JP5113846B2 - Acquisition device, test device, and manufacturing method - Google Patents

Description

  The present invention relates to an acquisition apparatus, a test apparatus, and a manufacturing method. In particular, the present invention relates to an acquisition apparatus, a test apparatus, and a manufacturing method including a flip-flop that acquires a signal at the timing of a strobe signal.

A test apparatus such as a semiconductor takes in a logical value of an output signal output from a device under test by a flip-flop. Then, the test apparatus determines pass / fail of the device under test based on the value captured by the flip-flop (see, for example, Patent Document 1). In addition, the test apparatus generates a strobe signal indicating the timing of taking in the logical value of the output signal from the timing generation unit, and provides it to the flip-flop.
JP 2002-116241 A

  By the way, when the strobe signal is given at the timing when the logical value of the signal to be observed is changing, the flip-flop has a different logical value depending on the logical value acquired immediately before (that is, the currently stored logical value). Will occur. For example, when a strobe signal is given at a predetermined timing when the observation target signal is changing from L logic to H logic, the flip-flop captures the H logic when the H logic is stored, but stores the L logic. In such a state, the phenomenon of taking in the L logic occurs.

  The range of the relative timing between the observation target signal and the strobe signal in which such a phenomenon occurs is called a dead band. The dead band in the flip-flop is considered to vary depending on, for example, manufacturing variations, internal circuit configurations, manufacturer differences, manufacturing processes, manufacturing lots, internal wiring paths, adjacent wiring capacities, and the like.

  As described above, since the flip-flop has a dead band, when the acquisition timing of the logical value of the observation target signal is controlled at a minute time interval, the logical value cannot be taken in with high accuracy. Further, a test apparatus using such a flip-flop cannot accurately determine the quality of the device under test when the timing of acquiring the logical value of the output signal of the device under test is controlled at a minute time interval.

  Then, an object of this invention is to provide the acquisition apparatus, test apparatus, and manufacturing method which can solve said subject. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous specific examples of the present invention.

  In order to solve the above-described problem, in the first embodiment of the present invention, a strobe generator that generates a strobe signal that indicates the timing at which a signal to be observed is to be captured, and a flip-flop that acquires the observation target signal at the timing of the strobe signal And a changing unit that changes the timing of the next strobe signal for taking in the next observation target signal based on the output state of the flip-flop.

  In the second embodiment of the present invention, a strobe generator that generates a strobe signal indicating the timing at which a signal to be observed is to be captured, and the strobe signal are delayed by different delay amounts and output as a plurality of delayed strobe signals. A plurality of delay units, a plurality of flip-flops provided corresponding to the plurality of delay units, each acquiring an observation target signal at the timing of the delayed strobe signal output from the corresponding delay unit, and at least one flip-flop Decision to determine the flip-flop to output the next observed value obtained from the next observed signal according to the next strobe signal, among the multiple flip-flops, according to the value of the last observed signal obtained And the output of the flip-flop determined by the determination unit among the output signals of the plurality of flip-flops. Signal, to provide an acquisition device including an output unit for outputting as the observed value of the next observation target signal.

  According to a third aspect of the present invention, there is provided a test apparatus for testing a device under test, a test signal supply unit for supplying a test signal for testing the device under test to the device under test, and the device under test being tested. An acquisition device that acquires a device output signal that is output in response to the signal, and a determination unit that determines pass / fail of the device under test based on the device output signal acquired by the acquisition device. A strobe generator that generates a strobe signal indicating the timing to be fetched, a flip-flop that acquires a device output signal at the timing of the strobe signal, and a next device for fetching the next device output signal based on the output state of the flip-flop There is provided a test apparatus having a change unit that changes the timing of a strobe signal.

  According to a fourth aspect of the present invention, there is provided a test apparatus for testing a device under test, a test signal supply unit for supplying a test signal for testing the device under test to the device under test, and the device under test being tested. An acquisition device that acquires a device output signal that is output in response to the signal, and a determination unit that determines pass / fail of the device under test based on the device output signal acquired by the acquisition device. Provided in correspondence with a plurality of delay units, a strobe generator that generates a strobe signal indicating the timing to be fetched, a plurality of delay units that delay the strobe signals by different delay amounts and output them as a plurality of delayed strobe signals A plurality of free signals that respectively obtain device output signals at the timing of the delayed strobe signals output from the corresponding delay units. According to the value of the previous device output signal acquired by the flop and at least one flip-flop, the next observed value obtained by acquiring the next device output signal according to the next strobe signal among the plurality of flip-flops. A determination unit that determines a flip-flop to be output; and an output unit that outputs the output signal of the flip-flop determined by the determination unit among the output signals of the plurality of flip-flops as an observation value of the next device output signal. A test apparatus is provided.

  According to a fifth aspect of the present invention, there is provided a manufacturing method for manufacturing a device, the manufacturing stage for manufacturing the device, and the manufactured device tested by the test apparatus of the third mode or the fourth mode. And a sorting step for sorting.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

FIG. 1 shows a configuration of a test apparatus 10 according to an embodiment of the present invention, together with a device under test 100. FIG. 2 shows a configuration of the acquisition device 14 according to the embodiment of the present invention. FIG. 3 shows an example of values obtained by the observation target signal 530, the strobe signal 540, and the flip-flop 26. FIG. 4 shows an example of the acquisition signal 550 output from the flip-flop 26 when the value of the observation target signal 530 acquired at the timing of the immediately preceding strobe signal 540 is H logic. FIG. 5 shows an example of the acquisition signal 550 output from the flip-flop 26 when the value of the observation target signal 530 acquired at the timing of the immediately preceding strobe signal 540 is L logic. FIG. 6 shows an example of changing the timing of the strobe signal 540 by the changing unit 28 when the observation target signal 530 is a rising edge. FIG. 7 shows an example of changing the timing of the strobe signal 540 by the changing unit 28 when the observation target signal 530 is a falling edge. FIG. 8 shows the configuration of the acquisition device 14 according to a first modification of the embodiment of the present invention. FIG. 9 shows an adjustment processing flow for adjusting the difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2 by the acquisition apparatus 14 according to the first modification shown in FIG. FIG. 10 shows a detailed processing flow in step S1001 of FIG. FIG. 11 illustrates an example of acquired values of the first observation target signal 560 (second observation target signal 570), the delayed strobe signal 600, and the flip-flop 26 during the process of step S1001. FIG. 12 shows a detailed processing flow in step S1002 of FIG. FIG. 13 shows an example of acquired values of the first observation target signal 560 (second observation target signal 570), the delayed strobe signal 600, and the flip-flop 26 during the process of step S1002. FIG. 14 shows the configuration of the acquisition device 14 according to the second modification of the embodiment of the present invention, together with the expected value generation unit 18. FIG. 15 shows a configuration of the acquisition device 14 according to a third modification of the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Test apparatus 12 Test signal supply part 14 Acquisition apparatus 16 Determination part 18 Expected value generation part 22 Level comparison part 24 Strobe generation part 26 Flip-flop 28 Change part 32 Delay part 34 Selection part 40 Switch 42 1st acquisition process part 44 2nd Acquisition processing unit 46 Adjustment unit 50 Edge determination unit 52 Storage unit 54 Determination unit 56 Output unit 100 Device under test 510 Test signal 520 Device output signal 530 Observation target signal 540 Strobe signal 550 Acquisition signal 560 First observation target signal 570 Second observation Target signal 600 Delayed strobe signal

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the claimed invention, and all combinations of features described in the embodiments are invented. It is not always essential to the solution.

  FIG. 1 shows a configuration of a test apparatus 10 according to this embodiment together with a device under test 100. The test apparatus 10 tests a device under test 100 such as a semiconductor memory.

  The test apparatus 10 includes a test signal supply unit 12, an acquisition device 14, and a determination unit 16. The test signal supply unit 12 supplies a test signal 510 for testing the device under test 100 to the device under test 100. The acquisition apparatus 14 acquires a device output signal 520 that the device under test 100 outputs in response to the test signal 510. The test apparatus 10 includes an H logic acquisition device for determining whether or not the device output signal 520 is H logic, and an L logic acquisition device for determining whether or not the device output signal 520 is L logic. May be. The determination unit 16 determines pass / fail of the device under test 100 based on the device output signal 520 acquired by the acquisition device 14.

  FIG. 2 shows a configuration of the acquisition device 14 according to the present embodiment. The acquisition device 14 receives the response signal (device output signal 520) output from the device under test 100 in response to the applied test signal 510, and acquires the logical value of the response signal at a specified timing (strobe timing). To do. Thereby, according to the acquisition device 14, the logical value of the response signal at the strobe timing can be determined. The acquisition device 14 includes a level comparison unit 22, a strobe generation unit 24, a flip-flop 26, and a change unit 28.

  The level comparison unit 22 receives the device output signal 520 having an analog waveform output from the device under test 100 and compares it with a threshold value. As an example, the level comparison unit 22 is a threshold between a level that should be determined as H logic and a level that should be determined that is not H logic, or a threshold between a level that should be determined as L logic and a level that should not be determined as L logic. Is compared with the device output signal 520. Then, the level comparison unit 22 outputs an observation target signal 530 having a logical waveform representing a logical value corresponding to the comparison result between the device output signal 520 and the threshold value. In the present embodiment, the level comparison unit 22 becomes H logic (or L logic) when the device output signal 520 is greater than or equal to the threshold value, and L logic (or H logic) when the observation target signal 530 is smaller than the threshold value. The observation target signal 530 is output.

  The strobe generator 24 generates a strobe signal 540 that indicates the timing at which the observation target signal 530 is to be captured (that is, the timing at which the device output signal 520 is to be captured). As an example, the timing of the strobe signal 540 output from the strobe generator 24 is variably controlled according to a controller or the like that operates according to the test program. As an example, the strobe generator 24 may generate a strobe signal 540 including a pulse waveform at a timing at which the observation target signal 530 should be taken.

  The flip-flop 26 receives the observation target signal 530 having the logic waveform, and latches the logical value represented by the observation target signal 530 at the timing of the strobe signal 540. Then, the flip-flop 26 outputs an acquisition signal 550 representing the latched logical value. In the present embodiment, the flip-flop 26 inputs the observation target signal 530 from the input end (D end). In the present embodiment, the flip-flop 26 receives the strobe signal 540 from the clock end.

  The flip-flop 26 acquires the value (H logic or L logic) of the observation target signal 530 input from the input terminal at the timing of the strobe signal 540 input from the clock terminal. The flip-flop 26 outputs an acquisition signal 550 representing the acquired value (H logic or L logic) from the output terminal (O terminal). Note that, even if the strobe signal 540 has the same timing, the flip-flop 26 may cause a minimal shift in acquisition timing due to manufacturing variation factors and other factors.

  The changing unit 28 changes the timing of the strobe signal 540 based on the output state of the flip-flop 26. That is, the changing unit 28 sets the next strobe signal 540 for capturing the next observation target signal 530 in accordance with the value of the previous observation target signal 530 acquired by the flip-flop 26 according to the previous strobe signal 540. Change the timing. In the present embodiment, the changing unit 28 takes in the value of the next observation target signal 530 according to whether the value of the observation target signal 530 acquired according to the immediately preceding strobe signal 540 is H logic or L logic. The timing of the next strobe signal 540 is switched.

  For example, the changing unit 28 may include a plurality of delay units 32 and a selection unit 34. Each of the plurality of delay units 32 delays the strobe signal 540 by a different delay amount. One of the plurality of delay units 32 may be a fixed delay amount such as a buffer circuit. The selection unit 34 receives the acquisition signal 550 that is an output signal of the flip-flop 26, selects one of the plurality of strobe signals 540 delayed by different delay amounts by the plurality of delay units 32, and This is supplied to the clock input terminal of the flip-flop 26.

  Here, in the present embodiment, the changing unit 28 includes an H-side delay unit 32-1, an L-side delay unit 32-2, and a selection unit 34. The H-side delay unit 32-1 and the L-side delay unit 32-2 delay the strobe signal 540 by different delay amounts. One of the H-side delay unit 32-1 and the L-side delay unit 32-2 may be a fixed delay amount. When the value of the immediately preceding observation target signal 530 is H logic, the selection unit 34 selects the strobe signal 540 delayed by the H-side delay unit 32-1 as the next strobe signal 540. When the value of the previous observation target signal 530 is L logic, the selection unit 34 selects the strobe signal 540 delayed by the L-side delay unit 32-2 as the next strobe signal 540. Thereby, the changing unit 28 can slightly change the delay amount of the acquisition timing (strobe timing) of the observation target signal 530 based on the output state of the flip-flop 26.

  FIG. 3 shows an example of values obtained by the observation target signal 530, the strobe signal 540, and the flip-flop 26. For example, the strobe generator 24 generates a strobe signal 540 at a designated phase timing for each basic period (test period) for the test by the test apparatus 10. The flip-flop 26 latches the value (H logic or L logic) of the observation target signal 530 at the timing when the strobe signal 540 is generated. In this manner, the flip-flop 26 can acquire the value of the observation target signal 530 for each test cycle.

  FIG. 4 shows an example of the acquisition signal 550 output from the flip-flop 26 when the value of the observation target signal 530 acquired at the timing of the immediately preceding strobe signal 540 is H logic. FIG. 5 shows an example of the acquisition signal 550 output from the flip-flop 26 when the value of the observation target signal 530 acquired at the timing of the immediately preceding strobe signal 540 is L logic.

  4A and 5A show the observation target signal 530 having the same waveform. FIG. 4B shows a strobe signal 540 generated at the timing of time t01, time t1, time t2, and time t3 with respect to the observation target signal 530 shown in FIG. (B) of FIG. 5 shows the strobe signal 540 generated at the timing of time t02, time t1, time t2, and time t3 with respect to the observation target signal 530 shown in (A).

  (C), (D), and (E) in FIG. 4 are obtained by obtaining the value of the observation target signal 530 using the strobe signal 540 at the time t01 and then using the strobe signal 540 at the times t1, t2, and t3. An acquisition signal 550 when the target signal 530 is acquired is shown. (C), (D), and (E) in FIG. 5 are obtained by obtaining the value of the observation target signal 530 using the strobe signal 540 at time t02 and then using the strobe signal 540 at times t1, t2, and t3. An acquisition signal 550 when the target signal 530 is acquired is shown.

  Note that time t01 indicates an arbitrary timing at which the observation target signal 530 is H logic. Time t02 indicates an arbitrary timing when the observation target signal 530 is L logic. Each of the times t1, t2, and t3 is a generation range of the strobe signal 540 next to the strobe signal 540 generated at the times t01 and t02, and the observation target signal 530 is changing from the L logic to the H logic. Indicates timing.

  Here, an ideal flip-flop always obtains a value with the same reproducibility regardless of the output state of the flip-flop 26 if the relative timings of the observation target signal 530 and the strobe signal 540 are the same. However, the actual flip-flop 26 may vary in reproducibility due to manufacturing variations and other factors. Here, the range where the reproducibility varies is called a dead band. The dead band varies depending on the circuit element to be used, manufacturing variation, and the like, and may be zero, but is expected to be about several picoseconds to several tens of picoseconds.

  For example, at the timing of time t1 in FIGS. 4 and 5, both L logics are acquired. In addition, the flip-flop 26 acquires the H logic at the time t3 in FIGS. 4 and 5, for example. However, when the relative timing between the observation target signal 530 and the strobe signal 540 is included in the dead band range in the flip-flop 26, the flip-flop 26 indicates that the value of the observation target signal 530 acquired immediately before is H logic or L Different values are obtained depending on the logic. For example, as shown in FIG. 4, when the value acquired immediately before is H logic, the flip-flop 26 acquires H logic at the timing of time t2. On the other hand, for example, as shown in FIG. 5, when the value acquired immediately before is L logic, the flip-flop 26 acquires L logic at the timing of time t2.

  FIG. 6 shows an example of changing the timing of the strobe signal 540 by the changing unit 28 when the observation target signal 530 is a rising edge. FIG. 7 shows an example of changing the timing of the strobe signal 540 by the changing unit 28 when the observation target signal 530 is a falling edge.

  When the observation target signal 530 is a rising edge, the dead band of the flip-flop 26 is in a range as shown in FIG. That is, the dead band in this case includes the switching timing (t11) at which the acquired signal 550 switches from L logic to H logic when the value of the immediately preceding observation target signal 530 is H logic, and the value of the immediately preceding observation target signal 530. When the signal is L logic, the acquisition signal 550 is between the switching timing (t12) at which the L signal is switched to the H logic. The dead band of the flip-flop 26 in the case of the rising edge is the switching timing (t11) when the value of the immediately preceding observation target signal 530 is H logic, and the value of the immediately preceding observation target signal 530 is L logic. Both the case before and after the switching timing (t12) in the case exists.

  When the observation target signal 530 is a falling edge, the dead band of the flip-flop 26 is in a range as shown in FIG. That is, the dead band in this case includes the switching timing (t21) at which the acquired signal 550 switches from H logic to L logic when the value of the immediately preceding observation target signal 530 is H logic, and the value of the immediately preceding observation target signal 530. When the signal is L logic, the acquisition signal 550 is between the switching timing (t22) at which the H signal is switched from H logic to L logic. The dead band of the flip-flop 26 in the case of the falling edge is the switching timing (t21) when the value of the immediately preceding observation target signal 530 is H logic, and the value of the immediately preceding observation target signal 530 is L logic. There are cases both before and after the switching timing (t22) in the case of the case.

  Here, in the present embodiment, the changing unit 28 performs the next observation according to the value (H logic or L logic) of the immediately preceding observation target signal 530 acquired by the flip-flop 26 according to the immediately preceding strobe signal 540. The timing of the next strobe signal 540 for capturing the target signal 530 is changed. In this case, the changing unit 28 determines the timing of the next strobe signal 540 when the value of the immediately preceding observation target signal 530 acquired by the flip-flop 26 according to the immediately preceding strobe signal 540 is H logic, A time difference corresponding to the dead band is provided between the timing of the next strobe signal 540 when the value of the observation target signal 530 immediately before acquired by the flip-flop 26 according to the strobe signal 540 is L logic.

  For example, as shown in FIG. 6, the switching timing (t12) when the value of the immediately preceding observation target signal 530 is L logic is the switching timing (t11) when the value of the immediately preceding observation target signal 530 is H logic. ) Later in time. In such a case, as an example, if the value of the immediately preceding observation target signal 530 is L logic, the changing unit 28 corresponds to the timing of the next strobe signal 540 for taking in the next observation target signal 530 to the dead band. Delay time difference. For example, if the value of the immediately preceding observation target signal 530 is logic H, the changing unit 28 does not delay the timing of the next strobe signal 540 for taking in the next observation target signal 530.

  Also, for example, as shown in FIG. 7, the switching timing (t21) when the value of the immediately preceding observation target signal 530 is H logic is the switching timing when the value of the immediately preceding observation target signal 530 is L logic. It is assumed that it is later in time than (t22). In such a case, for example, if the value of the immediately preceding observation target signal 530 is H logic, the changing unit 28 corresponds to the dead band timing of the next strobe signal 540 for capturing the next observation target signal 530. Delay time difference. For example, the change unit 28 does not delay the timing of the next strobe signal 540 for fetching the next observation target signal 530 if the value of the previous observation target signal 530 is L logic.

  In this manner, the changing unit 28 determines that the value of the immediately preceding observation target signal 530 is the logical value of the acquisition signal 550 when the logical switching timing of the acquisition signal 550 is later in time. The timing of the next strobe signal 540 for capturing the next observation target signal 530 is delayed by a time difference corresponding to the dead band, compared to the case where the logic switching timing is a logical value that is temporally previous. As a result, the changing unit 28 sets the flip-flop 26 to the flip-flop 26 regardless of the value of the observation target signal 530 acquired immediately before the relative timing between the observation target signal 530 and the strobe signal 540 is included in the dead band range. To obtain the same value. Therefore, according to the acquisition device 14, the value of the observation target signal 530 can be captured with high accuracy.

  FIG. 8 shows a configuration of the acquisition device 14 according to the first modification of the present embodiment. Since the test apparatus 10 according to the present modification has substantially the same configuration and function as the test apparatus 10 according to the present embodiment, the test apparatus 10 according to the present embodiment has substantially the same configuration and function as the members included in the test apparatus 10 according to the present embodiment. The same reference numerals are assigned, and the description will be omitted except for the following differences.

  The acquisition apparatus 14 according to the present modification further includes a switch 40, a first acquisition processing unit 42, a second acquisition processing unit 44, and an adjustment unit 46. The switch 40 causes the observation target signal 530 output from the level comparison unit 22 to be input to the input terminal of the flip-flop 26 during normal operation. At the time of adjustment, the switch 40 replaces the observation target signal 530 output from the level comparison unit 22 with the first observation target signal 560 and the second observation target signal 560 output from the first acquisition processing unit 42 and the second acquisition processing unit 44. An observation target signal 570 is input to the input terminal of the flip-flop 26.

  The first acquisition processing unit 42 outputs the first observation target signal 560 for adjustment to the flip-flop 26 in the first state in which the flip-flop 26 acquires the first logical value. Then, the first acquisition processing unit 42 acquires the first observation target signal 560 for adjustment from the strobe signal 540 selected according to the first logical value. The first logic value may be either H0 logic or L logic. The second logic value may be L logic when the first logic value is H logic, and may be H logic when the first logic value is L logic. For example, the first acquisition processing unit 42 has a waveform that is the first logic value (for example, H logic) at the timing of the previous strobe signal 540 and a predetermined timing within the generation range of the next strobe signal 540. , The first observation target signal 560 having a waveform that changes from the second logic value (for example, L logic) to the first logic value (for example, H logic) may be output to the flip-flop 26.

  The second acquisition processing unit 44 has the same waveform as the first observation target signal 560 with respect to the strobe signal 540 before the timing change by the changing unit 28 in the second state in which the flip-flop 26 acquires the second logical value. Is output to the flip-flop 26. Then, the second acquisition processing unit 44 acquires the second observation target signal 570 for adjustment from the strobe signal 540 selected according to the second logical value. For example, the first acquisition processing unit 42 has a waveform that is the second logic value (for example, L logic) at the timing of the immediately preceding strobe signal 540 and a predetermined timing within the generation range of the next strobe signal 540. , The second observation target signal 570 having a waveform that changes from the second logic value (for example, L logic) to the first logic value (for example, H logic) may be output to the flip-flop 26.

  The adjustment unit 46 includes the first observation target signal 560 and the second observation target signal 570 acquired by the flip-flop 26 by the first acquisition processing unit 42 and the second acquisition processing unit 44 so that the values thereof are the same. A difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2 selected according to the logic value and the second logic value is adjusted. For example, the adjustment unit 46 controls the strobe generation unit 24 to sequentially change the timing of the strobe signal 540 output from the strobe generation unit 24, while controlling the H-side delay unit 32-1 and the L-side delay unit 32. -2 delay amount difference is adjusted.

  FIG. 9 shows an adjustment processing flow for adjusting the difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2 by the acquisition apparatus 14 according to the first modification shown in FIG. First, the acquisition device 14 detects the start position of the dead band (S1001). Next, the acquisition apparatus 14 adjusts the difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2 so that the time difference corresponds to the dead band (S1002).

  FIG. 10 shows a detailed processing flow in step S1001 of FIG. FIG. 11 illustrates an example of acquired values of the first observation target signal 560 (second observation target signal 570), the delayed strobe signal 600, and the flip-flop 26 during the process of step S1001.

  In the process of step S1001, the adjustment unit 46 first matches the delay amounts of the H-side delay unit 32-1 and the L-side delay unit 32-2 (S1011). That is, the adjustment unit 46 sets the difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2 to zero.

  Next, the adjustment unit 46 repeatedly executes the processes of steps S1013 to S1015 while sequentially changing the timing of the strobe signal 540 (S1012 and S1016). For example, the adjustment unit 46 repeatedly executes the processing of steps S1013 to S1015 while sequentially shifting the timing of the strobe signal 540 from the position sufficiently before the start position of the dead band sequentially at a predetermined time interval.

  In the processing of steps S1013 to 1015, first, the adjustment unit 46 causes the first acquisition processing unit 42 to execute processing (S1013). In step S1013, for example, the first acquisition processing unit 42 outputs, to the flip-flop 26, a signal having a waveform that is H logic at the timing of the immediately preceding strobe signal 540, and sets the flip-flop 26 to the H logic state. To do. In step S <b> 1013, subsequently, the first acquisition processing unit 42 outputs the first observation target signal 560 having a waveform that rises from L logic to H logic at a predetermined timing to the flip-flop 26. Thereby, the first acquisition processing unit 42 can cause the flip-flop 26 to acquire the logical value of the first observation target signal 560 at the timing of the strobe signal 540 set by the adjustment unit 46.

  Next, the adjustment unit 46 causes the second acquisition processing unit 44 to execute processing (S1014). In step S1014, for example, the second acquisition processing unit 44 outputs, to the flip-flop 26, a signal having a waveform that is L logic at the timing of the previous strobe signal 540, and sets the flip-flop 26 to the L logic state. To do. In step S1014, subsequently, the second acquisition processing unit 44 has a second observation target signal having a waveform (the same waveform as step S1013) that rises from L logic to H logic at a predetermined timing (same timing as step S1013). 570 is output to the flip-flop 26. Thereby, the first acquisition processing unit 42 can cause the flip-flop 26 to acquire the logical value of the second observation target signal 570 at the timing of the strobe signal 540 set by the adjustment unit 46.

  Next, the adjustment unit 46 obtains the first observation target signal 560 (H state acquisition value) by the flip-flop 26 in step S1013, and obtains the second observation target signal 570 by the flip-flop 26 in step S1014. (L state acquisition value) is compared (S1015). Here, as shown in FIG. 11, the H state acquisition value and the L state acquisition value are the same value outside the dead band range, and are different values within the dead band range. Therefore, when the timing of the strobe signal is sequentially shifted backward from a position sufficiently before the start position of the dead band, the H state acquisition value and the L state acquisition value are initially the same, and the dead band A difference occurs when the start position is matched.

  Next, when the H state acquisition value and the L state acquisition value are the same in step S1015, the adjustment unit 46 repeats the processes of steps S1013 to S1015 (S1012 and S1016). If the H state acquisition value is different from the L state acquisition value in step S1015, the adjustment unit 46 exits the processes of steps S1012 to S1016 (S1016). In this way, the adjustment unit 46 can detect the start position of the dead band. And the adjustment part 46 will move a process to step S1002 of FIG. 9, if the process of step S1012-S1016 is exited.

  FIG. 12 shows a detailed processing flow in step S1002 of FIG. FIG. 13 shows an example of acquired values of the first observation target signal 560 (second observation target signal 570), the delayed strobe signal 600, and the flip-flop 26 during the process of step S1002.

  In the process of step S1002, the adjusting unit 46 repeatedly executes the processes of steps S1022 to S1024 while sequentially changing the difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2. (S1021, S1025). For example, the adjustment unit 46 repeats the processing from step S1022 to step S1024 while sequentially increasing the difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2 from 0 by a predetermined amount. Execute. In this case, the adjustment unit 46 may fix the other delay amount.

  Here, the adjustment unit 46 switches the logical value of the acquisition signal 550 when the value of the previous observation target signal 530 is L logic when the value of the previous observation target signal 530 is H logic. When the timing is later than the switching timing of the logical value of the acquisition signal 550, the delay amount of the L-side delay unit 32-2 may be sequentially increased. Further, the adjustment unit 46 may sequentially increase the delay amount of the H-side delay unit 32-1, when the relationship between the switching timings is reversed.

  In steps S1022 to 1024, the adjustment unit 46 first causes the first acquisition processing unit 42 to execute processing (S1022). In step S1022, for example, the first acquisition processing unit 42 outputs to the flip-flop 26 a signal having a waveform that is H logic at the timing of the immediately preceding strobe signal 540, and sets the flip-flop 26 to the H logic state. To do. Next, in step S1022, the first acquisition processing unit 42 outputs the first observation target signal 560 having a waveform that rises from L logic to H logic at a predetermined timing to the flip-flop 26. Thereby, the first acquisition processing unit 42 can cause the flip-flop 26 to acquire the logical value of the first observation target signal 560 at the timing of the strobe signal 540 set by the adjustment unit 46.

  Next, the adjustment unit 46 causes the second acquisition processing unit 44 to execute processing (S1023). In step S1023, for example, the second acquisition processing unit 44 outputs, to the flip-flop 26, a signal having a waveform that is L logic at the timing of the previous strobe signal 540, and sets the flip-flop 26 to the L logic state. To do. Next, in step S1023, the second acquisition processing unit 44, the second observation target signal having a waveform (same waveform as step S1022) rising from L logic to H logic at a predetermined timing (same timing as step S1022). 570 is output to the flip-flop 26. Thereby, the second acquisition processing unit 44 can cause the flip-flop 26 to acquire the logical value of the second observation target signal 570 at the timing delayed by the difference in delay amount from the timing of the strobe signal 540 in step S1022.

  Next, the adjustment unit 46 acquires the first observation target signal 560 (H state acquisition value) by the flip-flop 26 in step S1022 and the acquisition result of the second observation target signal 570 by the flip-flop 26 in step S1023. (L state acquisition value) is compared (S1024). Here, when the timing of the strobe signal selected when the immediately preceding logic value is L logic is sequentially shifted backward from the start position of the dead band, the H state acquisition value and the L state acquisition value are the first Are different, but are the same when the dead band end position is exceeded.

  Next, when the H state acquisition value is different from the L state acquisition value in step S1024, the adjustment unit 46 repeats the processes of steps S1022 to S1024 (S1021, S1025). Then, when the H state acquisition value becomes the same as the L state acquisition value in step S1024, the adjustment unit 46 exits the processes of steps S1021 to S1025 (S1025). As a result, the difference in delay amount between the H-side delay unit 32-1 and the L-side delay unit 32-2 becomes a value corresponding to the dead band. And the adjustment part 46 will complete | finish the process of step S1002 of FIG. 9, if the process of step S1021-S1025 is exited.

  As a result of the above processing, the adjustment unit 46 can set the difference in delay amount corresponding to the dead band between the H-side delay unit 32-1 and the L-side delay unit 32-2. As described above, according to the acquisition device 14 according to the present modification, the delay amount difference between the H-side delay unit 32-1 and the L-side delay unit 32-2 is adjusted to be a time difference corresponding to the dead band. can do.

  FIG. 14 shows the configuration of the acquisition device 14 according to the second modification of the present embodiment, together with the expected value generation unit 18. Since the test apparatus 10 according to the present modification has substantially the same configuration and function as the test apparatus 10 according to the present embodiment, the test apparatus 10 according to the present embodiment has substantially the same configuration and function as the members included in the test apparatus 10 according to the present embodiment. The same reference numerals are assigned, and the description will be omitted except for the following differences.

  The test apparatus 10 according to this modification further includes an expected value generation unit 18 that generates an expected value of the device output signal 520. In addition, the acquisition device 14 according to this modification further includes an edge determination unit 50.

  The edge determination unit 50 determines whether the observation target signal 530 has a rising edge or a falling edge at a timing according to the strobe signal 540. The edge determination unit 50 may determine a rising edge or a falling edge based on the expected value generated by the expected value generation unit 18.

  In the present modification, the changing unit 28 changes the timing of the next strobe signal 540 according to the value of the observation target signal 530 just acquired by the flip-flop 26 and the determination result by the edge determining unit 50. As an example, the changing unit 28 includes a rising edge H-side delay unit 32-3, a rising edge L-side delay unit 32-4, a falling edge H-side delay unit 32-5, and a falling edge L A side delay unit 32-6 and a selection unit 34 may be included.

  When the observation target signal 530 has a rising edge and the value of the immediately preceding observation target signal 530 is H logic, the selection unit 34 strobe signal delayed by the rising edge H-side delay unit 32-3. Select 540. The selection unit 34 is a strobe signal delayed by the rising edge L-side delay unit 32-4 when the observation target signal 530 has a rising edge and the value of the immediately preceding observation target signal 530 is L logic. Select 540. When the observation target signal 530 has a falling edge and the value of the previous observation target signal 530 is H logic, the selection unit 34 is delayed by the falling edge H-side delay unit 32-5. The strobe signal 540 is selected. When the observation target signal 530 has a falling edge and the value of the previous observation target signal 530 is L logic, the selection unit 34 is delayed by the falling edge L-side delay unit 32-6. The strobe signal 540 is selected.

  According to such an acquisition device 14, even when the dead band width differs between the rising edge and the falling edge, the same value for the flip-flop 26 is obtained regardless of the value of the observation target signal 530 acquired immediately before. You can get the value. Thereby, according to acquisition device 14, the value of observation object signal 530 can be taken in with sufficient accuracy.

  FIG. 15 shows a configuration of the acquisition device 14 according to a third modification of the present embodiment. Since the test apparatus 10 according to the present modification has substantially the same configuration and function as the test apparatus 10 according to the second modification, the test apparatus 10 according to the second modification has substantially the same configuration and function as the members included in the test apparatus 10 according to the second modification. The same reference numerals are given to the members, and the description will be omitted except for the differences.

  The acquisition device 14 according to the present modification includes a level comparison unit 22, a strobe generation unit 24, a plurality of delay units 32, a plurality of flip-flops 26, an edge determination unit 50, a plurality of storage units 52, and a determination. Part 54. The plurality of delay units 32 delay the strobe signals 540 by different delay amounts and output the delayed strobe signals 600 as a plurality of delayed strobe signals 600. For example, the acquisition device 14 includes a rising edge H-side delay unit 32-3, a rising edge L-side delay unit 32-4, a falling edge H-side delay unit 32-5, and a falling edge L. A side delay unit 32-6 and a selection unit 34 may be included.

  The plurality of flip-flops 26 are provided corresponding to the plurality of delay units 32. Each of the plurality of flip-flops 26 acquires the observation target signal 530 at the timing of the delayed strobe signal 600 output from the corresponding delay unit 32. As an example, the acquisition device 14 uses the rising edge H side flip-flop 26-3 corresponding to the rising edge H side delay unit 32-3 and the rising edge L corresponding to the rising edge L side delay unit 32-4. Side flip-flop 26-4, falling edge H side flip-flop 26-5 corresponding to falling edge H side delay unit 32-5, and falling edge corresponding to L side delay unit 32-6 for falling edge And a downstream edge L-side flip-flop 26-6.

  The edge determination unit 50 determines whether the observation target signal 530 has a rising edge or a falling edge at a timing according to the delayed strobe signal 600. For example, the edge determination unit 50 determines that the observation target signal 530 corresponds to the strobe signal 540 from the values of at least two next observation target signals 530 acquired by the at least two flip-flops 26 according to the next strobe signal 540. It may be determined whether or not there is a rising edge or a falling edge at the same timing.

  The plurality of storage units 52 are provided corresponding to the plurality of flip-flops 26. The plurality of storage units 52 store the value of the immediately preceding observation target signal 530 acquired from the immediately preceding delayed strobe signal 600 by the corresponding flip-flop 26. As an example, the acquisition device 14 includes a rising-edge H-side storage unit 52-3 corresponding to the rising-edge H-side flip-flop 26-3 and a rising-edge L corresponding to the rising-edge L-side flip-flop 26-4. Side storage section 52-4, falling edge H side storage section 52-5 corresponding to falling edge H side flip-flop 26-5, and falling edge corresponding to L side flip flop 26-6. And a downstream edge L-side storage unit 52-6.

  The determination unit 54 inputs the values stored in the plurality of storage units 52 and the determination results by the edge determination unit 50. Then, the determination unit 54 performs an edge from the value of the immediately preceding observation target signal 530 acquired by the at least one flip-flop 26 and the value of at least two next observation target signals 530 acquired by the at least two flip-flops 26. According to the determination result determined by the determination unit 50, the flip-flop 26 to which the next observation value is to be output is determined from among the plurality of flip-flops 26.

  The output unit 56 outputs the output signal of the flip-flop 26 determined by the determination unit 54 among the output signals of the plurality of flip-flops 26 as the observation value of the next observation target signal 530. For example, the output unit 56 is acquired by the rising edge H-side flip-flop 26-3 when the edge determination unit 50 determines that it is a rising edge and the logic value acquired immediately before is H logic. Select a value and output it. For example, when the edge determination unit 50 determines that the rising edge is detected and the logical value acquired immediately before is the L logic, the output unit 56 acquires the rising edge using the L-side flip-flop 26-4. Select the output value and output it. For example, when the edge determination unit 50 determines the falling edge and the logic value acquired immediately before is the H logic, the output unit 56 is acquired by the falling edge H-side flip-flop 26-5. Select the output value and output it. For example, the output unit 56, when the edge determination unit 50 determines a falling edge and the logical value acquired immediately before is L logic, the falling edge L-side flip-flop 26-6. Select and output the value obtained by.

  According to such an acquisition device 14, even when the dead band width differs between the rising edge and the falling edge, the same value for the flip-flop 26 is obtained regardless of the value of the observation target signal 530 acquired immediately before. You can get the value. Thereby, according to acquisition device 14, the value of observation object signal 530 can be taken in with sufficient accuracy. Note that the determination unit 54 selects the next flip-flop 26 from among the plurality of flip-flops 26 according to the value of the immediately preceding observation target signal 530 acquired by the at least one flip-flop 26 and the expected value of the next observation target signal 530. The flip-flop 26 to which the next observation value obtained from the observation target signal 530 according to the next strobe signal 540 is to be output may be determined.

  Further, the test apparatus 10 according to the present embodiment described above can be used in a manufacturing method for manufacturing a device. This manufacturing method includes a manufacturing stage for manufacturing a device and a sorting stage for testing and sorting the manufactured device by the test apparatus 10. According to such a manufacturing method, it is possible to manufacture a device selected with high accuracy.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

Claims (11)

A strobe generator for generating a strobe signal indicating the timing at which the signal to be observed is to be captured;
A flip-flop for acquiring the observation target signal at the timing of the strobe signal;
Based on the output state of the flip-flop, a changing unit that changes the timing of the next strobe signal for capturing the next observation target signal;
An acquisition device comprising: The changing unit is
A plurality of delay units for delaying the strobe signal by different delay amounts;
A selection unit that selects the next strobe signal according to the value of the immediately preceding observation target signal from among the plurality of strobe signals delayed by different delay amounts by the plurality of delay units;
Have
The acquisition apparatus according to claim 1, wherein the flip-flop inputs the next strobe signal selected by the selection unit. In the first state in which the flip-flop acquires the first logic value, the first observation target signal for adjustment is output to the flip-flop, and the strobe selected according to the first logic value A first acquisition processing unit to be acquired by a signal;
In the second state in which the flip-flop acquires the second logical value, the second adjustment signal having the same waveform as the first observation target signal with respect to the strobe signal before the timing change by the changing unit. A second acquisition processing unit that outputs the observation target signal to the flip-flop and acquires the observation target signal based on the strobe signal selected according to the second logic value;
The first acquisition processing unit and the second acquisition processing unit are selected according to the first logical value and the second logical value so that the values of the observation target signals acquired by the flip-flops are the same. An adjustment unit for adjusting a difference in delay amount of the delay unit;
The acquisition device according to claim 2, further comprising:   The acquisition apparatus according to claim 3, further comprising a level comparison unit that outputs the observation target signal having a logical value corresponding to a result of comparing the input signal with a threshold value. An edge determination unit for determining whether the observation target signal has a rising edge or a falling edge at a timing according to the strobe signal;
The acquisition device according to claim 3, wherein the changing unit changes a timing of the next strobe signal according to a value of the observation target signal acquired immediately before by the flip-flop and a determination result by the edge determination unit. . A strobe generator for generating a strobe signal indicating the timing at which the signal to be observed is to be captured;
A plurality of delay units that delay the strobe signals by different delay amounts and output a plurality of delayed strobe signals;
A plurality of flip-flops provided corresponding to the plurality of delay units, each acquiring the observation target signal at the timing of the delayed strobe signal output from the corresponding delay unit;
The next observation obtained by acquiring the next observation target signal in accordance with the next strobe signal among the plurality of flip-flops according to the value of the observation target signal immediately before acquired by at least one of the flip-flops. A determination unit for determining a flip-flop to output a value;
Among the output signals of the plurality of flip-flops, an output unit that outputs the output signal of the flip-flop determined by the determination unit as an observation value of the next observation target signal;
An acquisition device comprising: From the value of at least two next observation target signals acquired by at least two flip-flops according to the next strobe signal, the rising edge or the falling edge of the observation target signal at a timing according to the strobe signal An edge determination unit that determines whether or not
The determination unit determines the edge from the value of the observation target signal immediately before acquired by at least one of the flip-flops and the value of at least two next observation target signals acquired by at least two of the flip-flops. The acquisition apparatus according to claim 6, wherein a flip-flop to which the next observation value is to be output is determined among the plurality of flip-flops according to a determination result determined by the unit. A test apparatus for testing a device under test,
A test signal supply unit for supplying a test signal for testing the device under test to the device under test;
An acquisition device that acquires a device output signal that the device under test outputs according to the test signal;
A determination unit that determines pass / fail of the device under test based on the device output signal acquired by the acquisition device;
With
The acquisition device includes:
A strobe generator for generating a strobe signal indicating the timing at which the device output signal should be captured;
A flip-flop that obtains the device output signal at the timing of the strobe signal;
Based on the output state of the flip-flop, a changing unit that changes the timing of the next strobe signal for capturing the next device output signal;
Test equipment with A test apparatus for testing a device under test,
A test signal supply unit for supplying a test signal for testing the device under test to the device under test;
An acquisition device that acquires a device output signal that the device under test outputs according to the test signal;
A determination unit that determines pass / fail of the device under test based on the device output signal acquired by the acquisition device;
With
The acquisition device includes:
A strobe generator for generating a strobe signal indicating the timing at which the device output signal should be captured;
A plurality of delay units that delay the strobe signals by different delay amounts and output a plurality of delayed strobe signals;
A plurality of flip-flops provided corresponding to the plurality of delay units, each of which obtains the device output signal at the timing of the delayed strobe signal output from the corresponding delay unit;
The next observation that the next device output signal is acquired according to the next strobe signal among the plurality of flip-flops according to the value of the previous device output signal acquired by the at least one flip-flop. A determination unit for determining a flip-flop to output a value;
Among the output signals of the plurality of flip-flops, an output unit that outputs the output signal of the flip-flop determined by the determining unit as an observation value of the next device output signal;
Test equipment with An expected value generator for generating an expected value of the device output signal;
The determining unit is configured to select a next one of the plurality of flip-flops according to a value of the device output signal immediately before acquired by the at least one flip-flop and an expected value of the next device output signal. The test apparatus according to claim 9, wherein a flip-flop to output a next observation value obtained by obtaining a device output signal in accordance with the next strobe signal is determined. A manufacturing method for manufacturing a device, comprising:
A manufacturing stage for manufacturing the device;
A screening step of testing and sorting the manufactured device by the test apparatus according to claim 8 or claim 9;
A manufacturing method comprising:

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