CN1243341C - Speech test transition method - Google Patents

Abstract

The present invention relates to a method converting test vectors of test language on the basis of initial circulation into test vectors of test language on the basis of object circulation. The method comprises the procedures: a group of waveform templates for describing the definition of object test language are formed; the waveform of initial test language is decomposed into a group of composite events, wherein each event comprises at least one initial value for representing the waveform and subsequent data of the amount of boundaries; the templates are compared with the group of events; when matching is detected, the waveform data of object test language is stored, and corresponding parameters of the waveform of the initial test language are taken back; for all test waveforms of the initial test language, the procedures are repeated. Thereby, test vector files of the object test language are formed.

Description

Speech test transition method

The present invention relates to be used for test data conversion method, and relate in particular to the method for digital test vector that the digital test vector of writing with STIL (standard testing interface language) is converted to the test language of specific ATE (automatic test equipment) by the ATE (automatic test equipment) semiconductor test.

In with the semiconductor devices of automatic test equipment (ATE) or IC tester test as IC and LSI, the IC tester provides test signal or test pattern at the suitable pin place of semiconductor IC device that will be tested to it with the presumptive test sequential.The IC tester receives output signal in response to the IC device of test signal from be in test.The gating signal that output signal is produced by the IC tester is with scheduled timing gating or sampling, with itself and desired data relatively, determines whether the IC device correctly works.Usually, the sequential of test signal and gating signal defines with respect to the beginning sequential of each test loop (cycle) of IC tester.

As mentioned above, the IC tester produces test pattern and strobe pulse, i.e. test vector based on the digital test vector data of describing with specific tester language (form).This language of ATE (automatic test equipment) that is used for is because of fabricator's difference difference.

Recently, IEEE (electrotechnical, electronic IEEE) proposes a kind of test language STIL (standard testing interface language), as standard testing interface language (ieee standard 1450-1999).STIL provides computer-aided engineering (CAE), as the interface between logic testing simulator and the ATE (automatic test equipment).In CAE environment or EDA (electric design automation) environment, the help of semiconductor device by using computer system is got off to design and is tested this design by logic testing simulator or testing jig.Preferably, use the digital test vector that produces from logic simulation in during with IC tester test practical semiconductor.STIL is designed for and promotes a large amount of digital test vectors from the transformation of CAE environment to the automatic test equipment (ATE) environment.

The STIL test language becomes standard recently.But at present, most of ATE system does not use STIL as native language.These native languages that testing apparatus fabricator provides can not be compatible each other.Therefore, need effectively the STIL test language to be converted to the ATE native language.

Therefore, an object of the present invention is to provide efficiently a kind of and exactly a digital test vector based on the round-robin test language is converted to another method based on the round-robin test language.

Another object of the present invention provides a kind of speech test transition method, can efficiently and exactly be converted to object format to the test vector of STIL (standard testing interface language) form.

In the present invention, the method that test language based on original loop is converted to the test vector of based target round-robin test language comprises following step: read with the utilized waveform of target test language definition and form one group of template of describing waveform, wherein each template is corresponding to a waveform of target test language and comprise the data of the number at one section starting value representing waveform at least and the edge subsequently in the waveform; The waveform of the test vector of reading the test vector of original test language and original test language being represented is decomposed into one group of composition incident (constituent events), and wherein each incident comprises the data of the number at the starting value of representing waveform at least and edge subsequently; The relatively template that obtains from the waveform of target test language and this group incident that obtains from original test language; When detecting when coupling in the comparison step, the Wave data of storage target test language, and fetch the relevant parameter of waveform in the test vector of original test language, and the Wave data of storing this parameter and coupling makes up; All test vectors for original test language repeat above-mentioned steps, thereby form the test vector file of target test language.

Usually, original test language is the STIL (standard testing interface language) of ieee standard 1450-1999 regulation.Preferably, relatively the step of template and this group incident comprises with signal rank (level), ripple kind (wavekind) rank, character level and else changes the step of the different stage of test vector in proper order, wherein, a plurality of ripple kinds constitute signal, and a plurality of characters constitute the ripple kind.

This group incident that obtains from original test language is stored as sheet format, and this table has the row of the data of the number at the expression of being assigned to edge subsequently and starting value.The table of storing this group incident is optimised by the starting value of research particular event based on the done state of the incident generation of front, thereby simplifies the data in the table.

The format sample figure of the STIL of Fig. 1 signal that to be expression describe with the digital test vector of the test vector that constitutes expectation or sets of signals;

Fig. 2 is the format sample figure that expression constitutes the STIL of the edge sequential in each signal of waveform;

Fig. 3 is the format sample figure that the STIL of arrow pattern in each signal that constitutes waveform is described in expression;

Fig. 4 is the format sample figure that the STIL of schema stream in the test vector that constitutes the expectation waveform is described in expression;

Fig. 5 is the format sample figure of expression as the TDL (detecting descriptive language) of the local test language of the ATE system of assignee's exploitation of the present invention;

Fig. 6 A is the schematic diagram according to test language conversion of the present invention, the exemplary plot of the functional configuration of the test language conversion of Fig. 6 B invention;

Fig. 7 represents that STIL structure and TDL of equal value represent example, and expresses the waveform template of representing according to TDL;

Fig. 8 represents other example that STIL structure, the waveform corresponding with this STIL structure and TDL represent;

Fig. 9 represents another example that STIL structure, the waveform corresponding with this STIL structure and TDL represent, is used to explain optimized waveform;

Figure 10 A and 10B are the tables of expression array example, and this array is described starting value and number of edges, and representative is used to carry out the incident that the STIL test vector of pattern match of the present invention decomposes;

Figure 11 is a process flow diagram, and the process of ripple kind of the present invention is mated in expression with the test vector of different stage;

Figure 12 is a process flow diagram, and expression is recycled to the process that ripple kind of the present invention is mated in next circulation from the front;

Figure 13 represents the STIL test vector is converted to the basic thought of the test signal of clock for a long time of TDL, and this moment, the type of DUT pin was suitable for this multi-clock signal;

Figure 14 is the oscillogram of basic thought that expression is converted to the STIL test vector the multiplexed test vector of pin of TDL.

STIL (standard testing interface language) test language limits and uses the pattern and the time sequence information of representing to carry out device detection based on round-robin.Used form is not represented the language of any ATE system, but can be configured to provide when the design test program maximum flexibility.STIL does not just also extensively popularize as standard and its recently.Proposed a plurality of application software recent years, comprised universal test flow process, scan testing methods and ATPG (automatic test pattern generator) based on STIL.Current, most of ATE system does not use STIL as native language.Therefore, need be converted to the native language of target ATE system from STIL.This language is normally based on round-robin, thereby represents to be transformed into another from one based on round-robin.

In this patent specification, the inventor disclose from one based on the round-robin format conversion to another based on some related basic steps of the conversion method of round-robin form.The inventor also proposes some skills, and this makes the conversion of STIL carry out with effective means more.The conversion that the present invention represents is based on data analysis that STIL provides.For describing the present invention, by the detecting descriptive language (TDL) of the Advantest company exploitation of assignee of the present invention Tokyo as the sample object language, the principle that it embodied is general, and is suitable equally for other test language.

The example of the form of the STIL of Fig. 1-4 expression description digital test vector.Fig. 1 represents the form of signal and sets of signals, and Fig. 2 represents the form of edge sequential in each signal.Fig. 3 represents to describe the example of STIL form of the pattern of test vector, and Fig. 4 represents the SYIL format sample of description scheme stream.Fig. 5 represents the format sample figure as the TDL of target test language.

Template matches

Represent to be easy to finish based on the intermediate form of incident from one based on round-robin by using to the conversion of another expression.Here, incident is any variation, as the edge of test vector or not changing with respect to the sequential definition.Describe usually different substantially each other based on round-robin for two.Be converted to another and describe for one is described based on round-robin, to use expression that data decomposition is the basic comprising piece based on the incident of insertion based on round-robin.That is, input resolve into the formation incident based on round-robin form (STIL), and with goal description form (TDL) these incidents of recombinating.

This basic process shows in Fig. 6 A, and it is carried out based on vector to the conversion process based on vector.In the present invention, the test vector of STIL form is resolved into each incident, this incident with compare based on the template that produces as the waveform of the TDL definition of an example of target test language.This notion is represented by the dotted arrow among Fig. 6 A.When finding for certain template matches, the template of mating is listed in the file, transmit parameter in the corresponding STIL test vector to finish waveform to this document.Generate the TDL test vector by this way, shown in the dotted arrow among Fig. 6 A.

Fig. 6 B is of the present invention from the functional representation of STIL test language to the test vector conversion of TDL test language.STIL vector file 21 is files that storage will be converted into the STIL test vector of TDL vector through conversion process of the present invention.Usually, the STIL test vector in the STIL file 21 was obtained by the design phase of semiconductor devices, and promptly CAE (electric design automation) environment or EDA (computer-aided engineering) environment are as the result who carries out logic simulation.The STIL vector is broken down into the formation incident and is stored in the incident file 24 of decomposition.

As mentioned above, TDL is the test language by the exploitation of assignee Advantest of the present invention company, in order to set up test mode logic (LPAT) file.The form of TDL is stored in the TDL ripple kind class file 22.Each waveform of target test language TDL definition is converted into the corresponding template with one group of assembly.This waveform template is stored in the template file 25.

By comparer 26 in execution pattern coupling from the incident of incident file 24 and between from the template of template file 25.When finding coupling, be listed in the file 28 corresponding to the waveform of TDL, this document storing template matched data is represented.And the parameter details of the vector of the template that is used to mate is transferred to TDL﹠amp from the STIL vector; LPAT file 29.This vector details comprises sequential, pattern feature, edge type.Thereby, at TDL﹠amp; In the LPAT file 29, by the TDL test vector of aforementioned transfer process generation corresponding to the STIL test vector.

As an example, with reference to figure 7 and Fig. 8, STIL structure, the TDL of equal value below considering represents and corresponding waveform:

01{‘400ns’D/U；}＝＞NRZ；T1＝400ns；T2＝400ns

Wherein, the STIL structure in left side 01{ ' 400ns}D/U; }Refer to character " 0 " and specify negative edge (D), and character " 1 " is specified rising edge (U) at 400ns at 400ns.This STIL represents the waveform represented in the upper part corresponding to Fig. 8 and with non-return-to-zero (NRZ) waveform of TDL definition.In Fig. 8, the waveform of character " 0 " is represented the dash area (leaving beginning edge 400ns) from the beginning edge of test loop to drop edge T1.Dash area represents that this regional logic state is undefined.Thereby regardless of current logic state, character " 0 " all begins to define drop edge T1 at 400ns from test loop.Similarly, regardless of current logic state, the waveform of character " 1 " all begins to define drop edge T1 at 400ns from test loop.As mentioned above, this example of STIL structure is corresponding to the NRZ waveform of TDL.

Therefore, in conversion method of the present invention, use template matching method to finish the structure of describing the TDL waveform with the STIL waveform that decomposes.The waveform that can be used for given tester is read into also so that the mode that template is mated is easily stored when operation.Like this, the first step is set up template list to each waveform, as the NRZ that defines among the TDL.Template is characterised in that with this group { pattern feature, starting value, number of edges } subsequently describing waveform.Shown in the lower part that is illustrated in Fig. 7 of the NRZ waveform in the above-mentioned example.

In the template example of Fig. 7, the first module of each row is a mode characteristic, and it is right to connect following two unit representatives { starting value, number of edges subsequently }, and residual term is represented the title of particular edge.Shang Mian example can use the NRZ waveform to represent with following value thus:

01＞=0,0,0}, 0,1,1 400ns D}, 1,0,1,400ns U}, { 1,1,0} wherein shows { mode characteristic, starting value, number of edges subsequently }.The storage of all waveforms that limit by this way with target test language (being TDL in this example) allows the STIL waveform that will decompose and the performance (eapabilities) of given waveform simply to contrast.Thereby, in the template file 25 of Fig. 6 B, prepared template base.

In comparison, relatively STIL waveform of Fen Xieing and the template of TDL.The STIL waveform is broken down into each incident of expressing with the combination of starting value and number of edges.In the starting value of each incident of description STIL waveform and the incident file 24 that the number of edges destination data is stored in Fig. 6 B.Thereby, incident of decomposing by relatively starting value and number of edges and the comparison between the template.This conduct is carried out the inquiry of waveform, is inquiry basically: " can support many like this edges with this starting value? "

Should note tlv triple (triples) coupling of the composition waveform that the STIL waveform obtains to the mapping requirement and the result of template.In the above in the example, cause 4 tlv triple shown in the template of Fig. 7 from the character " 01 " of STIL.All these four tlv triple are all mapped, to represent these characters fully.Example hereto, NRZ can support the tlv triple of all requirements.

As another example of basic templates coupling, with reference to figure 8, STIL character, TDL below considering represent and waveform:

0{}1{‘200ns’U；’400ns’D；}＝＞RZ；T1＝200ns；T2＝400ns；

It is corresponding to (RZ) waveform that makes zero of TDL, and its waveform shows at the center section of Fig. 8.Thereby the template of the RZ waveform of TDL is set in the template file 25 of Fig. 6 B.

Template matches example shown in the part is very simple in front.Their direct and reference waveform, NRZ and RZ couplings.These waveforms can be used on the testing apparatus of moving with TDL, and it does not have any resource scarcity (resource penalty).But, in the Test Application of reality, also use more complicated waveform.Consider to have the following Example of the waveform shown in the first half of the lower part of Fig. 8 and Fig. 9: 01{ ' 100ns ' D, ' 200ns ' D/U; ' 400ns ' D}.This example mean character " 0 " specify negative edge at 100ns, negative edge at 200ns and negative edge at 400ns, wherein at least two edges are unnecessary and reality is not retained.Character " 1 " specify negative edge at 100ns, rising edge at 200ns and negative edge at 400ns.

Pattern character " 0 " can pass through NRZ or RZ Waveform Matching.Pattern character " 1 " will require more complicated waveform, as have value T3=100ns, T1=100ns, the XOR of T2=400ns (XOR OR).There are many reasons not wish to occur this situation.At first, if these two character reality can be used to (and their definition makes that this point is very possible) in the mode block, this will cause the type of flying (on-the fly) ripple kind conversion (switch).In a lot of ATE systems, this causes available resource-constrained.And in some systems, the use of XOR waveform can cause the minimizing of tester under some situation.Obviously this is not a desirable scheme for the Waveform Matching problem.Thereby following detailed description can be used for simplifying some skills of complicated match condition.

Untapped initial value

In STIL, all about information directly appearance in the waveform table structure of the waveform that will be used.This information is analyzed to determine available waveform characteristic.This information can be used to notify (informed) to optimize.In this part, check how the notion of " untapped initial value " helps to optimize to check.

At first, although should note using discontinuous character, a group mode character that offers given signal all defines continuous wave.Therefore, the initial state of given character experience is based on done state that the front character produced.Therefore this group end value is included in the information in the waveform table.The exception of this state is the signal starting value, and it can be provided with arbitrarily by the user.For making template matching algorithm optimization, it is indispensable that the user makes the selection of knowing perfectly well for starting value.

Again with reference to above-mentioned example, and express repeatedly among Fig. 8 and Fig. 9: 01{ ' 100ns ' D; ' 200ns ' D/U; ' 400ns ' D; And corresponding waveform.The complete process that this group character has been shown causes unwanted results.In analyzing this group character, known they with the end of " U " (risings) value.Therefore, by with " D " (decline) value initialization signal, and these are only available characters, and character will begin circulation never in " U " state.Waveform shown in the bottom left section of Fig. 9 describe reduce (almost) to shown in the lower right-most portion of Fig. 9 like that.Therefore, available simple R Z waveform (T1-200ns; T2=400ns) with this group character match.

Based on the table of analyzing

By untapped initial value notion, the mechanism of the waveform table of analyzing based on the STIL character is described with reference to the flow process of the table of figure 10A and 10B and Figure 11 and 12.This allows the requirement of all pattern characters is classified and formed the compound expression (composite representations) of these data with several levels (being S11 among Figure 11).Notice that these data need not compiled at all pins or pin group two ends, but only in signal, compiled.For each signal, the waveform condition data compiles with three ranks (S12 among Figure 11).

1. whole signal

Waveform table and

3. each pattern character

In theory, wish to use the behavioural characteristicization of single ripple kind to whole signal, thereby with these rank compiling data.This point has been failed, and then next logical level is a waveform table.Suppose that the converted-wave table does not often take place, and occurs over just from a mode block probably to another mode block during pattern.And if the conversion between the mode block takes place with the rank of PatternExec piece, these will be classified as the different test in the TDL coding, and any difference of ripple kind will not cause flying the type conversion.

At last, if the behavior of the pattern character in the waveform table can not be represented with single ripple kind, will attempt on each character rank, to mate.If this point has been failed, indicating that some the pattern characters in the STIL file comprise the unappeasable condition of test language of target ATE system.In some cases, the more advanced feature of target ATE system can be used to alleviate these problems.Under the other situation, this only reports out as a fatal error in the transfer process.

The data that will store with each rank of above-mentioned expression are identical on starting value that STIL pattern character requires and number of edges.This is stored as array, the characteristic of the dimension based target ATE system of this array.Above-mentioned by using " untapped initial value " technology can obviously reduce the capacity of array.Time number that the driving edge of being supported is set is read into when operation and used as being the one dimension of array each time.Another dimension is 2, may the starting value number be " 1 " or " 0 " in binary-logic system.Need the starting value of support and each combination of number of edges to be set to very (T).All the other are false (F).

Like this, for above-mentioned example:

0{}1{‘200ns’U；’400ns’D}＝＞RZO；

T1＝200ns；T2＝400ns

Array looks like the table shown in Figure 10 A, supposes that wherein each time is provided with maximum and can supports 4 to drive the edge.For another example:

23{‘100ns’D，‘200ns’D/U；‘400ns’D}

The table of Figure 10 B comprises additive term.This table has been described all information about these four waveform characters.Above-mentioned untapped initial value technology can be used for this table, because " 1 " is the initial value (unless being provided with during initialization) that produces never.As a result, the permutation that indicates " 1 " can be set to vacation, and this makes and produces and original identical situation with reference to the lower-left of figure 9 and the described situation of waveform in the lower right-most portion.This mechanism can be applicable to the table with any rank generation, and this rank is signal, waveform table and the pattern character of being discussed.

Provide description more specifically below about the template matches process.As mentioned above, each array (coupling array) of incident that forms the decomposition of starting value and number of edges produces in the incident file 24 of Fig. 6 B, with template file 25 in corresponding Wave data compare.In case produce above-mentioned " coupling array ", and this array reduced, realize coupling (S13 among Figure 11) to available waveforms by analyzing " untapped initial value ".As mentioned above, the waveform that can use of target ATE system (reading in when operation) is stored based on starting value and the number of edges supported in template file 25.Similar in the template is in above-mentioned coupling array, and except following this point: the item in each frame of the table of Figure 10 A and 10b is the set of ripple kind pointer to object of satisfying the combination of indicated starting value and number of edges.

Should notice that given ripple kind can appear among these tabulations several, this is because they can support that multiple { starting value, number of edges } is right.For example, will 0,0}, 0,2}, 1,0} and 1, find the RZO waveform in the 1} array element, because it can support all these combinations.Note, this reference be the RZO waveform of TDL, wherein do not have the activity (activity) of pattern character " 0 ".Thereby, exist 1, the 0} combination.For pattern character " 1 " and " 0 " industrial standard RZ; Waveform will return zero, and can not have 1, the 0} combination.

All combinations that ripple kind class object is supported it are all inquired about.For example, for through 0,0} item visit RZO object, matching process can simply be inquired the RZO object with regard to other combination: " support 0,2}? ", its result return true and " support 1,2}? ", its result returns vacation.Like this, matching process will be through { starting value, number of edges } minimum on the desired numeral to finding object, and the remaining expectation state of inquiry object.If any one has been failed in these inquiries, this ripple kind will not worked, and matching process proceeds to next in the original list and attempts this process once more.

In case after having carried out successfully coupling for given ripple kind, parameter value (S14 of Figure 11) must be set.The STIL character that decomposes comprises the time value of transformation, and ripple kind class object comprises the name character string of their relevant resource.For the situation of RZO waveform, and 0, the coupling of 2} situation with time value 200ns be associated with character string " T1 ", 400ns is associated with character string " T2 " and finishes.These pairings are stored in the table of the STIL character " 1 " that defines corresponding to waveform table.

When source format is based on round-robin, the advantage of available economy is arranged based on the analytical approach of waveform table.Information about the form that will be used to whole process is at first available, and its can be processed before mode switch begins, analyze and optimize.In case this finishes, vector is handled and is become very simple.STIL pattern character accessed (access) (S21 of Figure 12), recall to the signal value (being stored in the end of previous cycles) of (S22 of Figure 12) front and these data are used for visit for { starting value, STIL pattern character } to institute's canned data, promptly determine ripple kind and parameter information (S23 of Figure 12 and S24) by matching process.Afterwards, the storage end value begins (S25 of Figure 12) to be used for next round-robin.

This obviously is different from the situation that source format is based on incident, for example the VCD of verilog (value changes dump Value Change Dump) data.In this case, the ripple format information is not available at first usually.During processing vector, must carry out the coupling of source data and object wave shape.This can cause the relatively poor selection that can be avoided when using correct table analysis method.

Suppose following two circulations in waveform: if on a basis that is recycled to circulation (cycle-by-cycle), carry out template matches (this is not based on the normal condition of the analysis of table), first circulation may finish to be mapped to NRZ, and this is the simple wave form that satisfies system's predetermined parameter (constraints).Second circulation obviously is RZO.If it is known handling second circulation of first circulation time, first circulation also can be mapped to RZO, to fly the type conversion on preventing.Analytical approach based on table just provides this performance.

The output signal conversion

The description of front concentrates on the mapping of input STIL character to the TDL equivalents.Here, " input " refers to provides (driving) to give the test pattern of the pin of the device in the test.As previously mentioned, test vector comprises test pattern (input) and gating (output or comparison).Gating is the time sequential pulse of edge (not having pulse width) or window (predetermined pulse width), so that the device output signal is sampled.Here, the output mapping policy of description relates to the gating signal (comparison) of conversion STIL form to the TDL form.The state of STIL file appointment can directly be translated into the pattern character.For example, if all are all available, LHZX{ ' 0ns ' Z then; ' 0ns ' X; ' 260ns ' L/H/T/X} can directly be mapped to the edge gating of appropriate value.In other words, template matches is unnecessary in this is handled.Similarly, can be LHZX{ ' 0ns ' Z; ' 0ns ' X; ' 260ns ' l/h/t/x} is mapped to suitable window gating.

Having some to make about the output conversion notes.The firstth, some ATE do not allow to fly the conversion of type gating type.Like this, cannot mixed edge and window gating.Solution in this case is to make all be gated for the window gating, and the edge gating is made the narrowest window that system allows.Second be require in the circulation a plurality of gatings STIL pattern character can with target ATE system compatible or incompatible.The performance of family of ATE system is put into crossover tool, read source file in working time, with actual the appearing in the given target ATE system of which subclass of representing these features.This will comprise the state such as transformation and double-gate pattern.

The two-way signaling conversion

The two-way signaling conversion is the most complicated in whole process.Here, term " two-way " refers to for being assigned to test language as the test vector of the device pin of input and output from the conversion of STIL form to the native language form.Desired all features of above-mentioned input and output coupling all occur, and the proprietary supplementary features of two-way signaling are arranged.In addition, two-way signaling limits to some extent to above-mentioned test resource usually, and exceeds simple input and output setting.For example, owing to need the driver control signal to determine the direction state of two-way signaling, available number of edges is reduced.

The consideration of driver control is based on the performance of STIL pattern character feature and target ATE system.The standard example provides two driver start-up mode, simulation NRZ behavior, and another is used for RZ.Under the former situation, circulate in some some places and become " driving " (input) and all keep like this up to loop ends.For RZ, circulation becomes " driving " and in cycle period " comparison " (output).Note the circulation of " comparison " pattern and do not mean that actual comparing, only the vial pin is used as output.Consider the driving that is used for circulating and the target ATE performance of comparison, this difference is very important.

Notice that NRZ driver start-up mode requires tester still less, thereby be preferred, determine the driver start-up mode from the STIL mode characteristic thus.Unless the RZ pattern is used in specific (special) requirements, otherwise all selects this pattern.Just use the situation of RZ pattern when only " driving " zone is surrounded by " comparison " zone in same circulation.In fact comparison may not take place, and only be that device pin is used as output in explanation once more.The time value at driver control edge is determined from the fringe time of sense.

It is more complicated to comprise that type of driver information makes above-mentioned " coupling array " handle.The drive part of signal and available Waveform Matching, and the whole character of round-robin, just " driving " and " comparison " part compares with the performance of target ATE system.STIL comprises the notion of " driving preferential " incident.Comprise the most recently used motivation value in this meaning work system.For input signal, existing motivation value is last state of signal always, and this point does not need to consider.Output signal does not have driving condition, thereby this point is uncorrelated.Like this, drive preferentially only relevant with two-way signaling, wherein no matter have any in the middle of the gating behavior, it all represents last driving condition that signal obtains.In some ATE systems, the appearance of gating character influences the state of driver in the system.For example, if last " drivings " state is " D ", and the back be " H " and gating, can be set to " U " state for next one driving circulation driver." drive preferential " and be intended to handle this situation.Consider transition process, this existing state must keep the actual current state of driver.The result is corresponding to all possible to { preceding face amount drives preferential } like this, above shown in " coupling array " comprise 4 hurdles rather than 2 hurdles, promptly column headings (Figure 10 A and 10B) be 0,0}, 0,1}, 1,0} and 1,1}.

The data of using in these must correctly be used for " driving preferential " notion, so that correct work.Must be consistent as the original state of wanting that provides by " drive preferential " with the original value of the virtual condition one of driver.Use previous example, driver is in " U " state, owing to comprise " DrivePrior " or " P " incident in describing, STIL pattern character requires device to be in " D " state.Select to mate this pattern character waveform must with these values coordinations, the time on request pin from " U " state-driven to " D " state.This causes from STIL pattern character is described and the not obvious additional edge of finding out.

Special characteristic

With regard to the processing of the special characteristic that provides in the target testing system test language conversion is discussed further below.Those features that these feature representatives are found in assignee's ATE system, Advantest ModelT6600IC tester family, but they are very common and can find with some forms on various test macros.Like this, only do simple discussion to being used to shine upon STI1 information to the algorithm of these features.

Clock (multi-clock) signal for a long time

Clock (MCLK) signal type is commonly used to provide than the more pulse of the available pulse of ATE Systems Theory in each circulation for a long time.By being tester circulation disjunction that a series of subcycle (inside) and the copy that a plurality of basic waveforms are provided (one of each subcycle) produce waveform repeatedly fundamentally.The result be than test in the specified circulation the more edge, edge that may occur.

Use the key of MCLK example to be that waveform must comprise substantially repeatably unit in circulation.During above-mentioned template matching algorithm, the discovery that STIL pattern character comprises too many edge causes attempting to use the MCLK form to mate character.For this point can be proved effective, number of edges must be even number (the MCLK form is based on pulse).Consider the top waveform of Figure 13, can obtain the repeatably waveform condition that must satisfy of individual pulse.

For having repeatably unit, require all pulse widths identical.And, pulse distance must equal spacing (A) before first pulse add last pulse end spacing (B) and, as illustrated.This means to have substantially repeatably unit, this unit looks like T1=A, and the RZ of T2=A+PW and subcycle length are A+PW+B.If do not satisfy any one of these conditions, but monopulse repetitive substantially can not be provided.

But may produce dipulse repetitive substantially.Its requirement can obtain according to the following waveform of Figure 13.In this case, but each repeatable block has two pulses, and requires corresponding pulse width identical, and pulse indicates PW1 and PW2 in this case.Beginning and finish spacing summation must and the pitch match between the unit repeatedly, (unitary space that can be repeatedly=A+B) as mentioned above.And the spacing C between the pulse must be identical for all unit repeatedly.Like this, in this case, subcycle length is A+PW1+C+PW2+B.

Pin is multiplexed

In pin is multiplexed, makes up two tester channels and drive single pin.This makes the resource of two tester channels be used to same signal, and carries out in feasible driving (input) and comparison (output) same circulation in the ATE system, otherwise this point is unavailable.

Although use PMUX to make that the ATE programmed tasks is easier, it has increased the complicacy of transfer process by extra degree of freedom is provided.Can provide dirigibility although seem to wish it, make that the search of ripple kind space-like is slightly difficult, this is because there is not constraint condition exactly.

Discuss with regard to the implication of the PMUX on the various pin types below.

(1) input PMUX

The input pin mapping attempts to mate the performance of ripple kind by search ripple kind space-like and the condition of STIL pattern character is carried out.Done discussion above the details of this method.When input signal used PMUX, the responsibility of the condition of coupling STIL pattern character was shared between two tester channels.The problem that dirigibility brought that increases is one of definite " sharing condition " method.

A method that adopts is the simplest algorithm of not sharing of sharing.If possible, a pin is made all working, and another does not then do anything.As a result, a kind of trial is to first tester channels all edge map of STIL pattern character appointment.Here the coupling of Fa Shenging is with identical for the above-mentioned coupling of non-PMUX input signal.If coupling is attempted failure, promptly do not satisfy some subclass of the condition of STIL pattern character, then occur different.In the past, this situation or cause attempting to use MCLK perhaps caused reporting errors.Use under the situation of PMUX, an edge is moved to second channel from first passage, respectively first passage and second channel are attempted coupling.The mobile of edge proceeded, and all can mate up to the condition for all groups of two passage STIL pattern characters.

Algorithm increases complicacy hereto is need keep two to form the continuity of row of passages between being.Given passage " memory " is from its final state of last round-robin.But driver to the state of device by signal setting from the another one passage.For example, if passage 1 drives pin to " H " state, " H " will be as its original state.Now, suppose that passage 2 drives pin to " L " state, because the effect driver of passage 2 in fact but is in " L " state.Require two cooperations between the passage that comprises signal to prevent this situation.

As an example, consider the following signal of the top waveform of Figure 14: T0 represents loop limit.This signal is very simple, and is rendered as and has the NRZ character that is used for first signal.In fact, secondary signal does not obviously need to do anything except that keeping low level.Consider first solution of this problem, as shown in figure 14.

The signal that proposes for passage (pin) 1 provides rising edge at Ta, (second waveform at top among Figure 14) as desired.Because the second portion at signal does not have the edge, pin two does not need edge (the 3rd waveform at top among Figure 14).In the round-robin second portion, there is one to lower limb.Because pin two is in " L " state, does not produce the edge.

Obviously see that from this example in this case, straightforward procedure is inoperative.Because pin two does not have the edge, signal is with the waveform on the very similar pin one.This thing happens is because do not keep the continuity at passage two ends.Pin two need recognize that pin one finishes with " H " state, thereby will correctly keep in the system edge subsequently under the situation of " L " that be converted to the second round-robin Ta place.This can finish by the waveform of pin two above replacing with the waveform shown in Figure 15 bottom.

Here, sliced time pin two waveform be brought into " H " state.This is to not influence of composite signal, because because the effect driver of pin one is in " H " state.But it regulates pin two really, makes itself and pin one that consistent state be arranged.When the pin two part of devices to lower limb in second circulation when producing, this causes the downward transformation on the pin two at Tb place, just as desired.This proof must the treatment channel consistency problem for the PMUX signal.

(2) output PMUX

For with the coupling of normal mode, the conversion of output signal is simpler than the input conversion when PMUX exists.Circulation is divided into two parts, and the gating edge is assigned to two passages (pin) based on its position with respect to sliced time.For simply, be chosen as the centre in cycle sliced time.The gating edge that took place before this time is assigned to first passage, and take place afterwards those be assigned to second channel.The exception that can note of this rule is the window gating.Boundary segmentation that can be between passage they.Therefore, select make whole window gating fall in the passage sliced time.

(3) two-way PMUX

Use PMUX to allow to use other situation with two-way signaling with disabled those features.This is mainly used in the PMUX structure, rather than the pure signal that inputs or outputs.The most important applications of possible PMUX is if target ATE system does not allow to drive in the circulation and relatively, it also allows such execution.Specify the situation of a pure driving of round-robin or comparison behavior for the STIL pattern character of two-way signaling, handle actual with on to regard to the multiplexed situation of input and output pin described identical.When behavior is mixed, between passage, cuts apart round-robin and be based on direction conversion (switch) time sliced time.This causes two very natural responsibilities of interchannel to be cut apart.The notion continuous for the passage two ends of input signal discussion also is applicable to this, but the effect of gating in the middle of also must considering.

As mentioned above, according to the present invention, efficient and pin-point accuracy ground is converted to the target test language to the test vector of original test language.

Although certain illustrative and described only preferred embodiment here should be understood not deviating from spirit of the present invention and be intended under the situation of coverage and can carry out multiple modification and distortion to the present invention in the scope of the hint of above-mentioned instruction and appended claim.

Claims (8)

1. one kind the method that is converted to based target round-robin test language based on the test vector in the test language of original loop, comprises following step:

Read the utilized waveform that defines in the target test language and form one group of template of describing waveform, wherein each template is corresponding to a waveform of target test language and comprise the data of the number at one section starting value representing waveform at least and the edge subsequently in the waveform;

Read the test vector of original test language and the waveform of the test vector in the original test language is decomposed into one group of composition incident, wherein each composition incident comprises the data of the number at the starting value of representing waveform at least and edge subsequently;

The relatively template that obtains from the waveform of target test language and this group composition incident that obtains from original test language;

When detecting when coupling in the comparison step, the Wave data in the storage target test language, and retrieve the relevant parameter of waveform in the test vector of original test language, and the Wave data of the described parameter of storage and coupling makes up;

All test waveforms for original test language repeat above-mentioned steps, thereby the waveform that forms the target test language is represented.

2. according to the method for the conversion testing vector of claim 1, the step of wherein said relatively template and this group composition incident comprises: rank, other order of character level with signal rank, ripple kind are implemented comparison algorithm in different extraction ranks, wherein a plurality of described ripple kinds constitute described signal by the rank of described ripple kind, and a plurality of described characters constitute described ripple kind by described peace symbol kind rank.

3. according to the method for the conversion testing vector of claim 1, wherein, this group composition incident is stored as sheet format, and this table has the row of the data of the number at the expression of being assigned to edge subsequently and starting value.

4. according to the method for the conversion testing vector of claim 3, the table of wherein storing this group composition incident is optimised by the starting value of research specific composition incident based on the done state that previous groups becomes incident to produce, thereby simplifies the data in this table.

5. according to the method for the conversion testing vector of claim 1, wherein test vector comprises that the device that will offer in the test is as the drive signal of importing, and the gating signal that the output of device in the test is sampled and assessed, wherein, by relatively template and this group composition incident are checked coupling, the drive signal of original test language is converted to the target test language, and the gating signal of original test language is directly translated into the target test language simultaneously.

6. according to the method for the conversion testing vector of claim 1, wherein the waveform of the original test language of resource limit requirement place is assigned to a plurality of subcycles of target test language, wherein produce described a plurality of subcycle by multiplexed test loop clock in test macro, this test macro is operated by the target test language.

7. according to the method for the conversion testing vector of claim 1, wherein the waveform of original test language is assigned to a plurality of test channel of target test language, wherein with multiplexed these a plurality of test channel of the mode of test system configurations, to be connected to the single pin of the device in the test, this test macro is operated by the target test language.

8. the test vector standard testing interface language STIL is converted to the method for based target round-robin test language, comprises following step:

Read the utilized waveform that defines in the target test language and form one group of template of describing waveform, wherein each template is corresponding to a waveform of target test language and comprise the data of the number at one section starting value representing waveform at least and the edge subsequently in the waveform;

Read the test waveform of standard test interface language STIL form and the waveform of the test vector of standard testing interface language STIL form is decomposed into one group and form incident, wherein each composition incident comprises the data of the number at the starting value of representing waveform at least and edge subsequently;

The relatively template that obtains from the waveform of target test language and this group composition incident that obtains from standard testing interface language STIL waveform;

When detecting when coupling in the comparison step, the Wave data of storage target test language, and the relevant parameter of waveform in the test vector of search criteria test interface language STIL, and the Wave data of this parameter of storage and coupling makes up;

All test waveforms for standard testing interface language STIL repeat above-mentioned steps, thereby form the test vector file of target test language.

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