google Patents

Abstract

The invention provides an OTP (one time programmable) burning method and a microcontroller. Defining a program storage space and a data storage space, defining a plurality of calibration point spaces in the data storage space, wherein each calibration point space is used for storing an address of calibration data and actual calibration data; selecting a calibration point; invoking an OTP burning program; reading the value of the address 0, and acquiring the address of the current effective calibration data according to the value of the address 0; counting the number of times that the calibration has been performed; if the number of times is smaller than the threshold value of the calibration number of times, adding 1 to the address, writing new calibration data at a new address, storing the new calibration data at the address 0, finishing the burning, and exiting the OTP burning program; if the number of times is equal to the threshold value of the calibration number of times, prompting error reporting. According to the OTP memory system, each calibration point is assigned with an address, so that single calibration data can be conveniently burnt into OTP, the utilization efficiency of the OTP memory space is improved, and the burning time is greatly shortened. And the RAM is released after the burning of the single calibration point is completed, so that the calculated amount is small. The program storage space is saved, and the application of the microcontroller can be expanded.

Description

OTP (one time programmable) burning method and microcontroller

Technical Field

The invention relates to the technical field of semiconductors, in particular to an OTP (one time programmable) burning method and a microcontroller.

Background

OTP (One Time Programmable) is a memory type, meaning that it is one-time programmable and will not be changed and cleared again after the program has been burned into memory space. The multimeter microcontroller is provided with an 8K words OTP program memory, a 6K words program memory space and a 2K words data memory space can be set, and data to be written into EEPROM (Electrically Erasable Programmable read only memory) in the past is automatically written into an OTP memory area of the replaceable EEPROM through an internal low-voltage programming control circuit.

OTP memory is a one-time memory, unlike EEPROM, which is electrically erasable, so writing calibration data at a specific address is limited in number of times. The existing burning method divides the 2K words OTP into 16 groups, but at present, no matter the full-shift calibration or the single-shift calibration is carried out, 1 group of addresses are burnt after the calibration mode is entered, so that the calculated amount is large, the burning time is long, the OTP storage space is not fully utilized, and the waste is caused.

In a multimeter product, measurement function definition and calibration are usually carried out by matching with an EEPROM, when the data of the EEPROM is wrong, error of functions and performance of the multimeter is caused, and an IO (Input/Output) port is needed to control when a multimeter microcontroller is communicated with the EEPROM, and when the key and peripheral functions of the multimeter are more, the IO port is more intense, so that technicians can use a program storage space of the OTP to replace an EEPROM method to save the IO port, save hardware finished products, reduce power consumption, and simultaneously prepare the multimeter in mass production.

The existing method for replacing EEPROM is to divide the program memory of the multimeter microcontroller 8K into 2K words OTP as the data storage space to store the calibration data. If the EEPROM size 24C02 is taken as an example, 256 8 bits are used, so that the 2K words OTP can be divided into 16 groups, that is, the calibration data is burned for 256 bytes before exiting after entering the calibration mode each time, which results in serious burning time and part of address waste. The existing burning calibration flow is shown in fig. 1.

The limitations of the prior art can be seen from the burn calibration flow of fig. 1:

1) Because the partial gear precision of the universal meter is poor, full-gear calibration is not needed when the universal meter needs to enter a calibration mode, the calibration data of other calibration points are not changed when single-gear calibration is performed, and 1 group of addresses are required to be burnt when the universal meter exits from calibration, so that OTP storage space is not fully utilized, and waste is caused.

2) The calculation amount is large, and the requirement on the hardware system RAM (Random Access Memory) is high.

3) The burning time is long.

Disclosure of Invention

In view of the above drawbacks of the prior art, the present invention is directed to an OTP writing method and a microcontroller, which are used for solving the problems of low OTP memory space utilization, large calculation amount, severe requirements on a hardware system RAM, and excessively long OTP writing time in the prior art.

To achieve the above and other related objects, the present invention provides an OTP recording method, which at least includes:

1) Identifying a memory, and further calculating a memory space;

2) Program storage space and data storage space are allocated in the storage space, a plurality of calibration point spaces are allocated in the data storage space, and a current calibration data address space and a current calibration data space are allocated in each of the calibration point spaces;

3) Selecting a calibration point;

4) Starting OTP burning;

5) Reading the numerical value of the address space of the current calibration data, and acquiring the current effective calibration data according to the numerical value, thereby acquiring the position of the current effective calibration data in the calibration data space;

6) Counting the number of times that the calibration has been performed;

7) If the number of times is smaller than the threshold value of the calibration times, adding 1 to the position of the calibration data space, writing new calibration data in a new position, storing the new calibration data in the current calibration data address space, completing OTP burning, generating a secret key, and exiting OTP burning; if the number of times is equal to the threshold value of the calibration number of times, prompting error reporting, and returning to the step 3).

Optionally, the process of identifying the memory includes: judging whether the memory is legal or not by identifying the product serial number of the memory, and confirming that the memory is legal and then identifying the structure of the memory; the process of calculating the memory space is to calculate the memory space for OTP burning based on the structure of the memory.

Optionally, the first address of each calibration point space is set as the current calibration data address space.

Optionally, the calibration data space includes: a default calibration data space and a burnt calibration data space, wherein a second address of the calibration point space is set as the default calibration data space, and new calibration data cannot be written; the burn-in calibration data space is used for writing new calibration data.

Optionally, the step of selecting the calibration point comprises: retrieving the calibration points according to the address sequence of the storage space; then searching a calibration data space without burning, and selecting a calibration point for burning; and locks the calibration points that have completed burning for avoiding the locked calibration points from being retrieved again.

Optionally, the format of the key is set as follows: the software identification code, the memory hardware identification code and the random number are used for preventing the written calibration data from being stolen so as to ensure the safety of the OTP burning process.

The invention provides a microcontroller for realizing the OTP burning method, which at least comprises the following steps: the device comprises a burning module and a latching module, wherein:

the burning module is used for performing OTP burning;

the latching module corresponds to the burning module and is used for locking the burning module.

Optionally, the burning module further includes: the software version number, the hardware version number and the secret key prevent the burning module from being duplicated.

As described above, the OTP writing method and the microcontroller according to the invention have the following advantages:

1. each calibration point is assigned with an address, so that single calibration data can be conveniently burnt into OTP, OTP storage space is fully used, and the burning time is greatly shortened.

2. And the RAM is released after the burning of the single calibration point is completed, so that the calculated amount is small.

3. The program storage space is saved, and the application of the microcontroller can be expanded. For example, multimeters will save space for upgrading other functions.

Drawings

Fig. 1 is a schematic diagram of an exemplary burn calibration procedure according to the present application.

Fig. 2 is a schematic diagram of an OTP recording flow chart according to a first embodiment of the disclosure.

Fig. 3 is a diagram illustrating a micro-controller according to a second embodiment of the present application.

Description of element reference numerals

310. Burning module

320. Latch module

S1 to S7 steps

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.

Please refer to fig. 2 and 3. It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

Example 1

As shown in fig. 2, the present embodiment provides an OTP recording method, which at least includes:

s1: as shown in fig. 2, the memory is identified and the memory space is calculated.

Specifically, as an example, the process of identifying the memory includes: judging whether the memory is legal or not by identifying the product serial number of the memory, and confirming that the memory is legal and then identifying the structure of the memory; the process of calculating the memory space is to calculate the memory space for OTP burning based on the structure of the memory. It should be noted that, in addition to subtracting the space already recorded, the space that cannot be recorded is subtracted from the storage space used for OTP recording.

S2: as shown in fig. 2, the program memory space and the data memory space are allocated in the memory space, a plurality of calibration point spaces are allocated in the data memory space, and the current calibration data address space and the current calibration data space are allocated in each of the calibration point spaces.

Specifically, as an example, the first address of each of the calibration point spaces is set as the current calibration data address space. It should be noted that the current calibration data address space setting location includes, but is not limited to, the first address of the calibration point space, and should be set according to a specific usage scenario, which is not limited to this embodiment.

Specifically, as an example, the calibration data space includes: a default calibration data space and a burnt calibration data space, wherein a second address of the calibration point space is set as the default calibration data space, and new calibration data cannot be written; the burn-in calibration data space is used for writing new calibration data. It should be noted that, the default calibration data space and the setting of the recording calibration data space should consider an actual usage scenario, which is not limited to the embodiment.

Further, as an example, the program storage space is 7 kbytes and the data storage space is 1 kbyte as in the method flow shown in fig. 2. More specifically, as an example, as shown in the method flow of fig. 2, the calibration point space is 16 bytes, where the address 0 is used to store the address where the current valid calibration data is located; addresses 1 to 15 are used to hold the actual calibration data. Still further, as in the method flow shown in FIG. 2, the number of calibration points is equal to 64.

It should be noted that the program storage space and the data storage space should be set according to an actual usage scenario, and the present embodiment is not limited thereto. In the present embodiment, the number of calibration points=data storage space/standard point space, which is the number of calibration points equal to 64 calculation logic in the present embodiment. The space of the calibration points includes, but is not limited to, 16 bytes, and the specific configuration should consider the number of bits of the microcontroller, the size of the memory space of the microcontroller, and the specific system architecture of the product in which the microcontroller is located, which is not limited to the present embodiment.

S3: as shown in fig. 2, a calibration point is selected.

Specifically, as an example, the step of selecting the calibration point includes: retrieving the calibration points according to the address sequence of the storage space; then searching a calibration data space without burning, and selecting a calibration point for burning; and locks the calibration points that have completed burning for avoiding the locked calibration points from being retrieved again. It should be noted that, the calibration points which have been burned are locked, and the locked calibration points are not searched in the next selection of calibration points, so that the search time is saved, and the capacity of the program space is saved.

S4: as shown in fig. 2, OTP burning is started.

S5: as shown in fig. 2, the value of the address space of the current calibration data is read, and the current valid calibration data is obtained according to the value, so as to obtain the position of the current valid calibration data in the calibration data space.

Specifically, as an example, according to the example in step S2, the value of the address 0 in the calibration point can obtain the address of the currently valid calibration data, and the address 1 to the address 15 are used to save the actual calibration data. As an example, the address 1 stores default calibration data, and new calibration data cannot be written. It should be further noted that, as an example, the data at the address 1 is a default value before calibration, and functions as an initial value. More specifically, as an example, the address 2 to the address 15 are used to write new calibration data at the time of calibration. It should be noted that, the definition of the address function should be set according to the practical scenario, and is not limited to the present embodiment. Further, as an example, when calibrating, address 3 writes new calibration data, while new calibration data is written to address 0, when the value of address 0 is read, calibration data is obtained, thereby knowing that the current address 3 has already been written with calibration data.

S6: as shown in fig. 2, the number of times that calibration has been performed is counted.

S7: as shown in fig. 2, if the number of times is smaller than the calibration number threshold, adding 1 to the position of the calibration data space, writing new calibration data in the new position, storing new calibration data in the current calibration data address space, completing OTP writing, generating a key, and exiting OTP writing; if the number of times is equal to the threshold value of the calibration number of times, prompting error reporting, and returning to the step S3.

Specifically, as an example, according to the example in step S2, the calibration number threshold is equal to 14. It should be specifically noted that, in this embodiment, except that the address 1 cannot write new calibration data, the address 2 to the address 15 can write calibration data, which is why the number of calibrations is equal to 14. It should be noted that if the address 1 is written with new calibration data, the calibration data is saved to the address 0 at the same time. When the next writing of calibration data is performed, the value of the address 0 is read, and it is determined that the address 1 has been written with calibration data, so that the calibration data cannot be written at the address 1, and only the calibration data can be written from the address 2, that is, the number of times that calibration has been performed is 1, and the number of times that calibration has been performed is 13. If the burning is completed, a secret key is generated. More specifically, as an example, the format of the set key is: the software identification code, the memory hardware identification code and the random number are used for preventing the written calibration data from being stolen so as to ensure the safety of the OTP burning process to exit the OTP burning program. If the number of calibrations is equal to the threshold number of calibrations, the calibration point cannot be burned any more, and an available calibration point needs to be selected.

More specifically, as an example, to implement the OTP burning method according to the present embodiment, table 1 shows meaning and initial value information of the calibration point address, and table 2 shows information of the calibration point address 0, as follows:

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TABLE 1

Value of address 0	Address where valid calibration data is located
		FFFEH	Address 1
FFFCH	Address 2
		FFF8H	Address 3
FFF0H	Address 4
		FFE0H	Address 5
FFC0H	Address 6
		FF80H	Address 7
FF00H	Address 8
		FE00H	Address 9
FC00H	Address 10
		F800H	Address 11
F000H	Address 12
		E000H	Address 13
C000H	Address 14
		8000H	Address 15

TABLE 2

It should be noted that, a program storage space of 7K and a data storage space of 1K are set, and each calibration point is respectively allocated with 16 words of addresses, as shown in table 1, and is divided into two parts, namely, a first part is 1 word (address 0) for storing information of an address where the current valid calibration data is located, and a second part is 15words (address 1 to address 15) for storing the actual calibration data. The data at address 1 is used before calibration, the initial value is 8000H, and the initial values from address 2 to address 15 are all FFFFH, so that the data can be reliably stored during calibration. The number of permitted calibration times of each calibration point is 14, when the OTP recording subroutine is called, the address of the current valid calibration data is determined by the address 0 information, as shown in table 2, when the data at the address 0 is FFC0H, the data at the address 6 is the current valid calibration data, and the number of calibration times is 9. Further, new calibration data needs to be written next time on address 7. By the above-mentioned pushing, when the statistics times are 14 times, the calibration address is used up, and the error reporting reminding is displayed. Thus, the burning methods of tables 1 and 2 show that this example corresponds to the OTP burning method flow in the first embodiment shown in fig. 2.

Example two

As shown in fig. 3, this embodiment provides a microcontroller for implementing the OTP writing method according to the first embodiment, where the microcontroller includes: a burning module 310, a latch module 320, wherein:

as shown in fig. 3, the burning module 310 is configured to perform OTP burning.

Specifically, as an example, as shown in fig. 3, the burning module further includes: the software version number, the hardware version number and the secret key prevent the burning module from being duplicated. Wherein the software version number corresponds to the OTP burning program in the first embodiment; the hardware version number corresponds to the microcontroller; the key is used for encryption operation of the burning program.

As shown in fig. 3, the latch module 320, corresponding to the recording module 310, is used for locking the recording module, as an example. It should be noted that, if the writing module 310 completes the OTP writing operation, a serial number corresponding to the software version number, the hardware version number and the key is generated in the latch module 320, where the serial number is used to ensure that each microcontroller is unique, lock the writing module 310 that has completed the OTP writing operation, prevent the writing module 310 from being repeatedly written, and ensure safer application of the writing module 310. It should be noted that any scheme capable of ensuring the safe application of the burning module 310 is suitable, and is not limited to this embodiment.

It should be noted that, as an example, as shown in fig. 3, according to the OTP writing method mentioned in the first embodiment, the microcontroller sets a program storage space of 7K and a data storage space of 1K, allocates an address to each calibration point in combination with a function definition, finds a storage address of the calibration point through the function definition when writing OTP, determines an address of the calibration point that is currently valid calibration data according to the address 0 information, adds 1 when the number of accumulated calibrations is less than 14, and uses a circuit inside the microcontroller to write new calibration data. Therefore, the burning flow is simplified and the burning times are increased on the basis of not affecting the program space as much as possible, so that the purposes of not using an external EEPROM, saving space, upgrading and expanding the functions of the microcontroller, reducing the realization difficulty of a hardware finished product of the microcontroller and simplifying the mass production procedure of the product are achieved. It should be noted that the microcontroller includes, but is not limited to, a multimeter microcontroller and an electronic scale microcontroller, and is not limited to the present embodiment.

In summary, the present invention defines a program storage space and a data storage space, and defines a plurality of calibration point spaces in the data storage space, each calibration point space being used for storing an address of calibration data and actual calibration data; selecting a calibration point; invoking an OTP burning program; reading the value of the address 0, and acquiring the address of the current effective calibration data according to the value of the address 0; counting the number of times that the calibration has been performed; if the number of times is smaller than the threshold value of the calibration number of times, adding 1 to the address, writing new calibration data at a new address, storing the new calibration data at the address 0, finishing the burning, and exiting the OTP burning program; if the number of times is equal to the threshold value of the calibration number of times, prompting error reporting. According to the OTP memory system, each calibration point is assigned with an address, so that single calibration data can be conveniently burnt into OTP, the utilization efficiency of the OTP memory space is improved, and the burning time is greatly shortened. And the RAM is released after the burning of the single calibration point is completed, so that the calculated amount is small. The program storage space is saved, and the application of the microcontroller can be expanded. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (8)

1. An OTP burning method, wherein the OTP burning method at least comprises:

1) Identifying a memory, and further calculating a memory space;

2) Program storage space and data storage space are allocated in the storage space, a plurality of calibration point spaces are allocated in the data storage space, and a current calibration data address space and a current calibration data space are allocated in each of the calibration point spaces;

3) Selecting a calibration point;

4) Starting OTP burning;

5) Reading the numerical value of the address space of the current calibration data, and acquiring the current effective calibration data according to the numerical value, thereby acquiring the position of the current effective calibration data in the calibration data space;

6) Counting the number of times that the calibration has been performed;

7) If the number of times is smaller than the threshold value of the calibration times, adding 1 to the position of the calibration data space, writing new calibration data in a new position, storing the new calibration data in the current calibration data address space, completing OTP burning, generating a secret key, and exiting OTP burning; if the number of times is equal to the threshold value of the calibration number of times, prompting error reporting, and returning to the step 3).

2. The OTP burning method according to claim 1, wherein: the process of identifying memory includes: judging whether the memory is legal or not by identifying the product serial number of the memory, and confirming that the memory is legal and then identifying the structure of the memory; the process of calculating the memory space is to calculate the memory space for OTP burning based on the structure of the memory.

3. The OTP burning method according to claim 1, wherein: setting a first address of each calibration point space as the current calibration data address space.

4. The OTP burning method according to claim 1, wherein: the calibration data space includes: a default calibration data space and a burnt calibration data space, wherein a second address of the calibration point space is set as the default calibration data space, and new calibration data cannot be written; the burn-in calibration data space is used for writing new calibration data.

5. The OTP burning method according to claim 1, wherein: the step of selecting the calibration point comprises: retrieving the calibration points according to the address sequence of the storage space; then searching a calibration data space without burning, and selecting a calibration point for burning; and locks the calibration points that have completed burning for avoiding the locked calibration points from being retrieved again.

6. The OTP burning method according to claim 1, wherein: the format of the set key is: the software identification code, the memory hardware identification code and the random number are used for preventing the written calibration data from being stolen so as to ensure the safety of the OTP burning process.

7. A microcontroller for implementing an OTP burning method according to any one of claims 1-6, characterized by: the microcontroller comprises at least: the device comprises a burning module and a latching module, wherein:

the burning module is used for performing OTP burning;

the latching module corresponds to the burning module and is used for locking the burning module.

8. A microcontroller as defined in claim 7, wherein: the burning module further comprises: the software version number, the hardware version number and the secret key prevent the burning module from being duplicated.

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