ATE equipment client AC calibration method and system

Abstract

The invention relates to the field of integrated circuit automatic test equipment, in particular to an AC calibration method and system of an ATE equipment client, and solves the problems that in the prior art, an external TDC calibration board is needed, parallel calibration cannot be achieved, and the calibration time is long in the semiconductor automatic test equipment. The AC calibration method of the ATE equipment client comprises two parts of intra-group calibration and inter-group calibration, channels are grouped through loopback board cards, intra-group AC signal sending alignment calibration and intra-group AC signal receiving alignment calibration are carried out, inter-group calibration is carried out by changing a channel connection relation, finally, multi-board card parallel calibration is achieved, and the overall calibration time is shortened.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor automated test equipment, and in particular to a method and system for client AC calibration in ATE equipment. Background Art

[0002] In the field of semiconductor automated testing, AC calibration of ATE equipment (Auto Test Equipment) is extremely important, and its calibration accuracy directly affects the accuracy of semiconductor integrated circuit test results. Currently, AC calibration of ATE equipment is generally divided into two categories: DRV direction (Driver, i.e., drive signal direction) calibration and CMP direction (Comparator, i.e., comparison signal direction) calibration. The calibrations in these two directions are carried out in different external environments, and the calibration data obtained are closely related and interdependent.

[0003] Specifically, during the DRV direction calibration operation, an external TDC calibration board (Time-to-Digital Converter Calibration Board) is required to complete the measurement of the DRV direction signal delay. However, this requirement greatly limits the calibration of the equipment at the customer site. Since the customer site may not have a TDC calibration environment, the calibration work cannot be completed without a TDC calibration board, and the flexibility and operability of the equipment calibration are seriously affected. In addition, a TDC calibration board can only measure the digital board in one slot at the same time. The chip of the TDC calibration board only supports rising edge sampling, so the falling edge of the drive waveform needs to be reversed for measurement. This limitation means that boards in different slots cannot be calibrated at the same time, and can only be measured in sequence, resulting in low overall calibration efficiency.

[0004] When calibrating in the CMP direction, its calibration mechanism requires an external loopback cable to loop back adjacent channels. In this calibration mode, the calibration target needs to be achieved by driving waveforms for odd channels, measuring calibration for even channels, and alternating between driving waveforms for even channels and measuring calibration for odd channels. This calibration method is not only complicated and cumbersome in operation, but also cannot achieve parallel calibration between boards due to the limitations of its calibration logic and connection method. Therefore, it will further extend the time required for the entire AC calibration process, which will have an adverse impact on the efficient operation of ATE equipment.

[0005] In summary, the existing AC calibration technology of ATE equipment faces many difficulties in practical applications. A new calibration method is urgently needed to solve the inconvenience caused by the external TDC calibration board, realize parallel calibration of multiple boards and shorten the calibration time to meet the efficient and accurate development needs of the semiconductor testing industry. Summary of the invention

[0006] The object of the present invention is to provide a method and system for AC calibration of an ATE device client, so as to solve the problems in the prior art that an external TDC calibration board is required, parallel calibration cannot be performed, and the calibration time is long.

[0007] To achieve the above object, in the first aspect of the present invention, a method for AC calibration of an ATE device client is provided, and the method includes:

[0008] Dividing a plurality of channels to be calibrated into a plurality of calibration groups through a loopback board;

[0009] For the channels within the same calibration group, sequentially select the channels within the group as the driving channel and the receiving channel for in-group calibration, and the in-group calibration includes in-group AC signal transmission alignment calibration and in-group AC signal reception alignment calibration;

[0010] Change the channel connection relationship between calibration groups, reuse the steps of the in-group calibration for inter-group calibration, obtain the delay deviation between two adjacent groups before grouping, take one of the groups as a reference, obtain the delay difference between each group of channels and the reference group, and compensate the channel delay of the original grouping.

[0011] Preferably, in the method for AC calibration of the ATE device client, the step of the in-group AC signal transmission alignment calibration includes:

[0012] In the continuous operation state of the test mode, select one channel as the receiving channel, and sequentially use the remaining channels as the driving channels to send signals;

[0013] Capture the rising edge or falling edge moment of each driving channel, calculate the transmission delay difference and perform compensation.

[0014] Preferably, in the method for AC calibration of the ATE device client, the step of the in-group AC signal reception alignment calibration includes: select one channel as the driving channel to send a signal, and the remaining channels as the receiving channels;

[0015] Capture the rising edge or falling edge moment of each receiving channel, calculate the reception delay difference of each receiving channel and perform compensation.

[0016] Preferably, in the method for AC calibration of the ATE device client, before dividing the plurality of channels to be calibrated into several calibration groups, it includes: configuring all channels to be calibrated in the DCL mode, and setting the CMP comparison threshold to one Nth of the voltage value driven by the DRV signal, where N is the number of channels in each group.

[0017] Preferably, in the method for ATE device client AC calibration, one of the channels in each group is fixed to be configured in the CMP mode and terminated to GND through 50 Ohm.

[0018] Preferably, in the method for ATE device client AC calibration, during the in-group calibration process, when selecting a pair of transmit and receive channels for measurement, except for the drive channel and the receive channel, the remaining channels are configured in the high-impedance mode.

[0019] Preferably, in the method for ATE device client AC calibration, the steps of the inter-group calibration include: taking the calibration group with the slowest delay as the reference, calculating the delay deviation amount of the remaining groups relative to the reference group, and dynamically adjusting the delay parameters of each channel through the hardware register to align the final delays of all channels with the reference group.

[0020] Preferably, in the method for ATE device client AC calibration, the method further includes: performing an averaging process on the multi-channel measurement data to reduce the calibration deviation between channels.

[0021] Preferably, in the method for ATE device client AC calibration, the method supports independent sampling of the rising edge and the falling edge, and avoids the measurement error introduced by the slope difference through dynamically selecting the sampling edge type.

[0022] In the second aspect of the present invention, there is also provided an ATE device client AC calibration system, which includes:

[0023] A grouping module, configured to divide a plurality of channels to be calibrated into several calibration groups through a loopback board;

[0024] An in-group calibration module, configured to perform in-group AC signal transmit alignment calibration and in-group AC signal receive alignment calibration;

[0025] An inter-group calibration module, configured to perform inter-group calibration by changing the connection relationship between calibration groups;

[0026] A configuration module, configured to configure the modes and parameters of all channels;

[0027] A measurement module, configured to obtain the signal delay and the receive time deviation;

[0028] A compensation module, configured to perform dynamic delay compensation on the DRV and CMP directions of the channels.

[0029] Compared with the prior art, the present invention has at least the following technical effects:

[0030] The present invention divides the channels to be calibrated into several calibration groups through a loopback board card, performs intra-group calibration and inter-group calibration, does not require a TDC calibration board, and supports on-site calibration by customers; parallel calibration can be performed between multiple board cards, greatly saving the overall AC calibration time; it supports independent sampling of rising edges and falling edges, can dynamically select the sampling edge type, avoids measurement errors introduced by the slope differences of the edges, and at the same time averages the measurement data of multiple channels, thereby reducing the calibration deviation between channels and significantly improving the calibration accuracy. Description of the Drawings

[0031] Figure 1 It is a flowchart of the method for AC calibration of the ATE device client in an embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram of the AC calibration loopback relationship in an embodiment of the present invention. Detailed Embodiments

[0033] The following will describe in more detail a method and system for AC calibration of an ATE device client of the present invention with reference to the schematic diagrams, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the present invention.

[0034] For clarity, not all features of the actual embodiments are described. In the following description, well-known functions and structures are not described in detail because they would obscure the present invention with unnecessary details. It should be considered that in the development of any actual embodiment, a large number of implementation details must be made to achieve the specific goals of the developer, such as changing from one embodiment to another according to the relevant system or business limitations. In addition, it should be considered that such development work may be complex and time-consuming, but it is only routine work for those skilled in the art.

[0035] In the following paragraphs, the present invention will be described more specifically by way of example with reference to the drawings. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are all in a very simplified form and use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the embodiments of the present invention.

[0036] There are many defects in the AC calibration of ATE devices in the prior art. For example, the DRV direction calibration depends on an external TDC calibration board, and calibration cannot be performed if this device is not available at the customer site. Moreover, at the same time, one TDC calibration board can only measure the digital board cards of one slot, and parallel calibration cannot be performed between board cards, resulting in low calibration efficiency; the CMP direction calibration requires an external loopback cable and is calibrated through a specific odd-even channel interaction method, which is cumbersome and time-consuming.

[0037] In view of this, as Figure 1 shown, in view of these limitations of the prior art, this embodiment proposes a method for AC calibration of the ATE device client, to solve the problems that the device lacks a TDC calibration environment at the customer site and the calibration between boards is time-consuming due to the inability to perform parallel calibration. The method includes the following steps:

[0038] S1: Divide multiple channels to be calibrated into multiple calibration groups through a loopback board.

[0039] S2: For the channels within the same calibration group, sequentially select the channels within the group as the drive channel and the receive channel for in-group calibration. The in-group calibration includes in-group AC signal transmission alignment calibration and in-group AC signal reception alignment calibration;

[0040] S3: Change the channel connection relationship between calibration groups, and reuse the steps of the in-group calibration for inter-group calibration to obtain the delay deviation between two adjacent groups before grouping. Taking one of the groups as the reference, obtain the delay difference between each group of channels and the reference group, and compensate the channel delay of the original grouping.

[0041] It should be noted that in the prior art, the DRV direction calibration depends on an external TDC calibration board, and calibration cannot be performed if the corresponding environment is lacking at the customer site. However, through the innovative calibration method of this embodiment, the loopback board is used to divide the calibration groups for calibration, without relying on the TDC calibration board to measure signals, realizing independent AC calibration at the customer site, greatly improving the flexibility and adaptability of calibration, and effectively solving the problem of limited calibration environment.

[0042] Specifically, as Figure 2 shown, taking a certain ATE device as the research object, the client of this device has 27 channels. For the convenience of calibration operation, all 27 channels are divided into 3 calibration groups, and the specific implementation steps are described in detail as follows.

[0043] I. Preparation before calibration

[0044] Execute step S1: Divide 27 channels into 3 calibration groups, and denote the 3 calibration groups as Group1, Group2, and Group3 respectively. The 9 channels in each group are 0 - 8.

[0045] It should be noted that when executing step S1, the channel mode needs to be configured, that is, all channels to be calibrated are configured in the DCL (driver comparator load) mode, and the CMP comparison threshold is set to one Nth of the voltage value driven by the DRV signal, where N is the number of channels in each group.

[0046] Specifically, all 27 channels to be calibrated are configured in the DCL mode. Taking Group1 as an example, each group has 9 channels, so N = 9. According to the setting of 9 channels in each group, the CMP comparison threshold is set to one-ninth of the voltage value driven by the DRV signal. The purpose of setting the CMP comparison threshold is to enable CMP to accurately compare and detect the delay of the DRV signal during the subsequent calibration measurement. Specifically, 8 channels are set in the DCL mode.

[0047] Further, after the grouping in step S1 is completed, the fixed reference channels are set, that is, one channel in each group is fixedly configured in the CMP mode and terminated to GND through 50 Ohm.

[0048] Specifically, in each of the 9 channels (0 - 8) of Group1, Group2, and Group3, one channel is fixedly configured in the CMP mode and terminated to GND through a 50 Ohm resistor. For example, channel 0 is selected in Group1, channel 1 is selected in Group2, and channel 8 is selected in Group3 as the fixed reference channels within their respective groups. These fixed reference channels are used to provide a stable reference benchmark for the signal measurement of other channels during the subsequent calibration measurement, which helps to accurately calculate the delay difference between channels. The purpose of terminating the 50 Ohm to GND is to provide a stable reference level and reduce signal reflection and interference.

[0049] It should be noted that in the traditional calibration technology, the TDC calibration board can only measure the digital board cards of one slot at a time, and parallel calibration between board cards is not possible. The CMP direction calibration method is cumbersome, resulting in a long overall calibration time. This embodiment supports parallel calibration of multiple board cards. During the calibration process, multiple calibration groups can perform in-group calibration simultaneously, thereby greatly shortening the time required for the overall AC calibration, improving the usage efficiency of the device, and meeting the requirements of high-efficiency calibration for large-scale production testing.

[0050] II. In-group calibration

[0051] It should be noted that when performing in-group calibration on the channels within the same group in step S2, whenever a pair of transmit-receive channels is selected for measurement, except for the currently activated drive channel and receive channel, the remaining channels are configured in the high-impedance state mode. Among them, the receive channel uses the DFM (Data Fail Memory) technology to obtain the T moment of the rising edge or falling edge of the drive channel. The in-group calibration includes in-group AC signal transmission alignment calibration and in-group AC signal reception alignment calibration, and the in-group calibration is performed by sequentially selecting the channels within the group as the drive channel and the receive channel and measuring the transmission delay difference and reception delay difference of each channel.

[0052] (I) In-group calibration of Group1

[0053] 1. Intra-group AC signal transmission alignment calibration:

[0054] Select channel 0 as the receiving channel, and the remaining 8 channels (1 - 8) are used as driving channels to send signals in sequence. Ensure the stability of the measurement environment while the test mode is running continuously (PATTERN does not stop).

[0055] Specifically, for example, when performing intra-group calibration for Group1, select channel 1 as the driving channel and channel 0 as the receiving channel. Turn on the drive of channel 1 to make it send signals. Channel 0 remains in the CMP mode, and the remaining channels (channels 2 - 8) are configured in the high-impedance state mode to avoid interference caused by signal reflection between channels and ensure the accuracy of measurement. Channel 0 uses DFM technology to obtain the rising or falling edge time of the signal sent by channel 1, denoted as Tx1_0. For example, if the rising edge of the signal sent by channel 1 is detected by channel 0 at 10 nanoseconds, then Tx1_0 = 10 nanoseconds.

[0056] Continue to perform cyclic traversal within Group1. Next, channel 2 is used as the driving channel and channel 0 as the receiving channel to obtain the rising edge time of the signal of channel 2, denoted as tx2_0. Then, channel 3 is used as the driving channel and channel 0 as the receiving channel to obtain the rising edge time of the signal of channel 3, denoted as tx3_0. Thus, the delay data of all channels within Group1 relative to channel 0 is obtained. Among them, tx1_0 represents the delay of channel 1 relative to channel 0; tx2_0 represents the delay of channel 2 relative to channel 0... tx8_0 represents the delay of channel 8 relative to channel 0. Cyclically traverse all channels within the group to send or receive signals in sequence to obtain N*N delay data. In this embodiment, these data form a 9×9 delay data matrix (N = 9). The specific data presentation form is as shown in Table 1 below, where tx represents the driving channel that sends the signal and rx represents the receiving channel that receives the signal. In addition, in Table 1 below, the data that is both the sending channel and the receiving channel itself is recorded as 0.

[0057] Table 1

[0058]

[0059] Calculate the transmission delay difference between each drive channel and the receiving channel based on the above measurement data. For example, the time difference between Tx2_0 and Tx1_0 is the transmission delay difference of channel 2 relative to channel 1. It should be noted that to improve the measurement accuracy, during the measurement process, the channel data that is itself a transmitter needs to be removed. Through the N - 1 groups of data in each remaining group, N - 1 delay differences in the transmission or reception direction of the channels can be obtained. Multiple groups of sampled data are averaged to determine the delay differences between the channels within the group. Assume that 5 groups of samples are taken, and the transmission delay differences between channel 2 and channel 1 in each group are averaged to obtain a more accurate transmission delay difference between the channels within the group. Finally, based on these differences, the DRV direction of the channels within Group1 is compensated to achieve better time alignment when the channels send signals.

[0060] 2. Intra-group AC signal reception alignment calibration:

[0061] Before the intra-group AC signal reception alignment calibration operation, the intra-group AC signal transmission alignment calibration needs to be completed first. The specific calibration operations are as follows:

[0062] First, perform channel configuration. Select channel 0 as the drive channel to send signals, and the remaining 8 channels (channels 1 - 8) as receiving channels.

[0063] Next, each receiving channel uses DFM to obtain the rising edge or falling edge moment of the signal of drive channel 0. For easy recording and analysis, mark the moment when the receiving channel obtains the rising edge of the signal of drive channel 0. For example, the moment when receiving channel 1 obtains the rising edge of the signal of drive channel 0 is recorded as Rx1_0, the moment when receiving channel 2 obtains the rising edge of the signal of drive channel 0 is recorded as Rx2_0, and so on. Rx3_0, Rx4_0, Rx5_0, Rx6_0, Rx7_0, Rx8_0 can be obtained. In this embodiment, Rx1_0 represents the reception delay difference of receiving channel 1 relative to sending channel 0, Rx2_0 represents the reception delay difference of receiving channel 2 relative to sending channel 0, and so on for the others.

[0064] In this embodiment, based on the signal of drive channel 0, each receiving channel is successively processed for signal reception with drive channel 0 to obtain the rising edge or falling edge moment of the signal of each receiving channel. Then, taking the rising edge or falling edge moment of the selected drive channel 0 as the standard, each receiving channel is compensated, and then the reception delay difference between each receiving channel and drive channel 0 is calculated, thereby aligning the reception direction and the transmission direction, that is, compensating the theoretical delay of multiple receiving channels with a single drive channel to achieve CMP direction alignment. Through the above operations, the compensation of the CMP direction of the channels within Group1 can be achieved, thus ensuring the time accuracy when the channels within the group receive signals.

[0065] It should be noted that in the prior art, the TDC chip only supports rising-edge sampling, and the falling edge of the driving waveform needs to be measured in reverse, which is likely to introduce errors. In this embodiment, during the in-group AC signal calibration, it supports independent sampling of both rising and falling edges and can dynamically select the sampling edge type, avoiding measurement errors introduced due to different edge slopes. Additionally, in the in-group AC signal reception alignment calibration, by performing arithmetic averaging on the delay differences between the selected receiving channel and the remaining transmitting channels, the random errors in single measurements are effectively suppressed through the mean operation of multiple sets of data, smoothing the delay fluctuations caused by environmental interference or link differences during signal transmission, effectively reducing the calibration deviation between channels, thereby significantly improving the calibration accuracy, ensuring the accuracy of the test results of the ATE device for semiconductor integrated circuits, and ultimately improving the accuracy of the in-group AC signal reception alignment calibration.

[0066] (2) In-group calibration of Group 2

[0067] In-group AC signal transmission alignment calibration: In Group 2, select Channel 0 as the receiving channel, and Channels 1 - 8 are sequentially used as driving channels to send signals. According to the same measurement and calculation method as the in-group transmission alignment calibration of Group 1, obtain the transmission delay differences between each driving channel and the receiving channel, and compensate the DRV direction of the channels in Group 2 after averaging multiple sets of sampling data.

[0068] In-group AC signal reception alignment calibration: Select Channel 0 as the driving channel to send signals, and Channels 1 - 8 as the receiving channels. Use the same method as the in-group reception alignment calibration of Group 1 to calculate and average the reception delay differences between each receiving channel and the driving channel, and compensate the CMP direction of the channels in Group 2.

[0069] (3) In-group calibration of Group 3

[0070] In-group AC signal transmission alignment calibration: Select Channel 0 as the receiving channel, and Channels 1 - 8 are sequentially used as driving channels to send signals. Apply the same calibration process as the previous two groups to determine the transmission delay differences between the channels in the group, and complete the compensation of the DRV direction of the channels in Group 3.

[0071] In-group AC signal reception alignment calibration: Select Channel 0 as the driving channel to send signals, and Channels 1 - 8 as the receiving channels. By measuring and calculating the reception delay differences and performing averaging on multiple sets of sampling data, compensate the CMP direction of the channels in Group 3.

[0072] III. Inter-group calibration

[0073] In step S3, after changing the channel connection relationship between calibration groups, the connection relationship of the new calibration group is asFigure 2 As shown by the inter-group connection lines, the above-mentioned intra-group calibration steps are then performed again on the new calibration groups for inter-group calibration. First, measure the delay deviation between two adjacent groups before grouping. Taking one of the groups as the reference, obtain the delay difference between each group of channels and the reference group, and compensate for the channel delays of the original grouping.

[0074] In this embodiment, after changing the channel connection relationship between calibration groups, select a channel in Group1 (such as channel 6) as the reference drive channel and a channel in Group2 (such as channel 0) as the reference receive channel to obtain the delay deviation between Group1 and Group2. Using the same method, measure the delay difference between Group2 and Group3.

[0075] Furthermore, taking Group1 as the reference, calculate the delay differences of Group2 and Group3 relative to Group1. Assume that the delay difference of Group2 relative to Group1 obtained through measurement and calculation is ΔT1, and the delay difference of Group3 relative to Group1 is ΔT2. Then, dynamically adjust the delay parameters of each channel through the hardware register so that the final delays of all channels are aligned with the group with the slowest signal delay (assumed to be Group3). Specifically, for the channels in Group1, adjust the delay according to the difference of ΔT2 - ΔT1; for the channels in Group2, adjust the delay according to the difference of ΔT2, thereby completing the inter-group calibration and ensuring that the delays of all channels are highly consistent, improving the overall accuracy of calibration.

[0076] In summary, the existing calibration technology has complex operations, involving external connection of multiple devices and specific channel interaction methods. This calibration method makes the calibration process more concise and clear through clear and orderly intra-group calibration and inter-group calibration steps, combined with reasonable channel configuration and measurement methods. In actual operation, the staff only needs to perform channel configuration, measurement, and compensation operations according to the set steps to complete the calibration work, thereby reducing the operation difficulty and improving the operation convenience.

[0077] On the other hand of this embodiment, a system for AC calibration of an ATE device client is also provided. The system includes a grouping module, an intra-group calibration module, an inter-group calibration module, a configuration module, a measurement module, and a compensation module.

[0078] The grouping module is used to divide multiple channels to be calibrated into several calibration groups through a loopback board.

[0079] The intra-group calibration module is used to perform intra-group AC signal transmission alignment calibration and intra-group AC signal reception alignment calibration.

[0080] The inter-group calibration module is used to perform inter-group calibration by changing the connection relationship between calibration groups.

[0081] The configuration module is used to configure the modes and parameters of all channels; the configuration module is used to configure all channels into DCL mode, CMP mode or high-impedance mode, and set the CMP comparison threshold.

[0082] The measurement module is used to obtain signal delay and reception time deviation.

[0083] The compensation module is used to perform dynamic delay compensation on the DRV and CMP directions of the channels.

[0084] The ATE device client AC calibration system in this embodiment integrates multiple functional modules including grouping, calibration, configuration, measurement, and compensation. These modules work together to achieve the automation and intelligence of the calibration process. The integration method of this system can not only improve the stability and reliability of calibration, but also facilitate the subsequent maintenance and upgrade of the calibration system, providing a strong guarantee for the long-term stable operation of the ATE device.

[0085] In summary, in a method and system for ATE device client AC calibration provided by an embodiment of the present invention, the channels to be calibrated are divided into several calibration groups through a loopback board, and intra-group calibration and inter-group calibration are performed. Without a TDC calibration board, it supports on-site calibration by customers; parallel calibration can be performed between multiple boards, greatly saving the overall AC calibration time; it supports independent sampling of rising edges and falling edges, can dynamically select the sampling edge type, avoids measurement errors introduced by the slope differences of the edges, and at the same time performs average processing on the multi-channel measurement data, thereby reducing the calibration deviation between channels and significantly improving the calibration accuracy.

[0086] The above are only the preferred embodiments of the present invention and do not impose any limitation on the present invention. Any person skilled in the art within the technical field of the present invention, without departing from the technical solution of the present invention, makes any form of equivalent replacement or modification and other changes to the technical solution and technical content disclosed by the present invention, all of which fall within the content of the technical solution of the present invention and still belong to the protection scope of the present invention.

Claims

1. A method for AC calibration of an ATE device client, characterized in that: The method comprises the following steps: Divide multiple channels to be calibrated into multiple calibration groups through loopback boards; For channels in the same calibration group, the channels in the group are selected in turn as driving channels and receiving channels to perform intra-group calibration, wherein the intra-group calibration includes intra-group AC signal sending alignment calibration and intra-group AC signal receiving alignment calibration; The channel connection relationship between the calibration groups is changed, and the steps of the intra-group calibration are reused to perform inter-group calibration, so as to obtain the delay deviation between two adjacent groups before grouping, and take one of the groups as the benchmark to obtain the delay difference between the delay of each group of channels and the delay of the benchmark group, and compensate for the channel delay of the original group.

2. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: The step of calibrating the AC signal transmission alignment within the group includes: In the continuous running state of the test mode, one channel is selected as the receiving channel, and the remaining channels are sequentially used as driving channels to send signals; Capture the rising or falling edge moment of each drive channel, calculate the sending delay difference and compensate for it.

3. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: The step of alignment calibration of AC signal reception within the group includes: selecting one channel as a driving channel to send signals, and the remaining channels as receiving channels; Capture the rising edge or falling edge moment of each receiving channel, calculate the receiving delay difference of each receiving channel and compensate for it.

4. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: Before dividing the multiple channels to be calibrated into several calibration groups, the method includes: configuring all the channels to be calibrated to a DCL mode, and setting the CMP comparison threshold to one Nth of the voltage value driven by the DRV signal, where N is the number of channels in each group.

5. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: One of the channels in each group is fixedly configured in CMP mode and terminated to GND through a 50Ohm.

6. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: When performing intra-group calibration on channels in the same group, each time a pair of transmit and receive channels is selected for measurement, all channels except the currently enabled drive channel and receive channel are configured in high-impedance mode.

7. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: The inter-group calibration step includes: taking the calibration group with the slowest delay as a benchmark, calculating the delay deviation of the remaining groups relative to the benchmark group, and dynamically adjusting the delay parameters of each channel through hardware registers to align the final delay of all channels with the benchmark group.

8. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: The method further includes: performing average processing on the multi-channel measurement data to reduce the calibration deviation between channels.

9. The method for AC calibration of ATE equipment client according to claim 1, characterized in that: The method supports independent sampling of rising edge and falling edge and avoids measurement errors introduced by slope differences by dynamically selecting the sampling edge type.

10. A system for AC calibration of ATE equipment client, characterized in that: The system comprises: A grouping module, used for dividing a plurality of channels to be calibrated into a plurality of calibration groups through a loopback board; An intra-group calibration module, used for performing intra-group AC signal sending alignment calibration and intra-group AC signal receiving alignment calibration; An inter-group calibration module, used for performing inter-group calibration by changing the connection relationship between calibration groups; Configuration module, used to configure the modes and parameters of all channels; A measurement module is used to obtain signal delay and receiving time deviation; The compensation module is used to perform dynamic delay compensation on the DRV and CMP directions of the channel.

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