A digital chip trimming method based on improved Trim algorithm

Abstract

The invention discloses a digital chip trimming method based on an improved Trim algorithm, comprising the steps of: generating a trim code for a bit position that needs trimming, generating a trim virtual pattern; constructing a function in a program code; when trimming for the first time, first writing a code value corresponding to a center point threshold in the trim virtual pattern, executing the trim virtual pattern to write the code value into a corresponding register, measuring an output parameter value and comparing it with the center point threshold, judging whether the written value is correct by reading back the trim code; combining trim_code with other bit values, writing the trim virtual pattern, executing the pattern to write the trim value into a corresponding register, burning the value in the register into chip firmware, and ending trimming.

Description

Technical Field

[0001] The invention relates to the technical field of chip trimming, and in particular to a digital chip trimming method based on an improved Trim algorithm. Background Art

[0002] With the rapid development of the new energy vehicle industry, high-precision, high-quality, and low-cost digital chips are essential. In order to make digital chips meet the key parameter requirements of high precision and good consistency, it is necessary to use trim technology to adjust the internal circuit to improve its accuracy, while also improving the product yield and reducing product costs.

[0003] Trimming is the act of adjusting certain parameters of a chip by writing data to the chip from outside after the chip is manufactured, or changing the connection mode and working state of certain devices inside the chip through a specific method, so as to achieve the purpose of changing the performance or function of the chip. In the manufacture of chips, the advanced level of the process has a great influence on the parameters of the chip, especially the reference voltage item of the chip. In the process, the process has more or less some deviations. This deviation is reflected in a certain parameter of the chip, that is, the numerical distribution range of this parameter is very wide or the deviation is very serious. At this time, it is necessary to use Trimming to adjust this parameter.

[0004] like Figure 2 As shown, the commonly used Trim scheme uses the method of continuously loading the pattern corresponding to the trim code to read and write the register value, and repeatedly measures the parameter output value to determine whether the current trim code adjusts the parameter to the center threshold. This scheme has the problems of low efficiency, large development workload, redundant and cumbersome program code, high error rate, poor code portability, low economy, long testing time, high cost, etc., which not only makes it difficult to guarantee the test quality, but also greatly increases the mass production cost. Summary of the invention

[0005] In view of the above technical problems to be solved, the present invention provides a digital chip trimming method based on an improved Trim algorithm, which can ensure the accuracy and quality of key parameters and reduce the cost of mass production testing.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0007] A digital chip trimming method based on an improved Trim algorithm comprises the following steps:

[0008] Step S1, generating a trim code for the bit that needs to be trimmed according to the internal circuit structure of the digital chip, and generating a trim virtual pattern;

[0009] Step S2, constructing a function Bit_do_func() in the program code to implement the bit read and write operation corresponding to the trim code;

[0010] Step S3, when trimming for the first time, first write the code value corresponding to the center point threshold in the trim virtual pattern, execute the trim virtual pattern to write the code value into the corresponding register, then measure the output parameter value and compare it with the center point threshold, and confirm and judge whether the written value is correct by reading back the trim code;

[0011] Step S4, combine trim_code with other bit values, write trim virtual pattern, execute pattern to write trim value into corresponding register, burn the value in register into chip firmware, and trim is finished.

[0012] As a further improvement of the above technical solution:

[0013] Preferably, in step S1, a Label is added before the highest bit that needs to be trimmed in the trim virtual pattern for use in the read and write bit operations.

[0014] Preferably, in step S3, the output parameter value is compared with the center point threshold, and the output result is divided into two and then traversed one by one from small to large in a single direction using the successive approximation method. After each traversal, the code code is increased or decreased by a value. When it is determined that the parameter output value is pulled back to the center threshold, the current code code is written into the trim virtual pattern and the traversal is terminated.

[0015] Preferably, the step S3 specifically includes the following steps:

[0016] S3-1, when trim starts, trim_code=0, write the code value into the trim virtual pattern and write it into the corresponding register;

[0017] S3-2, measure the Pin output parameter value value_init;

[0018] S3-3, compare the output parameter value value_init with the center point threshold to see whether value_init is within (Lmin, Lmax);

[0019] S3-4, confirm and judge whether the written value is correct by reading back trim_code, if it is correct, proceed to step S4, if it is not correct, proceed to S3-5;

[0020] S3-5, when value_init is not within (Lmin, Lmax), determine whether trim_code is equal to (N / 2-1) or (N / 2). If trim_code is equal to (N / 2-1) or (N / 2), trim ends. If trim_code is not equal to (N / 2-1) and not equal to (N / 2), proceed to S3-6.

[0021] S3-6, determine whether value_init is greater than Lmax, write the code value into the trimvirtual pattern through the bit processing function, execute the pattern to write the code value into the corresponding register, and execute S3-2 in a loop.

[0022] Preferably, in S3-6, if value_init is greater than Lmax, then S3-7 is performed; if value_init is not greater than Lmax, then S3-8 is performed;

[0023] S3-7, trim_code starts from 0 and increases by 1, and the code value is written into trim virtualpattern through the bit processing function.

[0024] Execute the pattern to write the code value into the corresponding register and execute S3-2 in a loop;

[0025] S3-8, trim_code decreases by 1 from N, writes the code value into the trim virtualpattern through the bit processing function, executes the pattern to write the code value into the corresponding register, and executes S3-2 in a loop.

[0026] The digital chip trimming method based on the improved Trim algorithm provided by the present invention has the following advantages compared with the prior art:

[0027] The digital chip trimming method based on the improved Trim algorithm of the present invention simplifies the algorithm process and stabilizes the key parameters of the digital chip near the center point through the internal circuit trimming technology to meet the set accuracy requirements, which not only improves the trim accuracy and quality of the product, but also reduces the code development and maintenance difficulty by 60%, improves the code portability and high reusability, greatly reduces the test time and cuts the test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of trim in the present invention.

[0029] Figure 2 This is a flow chart of trim in the prior art.

[0030] Figure 3 The trim module and related circuit diagram of the present invention. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0032] like Figure 1 As shown, the digital chip trimming method based on the improved Trim algorithm of the present invention mainly improves the trimming accuracy of the chip by improving the Trim algorithm. The improved Trim algorithm includes the following steps:

[0033] Step S1, according to the internal circuit structure of the digital chip, generate the corresponding trim code for the bit that needs to be trimmed, generate a trim virtual pattern according to the communication protocol supported by the chip, and add a label in front of the highest bit that needs to be trimmed in the trim virtual pattern for the read and write bit operations.

[0034] Step S2, constructing a function Bit_do_func() in the program code to implement the bit read and write operations corresponding to the trim code, and calling the function in the trim code.

[0035] Step S3, when trimming for the first time, first write the code value corresponding to the center point threshold in the trim virtual pattern, execute the trim virtual pattern to write the code value into the corresponding register, then measure the output parameter value and compare it with the center point threshold, divide the output result into two and traverse it one by one from small to large in a single direction using the successive approximation method, increase the code value by one value (or decrease it by one value) after each traversal, and when it is determined that the parameter output value is pulled back to the center threshold, write the current code value into the trim virtual pattern and end the traversal.

[0036] Specifically:

[0037] S3-1, when trim starts, trim_code=0, the code value is written into the trim virtual pattern and into the corresponding register.

[0038] S3-2, measure the Pin output parameter value value_init.

[0039] S3-3, compare the output parameter value value_init with the center point threshold to see whether value_init is within (Lmin, Lmax).

[0040] S3-4, confirm and determine whether the written value is correct by reading back trim_code, if it is correct, proceed to step S4, if not, proceed to S3-5.

[0041] S3-5, when value_init is not within (Lmin, Lmax), determine whether trim_code is equal to (N / 2-1) or equal to (N / 2). If trim_code is equal to (N / 2-1) or equal to (N / 2), trim ends. If trim_code is not equal to (N / 2-1) and not equal to (N / 2), proceed to S3-6.

[0042] S3-6, determine whether value_init is greater than Lmax. If value_init is greater than Lmax, proceed to S3-7; if value_init is not greater than Lmax, proceed to S3-8.

[0043] S3-7, trim_code starts to increase by 1 from 0, writes the code value into the trim virtualpattern through the bit processing function, executes the pattern to write the code value into the corresponding register, and executes S3-2 in a loop.

[0044] S3-8, trim_code decreases by 1 from N, writes the code value into the trim virtualpattern through the bit processing function, executes the pattern to write the code value into the corresponding register, and executes S3-2 in a loop.

[0045] Step S4, combine trim_code with other bit values, write trim virtual pattern, execute the pattern to write the trim value into the corresponding register, then apply the required resources to the corresponding burning circuit pin, burn the value in the register into the chip firmware, and trim is completed.

[0046] Furthermore, the digital chip trimming method based on the improved Trim algorithm of this embodiment is as follows: Figure 3As shown, during the trim process, ATE accesses data to the digital IC through the I2C protocol. I2C_CTRL<7:0> is the control bit of the I2C protocol used to establish communication between the master device (ATE) and the controlled device (IC). The bus must be controlled by ATE and generate a serial clock (SCL) to control bus access, and generate start and stop conditions. I2C_ADDR<31:0> is the register address bit of the chip in this embodiment. ATE accesses its corresponding address through the I2C protocol and performs data read and write operations.

[0047] Furthermore, in this embodiment, the control module controls the peripheral circuits required by the IC in trimming, enables the corresponding pins or bits through I2C_EN and SEL_OSC_FREQ, inputs a valid signal to the chip PD_OSC and outputs a waveform through the CK_OUT pin after being processed by the internal circuit, measures the output pin parameter value value_init, and then performs trimming according to step S3. After finding the correct trim_code, the trim_code is written into the trim virtualpattern according to step S4, and the pattern is executed to write the trim value into the I2C_REG<31:0> register.

[0048] Before burning the firmware, you need to apply burning conditions or incentives to the chip, such as Figure 3 As shown in the figure, CLK_EN is enabled and a 1MHz square wave signal is applied to the CLK_IN pin, which maps the data in the I2C_REG<31:0> register address to the TRIM<31:16> and TRIM<15:0> addresses, and finally burns them into the chip firmware to complete the entire trimming process.

[0049] Compared with conventional digital chip trim, the digital chip trimming method based on the improved Trim algorithm of the present invention simplifies the algorithm process and stabilizes the key parameters of the digital chip near the center point through the internal circuit trimming technology to meet the set accuracy requirements. It not only improves the trim accuracy and quality of the product, but also reduces the code development and maintenance difficulty by 60%, improves the code portability and high reusability, greatly reduces the test time and cuts the test cost.

[0050] The above implementation cases are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, they are not intended to limit the present invention. Therefore, any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A digital chip trimming method based on an improved Trim algorithm, characterized in that: The following steps are involved: Step S1, generating a trim code for the bit that needs to be trimmed according to the internal circuit structure of the digital chip, and generating a trimvirtual pattern; Step S2, constructing a function Bit_do_func() in the program code to implement the bit read and write operation corresponding to the trim code; Step S3, when trimming for the first time, first write the code value corresponding to the center point threshold in the trim virtual pattern, execute the trim virtual pattern to write the code value into the corresponding register, then measure the output parameter value and compare it with the center point threshold, and confirm and judge whether the written value is correct by reading back the trim code; Step S4, combine trim_code with other bit values, write trim virtual pattern, execute pattern to write trim value into corresponding register, burn the value in register into chip firmware, and trim ends; The chip inputs a valid signal and outputs a waveform after being processed by an internal circuit, measures the output parameter value value_init, and then performs trimming according to step S3. After finding the correct trim_code, the trim_code is written into the trim virtual pattern according to step S4, and the pattern is executed to write the trim value into the register; In step S3, the output parameter value is compared with the center point threshold, and the output result is divided into two, and then it is traversed one by one in a single direction from small to large using the successive approximation method. After each traversal, the code is increased or decreased by a value. When it is determined that the parameter output value is pulled back to the center threshold, the current code is written into the trim virtual pattern and the traversal is terminated; The step S3 specifically includes the following steps: S3-1, when trim starts, trim_code=0, write the code value into the trim virtual pattern and write it into the corresponding register; S3-2, measure the Pin output parameter value value_init; S3-3, compare the output parameter value value_init with the center point threshold to see if value_init is within (Lmin, Lmax) Inside; S3-4, confirm and judge whether the written value is correct by reading back trim_code, if it is correct, proceed to step S4, if it is not correct, proceed to S3-5; S3-5, when value_init is not within (Lmin, Lmax), determine whether trim_code is equal to (N / 2-1) or (N / 2). If trim_code is equal to (N / 2-1) or (N / 2), trim ends. If trim_code is not equal to (N / 2-1) and not equal to (N / 2), proceed to S3-6. S3-6, determine whether value_init is greater than Lmax, write the code value into trim virtualpattern through the bit processing function, execute the pattern to write the code value into the corresponding register, and execute S3-2 in a loop.

2. The digital chip trimming method based on the improved Trim algorithm according to claim 1, characterized in that: In the step S1, a Label is added before the highest bit that needs to be trimmed in the trim virtual pattern for the read and write bit operations.

3. The digital chip trimming method based on the improved Trim algorithm according to claim 1, characterized in that: In S3-6, if value_init is greater than Lmax, then proceed to S3-7; if value_init is not greater than Lmax, then proceed to S3-8; S3-7, trim_code starts to increase by 1 from 0, writes the code value into the trim virtual pattern through the bit processing function, executes the pattern to write the code value into the corresponding register, and executes S3-2 in a loop; S3-8, trim_code starts from N and decreases by 1. The code value is written into the trim virtual pattern through the bit processing function. The pattern is executed to write the code value into the corresponding register, and S3-2 is executed in a loop.

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