JP4679351B2 - Protocol test apparatus and protocol test method - Google Patents

Description

  The present invention relates to a protocol test apparatus and a protocol test method, and more particularly to a protocol test apparatus for performing a protocol test of a test target apparatus by generating a transaction of a pattern according to a predetermined protocol, and a protocol test method using the protocol test apparatus About.

A protocol test is performed using a protocol checker at the time of operation check and performance evaluation of various interface devices. FIG. 11 is a diagram showing the role of the protocol checker.
The protocol checker 901 is connected to a signal path between a master 902 and a slave 903 that perform communication according to a predetermined protocol. In the illustrated example, when an access request (REQ) is transmitted from the master 902 according to the protocol, communication is performed such that the slave 903 that has received the request returns a response (ACK). The protocol checker 901 monitors the signal state between the master 902 and the slave 903, and outputs an error (ERROR) when a protocol violation is detected.

  As described above, the protocol checker plays an important role in the protocol test. Therefore, it is necessary to confirm whether the protocol checker operates correctly. In the test of the protocol checker, it is confirmed that ERROR is not generated when it is normal (communication conforming to the protocol is performed) and that ERROR is generated when it is abnormal (protocol violation occurs).

  FIG. 12 is a diagram showing a conventional protocol checker test method. In the conventional protocol checker test, protocol violation scenarios 905 that cause protocol violations are manually created one by one and are executed by the simulation control device 904. The simulation control apparatus 904 sends a protocol violation signal to the protocol checker 901 in accordance with the procedure of the protocol violation scenario 905, and confirms whether the protocol checker 901 generates a desired ERROR.

If the protocol violation scenario 905 is applied to the master 902 or the slave 903, the protocol test of the master 902 or the slave 903 can be performed.
In addition, set an operation command to ignore the frame, discard the frame to be sent, or change the frame to be sent to another frame and send it to the device under test to generate normal and abnormal conditions. There has also been proposed a protocol test method for performing (see, for example, Patent Document 1).
JP-A-6-244835 (paragraph numbers [0005] to [0006], FIG. 1)

However, a test using a conventional protocol test apparatus has a problem that it is difficult to perform sufficient verification.
Conventionally, for example, in order to check whether a protocol checker detects an abnormality as specified, it is necessary to manually create a scenario that causes a protocol violation, and it is difficult to create various patterns. It was.

  A simple example will be described. FIG. 13 is a diagram illustrating an example of protocol specifications and protocol violations. (1) is a diagram showing a signal state in a normal state according to the protocol specification of this example, and (2), (3) and (4) are diagrams showing signal states at the time of protocol violation. . 11, REQ is an output signal of the master 902, ACK is an output of the slave 903, and ERROR is an output signal of the protocol checker 901.

  FIG. 13 (1) shows the protocol specification of this example. When the master 902 makes an access request, REQ is asserted, and when ACK is asserted by the slave 903, it is disabled in the next cycle of the clock signal (CLK). Assert. REQ continues asserting until ACK is asserted. On the other hand, the slave 903 asserts ACK within 4 cycles when REQ is asserted, and deasserts it in the next cycle.

  For such a protocol, in (2), the master 902 asserts REQ, but deasserts before ACK is asserted by the slave 903. In this case, the protocol checker 901 generates ERROR in the next cycle after detecting that REQ is deasserted. In (3), the master 902 asserts REQ and the slave 903 asserts ACK, but is not deasserted. In this case, the protocol checker 901 generates ERROR in the next cycle after detecting that REQ is not deasserted. Further, in (4), the master 902 has not asserted REQ, but the slave 903 has asserted ACK. In this case, the protocol checker 901 generates ERROR in the next cycle after detection of ACK assertion. In addition, abnormal states are assumed such as when the master 902 asserts REQ but the slave 903 does not assert ACK even after 4 cycles, or when the slave 903 asserts ACK and does not deassert in the next cycle. The In conventional protocol tests, scenarios had to be created for each of these cases.

  Further, in the illustrated example for the case of individual patterns, eg (2), REQ is deasserted in one cycle, but REQ is asserted / deasserted in two or three cycles before ACK is asserted. Scenarios can also be assumed, and the number of scenarios that must be created further increases. As described above, even in the case of a simple protocol given as an example, a large number of protocol violation scenarios are required when testing is performed covering all items. If these are performed manually, not only will the load on the operator become heavy, but items may be missing. The same applies to a test performed by setting an operation command.

  In addition, there is a problem that it is impossible to quantitatively measure how much of the test items assumed based on the protocol has been completed. For example, if general coverage such as code coverage is used, programs and data that have been verified can be measured, but it has not been possible to measure how much the protocol test range has been covered.

  In addition, when the protocol checker 901 generates ERROR, the simulation is stopped and the state is maintained. In order to start the test with a different pattern, a manual reset had to be performed once. In addition, since each scenario is executed, it is difficult to create a situation in which an abnormal state occurs after a normal state continues for a predetermined period. In this way, there is a problem that it is not possible to continuously perform tests, and in order to perform tests of various patterns, complicated work is required.

  The present invention has been made in view of the above points, and provides a protocol test apparatus and a protocol test method capable of easily executing a protocol test of various patterns assumed according to a protocol. Objective. Another object of the present invention is to quantitatively measure how much the protocol test range is covered.

  In order to solve the above problems, the present invention provides a protocol test apparatus as shown in FIG. The protocol test apparatus includes a control unit 1a, a timing unit 1b, and a transaction generation unit 1c that operates as a pseudo master 2 and a pseudo slave 3.

  The control means 1a sets the time instructed in advance in the time measuring means 1b as a switching time for switching the normal operation mode and the transaction generation means 1c from the normal operation mode to the abnormal operation mode, and generates a transaction according to the device under test. Control means 1c. The normal operation mode is an operation mode in which a transaction conforming to a predetermined protocol is generated for the device under test, and the abnormal operation mode is an operation mode in which a transaction violating the predetermined protocol is generated for the device under test. The time measuring means 1b measures the set switching time, and when the switching time has elapsed, switches from the normal operation mode to the abnormal operation mode. The transaction generating unit 1c operates as a pseudo master 2 or a pseudo slave 3 depending on the test target device. The transaction generating means 1c includes a normal operation pattern storage unit 2a that stores a normal operation pattern that defines an operation in a normal operation mode, and an abnormal operation pattern storage unit 2b that stores an abnormal operation pattern that defines an operation in an abnormal operation mode. In the normal operation mode, the normal operation pattern storage unit 2a is selected. In the abnormal operation mode, the selection unit 2d selects the abnormal operation pattern storage unit 2b, and the selected normal operation pattern storage unit 2a or abnormal operation pattern storage unit 2b operates. It has a transaction generation unit 2e that reads a pattern and generates a transaction based on the operation pattern.

  In such a protocol test apparatus, the transaction generating means 1c is operated as the pseudo master 2 or the pseudo slave 3, or the pseudo master 2 and the pseudo slave 3 depending on the test target apparatus. The control means 1a sets the normal operation mode, sets the switching time in the time measuring means 1b, and starts the protocol test. Along with this, the time measuring means 1b starts measuring the switching time, and the transaction generating means 1c (the pseudo master 2 and the pseudo slave 3) starts processing. The case of the pseudo master 2 will be described. The normal operation mode is maintained from the start of the protocol test until the time measuring means 1b detects the elapse of the switching time, and the selection unit 2d selects the normal operation pattern storage unit 2a. The transaction generation unit 2e reads the normal operation pattern from the normal operation pattern storage unit 2a, and generates a transaction based on the normal operation pattern. Thereby, the device under test can perform a normal operation check. The time measuring means 1b detects the elapse of the switching time and switches the normal operation mode to the abnormal operation mode. In the pseudo master 2, the selection unit 2d selects the abnormal operation pattern storage unit 2b, and the transaction generation unit 2e generates a transaction based on the abnormal operation pattern read from the abnormal operation pattern storage unit 2b. Similar processing is performed for the pseudo slave 3. Thereby, the apparatus under test can check the operation at the time of abnormality.

  In addition, in order to solve the above-mentioned problem, in a protocol test method in which a protocol test is performed by generating a transaction of a pattern according to a predetermined protocol, the control unit generates a transaction conforming to the predetermined protocol for the device under test. When the normal operation mode is selected, the protocol test is started by setting the switching time for switching from the normal operation mode to the abnormal operation mode that generates a transaction that violates the specified protocol to the device under test. The means selects a normal operation pattern storage unit that stores a normal operation pattern that defines the operation in the normal operation mode, and generates a transaction based on the normal operation pattern read from the normal operation pattern storage unit. Time the set switching time When the switching time elapses, the normal operation mode is switched to the abnormal operation mode, and when the operation mode is switched to the abnormal operation mode, the transaction generating means stores the abnormal operation pattern that defines the operation in the abnormal operation mode. There is provided a protocol test method characterized by having a procedure for selecting a storage unit and generating a transaction based on an abnormal operation pattern read from the abnormal operation pattern storage unit.

  According to such a protocol test method, when the control unit sets the switching time in the time measuring unit and starts the protocol test, the transaction generating unit generates a transaction conforming to the protocol using the normal operation pattern. When the time measuring means detects the elapse of the switching time and switches from the normal operation mode to the abnormal operation mode, the transaction generating means generates a transaction using the abnormal operation pattern.

  In the present invention, the protocol test apparatus generates a transaction based on a normal operation pattern until an arbitrarily set switching time elapses, and generates a transaction based on an abnormal operation pattern after the switching time elapses. . In this way, a desired protocol test can be easily executed by switching the transaction supplied to the device under test from the normal state to the abnormal state at an arbitrary timing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the concept of the invention applied to the embodiment will be described, and then the specific contents of the embodiment will be described.
FIG. 1 is a conceptual diagram of the invention applied to the embodiment of the present invention.

  The protocol test apparatus according to the present invention includes a control unit 1a, a timing unit 1b, and a transaction generation unit 1c that operates as a pseudo master 2 or a pseudo slave 3. Here, a series of events executed between the communication master and the communication slave according to the selected operation pattern is referred to as a transaction.

  The transaction generation means 1c is a pseudo master 2 that simulates the operation of the communication master, a pseudo slave 3 that simulates the operation of the communication slave, or the pseudo master 2 and the pseudo slave 3 according to the test target device according to the control means 1a. Operate. For example, when performing a protocol checker test for checking whether communication between communication devices conforms to a protocol, the protocol checker is connected and operated as a pseudo master 2 and a pseudo slave 3 to thereby establish a communication master and a communication slave. Signals and data states based on the communication protocol executed between them can be reproduced and supplied to the protocol checker for testing. When testing a communication slave, the communication slave is connected and the protocol test apparatus is operated as a pseudo master 2 to reproduce signals and data states transmitted from the communication master to the communication slave. Can be supplied. When testing the communication master, the test can be similarly performed by operating the protocol test apparatus as the pseudo slave 3.

  The control unit 1a controls the entire protocol test by setting the designated switching time in the time measuring unit 1b and performing control to operate the transaction generating unit 1c as the pseudo master 2 and the pseudo slave 3.

  The timing means 1b measures the switching time set by the control means 1a, and when this switching time has elapsed, switches the normal operation mode of the pseudo master 2 and the pseudo slave 3 to the abnormal operation mode.

  Hereinafter, a case will be described in which the test target apparatus is a protocol checker and the transaction generating unit 1c is operated as a pseudo master 2 and a pseudo slave 3. Here, the protocol checker is connected to the protocol test apparatus so that the REQ (4a) output from the pseudo master 2 and the ACK (4b) output from the pseudo slave 3 are input.

  The pseudo master 2 includes a normal operation pattern storage unit 2a, an abnormal operation pattern storage unit 2b, a setting unit (random generator) 2c, a selection unit 2d, and a transaction generation unit 2e. The pseudo slave 3 has the same configuration.

  The normal operation pattern storage unit 2a is a storage unit that stores a normal operation pattern that defines the operation of the pseudo master 2 in a normal operation mode in which a transaction conforming to a predetermined protocol is generated for a test target device. The abnormal operation pattern storage unit 2b is a storage unit that stores an abnormal operation pattern that defines the operation of the pseudo master 2 in an abnormal operation mode in which a transaction that violates a predetermined protocol is generated for the device under test.

  The setting unit 2c has a function of a random generator for generating a random number, and is a random value for a pointer indicating an operation pattern read from the normal operation pattern storage unit 2a and the abnormal operation pattern storage unit 2b, an operation pattern execution interval, or the like. Is sent to the transaction generation unit 2e.

The selection unit 2d selects the normal operation pattern storage unit 2a when the operation mode is the normal operation mode, and selects the abnormal operation pattern storage unit 2b when the operation mode is the abnormal operation mode.
The transaction generation unit 2e reads the operation pattern from the normal operation pattern storage unit 2a or the abnormal operation pattern storage unit 2b selected by the selection unit 2d according to the pointer set by the setting unit 2c, and generates a transaction based on the read operation pattern Let

The operation of the protocol test apparatus configured as described above will be described.
The control unit 1a sets a switching time in the time measuring unit 1b, initializes the pseudo master 2 and the pseudo slave 3, and starts a protocol test. At initialization, the operation mode is the normal operation mode. The switching time setting format is arbitrary. For example, in addition to time, the setting of the number of cycles from the start, the number of repetitions of the normal operation pattern, and the like can be set. In addition, a random value can be set instead of a fixed value.

  In the pseudo master 2, the selection unit 2d selects the normal operation pattern storage unit 2a because the normal operation mode is set. Further, the setting unit 2c sets a pointer that indicates which one of a plurality of normal operation patterns stored in the normal operation pattern storage unit 2a is selected, and generates a transaction together with the setting of the interval between the operation patterns and the operation patterns. Notify unit 2e. As the value, a value randomly set by an internal random generator is used. The transaction generation unit 2e reads the operation pattern stored in the area designated by the setting unit 2c from the normal operation pattern storage unit 2a selected by the selection unit 2d, and generates a transaction based on the read operation pattern. The operation of the pseudo slave 3 is the same. As a result, between the pseudo master 2 and the pseudo slave 3, a plurality of operation patterns conforming to the protocol are selected at random, and transactions are repeatedly generated. Various REQ (4a) and ACK (4b) signals in the normal state are exchanged between the pseudo master 2 and the pseudo slave 3 according to the operation pattern selected at random.

  The protocol checker connected to the signal path between the pseudo master 2 and the pseudo slave 3 checks whether the input REQ (4a) and ACK (4b) conform to the protocol. In the specification of the protocol checker, it is required not to generate ERROR during the normal operation mode, and by sufficiently generating various normal patterns in this way, sufficient verification can be performed.

  When the time measuring means 1b detects that the switching time has been reached, the normal operation mode is switched to the abnormal operation mode. In the pseudo master 2, the selection unit 2d selects the abnormal operation pattern storage unit 2b. Although the operation of the setting unit 2c does not change, the transaction generation unit 2e reads the operation pattern stored in the area designated by the setting unit 2c from the abnormal operation pattern storage unit 2b selected by the selection unit 2d, and converts the operation pattern to the read operation pattern. Generate a transaction based on this. The operation of the pseudo slave 3 is the same. As a result, between the pseudo master 2 and the pseudo slave 3, an operation pattern that violates the protocol is selected and a transaction is generated, so that the protocol violation REQ (4 a) and ACK (4 b) are input to the protocol checker. Become. In the specification of the protocol checker, in abnormal operation mode, it is required to detect a protocol violation and generate an ERROR. By generating a randomly selected abnormality pattern in this way, verification at the time of abnormality can be performed. It becomes possible. In addition, unlike the conventional protocol test, where the scenario is executed independently, it is possible to create a state in which abnormal operation has occurred while continuing normal operation, and it is possible to carry out verification according to reality. is there.

  In order to restart the protocol test from the state where the error is once set, it is necessary to reset the protocol checker, the pseudo master 2 and the pseudo slave 3. Therefore, if a reset function is added to the control means 1a and reset is performed after ERROR, protocol tests can be continuously performed.

  As described above, since any operation pattern including a normal operation pattern and an abnormal operation pattern can be repeatedly generated at an arbitrary interval, it is possible to easily execute protocol tests of various patterns assumed according to the protocol. It is possible to perform sufficient verification.

  Furthermore, by storing the pattern in which the protocol test is executed, it is possible to quantitatively measure how much all the test patterns that can be generated by the protocol test apparatus have been executed. In the following description, such measurement is referred to as protocol coverage.

  Hereinafter, the embodiment will be described in detail with reference to the drawings, taking as an example a case where the embodiment is applied to a protocol checker test. Since the protocol checker is applied to a protocol test of a communication device, it is desirable to perform a test covering all assumed patterns.

FIG. 2 is a diagram illustrating a test configuration of the protocol checker according to the embodiment of this invention.
The test configuration of the protocol checker according to the embodiment is a configuration in which the protocol checker 40 is connected to a protocol test apparatus including a simulation control unit 11, a timer 12, a reset unit 13, a protocol coverage measurement unit 14, a pseudo master 20, and a pseudo slave 30. Take.

  The simulation control unit 11 acquires the error status of the protocol test from the protocol checker 40 and the coverage status of the protocol test from the protocol coverage measurement unit 14, and gives instructions to the timer 12 and the reset unit 13, thereby giving the pseudo master 20 a communication master and a pseudo slave. 30 controls the operation of the communication slave and controls the entire protocol test.

The timer 12 measures the switching time set by the simulation control unit 11 and outputs an operation mode switching instruction when the timer setting time at which the switching time has elapsed is reached.
When instructed by the simulation control unit 11, the reset unit 13 initializes the protocol checker 40, the pseudo master 20, and the pseudo slave 30.

  The protocol coverage measurement unit 14 monitors REQ and ACK, and includes all the test patterns covered by the protocol test, such as combinations of normal operation patterns, abnormal operation patterns, and operation pattern intervals that the pseudo master 20 and the pseudo slave 30 have. , Check which one was executed and measure protocol coverage quantitatively.

  The pseudo master 20 is the same as the pseudo master 2 of FIG. 1, and as a communication master, generates a transaction based on the normal operation pattern stored in the normal operation pattern storage unit in the normal operation mode, and abnormal in the abnormal operation mode. A transaction is generated based on the abnormal operation pattern stored in the operation pattern storage unit. The selected operation pattern and the operation pattern and the execution interval of the operation pattern are selected at random. The pseudo slave 30 is the same as the pseudo slave 3 in FIG. 1 and generates a transaction based on a normal operation pattern and an abnormal operation pattern as a communication slave.

  The protocol checker 40 inputs the REQ of the pseudo master 20 and the ACK of the pseudo slave 30 and checks whether each signal conforms to the protocol. When a protocol violation is detected, ERROR is generated and output to the simulation control unit 11. Further, a reset process is performed by a reset signal output from the reset unit 13.

A test method for the protocol checker having such a configuration will be described.
FIG. 3 is a flowchart showing a protocol checker test method according to the embodiment of the present invention.

  The normal operation pattern that prescribes the operation at the time of normal operation and the abnormal operation pattern that prescribes the operation at the time of abnormal operation are stored in the storage unit, the switching time is set in the timer 12, and the test of the protocol checker 40 starts. Is done.

[Step S01] The reset unit 13 resets the protocol checker 40 to be tested. As a result, the protocol checker 40 returns to the initial state.
[Step S02] The pseudo master 20 and the pseudo slave 30 are reset together with the protocol checker 40, and the operation mode returns to the normal operation mode. Therefore, the pseudo master 20 and the pseudo slave 30 generate a transaction conforming to the protocol based on the normal operation mode stored in the normal operation mode storage unit.

  [Step S03] It is checked whether or not the protocol checker 40 is outputting ERROR. Hereinafter, the fact that the protocol checker outputs ERROR is called firing. Since the operation is performed in the normal operation mode, only a transaction that conforms to the protocol is generated. If ERROR is detected, it is determined that the protocol checker 40 has malfunctioned, and the process proceeds to step S09.

  [Step S04] If ERROR is not detected, it can be determined that the protocol checker 40 is not malfunctioning. The state of the timer 12 is checked, and it is determined whether or not the timer set time for switching to the abnormal operation mode has been reached. If the timer set time has not been reached, the process returns to step S02 to perform the next transaction process.

  [Step S05] When the timer set time has been reached, the normal operation mode is switched to the abnormal operation mode. In the abnormal operation mode, the pseudo master 20 and the pseudo slave 30 generate a transaction that violates the protocol based on the abnormal operation mode stored in the abnormal operation mode storage unit.

  [Step S06] It is checked whether or not the protocol checker 40 has fired. Since the operation is in the abnormal operation mode, only a transaction that violates the protocol is generated. If the protocol checker 40 is normal, the transaction is fired. If ERROR is not detected, it is determined that the protocol checker 40 has malfunctioned, and the process proceeds to step S09.

  [Step S07] When ERROR is detected, it can be determined that the protocol checker 40 is not malfunctioning. Examine the protocol coverage and determine if it has reached 100%. If it has not reached 100%, that is, if all the test items have not been completed, the process returns to step S01 and the test procedure is repeated.

  [Step S08] When the protocol coverage has reached 100%, it is determined that the operation is normal through all the test items, the normal determination result of the protocol checker 40 is output, and the process ends.

  [Step S09] Since a malfunction has occurred in which fire does not occur in the normal operation mode or fire does not occur in the abnormal operation mode, the protocol checker 40 outputs an abnormality determination result and ends the process.

  Thus, according to the present embodiment, in the normal operation mode, it is always monitored whether or not the protocol checker is ignited, and if it is ignited, the protocol test is terminated as a protocol checker malfunction. On the other hand, in the abnormal operation mode, it is monitored whether or not the protocol checker is ignited, and if it is not ignited, the protocol test is terminated as a protocol checker malfunction. Since these normal operation and abnormal operation are repeated until the protocol coverage reaches 100%, the protocol checker can be sufficiently evaluated.

Hereinafter, details of each process will be described in order.
First, normal operation patterns and abnormal operation patterns used in the embodiment will be described. The pseudo master 20 and the pseudo slave 30 generate a transaction according to the normal operation pattern in the normal operation mode and according to the abnormal operation pattern in the abnormal operation mode.

  FIG. 4 is a diagram showing a normal operation pattern according to the embodiment of the present invention. The protocol specification of the embodiment is the same as the protocol specification shown in (1) of FIG. 13, the master asserts “REQ is asserted until ACK is asserted, and deasserts in the next cycle when ACK is asserted. The slave “asserts ACK within 4 cycles when REQ is asserted and deasserts in the next cycle”.

  In the normal operation mode, the pseudo master 20 and the pseudo slave 30 perform an operation conforming to the protocol according to the normal operation pattern a (101). Furthermore, for this normal operation pattern, as shown in the figure, a variation of the number of cycles from when REQ is asserted to when ACK is asserted is prepared. Pattern 1 is after 1 cycle, Pattern 2 is after 2 cycles Pattern 3 is asserted after 3 cycles and Pattern 4 is asserted after 4 cycles. These normal operation patterns are stored in the normal operation pattern storage unit.

FIG. 5 is a diagram showing an abnormal operation pattern according to the embodiment of the present invention.
In the example of the embodiment, there are five types of abnormal operation patterns from the abnormal operation pattern A (102) to the abnormal operation pattern E (106) in the abnormal operation mode. The abnormal operation pattern A (102) is “a pattern in which REQ is deasserted before ACK is asserted”, and four patterns are prepared for the number of cycles until REQ is asserted. The abnormal operation pattern B (103) is “a pattern in which REQ is not deasserted even if ACK is asserted”, and four patterns are prepared for the number of cycles after ACK is deasserted until REQ is deasserted. The abnormal operation pattern C (104) is “a pattern in which ACK is asserted before REQ is asserted”, and four cycles are prepared after ACK is asserted until REQ is asserted. The abnormal operation pattern D (105) is “a pattern in which ACK is not asserted within 4 cycles even when REQ is asserted”, and four patterns of cycles from when REQ is asserted until ACK is asserted are prepared. Yes. The abnormal operation pattern E (106) is “a pattern in which ACK is not deasserted in the next cycle after ACK is asserted”, and four patterns of cycles from when ACK is asserted until ACK is deasserted are prepared. Yes. These are stored in the abnormal operation pattern storage unit.

  In the above embodiment, the number of cycles for each operation pattern is limited to four for each operation pattern. However, evaluation with higher quality can be performed by expanding the number of patterns. Moreover, the pattern variation according to the number of cycles can be automatically developed from the original operation pattern. As a result, it is possible to reduce the trouble of creating an operation pattern. This process may be performed in the protocol test apparatus or an external apparatus.

  The above normal operation pattern and abnormal operation pattern are stored and stored in the storage unit. Since the operation pattern of the embodiment is common to the master and the slave, the storage units of the pseudo master 20 and the pseudo slave 30 can be made common.

  Next, timer setting (step S02) will be described. In the timer setting, an arbitrary switching time is set in the timer 12. The switching time may be an arbitrary time set by the user or may be set at random.

The relationship between the timer 12, the normal operation mode, and the abnormal operation mode will be described. FIG. 6 is a diagram showing transition of the operation mode according to the embodiment of the present invention.
When the reset 203 is performed, the pseudo master 20, the pseudo slave 30, and the protocol checker 40 are initialized, and the operation starts in the normal operation mode 201. In addition, the counter of the timer 12 is also initialized and starts measuring the switching time 205. During the normal operation mode 201, a transaction conforming to the protocol is repeatedly generated, and it is checked whether the protocol checker 40 malfunctions and fires.

  When the switching time 205 elapses from the reset 203 time point and the timer setting time 204 is reached, the operation mode is switched to the abnormal operation mode 202. During the abnormal operation mode 202, a transaction that violates the protocol is generated, and it is checked whether the protocol checker 40 detects the protocol violation and fires.

When the reset 203 is generated again, the normal operation mode 201 is resumed and the timer 12 starts counting.
As described above, the protocol test apparatus repeats the state transition of transitioning to the normal operation mode 201 at the reset 203 and transitioning to the abnormal operation mode 202 at the timer setting time 204.

Next, the normal operation mode (step S03) process will be described. FIG. 7 is a waveform diagram showing a transaction in the normal operation mode according to the embodiment of the present invention.
In the normal operation mode, out of normal operation patterns stored in the normal operation pattern storage unit, an arbitrary pattern randomly selected by the setting unit is read and executed. The execution interval between the normal operation pattern and the next normal operation pattern is also set at random by the setting unit. In the example shown in the figure, among the normal operation patterns shown in FIG. 4, pattern 2 (a-2) “If REQ is asserted, ACK is asserted after two cycles” is selected and executed. Further, pattern 1 (a-1) is selected and executed as the next normal operation pattern. One cycle is set as the execution interval 210 between the normal operation pattern a-2 and the next normal operation pattern a-1.

  In this way, in the normal operation mode, normal operation patterns read according to randomly set pointers are executed one after another with the same execution interval set at random. This makes it possible to verify the protocol checker during normal operation using various normal operation patterns.

  Next, the abnormal operation mode (step S05) process will be described. FIG. 8 is a waveform diagram showing a transaction when transitioning from the normal operation mode to the abnormal operation mode according to the present embodiment.

  Once an abnormality occurs, it is necessary to reset the pseudo master 20, the pseudo slave 30, and the protocol checker 40 in order to resume the operation correctly. Therefore, for the abnormal operation mode, the execution interval between the pattern execution in the normal operation mode and the pattern execution in the abnormal operation mode is set at random. In the example shown in the figure, the normal operation pattern a-1 is executed in the normal operation mode, and after transitioning to the abnormal operation mode, the pattern 1 (B-1) of the abnormal operation B is executed. Two cycles are set as the execution interval 220 between the normal operation pattern a-1 and the abnormal operation pattern B-1.

  The timer setting time for switching to the abnormal operation mode by the timer 12 is set regardless of the execution state of the transaction process. For this reason, at the timer setting time, there is no guarantee that a series of transactions in the normal operation mode has been completed. Therefore, by setting the execution interval of the abnormal operation pattern from the normal operation pattern and determining the transaction generation timing according to this, the transaction of the abnormal operation pattern can be generated after the transaction of the normal operation pattern is correctly completed. it can.

Next, the coverage (step S07) process will be described.
Protocol coverage is the degree of test coverage that indicates how many of the test patterns that can be executed have been completed.
Protocol coverage = (number of executions / total number) x 100
Represented by The number of executions is the number of test patterns already executed, and the total number is the total number of test patterns that can be executed. The test pattern in the embodiment refers to a test item that combines an operation pattern, an operation pattern executed after the operation pattern, and an execution interval thereof. A specific example will be described.

  FIG. 9 is a diagram showing a protocol coverage measurement table (normal / normal) according to the embodiment of this invention. The pattern (front) indicates a pattern that is executed before, and the pattern (after) indicates a pattern that is subsequently executed after a pattern execution interval after the pattern (front) ends.

  The protocol coverage measurement table (normal / normal) 111 is an example of a protocol coverage measurement table when the normal operation pattern a (101) shown in FIG. 4 is executed. Here, a-1 indicates that variation 1 of “a. Normal operation pattern” in the normal operation pattern a (101) is “ACK is asserted after one cycle when REQ is asserted”. The same applies hereinafter. The protocol coverage measurement table (normal / normal) 101 includes all normal operation patterns a-1, a-2, a-3, a-4 and execution intervals 1 cycle, 2 cycles, 3 cycles and 4 cycles. A combination is set. The protocol coverage measurement unit 14 monitors the transaction and sets a flag in the table column corresponding to the transaction. For example, if a normal operation pattern a-2, an execution interval of 3 cycles, and the next normal operation pattern a-4 are selected, a flag is set in the corresponding column (position ● in the figure).

By calculating the ratio of the set flag to the total number of cases, the protocol coverage can be calculated.
FIG. 10 is a diagram showing a protocol coverage measurement table (normal / abnormal) according to the embodiment of this invention. The configuration of the protocol coverage measurement table is the same as in the case of FIG. 9 except that the operation pattern to be executed later is an abnormal operation pattern, so the description of the same part is omitted.

  The protocol coverage measurement table (normal / abnormal) 112 stores each of the abnormal operation patterns A, B, C, D, and E shown in FIG. 5 after the normal operation pattern a (101) shown in FIG. 4 is executed. It is an example of the table for protocol coverage measurement when a pattern is executed. The protocol coverage measurement unit 14 monitors the transaction and sets a flag in the table column corresponding to the transaction.

  In the coverage process, it is checked whether or not the protocol coverage calculated from the flag set in this way has reached 100%, and the protocol test is automatically repeated until all test patterns are executed. If the protocol coverage reaches 100% (all fields are filled), the validity of the protocol checker is quantitatively guaranteed.

As described above, in this embodiment, the protocol checker can be sufficiently evaluated.
By connecting the pseudo master and the actual slave to be tested, or connecting the actual master to be tested and the pseudo slave, the real slave / real master during normal / abnormal operation of the pseudo master / pseudo slave It is also possible to check the behavior. In particular, confirming that the real slave / real master does not hang up during the abnormal operation of the pseudo master / pseudo slave is an important test item in the verification of the real master / real slave.

  The above processing functions can be realized by a computer. In that case, a program describing the processing contents of the functions that the protocol test apparatus should have is provided. By executing the program on a computer, the above processing functions are realized on the computer. The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory. Examples of the magnetic recording device include a hard disk device (HDD), a flexible disk (FD), and a magnetic tape. Examples of the optical disc include a DVD (Digital Versatile Disc), a DVD-RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only Memory), and a CD-R (Recordable) / RW (ReWritable). Magneto-optical recording media include MO (Magneto-Optical disk).

  When distributing the program, for example, portable recording media such as a DVD and a CD-ROM in which the program is recorded are sold. It is also possible to store the program in a storage device of a server computer and transfer the program from the server computer to another computer via a network.

  The computer that executes the program stores, for example, the program recorded on the portable recording medium or the program transferred from the server computer in its own storage device. Then, the computer reads the program from its own storage device and executes processing according to the program. The computer can also read the program directly from the portable recording medium and execute processing according to the program. Further, each time the program is transferred from the server computer, the computer can sequentially execute processing according to the received program.

(Supplementary note 1) In a protocol test apparatus that generates a transaction of a pattern according to a predetermined protocol,
A normal operation pattern storage unit for storing a normal operation pattern that defines an operation in a normal operation mode for generating a transaction conforming to the predetermined protocol for the device under test, and a violation of the predetermined protocol for the device under test An abnormal operation pattern storage unit that stores an abnormal operation pattern that defines an operation in an abnormal operation mode that generates a transaction to be performed; and the normal operation pattern storage unit in the normal operation mode; and A selection unit that selects an abnormal operation pattern storage unit; and a transaction generation unit that reads an operation pattern from the normal operation pattern storage unit selected by the selection unit or the abnormal operation pattern storage unit and generates a transaction based on the operation pattern; A transaction generating means having
Timing the set switching time, and when the switching time has elapsed, timing means for switching the normal operation mode to the abnormal operation mode;
Control means for setting the switching time in the time measuring means and controlling the transaction generating means according to the test target device;
A protocol testing apparatus comprising:

(Supplementary Note 2) The control means includes:
When the device under test is a protocol checker that checks whether communication between communication devices conforms to the protocol, the transaction generation means includes a pseudo master that executes the operation of the communication master, and the operation of the communication slave. Operate as a pseudo slave to execute,
The protocol testing apparatus according to supplementary note 1, wherein:

(Supplementary Note 3) The protocol test apparatus further includes an initialization unit that initializes the test target apparatus.
When the control means is switched to the abnormal operation mode, the initialization means initializes the device under test, and repeatedly operates the time measuring means and the transaction generation means until a predetermined termination condition is satisfied. ,
The protocol testing apparatus according to supplementary note 1, wherein:

(Supplementary Note 4) The control means includes
The transactions executed by the transaction generation means are monitored, and the total test is performed according to the test coverage measured by calculating the ratio of the already executed transactions to the total test patterns that can be generated by the transaction generation means. 4. The protocol test apparatus according to appendix 3, wherein the predetermined end condition is that the execution of the pattern is detected.

(Supplementary Note 5) The control means includes:
The protocol test apparatus according to appendix 3, wherein the switching time is set at random each time the protocol test is repeated.

(Supplementary Note 6) The transaction generation means includes:
A read pointer that points to a storage area for the normal operation pattern and the abnormal operation pattern read by the transaction generation unit from the normal operation pattern storage unit and the abnormal operation pattern storage unit, and the operation pattern read by the transaction generation unit A setting unit that randomly sets an execution interval until the transaction is generated based on the operation pattern read out after the transaction is generated based on
The protocol test apparatus according to appendix 1, characterized by comprising:

(Appendix 7) The setting unit
Randomly set an execution interval between the normal operation pattern and the next read normal operation pattern, and an execution interval between the normal operation pattern and the next read abnormal operation pattern.
The protocol test apparatus according to supplementary note 6, wherein:

(Supplementary Note 8) The protocol test apparatus further includes:
Measuring means for monitoring the transaction executed by the transaction generation means and calculating a ratio of the already executed transactions to all test patterns that can be generated by the transaction generation means to measure test coverage;
The protocol test apparatus according to appendix 1, characterized by comprising:

(Supplementary Note 9) The measuring means includes
After generating the transaction based on the normal operation pattern stored in the normal operation pattern storage unit, the abnormal operation pattern stored in the abnormal operation pattern storage unit, and the operation pattern read by the transaction generation unit Then, all combinations of execution intervals until the generation of the transaction based on the operation pattern that is read next are used as the all test patterns.
The protocol test apparatus according to appendix 8, wherein

(Supplementary Note 10) In a protocol test method for performing a protocol test by generating a transaction pattern according to a predetermined protocol,
The control means counts the switching time for switching from the normal operation mode for generating a transaction conforming to the predetermined protocol to the test target device to the abnormal operation mode for generating a transaction that violates the predetermined protocol for the test target device. Set the method to start the protocol test,
When in the normal operation mode, the transaction generation means selects a normal operation pattern storage unit that stores a normal operation pattern that defines an operation in the normal operation mode, and reads the normal operation pattern read from the normal operation pattern storage unit Generate the transaction based on the behavior pattern,
The timing means counts the set switching time, and when the switching time has elapsed, switches the normal operation mode to the abnormal operation mode,
When the operation mode is switched to the abnormal operation mode, the transaction generation unit selects an abnormal operation pattern storage unit that stores an abnormal operation pattern that defines an operation in the abnormal operation mode, and the read out from the abnormal operation pattern storage unit Generating the transaction based on an abnormal behavior pattern;
A protocol test method characterized by comprising a procedure.

It is a conceptual diagram of the invention applied to embodiment of this invention. It is the figure which showed the test structure of the protocol checker of embodiment of this invention. It is the flowchart which showed the test method of the protocol checker of embodiment of this invention. It is the figure which showed the normal operation | movement pattern of embodiment of this invention. It is the figure which showed the abnormal operation | movement pattern of embodiment of this invention. It is the figure which showed the transition of the operation mode of embodiment of this invention. It is the wave form diagram which showed the transaction at the time of the normal operation mode of embodiment of this invention. It is the wave form diagram which showed the transaction at the time of changing to the time of the abnormal operation mode from the time of the normal operation mode of this Embodiment. It is the figure which showed the table for protocol coverage measurement (normal / normal) of embodiment of this invention. It is the figure which showed the table for protocol coverage measurement (normal / abnormal) of embodiment of this invention. It is the figure which showed the role of the protocol checker. It is the figure which showed the test method of the conventional protocol checker. It is the figure which showed an example of protocol specification and protocol violation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Control means 1b Time measuring means 1c Transaction generation means 2 Pseudo master 2a Normal operation pattern memory | storage part 2b Abnormal operation pattern memory | storage part 2c Setting part (random generator)
2d selection unit 2e transaction generation unit 3 pseudo slave 4a REQ
4b ACK

Claims (5)

In a protocol test apparatus that generates a transaction pattern according to a predetermined protocol,
A normal operation pattern storage unit for storing a normal operation pattern that defines an operation in a normal operation mode for generating a transaction conforming to the predetermined protocol for the device under test, and a violation of the predetermined protocol for the device under test An abnormal operation pattern storage unit that stores an abnormal operation pattern that defines an operation in an abnormal operation mode that generates a transaction to be performed; and the normal operation pattern storage unit in the normal operation mode; and A selection unit that selects an abnormal operation pattern storage unit; and a transaction generation unit that reads an operation pattern from the normal operation pattern storage unit selected by the selection unit or the abnormal operation pattern storage unit and generates a transaction based on the operation pattern; A transaction generating means having
Timing the set switching time, and when the switching time has elapsed, timing means for switching the normal operation mode to the abnormal operation mode;
Control means for setting the switching time in the time measuring means and controlling the transaction generating means according to the test target device;
A protocol testing apparatus comprising: The protocol test apparatus further includes an initialization unit that initializes the test target apparatus,
When the control means is switched to the abnormal operation mode, the initialization means initializes the device under test, and repeatedly operates the time measuring means and the transaction generation means until a predetermined termination condition is satisfied. ,
The protocol test apparatus according to claim 1. The transaction generation means includes
A read pointer that points to a storage area for the normal operation pattern and the abnormal operation pattern read by the transaction generation unit from the normal operation pattern storage unit and the abnormal operation pattern storage unit, and the operation pattern read by the transaction generation unit A setting unit that randomly sets an execution interval until the transaction is generated based on the operation pattern read out after the transaction is generated based on
The protocol test apparatus according to claim 1, comprising: The protocol test apparatus further includes:
Measuring means for monitoring the transaction executed by the transaction generation means and calculating a ratio of the already executed transactions to all test patterns that can be generated by the transaction generation means to measure test coverage;
The protocol test apparatus according to claim 1, comprising: In a protocol test method for performing a protocol test by generating a transaction of a pattern according to a predetermined protocol,
The control means counts the switching time for switching from the normal operation mode for generating a transaction conforming to the predetermined protocol to the test target device to the abnormal operation mode for generating a transaction that violates the predetermined protocol for the test target device. Set the method to start the protocol test,
When in the normal operation mode, the transaction generation means selects a normal operation pattern storage unit that stores a normal operation pattern that defines an operation in the normal operation mode, and reads the normal operation pattern read from the normal operation pattern storage unit Generate the transaction based on the behavior pattern,
The timing means counts the set switching time, and when the switching time has elapsed, switches the normal operation mode to the abnormal operation mode,
When the operation mode is switched to the abnormal operation mode, the transaction generation unit selects an abnormal operation pattern storage unit that stores an abnormal operation pattern that defines an operation in the abnormal operation mode, and the read out from the abnormal operation pattern storage unit Generating the transaction based on an abnormal behavior pattern;
A protocol test method characterized by comprising a procedure.

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