JP5825409B2 - Verification support program, verification support apparatus, and verification support method - Google Patents

Description

  The present invention relates to a verification support program, a verification support apparatus, and a verification support method that support circuit verification.

  Conventionally, a simulation using an assertion about a circuit to be verified and a simulation for monitoring a register of the circuit to be verified have been disclosed.

JP 2008-181227 A

  However, in the above-described conventional technology, when creating a circuit model that behaves favorably according to the specification of the circuit to be verified, if the specification is complicated, it takes a very long time to create a circuit model that behaves correctly. was there.

  On the other hand, even if the accuracy of the circuit model is low, if the assertion (also referred to as assert property or verification property) for the circuit to be verified can be correctly described from the specification, it is detected that there is an error in the behavior of the circuit to be verified in the circuit model. can do. However, when the verifier describes the assertion for the circuit to be verified, it is difficult to describe the assertion when there are a plurality of verification scenarios for one register.

  Therefore, when the value of the register changes outside the verification scenario defined by the assertion, there is a problem that it cannot be detected by the assertion. In addition, when the verification target circuit operates with multiple clocks, the behavior of the circuit model becomes more complex, so it is more difficult to detect changes in register values outside the verification scenario defined in the assertion. There was a problem.

  In one aspect, an object of the present invention is to provide a verification support program, a verification support apparatus, and a verification support method capable of facilitating specification of a bug outside a scenario defined for a circuit.

  As one aspect of the present invention, an assertion established during simulation of the circuit is detected from an assertion group that defines a register value to be satisfied by the circuit, and at the clock timing next to the clock timing at which the assertion is detected, Update the expected value of the register to the value of the register specified by the assertion, detect a change in the value of the register, and if a change in the value of the register is detected, the value of the register after the change And whether the expected value of the register after the update matches, determines whether the change in the value of the register is correct based on the determined determination result, and outputs the determined determination result A verification support program, a verification support device, and a verification support method are proposed.

  Further, a register operating with a plurality of clocks in a circuit is established during simulation of the circuit from among an assertion group that defines the value of the register to be satisfied at the clock timing of any one of the plurality of clocks. Detect an assertion, detect a change in the value of the register, and for each clock of the plurality of clocks, for each clock timing that comes first after the clock timing at which the change in the value of the register is detected It is determined whether or not the clock as the timing and the clock specified by the detected assertion are the same clock, and whether or not the change in the register value is correct is determined based on the determined determination result. Support program, verification support device, and verification support method for outputting the determined result It proposed.

  According to one embodiment of the present invention, there is an effect that it is possible to easily identify a bug outside a scenario defined for a circuit.

FIG. 1 is an explanatory diagram of an example of checking a circuit to be verified by assertion according to the first embodiment. FIG. 2 is a block diagram of a hardware configuration example of the verification support apparatus according to the first embodiment. FIG. 3 is a block diagram of a functional configuration example of the verification support apparatus according to the first embodiment. FIG. 4 is a block diagram illustrating a functional configuration example of the checker module. FIG. 5 is a flowchart of an editing process procedure of the assertion group 310 by the verification support apparatus according to the first embodiment. FIG. 6 is a flowchart illustrating an expected value update processing procedure during simulation of the circuit to be verified by the checker module CMi. FIG. 7 is a flowchart showing a correct / incorrect detection process procedure during simulation of a circuit to be verified by the checker module CMi. FIG. 8 is an explanatory diagram showing an example of occurrence of a false error in the case of a plurality of clocks. FIG. 9 is an explanatory diagram (part 1) illustrating an example of an error detection operation with a plurality of clocks. FIG. 10 is an explanatory diagram (part 2) of the error detection operation example with a plurality of clocks. FIG. 11 is an explanatory diagram (part 3) of the error detection operation example with a plurality of clocks. FIG. 12 is an explanatory diagram (part 4) of an error detection operation example with a plurality of clocks. FIG. 13 is an explanatory diagram (part 5) illustrating an example of an error detection operation with a plurality of clocks. FIG. 14 is an explanatory diagram (part 1) of an error detection operation example 2 with a plurality of clocks. FIG. 15 is an explanatory diagram (part 2) of the error detection operation example 2 with a plurality of clocks. FIG. 16 is an explanatory diagram (part 3) of the error detection operation example 2 with a plurality of clocks. FIG. 17 is an explanatory diagram (part 4) of the error detection operation example 2 with a plurality of clocks. FIG. 18 is an explanatory diagram (part 5) of the error detection operation example 2 with a plurality of clocks. FIG. 19 is a block diagram of a functional configuration example of the verification support apparatus according to the second embodiment. FIG. 20 is a block diagram illustrating a functional configuration example of the mutual checker module group CCMi. FIG. 21 is a flowchart of an editing / creation process procedure performed by the verification support apparatus according to the second embodiment. FIG. 22 is a flowchart showing the establishment notification processing procedure during simulation of the circuit to be verified by the mutual checker module CCMij. FIG. 23 is a flowchart showing a starting process procedure of the check process CPij during simulation of the circuit to be verified by the mutual checker module CCMij. FIG. 24 is a flowchart showing an execution processing procedure of the check process CPij started in FIG.

  Exemplary embodiments of a verification support program, a verification support apparatus, and a verification support method according to the present invention will be described below in detail with reference to the accompanying drawings. Hereinafter, the verification target circuit operating with a single clock will be described in the first embodiment, and the verification target circuit operating with a plurality of clocks will be described in the second embodiment. Further, the register that is the object of assertion in the register group in the circuit to be verified is referred to as “register R”.

(Embodiment 1)
<Example of checking target circuit by assertion>
FIG. 1 is an explanatory diagram of an example of checking a circuit to be verified by assertion according to the first embodiment. Assertion is data that defines the properties that the design of the circuit to be verified should satisfy. In FIG. 1, it is assumed that assertions A1 and A2 are defined as examples of assertions. The assertion A1 is described using a hardware description language such as Verilog, for example.

  The assertion A1 is an assertion for checking that “the value of the register R changes to“ 3 ”after one cycle when“ 1 ”is input to the input I at the rising edge of the clock Clk” ”. The assertion A2 is an assertion for checking that “the value of the register R changes to“ 4 ”after one cycle when“ 2 ”is input to the input I at the rising edge of the clock Clk” ”.

  In addition, “updateR_spec” is described in the assertions A1 and A2. The description inserted at the end such as “updateR_spec” is a subroutine called when the assertion at the insertion destination is established. The “updateR_spec” that is the insertion description in this case is a description instructing the update of the expected value R_spec. Therefore, when the assertion at the insertion destination is assertion A1 and the assertion A1 is established, the expected value R_spec is updated to the value “3” of the register R in the assertion A1.

  The circuit to be verified is a circuit model that operates with the clock Clk and defines the behavior of the input I and the register R. Specifically, the input I changes from “5” to “1” at the rising time t1 of the clock Clk. The register R changes from “2” to “3” at the rising time t2 of the clock Clk, and changes from “3” to “5” at the time t5.

  Here, when the input I changes from “5” to “1” at time t1, the value of the register R changes from “2” to “3” at the rising time t2 after one cycle. It is checked that A1 is established.

  Thus, when it is confirmed that the assertion A1 is established, the expected value R_spec of the register R is updated from “2” to “3” at the rising time t3 after one cycle. As a result, the expected value R_spec of the register R after the rising time t3 becomes R_spec = 3, which matches the value of the register R (R = 3) in the circuit model in which the assertion A1 is established, and can maintain consistency. .

  On the other hand, at the rising time t5 of the clock Clk, the value of the register R changes from “3” to “5”, but this is an unexpected change that is not the same as any of the assertions A1 and A2. Specifically, at the rising time t6 after one cycle, the value “5” of the register R and the expected value R_spec “3” do not coincide with each other, and therefore an error is assumed as a change in the value of the register R outside the assertion. Detected.

  As described above, in this embodiment, when assertions A1 and A2 are established as in the behavior at the rise times t1 to t2, the expected value R_spec of the register R is changed to the value of the register R when the assertions A1 and A2 are established. By updating to the value, the value of the register R matches the expected value R_spec after the assertions A1 and A2 are established. Therefore, it can be ensured that the value of the register R does not change outside the assertions A1 and A2 for the verification target circuit after the assertions A1 and A2 are established until an unexpected change occurs in the register R.

  On the other hand, when the value of the register R changes outside the assertions A1 and A2, such as an unexpected change of the register R at the rise time t5, an error is notified so that it is not defined in the assertions A1 and A2. Regardless, bugs can be easily identified. As described above, since a bug that occurs in a scenario that is not defined in the assertions A1 and A2 can be detected, the bug can be detected even when the behavior of the circuit to be verified cannot be covered by the assertion.

  The verifier can debug the identified bug to ensure that the value of the register R does not change outside the assertion for the circuit to be verified.

<Hardware configuration example of verification support device>
FIG. 2 is a block diagram of a hardware configuration example of the verification support apparatus according to the first embodiment. In FIG. 2, the verification support apparatus includes a CPU (Central Processing Unit) 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory) 203, a magnetic disk drive 204, a magnetic disk 205, and an optical disk drive 206. An optical disk 207, a display 208, an I / F (Interface) 209, a keyboard 210, a mouse 211, a scanner 212, and a printer 213. Each component is connected by a bus 200.

  Here, the CPU 201 controls the entire verification support apparatus. The ROM 202 stores a program such as a boot program. The RAM 203 is used as a work area for the CPU 201. The magnetic disk drive 204 controls reading / writing of data with respect to the magnetic disk 205 according to the control of the CPU 201. The magnetic disk 205 stores data written under the control of the magnetic disk drive 204.

  The optical disk drive 206 controls reading / writing of data with respect to the optical disk 207 according to the control of the CPU 201. The optical disk 207 stores data written under the control of the optical disk drive 206, or causes the computer to read data stored on the optical disk 207.

  The display 208 displays data such as a document, an image, and function information as well as a cursor, an icon, or a tool box. As the display 208, for example, a CRT, a TFT liquid crystal display, a plasma display, or the like can be adopted.

  An interface (hereinafter abbreviated as “I / F”) 209 is connected to a network 214 such as a LAN (Local Area Network), a WAN (Wide Area Network), and the Internet through a communication line. Connected to other devices. The I / F 209 controls an internal interface with the network 214 and controls data input / output from an external device. For example, a modem or a LAN adapter may be employed as the I / F 209.

  The keyboard 210 includes keys for inputting characters, numbers, various instructions, and the like, and inputs data. Moreover, a touch panel type input pad or a numeric keypad may be used. The mouse 211 performs cursor movement, range selection, window movement, size change, and the like. A trackball or a joystick may be used as long as they have the same function as a pointing device.

  The scanner 212 optically reads an image and takes in the image data into the verification support apparatus. The scanner 212 may have an OCR (Optical Character Reader) function. The printer 213 prints image data and document data. As the printer 213, for example, a laser printer or an ink jet printer can be employed.

<Functional configuration example of verification support device>
Next, a functional configuration example of the verification support apparatus according to the first embodiment will be described.

  FIG. 3 is a block diagram of a functional configuration example of the verification support apparatus according to the first embodiment. The verification support apparatus includes an edit processing unit 301 and a checker module group CM. The edit processing unit 301 includes a selection unit 311 and an editing unit 312. Specifically, the edit processing unit 301 (selection unit 311 and editing unit 312) and the checker module group CM are stored in a storage device such as the ROM 202, the RAM 203, the magnetic disk 205, and the optical disk 207 shown in FIG. The function is realized by causing the CPU 201 to execute the program or by the I / F 209.

  The assertion groups 310 and 320 are a set of assertions regarding the circuit to be verified. The assertion group 310 is an assertion group before editing by the editing processing unit 301. The assertions in the assertion group 310 are, for example, assertions in which “updateR_spec” is not inserted in the assertions A1 and A2 in FIG. On the other hand, the assertion group 320 is an edited assertion group in which the assertion group 310 is edited by the editing processing unit 301. The assertions in the assertion group 320 are, for example, the assertions A1 and A2 in FIG.

  The selection unit 311 selects an unselected assertion from the assertion group 310. The selection unit 311 continues to select until there is no unselected assertion. The editing unit 312 inserts an update instruction description for instructing the update of the expected value of the register in the circuit to be verified into the assertion (selection assertion) selected by the selection unit 311. The inserted update instruction description is a description for calling an expected value update subroutine.

  An example of the update instruction description is “updateR_spec” shown in FIG. “UpdateR_spec” is a subroutine for updating “R_spec” in the assertion at the insertion destination. As described above, the editing unit 312 can generate an edited assertion group 320 by inserting an update instruction description for each selected assertion. The edited assertion group 320 is referred to by the checker module group CM.

  The checker module group CM includes n checker modules CM1,..., CMi,..., CMn prepared for each register in the circuit to be verified (n is the number of registers defined by the assertion). The checker module CMi has the same processing contents except for the register to be checked and the assertion (assertion in the assertion group 320).

  FIG. 4 is a block diagram illustrating a functional configuration example of the checker module. The checker module CMi includes a first detection unit 401, an update unit 402, a second detection unit 403, a determination unit 404, and an output unit 405. Specifically, the first detection unit 401 to the output unit 405 cause the CPU 201 to execute a program stored in a storage device such as the ROM 202, the RAM 203, the magnetic disk 205, and the optical disk 207 illustrated in FIG. Alternatively, the function is realized by the I / F 209.

  The first detection unit 401 detects an assertion that is established during simulation of the verification target circuit from the assertion group 320 that defines the value of the register R that should be satisfied by the verification target circuit that operates with a single clock Clk. As long as it operates with a single clock Clk, the entire circuit to be verified may be used, or a part of the circuit block of the circuit to be verified may be used. The first detection unit 401 detects an assertion (assertion in the assertion group 320) established for the target register R in the checker module CMi during simulation. For example, as shown in FIG. 1, the first detection unit 401 detects that the assertion A1 is established among the assertions A1 and A2 at the time t2 of the single clock Clk.

  The update unit 402 updates the expected value R_spec of the register R to the value of the register R defined by the assertion at the clock timing next to the clock timing at which the assertion is detected by the first detection unit 401. Specifically, the update unit 402 is an expected value R_spec update subroutine for executing the update instruction description “updateR_spec” of the asserted assertion. As a result, the expected value R_spec is updated to the value of the register R being simulated (that is, the value of the register R in the assertion that has been established) at the time next to the detection time. Therefore, after updating by the updating unit 402, if the circuit to be verified is designed correctly, the value of the register R and the expected value R_spec should be the same value unless the assertion is established.

  The second detection unit 403 detects a mismatch between the expected value R_spec of the register R and the value of the register R after being updated by the update unit 402. Specifically, for example, the second detection unit 403 monitors a change in the value of the register R targeted by the checker module CMi at every rising time of the clock Clk (or at every falling time). Thus, if the circuit to be verified is designed correctly, the value of the register R and the expected value R_spec should match unless any assertion about the register R in the assertion group 320 is established. On the other hand, if they do not match, the register R has changed not defined in the assertion group 320.

  The determination unit 404 determines whether the change in the value of the register R is correct based on the detection result detected by the second detection unit 403. Specifically, for example, when the mismatch is detected by the second detection unit 403, the determination unit 404 has a change in the value of the register R that is not defined by the assertion group 320 (an erroneous change). And decide. On the other hand, if a match is detected by the second detection unit 403, it is determined that the change in the value of the register R is an expected change (correct change).

  Note that the determination unit 404 may execute the determination process only when a mismatch is detected by the second detection unit 403. The second detection unit 403 performs detection processing every time, but since the number of mismatch detections is considered to be less than the number of match detections, the verification support process is accelerated by executing the determination process only when there is a mismatch. Can be achieved.

  The output unit 405 outputs the determination result determined by the determination unit 404. Specifically, for example, when the determination unit 404 determines that the change is an erroneous change, the output unit 405 outputs the time when the register R mismatch is detected and the identification information of the register R. The identification information is information that uniquely identifies the register R, for example, a register name. For example, in the example of FIG. 1, the output unit 405 outputs {NG, time t5, R}.

  Further, the output unit 405 outputs the time that is the next cycle of the time when the mismatch of the register R is detected and the identification information of the register R. For example, in the example of FIG. 1, the output unit 405 outputs {NG, time t6, R}. At this time, the value of the register R may also be output. In this case, the output unit 405 outputs {NG, time t6, R = 5}. Note that the output unit 405 may output the time when the match is detected and the identification information of the register R when the determination unit 404 determines that the change is correct. For example, in the example of FIG. 1, the output unit 405 outputs {OK, time t3, R}.

  Such an output result may be displayed on the display 208, printed out on the printer 213, or transmitted to a communicable computer. Further, it may be stored in a storage device (RAM 203, magnetic disk 205) in the verification support apparatus.

<Editing procedure>
FIG. 5 is a flowchart of an editing process procedure of the assertion group 310 by the verification support apparatus according to the first embodiment. The selection unit 311 determines whether there is an unselected assertion from the assertion group 310 (step S501).

  When there is an unselected assertion (step S501: Yes), the selection unit 311 selects one unselected assertion from the assertion group 310 (step S502). Then, the editing unit 312 inserts an update instruction description for calling an expected value update subroutine in the selected assertion (step S503). Thereafter, the editing unit 312 holds the selected assertion in the storage device in the verification support apparatus (step S504), and returns to step S501.

  In step S501, if there is no unselected assertion (step S501: No), the editing process is terminated because the editing is completed. Thus, since the unedited assertion group 310 is edited into the assertion group 320 into which the update instruction description is inserted, the expected value R_spec can be automatically updated when the assertion is established in the check process in the checker module group CM. .

<Expected value update processing procedure during simulation of circuit to be verified by checker module CMi>
FIG. 6 is a flowchart illustrating an expected value update processing procedure during simulation of the circuit to be verified by the checker module CMi.

  First, the first detection unit 401 waits until an assertion established during simulation of the verification target circuit is detected from the assertion group 320 for the register R targeted by the checker module CMi (step S601: No). . When it is detected (step S601: Yes), the update unit 402 updates the value of the register R of the detection assertion to the expected value R_spec in the next cycle (next clock timing) (step S602). Then, the process returns to step S601. The flowchart of FIG. 6 ends when the simulation of the verification target circuit ends.

<Procedure detection processing procedure during simulation of circuit to be verified by checker module CMi>
FIG. 7 is a flowchart showing a correct / incorrect detection process procedure during simulation of a circuit to be verified by the checker module CMi. In FIG. 7, the rising time of the clock Clk is detected as an example, but the falling time may be used.

  First, the second detection unit 403 waits for the rising time of the clock Clk (step S701: No), and when the rising time is reached (step S701: Yes), the value of the register R matches the expected value R_spec. Whether or not (step S702). If they match (step S702: YES), the process returns to step S701.

  On the other hand, when there is a mismatch (step S702: No), the determination unit 404 determines that the change in the value of the register R is an incorrect change that is not defined in the assertion group 320 in the next cycle (next clock timing). Determination is made (step S703). And the output part 405 outputs a determination result (step S704), and returns to step S701. The flowchart in FIG. 7 ends when the simulation of the verification target circuit ends.

  Thus, according to the first embodiment, every time an assertion is made, the expected value R_spec is updated to the value of the register R. After the update, if the design is correct, the value of the register R and the expected value R_spec are Keep matching. Therefore, if a mismatch between the value of the register R and the value of the expected value R_spec is detected, the value of the register R has changed even though no assertion of the assertion group 320 is established.

  Therefore, since it is found that the change is not defined in any assertion of the assertion group 320, it is possible to efficiently detect a bug that cannot be detected by the assertion group. The verifier can debug the identified bug to ensure that the value of the register R does not change outside the assertion for the circuit to be verified.

  Further, although the verification target circuit of the first embodiment described above is a circuit that operates with a single clock Clk, even if the verification target circuit operates with a plurality of clocks, the verification target circuit is set as a verification target for each clock domain. Thus, the first embodiment can also be applied.

(Embodiment 2)
Next, a second embodiment will be described. In the first embodiment, there is only one clock for operating the target register R. For this reason, an update instruction description is inserted into the assertion, and the expected value R_spec is updated when the assertion is established, so that “if the design is correct, the value of the register R and the expected value R_spec match”. As a result, if the value of the register R and the expected value R_spec do not match, it is an erroneous change that is not defined in any assertion of the assertion group 320 as an unexpected change in the value of the register R. Was detected.

  On the other hand, when there are a plurality of clocks for operating the target register R, a false error occurs. Specifically, when the expected value R_spec is updated at a time next to the assertion establishment time as in the first embodiment, if the next time is a clock different from the clock at the assertion establishment time, the register R The value and the expected value R_spec do not match. This will be described below with reference to FIG.

<Example of false error occurrence>
FIG. 8 is an explanatory diagram showing an example of occurrence of a false error in the case of a plurality of clocks. In FIG. 8, it is assumed that assertions A11 and A12 are defined for the register R. The assertion A11 is an assertion for checking that “the value of the register R changes to“ 3 ”after one cycle when“ 1 ”is input to the input I at the rising edge of the clock Clk1”. The assertion A12 is an assertion for checking that “the value of the register R changes to“ 4 ”after one cycle when“ 2 ”is input to the input I at the rising edge of the clock Clk2.”

  In FIG. 8, when the value of the input I changes from “5” to “1” at the rising time t21 of the clock Clk2, the value of the register R changes from “2” to “3” at the rising time t22 of the clock Clk2. ing. For this reason, assertion A11 will be materialized. Then, as in the first embodiment, the next time for updating the expected value R_spec of the register R is the rising time t23 of the clock Clk2.

  For this reason, at the rising times t14 to t17 of the clock Clk1 between the rising times t22 to t23 of the clock Clk2, a mismatch (“3” ≠ “2”) between the value of the register R and the expected value R_spec occurs. . That is, between the rising times t22 and t23 of the clock Clk2, an error is detected as not asserting A11 even though it operates in the same manner as assertion A11.

  For this reason, in the second embodiment, even when the register R in the circuit to be verified operates with a plurality of clocks, a bug that cannot be detected by the assertion group 320 without causing the false error described above is efficiently generated. An example of detection will be described. In the second embodiment, as an example, the number of clocks is 3 (Clk1 to Clk3). 9 to 13 describe an example in which no error occurs, and FIGS. 14 to 18 describe an example in which an error can be detected.

<Error detection operation example 1 with multiple clocks>
9 to 13 are explanatory diagrams showing an error detection operation example 1 with a plurality of clocks. The error detection operation example 1 with a plurality of clocks is an operation example in which the assertion A20 is checked without generating the false error described above when the assertion A20 is established.

  FIG. 9 shows an initial state. In FIG. 9, a mutual checker module is prepared for each clock of the same register R. CoChecker1 (R, Clk1) is a mutual checker module CCMi1 that detects assertion when the register R operates with the clock Clk1. CoChecker2 (R, Clk2) is a mutual checker module CCMi2 that detects the assertion when the register R operates with the clock Clk2.

  CoChecker3 (R, Clk3) is a mutual checker module CCMi3 that detects assertion when the register R operates with the clock Clk3. In this manner, the mutual checker module is generated for the same register R by the number of clocks.

  Also, in FIGS. 9 to 13, as an example, it is detected whether or not the assertion A20 is established. The assertion A20 is an assertion for checking that “the value of the register R changes to“ 3 ”after one cycle when“ 1 ”is input to the input I at the rising edge of the clock Clk2” ”.

  Note that “CoChecker2.triggerOK” inserted in the assertion A20 is a subroutine called when the insertion destination assertion is established. “CoChecker2.triggerOK” is an establishment notification subroutine for notifying the mutual checker module CCMi2 of the establishment notification “OK” of the assertion A20 to the check process.

  FIG. 10 shows the transition state from FIG. FIG. 10 shows a state where the check processes CPi1 to CPi3 are started in the mutual checker modules CCMi1 to CCMi3. The check processes CPi1 to CPi3 are started when a change in the value of the register R is detected.

  In FIG. 10, since the value of the input I changes from “5” to “1” at the rising time t21 of the clock Clk2, the value of the register R changes from “2” to “3” at the rising time t22 of the clock Clk2. This behavior satisfies Assertion A20. Since the value of the register R changes from “2” to “3” at time t22 of the clock Clk2, the check processes CPi1 to CPi3 are started at time t22 of the clock Clk2.

  In the check processes CPi1 to CPi3, when starting, the global variable C is incremented. In this example, since the number of mutual checker modules is 3, C = 3. That is, the global variable C is the number of clocks for operating the same register R. Note that C is decremented sequentially.

  When C is decremented and all the check processes CPi1 to CPi3 are completed before C = 0, the false error shown in FIG. 8 is changed to the next time t23 from the rising time t22 of the clock Clk2, which is the establishment time of the assertion A20. This means that the fact that the assertion A20 has been established can be properly checked without being generated. On the other hand, when C = 0 at the end of all the check processes CPi1 to CPi3, a change in the value of the register R that is not defined in any assertion of the assertion group is detected.

  FIG. 11 shows the transition state from FIG. In FIG. 11, the time when the register R is operated next to t22, which is the time when the assertion A20 is established, is the time t14 of the clock Clk1. Therefore, the mutual checker module CCMi1 monitoring the operation at the clock Clk1 waits for the assertion notification “OK” of the assertion A20, but does not hold at the time t14. For this reason, since the mutual checker module CCMi1 cannot accept the establishment notification “OK” at time t14, the check process CPi1 decrements C to C = 2. Then, the check process CPi1 ends.

  FIG. 12 shows the transition state from FIG. In FIG. 12, the time when the register R is operated next to the rising time t14 of the clock Clk1 that is the end time of the check process CPi1 is the rising times t15 to t17 of the clock Clk1, but the check process CPi1 of the mutual checker module CCMi1 Has already ended. Therefore, the time when the register R is operated after the time t17 of the clock Clk1 is the rising time t23 of the clock Clk2. Therefore, the mutual checker module CCMi2 monitoring the operation at the clock Clk2 waits for the assertion notification “OK” of the assertion A20.

  Since the time t23 is the time after the establishment time t22 of the assertion A20, the establishment notification subroutine “CoChecker2.triggerOK” of the mutual checker module CCMi2 is called. Thus, the mutual checker module CCMi2 issues an assertion notification “OK” of the assertion A20 to the check process CPi2, so that the check process CPi2 can receive the notification “OK” of the assertion A20. The check process CPi2 that has received the establishment notification “OK” ends without decrementing C (with C = 2).

  FIG. 13 shows the transition state from FIG. In FIG. 13, the time when the register R is operated next to the time t23 of the clock Clk2 which is the end time of the check process CPi2 is the rising time t32 of the clock Clk3. Therefore, the mutual checker module CCMi3 monitoring the operation at the clock Clk3 waits for the assertion notification “OK” of the assertion A20, but does not hold at the rising time t32.

  For this reason, since the mutual checker module CCMi3 cannot accept the establishment notification “OK” at the rising time t32, the check process CPi3 decrements C to C = 1. Then, the check process CPi3 ends. Therefore, all the check processes CPi1 to CPi3 are completed before C = 0.

  As described above, in the second embodiment, the false error shown in FIG. 8 does not occur between the rising times t22 and t23 of the clock Clk2, which is the establishment time of the assertion A20, and the assertion A20 is established. Can be checked for suitability.

<Error detection operation example 2 with multiple clocks>
14 to 18 are explanatory diagrams showing an error detection operation example 2 with a plurality of clocks. In error detection operation example 2 with a plurality of clocks, when assertion A20 is not established, an operation for detecting a change in the value of register R that is not defined in any assertion of the assertion group without generating the false error described above. It is an example.

  FIG. 14 shows an initial state. In FIG. 14, mutual checker modules CCMi1 to CCMi3 are prepared for the same register R for each clock. The difference between the initial state of FIG. 9 and the initial state of FIG. 14 is that in FIG. 9, the value of the register R changes from “2” to “3” at the rising time t22 of the clock Clk2, whereas in FIG. The value of the register R changes from “2” to “4” at the rising time t22 of the clock Clk2.

  FIG. 15 shows the transition state from FIG. FIG. 15 shows a state where the check processes CPi1 to CPi3 are started in the mutual checker modules CCMi1 to CCMi3. The check processes CPi1 to CPi3 are started when a change in the value of the register R is detected.

  In FIG. 15, since the value of the input I changes from “5” to “1” at the rising time t21 of the clock Clk2, the value of the register R changes from “2” to “4” at the rising time t22 of the clock Clk2. This behavior does not satisfy Assertion A20. Since the value of the register R changes from “2” to “4” at the rising time t22 of the clock Clk2, the check processes CPi1 to CPi3 are started at the rising time t22 of the clock Clk2.

  In the check processes CPi1 to CPi3, when starting, the global variable C is incremented. In this example, since the number of mutual checker modules is 3, C = 3. That is, the global variable C is the number of clocks for operating the same register R. Note that C is decremented sequentially.

  When C is decremented and all the check processes CPi1 to CPi3 are finished before C = 0, the false error shown in FIG. This means that the fact that the assertion A20 has been established can be properly checked without being generated. On the other hand, when C = 0 at the end of all the check processes CPi1 to CPi3, a change in the value of the register R that is not defined in any assertion of the assertion group is detected.

  FIG. 16 shows the transition state from FIG. In FIG. 16, the time when the register R is operated after the time t22 when the value of the register R changes is the rising time t14 of the clock Clk1. Therefore, the mutual checker module CCMi1 monitoring the operation at the clock Clk1 waits for the assertion notification “OK” of the assertion A20, but does not hold at the time t14. For this reason, since the mutual checker module CCMi1 cannot accept the establishment notification “OK” at time t14, the check process CPi1 decrements C to C = 2. Then, the check process CPi1 ends.

  FIG. 17 shows the transition state from FIG. In FIG. 17, the time when the register R is operated after the time t14 that is the end time of the check process CPi1 is the time t15 to t17 of the clock Clk1, but the check process CPi1 of the mutual checker module CCMi1 has already ended. Yes. For this reason, the time when the register R is operated after the rise time t17 of the clock Clk1 is the rise time t23 of the clock Clk2. Therefore, the mutual checker module CCMi2 monitoring the operation at the clock Clk2 waits for the assertion notification “OK” of the assertion A20.

  The time t23 is the time after the time t22 when the register R is changed by the clock Clk2, but the assertion A20 is not established. Accordingly, since the mutual checker module CCMi2 cannot accept the establishment notification “OK” at time t23, the check process CPi2 decrements C to C = 1. Then, the check process CPi2 ends.

  FIG. 18 shows the transition state from FIG. In FIG. 18, the time when the register R is operated after the time t23 that is the end time of the check process CPi2 is the time t32 of the clock Clk3. Therefore, the mutual checker module CCMi3 monitoring the operation at the clock Clk3 waits for the assertion notification “OK” of the assertion A20, but does not hold at the time t32. For this reason, since the mutual checker module CCMi3 cannot accept the establishment notification “OK” at time t32, the check process CPi3 decrements C to C = 0. Then, the check process CPi3 ends.

  As described above, since C = 0 when all the check processes CPi1 to CPi3 are completed, a change in the value of the register R that is not defined in any assertion of the assertion group is detected at the rising time t22 of the clock Clk2. . As a result, even when the register in the circuit to be verified operates with a plurality of clocks, it is possible to efficiently detect a bug that cannot be detected by the assertion group without generating the false error described above.

<Functional configuration example of verification support device>
Next, a functional configuration example of the verification support apparatus according to the second embodiment will be described. In addition, the same code | symbol is attached | subjected to the same structure as Embodiment 1, and the description is abbreviate | omitted. Also, the hardware configuration example of the verification support apparatus according to the second embodiment is the same as that in FIG.

  FIG. 19 is a block diagram of a functional configuration example of the verification support apparatus according to the second embodiment. The verification support apparatus includes an editing / creation processing unit 1900 and a mutual checker module group set CCM. The editing / creation processing unit 1900 includes a selection unit 1901, an editing unit 1902, a specifying unit 1903, and a creating unit 1904.

  Specifically, the editing / creation processing unit 1900 (selection unit 1901 to creation unit 1904) and the mutual checker module group set CCM are, for example, storage devices such as the ROM 202, the RAM 203, the magnetic disk 205, and the optical disk 207 shown in FIG. The function is realized by causing the CPU 201 to execute the program stored in the, or by the I / F 209.

  An assertion group 1910 is an assertion group before editing by the editing / creation processing unit 1900. The assertion in the assertion group 1910 is an assertion in which “CoChecker2.triggerOK” is not inserted in the assertion A20 of FIG. On the other hand, the assertion group 1920 is an edited assertion group in which the assertion group 1910 is edited by the editing / creation processing unit 1900. The assertion in the assertion group 1920 is, for example, the assertion A20 in FIG.

  The selection unit 1901 selects an unselected assertion from the assertion group 1910. The selection unit 1901 continues to select until there is no unselected assertion. The editing unit 1902 inserts a description regarding the establishment notification that notifies the establishment of the assertion into the assertion selected by the selection unit 1901 (selection assertion). The inserted description about the establishment notification is a description for calling a subroutine for notifying the check process of the assertion establishment.

  The description regarding the establishment notification is, for example, “CoChecker2.triggerOK” shown in FIG. “CoChecker2.triggerOK” is a subroutine that causes “CoChecker2” to issue “OK” to “CoChecker2” when the insertion destination assertion is established.

  Generally, if it is desired to notify the mutual checker module CCMi # about the assertion establishment at the rising edge (or falling edge) of the clock Clk #, “CoChecker # .triggerOK” may be used. As described above, the editing unit 1902 can generate an edited assertion group 1920 by inserting a description relating to the notification of establishment for each assertion. The edited assertion group 1920 is referred to by the mutual checker module group set CCM.

  The identifying unit 1903 identifies the register identification information and the clock identification information from the assertion after the subroutine is inserted. The register identification information is information for uniquely specifying a register, for example, a register name. The clock identification information is information that uniquely identifies a clock, and is, for example, a clock name. For example, when the selected assertion is assertion A20, “R” is specified as the register name and “Clk2” is specified as the clock name.

  The creation unit 1904 creates a mutual checker module group based on the register identification information and the clock identification information specified by the specification unit 1903. Specifically, for example, since the total number of clocks is known (here, three of Clk1 to Clk3), when the clock name “Clk2” is identified, the mutual checker modules CCMi1 to CCMi1 are identified for the identified register R. Create CCMi3. Since the creation unit 1904 previously holds the operation description of the mutual checker module CCMi as a template, it can be created simply by giving the register name and the clock name to the template.

  The mutual checker module group set CCM is a mutual checker module group CCM1,..., CCMi,. n is the number of registers defined in the assertion. The mutual checker module group CCMi has the same processing contents except for the register to be checked and the assertion (assertion in the assertion group 1920).

<Functional configuration example of mutual checker module>
FIG. 20 is a block diagram illustrating a functional configuration example of the mutual checker module group CCMi. The mutual checker module group CCMi includes a first detection unit 2001, a second detection unit 2002, a determination unit 2003, a generation unit 2004, a determination unit 2005, and an output unit 2006.

  Specifically, the first detection unit 2001 to the output unit 2006 cause the CPU 201 to execute a program stored in a storage device such as the ROM 202, the RAM 203, the magnetic disk 205, and the optical disk 207 illustrated in FIG. Alternatively, the function is realized by the I / F 209.

  The first detection unit 2001 includes a circuit that operates with a plurality of clocks, from among an assertion group that defines the value of the register R that should be satisfied at the timing of any one of the plurality of clocks for the register R in the circuit. Detect assertions made during simulation.

  Specifically, for example, an assertion established during the simulation is detected from the assertion group 1920 for the circuit to be verified that operates the internal register R by three clocks Clk1 to Clk3. For example, as illustrated in FIG. 20, the first detection unit 2001 detects an assertion A20 that is established at time t22 of the clock Clk2 from the assertion group 1920.

  The second detection unit 2002 detects a change in the value of the register R. It does not matter whether the change in the value of the register R here is a case where the assertion is established. For example, as illustrated in FIG. 10, the second detection unit 2002 detects a change in the value of the register R (“2” → “3”) at the time t22 of the clock Clk2 by the mutual checker module CCMi2. Similarly, as shown in FIG. 15, the second detection unit 2002 detects a change in the value of the register R (“2” → “4”) at the time t22 of the clock Clk2 by the mutual checker module CCMi2.

  For each clock of the plurality of clocks, the determination unit 2003 determines the clock that becomes the current time for each clock timing that arrives first after the clock timing at which the change in the register value is detected by the second detection unit 2002. It is determined whether or not the clock defined by the assertion detected by the first detection unit 2001 is the same clock. Specifically, for example, the determination unit 2003 is not executed when the first detection unit 2001 does not detect the assertion. That is, the determination unit 2003 is not executed in the examples of FIGS.

  On the other hand, in the example of FIGS. 9 to 13, the assertion of the assertion A20 is detected in the state of FIG. Accordingly, as shown in FIG. 11, the determination unit 2003 determines that the clock t1 that arrives first after the time t22 when the change in the value of the register R is detected in the clock Clk1 is defined by the assertion A20 that is established. It is determined whether or not the same clock as Clk2. Since the time t14 belongs to the clock Clk1, it is not the same clock as the clock Clk2 defined by the established assertion A20.

  Similarly, as shown in FIG. 12, in the clock Clk2, the determination unit 2003 defines the first arrival time t23 after the time t22 when the change in the value of the register R is detected as defined by the established assertion A20. It is determined whether or not the clock is the same as the clock Clk2. Since the time t23 belongs to the clock Clk2, it is the same clock as the clock Clk2 defined by the established assertion A20.

  Further, as shown in FIG. 13, the determination unit 2003 determines that the clock t1 that arrives at the first time t32 after the time t22 when the change in the value of the register R is detected is defined in the clock Clk3. It is determined whether or not the same clock as Clk2. Since the time t32 belongs to the clock Clk3, it is not the same clock as the clock Clk2 defined by the established assertion A20.

  When a change in the value of the register R is detected by the second detection unit 2002, the generation unit 2004 generates a check process group that waits for a notification of establishment that notifies the assertion establishment for each clock for the register R. Specifically, for example, as shown in FIGS. 9 to 18, check processes CPi1 to CPi3 are generated for the mutual checker modules CCMi1 to CCMi3. When the check processes CPi1 to CPi3 are generated, the global variable C is incremented. As a result, the total number of clocks Clk1 to Clk3 is m = C.

  Thereafter, in the case of FIGS. 9 to 13, when the determination unit 2003 determines that the clocks are the same, the subroutine specified by the description relating to the notification of establishment inserted in the determined assertion is called. Then, among the mutual checker modules CCMi1 to CCMi3, the mutual checker module CCMi2 related to the clock Clk2 having the same clock can receive the establishment notice by executing the called establishment notification subroutine.

  In the examples of FIGS. 14 to 18, since the assertion is not established, the determination unit 2003 does not determine that the clocks are the same. In each of the examples in FIGS. 9 to 13 and FIGS. 14 to 18, the global variable C is decremented whenever it is determined that the clocks are not the same.

  The determining unit 2005 determines whether the change in the value of the register R is correct based on the determination result determined by the determining unit 2003. Specifically, for example, when it is determined by the determination unit 2003 that the same clock is one of the clocks Clk1 to Clkm in the determination of the same clock, the global variable C is C = 0 even if it is decremented. Therefore, it is determined that the change in the value of the register R is a correct change as expected.

  For example, as shown in the examples of FIGS. 9 to 13, since it is determined that the clock is the same as the clock Clk2 of the assertion A20 established at the time t23 of the clock Clk2, the change in the value of the register R at the time t22 of the clock Clk2 Determines that it is the correct change as expected (according to assertion A20).

  On the other hand, if it is determined by the determination unit 2003 that none of the clocks Clk1 to Clkm is the same, the global variable C is decremented and finally C = 0. Therefore, the change in the value of the register R is determined to be an erroneous change that is not defined in any assertion.

  For example, as shown in the examples of FIGS. 14 to 18, since the assertion A20 is not established due to the change in the value of the register R at the time t22 of the clock Clk2, the description regarding the establishment notification inserted in the assertion A20 is used. The establishment notification subroutine cannot be called. Therefore, C is decremented each time, and finally C = 0. Thereby, the change in the value of the register R at time t22 of the clock Clk2 is determined to be an erroneous change that is not defined in any assertion.

  The output unit 2006 outputs the determination result determined by the determination unit 2005. Specifically, for example, when the determining unit 2005 determines that the change is an erroneous change, the output unit 2006 outputs the clock in which the change in the value of the register R is detected, the changed clock timing, and the identification information of the register R. To do. The identification information is information that uniquely identifies the register R, for example, a register name. For example, in the examples of FIGS. 14 to 18, the output unit 2006 outputs {NG, clock Clk2, time t22, R}. At this time, the value of the register R may also be output. In this case, the output unit 2006 outputs {NG, clock Clk2, time t22, R = 4}.

  Further, the output unit 2006 may output the detected clock of the value of the register R, the changed clock timing, and the identification information of the register R when the determining unit 2005 determines that the change is correct. . For example, in the example of FIGS. 9 to 13, the output unit 2006 outputs {OK, clock Clk2, time t22, R}. At this time, the value of the register R may also be output. In this case, the output unit 2006 outputs {OK, clock Clk2, time t22, R = 3}.

  In addition, when the determining unit 2005 determines that the change is correct, the output unit 2006 displays the clock at which the change in the value of the register R is detected, the time when the establishment notification “OK” is received, and the identification information of the register R. It is good also as outputting. For example, in the example of FIGS. 9 to 13, the output unit 2006 outputs {OK, clock Clk2, time t23, R}. At this time, the value of the register R may also be output. In this case, the output unit 2006 outputs {OK, clock Clk2, time t23, R = 3}.

  Such an output result may be displayed on the display 208, printed out on the printer 213, or transmitted to a communicable computer. Moreover, you may store in the memory | storage device in a verification assistance apparatus.

<Edit / Create procedure>
FIG. 21 is a flowchart of an editing / creation process procedure performed by the verification support apparatus according to the second embodiment. The selection unit 1901 determines whether there is an unselected assertion from the assertion group 1910 (step S2101).

  When there is an unselected assertion (step S2101: Yes), the selection unit 1901 selects one unselected assertion from the assertion group 1910 (step S1902). Then, the editing unit 1902 inserts a description related to the establishment notification that calls the establishment notification subroutine for notifying the establishment notification into the selection assertion (step S2103). Thereafter, the editing unit 1902 holds the selected assertion after insertion in the storage device in the verification support apparatus (step S2104).

  Further, the identifying unit 1903 identifies, from the selected assertion, clock identification information and register identification information defined by the selected assertion (step S2105). Then, the creation unit 1904 determines whether the checker module group CCMi has been created for the identified clock identification information and register identification information (step S2106).

  If it has been created (step S2106: Yes), the process returns to step S2101. On the other hand, if it has not been created (step S2106: No), the creation unit 1904 creates a checker module group CCMi for the identified clock identification information and register identification information, and holds it in the storage device (step S2107). . Thereafter, the process proceeds to step S2101.

  If there is no unselected assertion in step S2101 (step S2101: No), the editing / creating process ends. As a result, since the unedited assertion group 1910 is edited into the assertion group 1920 in which the description about the establishment notification is inserted, a false error is generated when the assertion is established in the check process in the mutual checker module group set CCM. It is possible to specify whether the change in the value of the register R is correct.

<Procedure notification processing procedure during simulation of circuit to be verified by mutual checker module CCMij>
FIG. 22 is a flowchart showing the establishment notification processing procedure during simulation of the circuit to be verified by the mutual checker module CCMij.

  First, the first detection unit 2001 waits until an assertion established during simulation of the circuit to be verified is detected from the assertion group 1920 for the register R targeted by the mutual checker module group CCMi (step S2201: No). If it is detected (step S2201: Yes), the mutual checker module CCMij notifies the check process CPij of the establishment notice “OK” by reading the establishment notification subroutine described in the established assertion (step S2201: Yes). S2202). Then, the process returns to step S2201. The flowchart of FIG. 22 ends when the simulation of the verification target circuit ends.

<Starting procedure of check process CPij during simulation of circuit to be verified by mutual checker module CCMij>
FIG. 23 is a flowchart showing a starting process procedure of the check process CPij during simulation of the circuit to be verified by the mutual checker module CCMij. First, the second detection unit 2002 waits until the value of the register R targeted by the mutual checker module group CCMi changes (step S2301: No). When a change in the value of the register R is detected (step S2301: Yes), the mutual checker module CCMij starts the check process CPij (step S2302).

  Then, the global variable C is incremented (step S2303). Since there are m total clocks of the mutual checker module CCMij, C = m is obtained by incrementing each mutual checker module CCMij. Thereby, the start process of the check process CPij is completed.

<Execution processing procedure of check process CPij>
FIG. 24 is a flowchart showing an execution processing procedure of the check process CPij started in FIG. In FIG. 24, the rising time of the clock Clk is detected as an example, but it may be the falling time.

  First, the second detection unit 2002 waits for the rising time of the clock Clk (step S2401: No), and when the rising time is reached (step S2401: Yes), the establishment notification “OK” is received from the mutual checker module CCMij. It is determined whether or not it has been done (step S2402). If it is received (step S2402: YES), the check process CPij is terminated without decrementing the global variable C (step S2407).

  On the other hand, if not received (step S2402: No), the determination unit 2003 decrements the global variable C (step S2403), and determines whether or not C after decrementing is C> 0 (step S2404). . If C> 0 (step S2404: YES), the process proceeds to step S2407 and the check process CPij is terminated (step S2407).

  On the other hand, if C> 0 is not satisfied (step S2404: NO), the determination unit 2005 determines that the change in the value of the register R is an erroneous change that is not defined in any assertion (step S2405). Then, the output unit 2006 outputs the determination result determined by the determination unit 2005 (step S2406) and ends the check process CPij (step S2407).

  As described above, according to the second embodiment, each time an assertion is established, the check process CPij is started for each mutual checker module CCMij to wait for a notice of establishment. If there is at least one check process CPij that has received a notification of establishment, it is guaranteed that the change in the value of the register R is an expected change according to the assertion. On the other hand, if there is no check process CPij that has received the notification of establishment, it is found that the change in the value of the register R is an erroneous change that is not defined in any assertion.

  As described above, in the second embodiment, when an assertion is established, it is possible to appropriately check that the assertion is established without generating a false error as shown in FIG. Further, when the value of the register R simply changes without the assertion being established, it is possible to detect a change in the value of the register R that is not defined in any assertion in the assertion group.

  Thereby, even when the register R in the circuit to be verified operates with a plurality of clocks, it is possible to efficiently detect a bug that cannot be detected by the assertion group without generating the above-described false error. The verifier can debug the identified bug to ensure that the value of the register R does not change outside the assertion for the circuit to be verified.

  The verification support method described in this embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. The verification support program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer.

  The following additional notes are disclosed with respect to the embodiment described above.

(Supplementary note 1) a first detection step of detecting an assertion that is established during simulation of the circuit from among assertion groups that define a register value that the circuit should satisfy;
An update step of updating the expected value of the register to the value of the register defined by the assertion at a clock timing next to the clock timing at which the assertion is detected by the first detection step;
A second detection step of detecting a mismatch between the expected value of the register and the value of the register after being updated by the updating step;
A determination step for determining whether the change in the value of the register is correct based on the detection result detected by the second detection step;
An output step of outputting the determination result determined by the determination step;
A verification support program characterized by causing a computer to execute.

(Supplementary note 2)
When a mismatch between the expected value of the register after the update and the value of the register is detected by the second detection step, the change in the register value is a change that is not defined by the assertion group. The verification support program according to supplementary note 1, wherein the verification support program is determined.

(Supplementary note 3)
When a match between the expected value of the register after the update and the value of the register is detected by the second detection step, it is determined that the change in the value of the register is a change as expected. The verification support program according to Supplementary Note 1 or 2, which is a feature.

(Appendix 4) The output step
4. The verification support program according to any one of appendices 1 to 3, wherein a clock timing at which the register mismatch is detected and identification information of the register are output.

(Appendix 5) The output step
The verification support program according to any one of appendices 1 to 3, wherein a clock timing next to a clock timing at which the register mismatch is detected and identification information of the register are output.

(Supplementary note 6) Any one of Supplementary notes 1 to 5, which causes the computer to execute the first detection step, the update step, the second detection step, and the determination step for each register in the circuit. The verification support program according to any one of the above.

(Supplementary note 7) a selection step of sequentially selecting unselected assertions from the assertion group;
For each assertion selected in the selection step, by causing the computer to execute an editing step for editing the assertion group by inserting an update instruction description for instructing an update of the expected value of the register,
The first detection step includes
Detecting assertions that are established during simulation of the circuit from the assertion group after editing by the editing step,
The update process includes:
According to the update instruction description inserted in the assertion detected by the first detection step, the expected value of the register is updated to the value of the register defined by the assertion detected by the first detection step. The verification support program according to any one of supplementary notes 1 to 6, wherein:

(Supplementary Note 8) For a register operating with a plurality of clocks in a circuit, from among an assertion group that defines a value of the register to be satisfied at a clock timing of any one of the plurality of clocks, during simulation of the circuit A first detection step for detecting the assertion to be established;
A second detection step of detecting a change in the value of the register;
For each clock of the plurality of clocks, for each clock timing that arrives first after the clock timing at which the change in the register value is detected by the second detection step, the clock that becomes the clock timing and the first clock A determination step of determining whether or not the clock defined by the assertion detected by the detection step is the same clock;
A determination step for determining whether the change in the value of the register is correct based on the determination result determined by the determination step;
An output step of outputting the determination result determined by the determination step;
A verification support program characterized by causing a computer to execute.

(Supplementary note 9)
If it is determined by the determination step that the clock of any one of the plurality of clocks is the same clock as the clock specified by the assertion, the change in the value of the register is determined to be an expected change. The verification support program according to appendix 8, characterized in that.

(Supplementary Note 10)
If no assertion that is established during simulation of the circuit is detected by the first detection step and a change in the value of the register is detected by the second detection step, the value of the register 10. The verification support program according to appendix 8 or 9, wherein the change is determined to be a change not defined in the assertion group.

(Additional remark 11) When the change of the value of the said register is detected by the said 2nd detection process, the production | generation process which produces | generates the check process group which waits for the establishment notification which notifies assertion establishment for every clock about the said register is carried out to the said computer Let it run
The determination step includes
9. The verification support program according to appendix 8, wherein, in the check process group generated by the generation step, it is determined whether or not there is a check process that has received the notification of establishment from the assertion.

(Supplementary note 12)
The supplementary note 11 is characterized in that, when the determination step determines that there is a check process that has received the notification of establishment from the assertion, the change in the register value is determined to be an expected change. Verification support program.

(Supplementary note 13)
When it is determined by the determination step that there is no check process that has received the notification of establishment from the assertion, it is determined that the change in the value of the register is a change that is not defined in the assertion group. The verification support program according to Supplementary Note 11 or 12.

(Supplementary Note 14) A selection step of sequentially selecting unselected assertions from the assertion group;
For each assertion selected in the selection step, by causing the computer to execute an editing step of editing the assertion group by inserting a description related to the notification of establishment.
The first detection step includes
The verification support program according to any one of appendices 10 to 12, wherein an assertion that is established during simulation of the circuit is detected from the assertion group that has been edited by the editing step.

(Supplementary Note 15) The output step includes
The verification support program according to any one of appendices 8 to 14, wherein a clock timing at which the value of the register has changed and identification information of the register are output.

(Supplementary Note 16) The output step includes
15. The verification support program according to any one of appendices 8 to 14, wherein a clock timing next to a clock timing at which the value of the register has changed and identification information of the register are output.

(Supplementary note 17) Any one of Supplementary notes 8 to 16, wherein the computer performs the first detection step, the second detection step, the determination step, and the determination step for each register in the circuit. The verification support program according to any one of the above.

(Supplementary Note 18) First detection means for detecting an assertion established during simulation of the circuit from among assertion groups that define a register value to be satisfied by the circuit;
Updating means for updating the expected value of the register to the value of the register defined by the assertion at a clock timing next to the clock timing at which the assertion is detected by the first detecting means;
Second detection means for detecting a mismatch between the expected value of the register and the value of the register after being updated by the update means;
Determining means for determining whether the change in the value of the register is correct based on a detection result detected by the second detecting means;
Output means for outputting the determination result determined by the determination means;
A verification support apparatus comprising:

(Supplementary Note 19) A register operating in a plurality of clocks in a circuit, from among an assertion group that defines a value of the register to be satisfied at a clock timing of any one of the plurality of clocks, during simulation of the circuit First detecting means for detecting an assertion that is established;
Second detection means for detecting a change in the value of the register;
For each clock of the plurality of clocks, for each clock timing that arrives first after the clock timing at which a change in the value of the register is detected by the second detection means, the clock that becomes the clock timing and the first clock Determining means for determining whether the clock defined by the assertion detected by the detecting means is the same clock;
Determining means for determining whether the change in the value of the register is correct or not based on the determination result determined by the determining means;
Output means for outputting the determination result determined by the determination means;
A verification support apparatus comprising:

(Supplementary note 20)
A first detection step of detecting an assertion that is established during simulation of the circuit from among an assertion group that defines a register value to be satisfied by the circuit;
An update step of updating the expected value of the register to the value of the register defined by the assertion at a clock timing next to the clock timing at which the assertion is detected by the first detection step;
A second detection step of detecting a mismatch between the expected value of the register and the value of the register after being updated by the updating step;
A determination step for determining whether the change in the value of the register is correct based on the detection result detected by the second detection step;
An output step of outputting the determination result determined by the determination step;
The verification support method characterized by performing this.

(Supplementary note 21)
An assertion that is established during simulation of the circuit is selected from among an assertion group that defines a value of the register to be satisfied at a clock timing of any one of the plurality of clocks for a register that operates with a plurality of clocks in the circuit. A first detection step to detect;
A second detection step of detecting a change in the value of the register;
For each clock of the plurality of clocks, for each clock timing that arrives first after the clock timing at which the change in the register value is detected by the second detection step, the clock that becomes the clock timing and the first clock A determination step of determining whether or not the clock defined by the assertion detected by the detection step is the same clock;
A determination step for determining whether the change in the value of the register is correct based on the determination result determined by the determination step;
An output step of outputting the determination result determined by the determination step;
The verification support method characterized by performing this.

301 editing processing unit 311 selection unit 312 editing unit 401 first detection unit 402 update unit 403 second detection unit 404 determination unit 405 output unit 1900 editing / creation processing unit 1901 selection unit 1902 editing unit 1903 identification unit 1904 creation unit 2001 First detection unit 2002 Second detection unit 2003 Determination unit 2004 Generation unit 2005 Determination unit 2006 Output unit

Claims (10)

An assertion that is established during simulation of the circuit is selected from among an assertion group that defines a value of the register to be satisfied at a clock timing of any one of the plurality of clocks for a register that operates with a plurality of clocks in the circuit. A first detection step to detect;
A second detection step of detecting a change in the value of the register;
For each clock of the plurality of clocks, for each clock timing that arrives first after the clock timing at which the change in the register value is detected by the second detection step, the clock that becomes the clock timing and the first clock A determination step of determining whether or not the clock defined by the assertion detected by the detection step is the same clock;
A determination step for determining whether the change in the value of the register is correct based on the determination result determined by the determination step;
An output step of outputting the determination result determined by the determination step;
A verification support program characterized by causing a computer to execute. The determination step includes
If it is determined by the determination step that the clock of any one of the plurality of clocks is the same clock as the clock specified by the assertion, the change in the value of the register is determined to be an expected change. The verification support program according to claim 1, wherein: The determination step includes
If no assertion that is established during simulation of the circuit is detected by the first detection step and a change in the value of the register is detected by the second detection step, the value of the register The verification support program according to claim 1, wherein the change is determined to be a change that is not defined in the assertion group. When a change in the value of the register is detected by the second detection step, the computer is caused to execute a generation step of generating a check process group that waits for establishment notification for notifying establishment of assertion for each clock for the register,
The determination step includes
2. The verification support program according to claim 1, wherein, in the check process group generated by the generation step, it is determined whether or not there is a check process that has received the notification of establishment from the assertion. The determination step includes
5. The method according to claim 4, wherein when the determination step determines that there is a check process that has received the notification of establishment from the assertion, the change in the value of the register is determined to be an expected change. The verification support program described. The determination step includes
When it is determined by the determination step that there is no check process that has received the notification of establishment from the assertion, it is determined that the change in the value of the register is a change that is not defined in the assertion group. The verification support program according to claim 4 or 5. A selection step of sequentially selecting unselected assertions from the assertion group;
For each assertion selected in the selection step, by causing the computer to execute an editing step of editing the assertion group by inserting a description related to the notification of establishment.
The first detection step includes
6. The verification support program according to claim 4 or 5, wherein an assertion that is established during simulation of the circuit is detected from the assertion group that has been edited by the editing step.   8. The computer according to claim 1, wherein the computer executes the first detection step, the second detection step, the determination step, and the determination step for each register in the circuit. The verification support program described in 1. An assertion that is established during simulation of the circuit is selected from among an assertion group that defines a value of the register to be satisfied at a clock timing of any one of the plurality of clocks for a register that operates with a plurality of clocks in the circuit. First detecting means for detecting;
Second detection means for detecting a change in the value of the register;
For each clock of the plurality of clocks, for each clock timing that arrives first after the clock timing at which a change in the value of the register is detected by the second detection means, the clock that becomes the clock timing and the first clock Determining means for determining whether the clock defined by the assertion detected by the detecting means is the same clock;
Determining means for determining whether the change in the value of the register is correct or not based on the determination result determined by the determining means;
Output means for outputting the determination result determined by the determination means;
A verification support apparatus comprising: Computer
An assertion that is established during simulation of the circuit is selected from among an assertion group that defines a value of the register to be satisfied at a clock timing of any one of the plurality of clocks for a register that operates with a plurality of clocks in the circuit. A first detection step to detect;
A second detection step of detecting a change in the value of the register;
For each clock of the plurality of clocks, for each clock timing that arrives first after the clock timing at which the change in the register value is detected by the second detection step, the clock that becomes the clock timing and the first clock A determination step of determining whether or not the clock defined by the assertion detected by the detection step is the same clock;
A determination step for determining whether the change in the value of the register is correct based on the determination result determined by the determination step;
An output step of outputting the determination result determined by the determination step;
The verification support method characterized by performing this.

Images