JP5287955B2 - Behavioral synthesis apparatus, method, and program having test bench generation function - Google Patents

Description

  The present invention relates to a behavioral synthesis apparatus, method, and program for generating an RTL (Register Transfer Level) circuit description that describes a specific function (circuit) from an operation level circuit description that describes the operation of a semiconductor integrated circuit. The present invention relates to a behavioral synthesis apparatus, a behavioral synthesis method, and a behavioral synthesis program that can output a test bench for verifying a generated RTL circuit.

  In recent years, in the design of system LSIs, a design method of designing at a high level of abstraction and generating RTL by behavioral synthesis has begun to be adopted.

  In this type of design method, first, an operation description for realizing a desired operation of the system LSI is designed.

  Next, it is confirmed by operation simulation whether the designed operation description surely achieves the desired operation of the circuit, that is, whether the design is correct.

  If the design is correct, the behavioral description is converted into RTL using behavioral synthesis.

  When designing an LSI using the above design method, there is a demand to use the test vector used in the operation simulation in the RTL simulation after the behavioral synthesis. This request has the following first and second purposes, for example.

  First, it is to confirm whether the behavior description before behavioral synthesis and the RTL after behavioral synthesis realize the same function.

  If the behavioral description and the RTL do not realize the same function, it does not make sense to confirm that the behavioral description achieves the desired behavior of the circuit by behavioral simulation. This is because a circuit that realizes a desired operation cannot be designed as a result.

  Conventionally, whether the behavioral description and the RTL have the same function is confirmed by using the same test vector for the behavioral simulation and the RTL simulation, and comparing that the simulation results are the same. ing.

  Second, it is for confirming the performance of the circuit after behavioral synthesis.

  In general, since the behavioral description does not include timing information, it is not possible to confirm the circuit performance such as how much time is required to achieve a certain function.

  On the other hand, by performing RTL simulation, the time required to achieve a certain function, that is, the circuit performance can be obtained.

  Therefore, in the conventional method, whether or not the designed behavior description can achieve the desired performance is determined based on the circuit performance measured by the RTL simulation using the same test vector in the behavior simulation and the RTL simulation.

  However, the test vector used in the operation simulation cannot be used in the RTL simulation as it is.

  The reason is because of problems of input application timing and output observation timing.

  Generally, there is no concept of time (clock) in the behavioral description. Or even if there is a concept of time, the granularity is different from the time of RTL. Therefore, even if the input data series of the test vector used in the operation simulation is applied for each clock in the RTL simulation, the same result as in the operation simulation cannot be obtained. Similarly, even if the output is observed for each clock in the RTL simulation, the same result as in the operation simulation cannot be obtained.

  Japanese Patent Application Laid-Open No. 2005-78402 discloses a behavioral synthesis system for solving the above problems. The behavioral synthesis system described in Patent Document 1 is mainly the same as the behavioral simulation even if the input data series of the test vector used in the behavioral simulation is applied for each clock in the RTL simulation. It is intended to solve the problem that results cannot be obtained. This conventional behavioral synthesis system is based on the premise that a file reading function for reading an input sequence from a file and a file writing function for writing an output sequence to a file are described in the behavior description. The file reading function and the file writing function are collectively referred to as a file function. This conventional behavioral synthesis system is composed of syntax analysis means, control data flow graph creation means, scheduling and binding means, test bench generation means, and RTL generation means. The conventional behavioral synthesis system having such a configuration operates as follows.

  That is, the file function in the operation description is left in the syntax analysis unit and the control data flow graph creation unit.

  Based on the created control data flow graph, RTL is created by performing resource binding and scheduling.

  On the created RTL, file input related to the file function using the select signal of the multiplexer that switches the data from the first input terminal, the input of the variable, or the select signal of the multiplexer that switches the data output to the output terminal Or represents the conditions for file output.

  However, the behavioral synthesis system described in Patent Document 1 has a problem that there is a file function in the behavioral description, and it can be applied only to the behavioral description that satisfies the prerequisite.

  An example of the equivalence checking method is disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 2004-145712). The equivalence verification method described in Patent Document 2 is mainly intended to solve the first problem described above. In this equivalent verification method, the comparison timing is obtained based on the number of delay cycles from the time when the input signal is determined to the time when the output signal is determined in the RTL simulation result, the value of the output signal of the RTL simulation result at the comparison timing, and the operation Compared with the simulation output signal, there is a problem that the types of circuits to which the method can be applied are limited.

  This is because there is no consideration for circuits having different input value application timings for each input signal.

  Furthermore, when the number of cycles until the output signal is determined changes depending on the input data, the comparison timing cannot be obtained based on the “number of delayed cycles from the time when the input signal is determined until the time when the output signal is determined”. This is because there is no consideration.

  Patent Document 3 (US Pat. No. 6,845,341) discloses a performance evaluation system. This performance evaluation system generally operates as follows. That is, a test bench that simultaneously executes operation simulation and RTL simulation is created. Between the behavioral description and the test bench, and between the RTL and the test bench, modules for absorbing differences in input timing and output timing of the behavioral simulation and the RTL simulation are inserted. In this way, the operation simulation and the RTL simulation input the same test vector (vector), and the performance is evaluated by measuring the number of clocks required for the RTL to execute the simulation.

JP-A-2005-78402 JP 2004-145712 A US Pat. No. 6,845,341 (US 6,845,341 B2) (FIG. 2)

  The conventional system has a problem that the test vector used in the operation simulation cannot be used in the RTL simulation as it is.

  The reason is because of the problems of input application timing and output observation timing as described above. Various proposals made to solve this problem are not sufficient as mentioned above.

  Another reason for the above problem is sharing of input terminals and output terminals. In general, an input terminal and an output terminal of a behavior description do not always have a one-to-one correspondence with an RTL input terminal and an output terminal.

  Furthermore, another reason for the above problem is due to behavioral problems that cannot be expressed in behavioral descriptions. Many behavioral descriptions do not specify input / output behavior during reset. For example, when the C language is used for the behavioral description, the behavior of the input / output during the reset is not specified (there is a language for the behavioral description that designates the behavior of the input / output during the reset like the SystemC language).

  Therefore, even if the input value is applied and the output value is observed during the reset period during the RTL simulation, the same result as the operation simulation cannot be obtained.

  Furthermore, another reason for the problem is due to a problem of an external model (such as a shared memory model, a memory model, and an arithmetic unit model). In behavioral synthesis, an array in the behavioral description is realized with a memory in the RTL, and a variable in the behavioral description is realized in a register outside the module in the RTL.

  Further, when the operation in the operation description is realized by the RTL arithmetic unit, it may be output as a black box in which the details of the internal logic of the arithmetic unit are omitted.

  Therefore, in the RTL simulation, the simulation cannot be executed unless a simulation model of the memory, a register outside the module, and a simulation model of the arithmetic unit output as a black box are prepared.

  Therefore, the present invention was created based on the recognition of the above problems, and its purpose is to output a test bench that makes it possible to use a test vector used before behavioral synthesis for a circuit obtained after behavioral synthesis. An object is to provide a behavioral synthesis apparatus, method, and program.

  In order to solve the above-described problems, the invention disclosed in the present application is generally configured as follows.

  According to the present invention, the number of clocks from reset release to the circuit is measured, and when the number of clocks coincides with a predetermined value, the application of the input to the circuit and the observation of the output of the circuit are performed. A behavioral synthesis device including a test bench generating means for generating a bench is provided.

  According to the present invention, a test bench that measures the number of clocks from the release of reset to a circuit and applies an input to the circuit and observes the output of the circuit when the number of clocks matches a predetermined value. A behavioral synthesis method including the above-described steps is provided.

  According to the present invention, there is provided a test bench that measures the number of clocks from reset release to a circuit and applies an input to the circuit and observes the output of the circuit when the number of clocks matches a predetermined value. A program for causing a computer to execute a test bench generation process to be created is provided.

  According to the present invention, the same test vector can be used in the operation simulation and the RTL simulation. This is because, in the present invention, a test bench that can use the test vector used before the behavioral synthesis for the circuit obtained after the behavioral synthesis can be output.

It is a block diagram which shows the structure of the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the 1st Embodiment of this invention. It is a figure which shows an example of action description. It is a figure which shows an example of a scheduling result. It is a figure which shows an example of a binding result. It is a figure which shows an example of a binding result. It is a figure which shows an example of the description after FSM production | generation. It is a figure which shows an example of the description by which the input application timing signal, the output observation timing signal, and its logic were created. It is a figure which shows an example of a test bench. It is a block diagram which shows the structural example of the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the 2nd Embodiment of this invention. It is a figure which shows an example of action description. It is a block diagram which shows the structural example of the 3rd Embodiment of this invention. It is a figure which shows an example of the operation description used in an Example. It is a figure which shows an example of a scheduling result. It is a figure which shows an example of the description after FSM production | generation. It is a figure which shows an example of the description which recorded the input application timing and the output observation timing. It is a figure which shows an example of a test bench. It is a figure which shows an example of a test bench. It is a figure which shows an example of a test bench. It is a figure which shows an example of action description. It is a figure which shows an example of RTL. It is a figure which shows an example of a test bench.

  The above-described present invention will be described with reference to the accompanying drawings in order to explain in more detail.

<Embodiment 1>
Referring to FIG. 1, a behavioral synthesis system (apparatus) according to a first embodiment of the present invention includes a computer (central processing unit; processor; data processing unit) 100 that operates under program control, and data storage means (data). Storage device) 110.

  A computer (central processing unit; processor; data processing unit) 100 includes a scheduling unit 101, a binding unit 102, an FSM (finite state machine) generation unit 103, an input application / output observation timing signal generation unit 104, and an RTL ( HDL (Hardware Description Language) generating means (RTL generating means) 105 such as a register transfer level) and a test bench generating means 106 are included. Each of these means generally operates as follows.

  The scheduling unit 101 assigns the behavior description to the state. That is, operations in the behavior description, condition determination, value input from the input terminal, value output to the output terminal, array reading, and array writing are assigned to the states to be executed.

The binding means 102 assigns the behavior description to the hardware resource. That is,
The operation in the operation description is used as an arithmetic unit.
Change the input terminal in the behavior description to the RTL input terminal.
The output terminal in the behavior description is the RTL output terminal.
Allocates the array in the operation description to the RTL memory or register file.

  At this time, a plurality of input signals in the behavioral description may be assigned to one RTL input signal, or a plurality of output signals in the behavioral description may be assigned to one RTL output signal. Similarly, a plurality of operations in the behavioral description may be assigned to one RTL calculator. These are called “hardware resource sharing”.

  The finite state machine (FSM) generation means 103 creates a finite state machine (FSM) that controls state transition and a control logic circuit that controls hardware resources. The control logic circuit for controlling the hardware resource is a logic for controlling the hardware resource in accordance with the assignment to the state obtained by the scheduling means 101 and the assignment to the hardware resource obtained by the binding means 102. Circuit. That is, a logic circuit for being executed by an assigned computing unit in a state in which an operation in the behavior description is assigned, a logic circuit for executing a condition determination in the behavior description in an assigned state, and The value input from the RTL input terminal and the value input to the output terminal in the state where the value input from the input terminal in the operation description, the value output to the output terminal, the array read, and the array write are respectively assigned. It is a logic circuit to be realized by output, memory reading and memory writing.

  The input application / output observation timing signal generation means 104 creates a new signal terminal corresponding to each of the input terminal and the output terminal. This signal is referred to as “input application / output observation timing signal”.

  Further, the input application / output observation timing signal generation unit 104 outputs a predetermined value (““ ”to the input application / output observation timing signal only in a state and a condition in which values are input / output to the corresponding input signal / output signal, respectively. A logic circuit is created so that an “active value” is output.

  The RTL generation unit 105 converts the FSM and control logic circuit created by the finite state machine generation unit 103, the logic circuit created by the input application / output observation timing signal generation unit 104, and hardware resources into HDL, Store in the storage device 110.

  The test bench generation means 106 creates a test bench. The test bench observes the input application / output observation timing signal, and creates a logic that applies the input when the active value is output to the signal or observes the output and collates it with the expected value. The test bench generation unit 106 stores the created test bench in the storage device 110.

  Note that the behavioral synthesis device according to the present embodiment may be configured by an LSI, a logic circuit, or the like that realizes the functions of the components illustrated in FIG. 1, and is configured by an information processing device (computer) as illustrated in FIG. It may be realized.

  2 includes a processing device 100 including a CPU, a storage device 110, and a recording medium (also referred to as a “storage medium”) 500. The processing device 100 is stored in the recording medium 500. The behavioral synthesis program is read, and the processing of the scheduling unit 101 and the binding (accompanying information conversion) unit 102 of the present embodiment described below is executed by the CPU according to the behavioral synthesis program.

  Further, the memory area of the storage device 110 is divided into an operation description storage unit 111, an RTL storage unit 112, and a test bench storage unit 113, and used.

  Next, the overall operation of the present embodiment will be described in detail with reference to the flowcharts of FIGS.

  The behavior description storage unit 111 stores behavior descriptions in advance. The operation description is a hardware description language (HDL) such as Verilog-HDL, VHDL, or SystemVerilog, or a programming language such as C language, C ++ language, C # language, SystemC, SpecC, Java (registered trademark), Perl, Scheme, or Lisp. It is expressed by In some cases, the language is expressed in C language, C ++ language, or Java (registered trademark) in an extended language for expressing a circuit. The behavioral description is prepared by a designer, for example.

  First, the computer 100 reads an operation description from the operation description storage unit 111 in the storage device 110 and assigns the operation description to a state by the scheduling unit 101 in the computer 100. That is, operations in the behavior description, condition determination, input, output, array read, and array write are assigned to the states (step A1 in FIG. 3).

Next, the behavior description is assigned to the hardware resource by the binding means 102. That is,
The operation in the operation description is used as an arithmetic unit.
Input to the input terminal
Output to output terminal
The array is assigned to a memory or register file (step A2 in FIG. 3).

  Further, the FSM generation means 103 creates a finite state machine (FSM) that controls state transition and logic that controls hardware resources (step A3 in FIG. 3).

  Further, the input application / output observation timing signal generation means 104 creates an input application / output observation timing signal and a logic circuit for the signal (step A4 in FIG. 3).

  Further, the FTL and the control logic circuit created by the finite state machine generation means 103 in step A3 by the RTL generation means 105, the logic circuit created by the input application / output observation timing signal generation means in step A4, and hardware The resource is converted into HDL and stored in the storage device 110 (step A5 in FIG. 3). VHDL, Verilog-HDL, SystemVerilog, SystemC, SpecC, C language, C ++ language, C # language, etc. are used for HDL.

  A test bench is generated by the test bench generation means 106. The test bench generation means 106 stores the created test bench in the storage device 110 (step A6). The test bench is also expressed using VHDL, Verilog-HDL, SystemVerilog, SystemC, SpecC, C language, C ++ language, C # language, and the like, similar to RTL.

  Next, the effect of this Embodiment is demonstrated.

  In the present embodiment, the input application / output observation timing signal generation unit 104 generates a signal for transmitting the state and condition in which values are input and output to the corresponding input signal / output signal, and the conditions to the outside, The test bench generation unit 106 is configured to observe the signal and apply the input, or to create the test bench that observes the output and matches the expected value. A test bench can be created in which the output is applied or the output is observed and checked against the expected value.

<Embodiment 2>
Next, a second embodiment of the present invention will be described. FIG. 11 is a diagram showing the configuration of the second exemplary embodiment of the present invention. FIG. 12 is a flowchart for explaining the operation of the second exemplary embodiment of the present invention. Referring to FIG. 11, in the second embodiment of the present invention, a computer (central processing unit; processor; data processing unit) 100 operating by program control is the same as that in the first embodiment shown in FIG. The input application / output observation timing signal generation unit 104 is deleted, and another test bench generation unit 107 is provided instead of the test bench generation unit 106. Referring to FIG. 12, steps A4 and A6 are deleted from the flowchart of FIG. 3, and step A7 is newly added.

  The test bench generating means 107 in the present embodiment differs from the test bench generating means 106 in the first embodiment in the following points.

  That is, the test bench generating means 107 recognizes the signal in the behavior description as the input application / output observation timing signal. After that, the signal is observed, and an input is applied when an active value is output to the signal, or a logic is created such that the output is observed and collated with an expected value (step A7 in FIG. 12). Then, the created test bench is stored in the storage device 110.

<Embodiment 3>
Referring to FIG. 14, the third embodiment of the present invention is such that a computer (central processing unit; processor; data processing unit) 100 operating under program control is the same as that in the first embodiment shown in FIG. The input application / output observation timing signal generation means 104 is replaced with an input application / output timing recording means 108, and a test bench generation means 109 is provided instead of the test bench generation means 106.

  The input application / output observation timing recording means 108 generally operates as follows.

  Referring to the control data flow graph, record the number of clocks from when reset is released until the input value is applied, and the period from application of the input to application of the next input for each input. . At the same time, the number of clocks from when reset is released until the output value becomes valid and the period from when the output value becomes valid until the next output value becomes valid are recorded for each output signal. .

  The test bench generating means 109 generally operates as follows. When the input / output timing recorded by the input application / output timing recording means 108 is read and the number of clocks after the reset signal is released is measured, and the number of clocks coincides with the number of clocks to which the input is applied, or A test bench for applying an input is created when the period for applying the input coincides. At the same time, when the number of clocks after reset is released matches the number of clocks until the output becomes valid, or when the period until the output becomes valid, the output is observed and expected. Create a test bench that matches the values. The created test bench is stored in the storage device 110.

  This embodiment is different from Patent Document 2 in the following points. That is, the output observation timing is determined based on the cycle and period after the reset is released, not the delay cycle after the input is confirmed.

  Even if it is a circuit to which the invention disclosed in Patent Document 2 cannot be applied by applying input and observing output based on the number of cycles after reset is released without distinguishing between input and output, The invention can be applied.

<Embodiment 4>
Next, a fourth embodiment of the present invention will be described. In the fourth embodiment of the present invention, a computer (central processing unit; processor; data processing unit) 100 that operates under program control has a test bench generating means 106 in the first embodiment shown in FIG. However, it differs in that it has the following functions.

  The test bench created by the test bench generation means 106 observes the reset signal in addition to the input application / output observation timing signal, and the reset signal is valid even if an active value is output to the input application / output observation signal. During this period, neither input application nor output observation is performed. The created test bench is stored in the storage device 110.

  The test bench generating means 106 also operates as outlined below. That is, the test bench created by the test bench generation means 106 observes a stall signal in addition to the input application / output observation timing signal, and even if an active value is output to the input application / output observation signal, the stall signal While is valid, neither input application nor output observation is performed. The created test bench is stored in the storage device 110.

<Embodiment 5>
Next, a fifth embodiment of the present invention will be described. In the fifth embodiment of the present invention, the computer (central processing unit; processor; data processing unit) 100 that operates under program control is replaced by the test bench generation unit 106 in the first embodiment shown in FIG. The difference is that it has the following functions. The test bench generating means 106 operates generally as follows.

  When the RTL obtained by the RTL generation unit 105 cannot execute the simulation alone, a test bench having a necessary simulation model is generated correspondingly.

  The case where the simulation cannot be performed by the RTL alone includes, for example, an array in the behavioral description, and an interface circuit for accessing the memory may be generated in the RTL. In this case, a test bench having a simulation model for the memory is created.

  In addition, for example, there are complex operations such as multiplication and division in the behavioral description. On the other hand, the RTL may output the operation part as a black box. In this case, a test bench having a simulation model of the operation corresponding to this is created.

  In the following, description will be made using some specific examples.

<Example 1>
First, a first embodiment of the present invention will be described. The first example of the present invention corresponds to the first embodiment of the present invention described above. Referring to FIG. 4, an operation description is illustrated. The behavioral description of FIG. 4 is expressed in C language.

The input terminal of the function func () is an int type variable a, b, c, d, and the output terminal is an int type variable o. The output value o of the function is
When the value of input c is 0, it is the sum of all inputs (a, b, c, d),
When the value of the input c is other than 0, the sum of the inputs a and b is obtained. The behavior description is stored in advance in the behavior description storage unit 111 of the storage device 110.

  The behavioral synthesis device of the first embodiment reads the behavioral description of FIG. 4 from the behavioral description storage unit 111 of the storage device 110, the RTL generation unit 105 creates the RTL shown in FIG. 9, and the test bench generation unit 106 The test bench shown in FIG. 10 is created and stored in the RTL storage unit 112 and the test bench storage unit 113 of the storage device 110, respectively.

  First, the scheduling means 101 in the computer 100 assigns an operation description to a state (step A1 in FIG. 3). That is, operations in the behavior description, condition determination, input, output, array read, and array write are assigned to states.

The behavioral description of FIG.
In line 5, inputs a and b and addition +,
In line 6, input c and condition determination ==,
In line 7 input c, d and addition +,
9th line addition + and output o
Is specified.

Referring to FIG. 5, the assignment to the state by the scheduling means 101 is illustrated. In FIG. 5, the scheduling means 101
The inputs a and b and the addition + in the fifth row are in the state STATE1.
6th line input c and condition determination ==, and 7th line input c, d and addition + are in state STATE2, respectively.
The addition + and the output o in the ninth line are in the state STATE3.
It is shown that it is assigned to.

  Next, the binding means 102 in the computer 100 assigns the operation description to the hardware resource (step A2 in FIG. 3).

That is,
The operation in the operation description is used as an arithmetic unit.
The input terminal of the behavior description is the input terminal of RTL,
The output terminal of the behavior description is the output terminal of RTL,
Allocates an array of behavior descriptions to the RTL memory or register file.

  Referring to FIG. 6, the assignment by the binding means 102 to the calculator is schematically illustrated.

  In FIG. 6 (A), the addition of the fifth row +, the addition of the seventh row +, and the addition of the ninth row + are all assigned to one arithmetic unit ADD (FIG. 6 (D)). It is shown that the condition determination == is assigned to the comparator EQ (FIG. 6E).

  Further, referring to FIG. 7, the assignment to the input terminal and the output terminal by the binding means 102 is illustrated.

The input a in the fifth row in FIG. 7A and the input c in the sixth and seventh rows are connected to the input terminal iport1 (FIG. 7B).
The input b in the fifth row and the input d in the seventh row in FIG. 7A are connected to the input terminal iport2 (FIG. 7C).
The output o in the 10th row in FIG. 7A is connected to the output terminal “opport 1” (FIG. 7F).
Each is assigned.

  Next, the finite state machine (FSM) generation means 103 creates a finite state machine (FSM) that controls state transition and a control logic circuit that controls hardware resources (step A3 in FIG. 3).

  Referring to FIG. 8, a finite state machine, a control logic circuit, and hardware resources controlled by the control logic circuit are illustrated. This example is expressed in Verilog-HDL. In the example shown in FIG. 8, the finite state machine and the control logic circuit are expressed by a state register state and a case () statement. Note that FIG. 8 is simply divided into FIGS. 8A and 8B for convenience of drawing, and the range of module (input / output terminal list)... Endmodule is one circuit module.

  As hardware resources, an input terminal, an output terminal, an arithmetic unit, and a storage element (register) are used. Iport1 and iport2 are used for the input terminals. The output terminal is port1. As an arithmetic unit, an adder ADD and a comparator EQ are used, but in the example shown in FIG. 8, they are expressed as addition +, comparison ==. For the storage element (register), v0 and v1 are used. In addition, a reset signal rst and a clock signal clk are used. The module main operates as follows.

  The following operations are performed at the rising event of the clock signal clk. When the input of the reset terminal rst is 1, the value of the state register state is set to T_STATE1, and the registers v0, v1, and o_t are initialized to 0.

  When the input of the reset terminal rst is not 1 at the rising event of the clock signal clk, the following operation is performed. When the value of the status register state is T_STATE1, the values are read from the input terminals iport1 and iport2, the sum of the values is calculated by the adder ADD, and the calculation result is stored in the register v0. Further, the value of the status register state is updated to T_STATE2.

  When the value of the status register state is T_STATE2, the values are read from the input terminals iport1 and iport2, respectively, and the value of iport1 is compared by the comparator EQ. When the value read from the input terminal iport1 is 0, the sum of the read values is calculated by the adder ADD, and the calculation result is stored in the register v1. Further, the value of the status register state is updated to T_STATE3.

  When the value of the status register state is T_STATE3, the sum of the values of the registers v0 and v1 is calculated by the adder ADD, and is output to the output terminal “port1”. Further, the value of the status register state is updated to T_STATE1.

  The value of the status register state is updated in the order of T_STATE1, T_STATE2, T_STATE3, T_STATE1,.

  The test bench applies the values of the inputs a, b, c, and d to the input terminals iport1 and iport2, respectively, at an appropriate timing, and observes the value of the output terminal “port1” at an appropriate timing, whereby the function func ( ) Operation.

  Next, the input application / output observation timing signal generation unit 104 creates an input application / output observation timing signal and a logic circuit for the signal (step A4 in FIG. 3).

  Referring to FIG. 9, an example in which an input application / output observation timing signal and a logic circuit for the signal are added to FIG. 8 is illustrated.

  The behavioral description of FIG. 4 has input terminals a, b, c, d and an output terminal o. Referring to FIG. 9, input application timing signals a_e, b_e, c_e, and d_e are added to inputs a, b, c, and d. Further, an output observation timing signal o_e is added to the output signal o. A logic circuit for determining each output value is also added.

  The value corresponding to the fifth line of the input signal a in the behavioral description is acquired from the input terminal iport1 in the state STATE1 in the RTL resulting from the behavioral synthesis by the scheduling unit and the binding unit. Therefore, a logic circuit (assign a_e = (state == T_STATE1)? 1'b1: 1'b0;) is generated so that the input application timing signal a_e also becomes an active value (1 (High)) only in the state STATE1. Has been.

  Similarly, the output signal o is output to the output terminal “port1” in the state STATE3. Therefore, the output observation timing signal o_e is generated by a logic circuit (assign o_e = (state == T_STATE3)? 1'b1: 1'b0;) that becomes an active value (1 (High)) only in the state STATE3. Has been.

  Next, the RTL generation means 105 converts the FSM, the control logic circuit, the input application / output observation timing signal, its logic circuit, and hardware resources into HDL, and stores them in the storage device 110 (FIG. 3). Step A5). FIG. 9 illustrates HDL (Verilog-HDL) created by the RTL generation unit 105.

  Next, a test bench is generated by the test bench generation means 106. The test bench observes the input application / output observation timing signal, and creates a logic that applies the input when the active value is output to the signal or observes the output and collates it with the expected value.

  Referring to FIG. 10, the test bench created by the test bench generating means 106 is shown. The example of FIG. 10 is expressed by pseudo code similar to Verilog-HDL. The generated test bench generally operates as follows.

  Assuming that the value of the input signal a is obtained from the input terminal iport1 when the value of the input application timing signal a_e is an active value (1 (High)), the input value of the input signal a is input to the input terminal iport1. Apply. Assuming that the value of the input signal b is acquired from the input terminal iport1 when the value of the input application timing signal b_e is the active value (1 (High)), the input value of the input signal b is input to the input terminal iport1. Apply. Assuming that the value of the input signal c is obtained from the input terminal iport2 when the value of the input application timing signal c_e is an active value (1 (High)), the input value of the input signal c is input to the input terminal iport2. Apply. Assuming that the value of the input signal d is obtained from the input terminal iport2 when the value of the input application timing signal d_e is an active value (1 (High)), the input value of the input signal d is input to the input terminal iport2. Apply.

  Similarly, when the value of the output observation timing signal o_e is an active value (1 (High)), it is assumed that the value of the output signal o is output from the output terminal “opport1”, and the value of the output terminal “port1” is observed. Then, comparison is made with the expected value of the output signal o. In FIG. 10, a module main duty (input / output terminal list) is a test target module.

<Example 2>
Next, a second embodiment of the present invention will be described. This example corresponds to the second embodiment described with reference to FIGS. 11 and 12. Referring to FIG. 13, an example of behavior description is shown. The behavioral description of FIG. 13 includes output signals a_e, b_e, c_e, d_e, and o_e as compared with the behavioral description of FIG. 4, and the output signals are displayed on the 16th, 17th, 20th, and 23rd lines. The difference is that output operations to a_e, b_e, output signal c_e, output signal d_e, and output signal o_e are specified.

  In the behavioral description of FIG. 13, output signals a_e, b_e, c_e, d_e, and o_e are output signals representing the input timing and output timing of a, b, c, d, and o, respectively. In the circuit description section, an operation for outputting an active value (1) when there is an input / output access of a corresponding signal is designated.

  In the declaration part, the signal b_e is specified by a comment (pragma) that the corresponding signal is b and b_e is a signal that specifies the input timing of b. 2nd line: “input int b; // pragma enable_signal_is b_e” comment symbol “//” below “pragma enable_signal_is b_e” is an instruction (pragma) to the simulator and b_e is a signal that specifies the input timing of b It stipulates that

  Conversely, the signal c is designated by a comment (pragma) that the corresponding signal is c_e, and that c_e is a signal that designates the input timing of c. 7th line: "output int c_e; // pragma enable_signal_for c" comment symbol "//" and below "pragma enable_signal_for c" is an instruction (pragma) to the simulator, c_e specifies the input timing of c It stipulates that

  The behavioral synthesis apparatus according to the second embodiment of the present invention reads the behavioral description of FIG. 13 from the behavioral description storage unit 111 of the storage device 110 of FIG. 11, and schedules 101, binding means 102, FSM generation means 103, RTL. The module main illustrated in FIG. 9 is generated through the generation unit 105. The operation of the module main is as described above.

  Next, a test bench is generated by the test bench generation means 107 of FIG. The test bench observes the input application / output observation timing signal, and creates a logic that applies the input when the active value is output to the signal or observes the output and collates it with the expected value. At this time, the signal originally present in the operation description is used as the input application / output observation timing signal.

  Referring to FIG. 10, the created test bench is illustrated. This example is expressed in pseudo code similar to Verilog-HDL.

  A_e is used as the input application timing signal of the signal a. This is a signal determined based on the similarity of signal names.

  B_e is used for the input application timing signal of the signal b. This is a signal determined based on the comment (pragma) of the signal b (see FIG. 13).

  C_e is used as the input application timing signal of the signal c. This is a signal determined based on the comment (pragma) of the signal c (see FIG. 13).

  D_e is used as the input application timing signal of the signal d. This is a signal determined from the fact that the reference to the signal d and the output to the signal d_e are described in parallel in the behavioral description (see lines 19 and 20 in FIG. 13).

  The operation of the test bench in FIG. 10 is as described above.

<Example 3>
Next, a third embodiment of the present invention will be described. The third embodiment of the present invention corresponds to the third embodiment described with reference to FIG. Referring to FIG. 15, an example of behavioral description is shown. In FIG. 15, the input of the function func () is int type variables a, b, c and d, and the outputs are int type variables o1 and o2. The output o1 of the function func () is the sum of the inputs a and b, and the output o2 is the sum of the inputs a, b, c and d.

  The behavioral description is stored in advance in the behavioral description storage unit 111 of the storage device 110 in FIG.

  The behavioral synthesis device according to the third embodiment of the present invention reads the behavioral description of FIG. 15 from the behavioral description storage unit 111 of the storage device 110 of FIG. 14, and the RTL generation means 105 performs the RTL shown in FIG. The test bench generation unit 109 creates the test bench of FIG. 19 and stores them in the RTL storage unit 112 and the test bench storage unit 113 of the storage device 110, respectively.

  First, the scheduling unit 101 in the computer 100 assigns an operation description to a state. That is, operations in the behavior description, condition determination, input, output, array read, and array write are assigned to states.

The behavioral description in FIG.
Input a, b and addition + on line 11
Input b, c and addition + on line 12
On line 13, output o1,
On line 14, add +,
Output o2 on line 15
Is specified.

  Referring to FIG. 16, state assignment by the scheduling unit 101 is illustrated. In FIG. 16, the scheduling means 101 causes the inputs a and b and addition + on the 11th row to STAGE1, the inputs b and c and addition + on the 12th row to STAGE2, and the output o1 and 14th row on the 13th row. The addition + indicates that the stage 3 is allocated, and the output o2 in the 15th row is allocated to the stage 4.

  Next, the module main of FIG. 17 is generated through the binding means 102 and the FSM generation means 103 in the computer 100.

  Referring to FIG. 17, a module main obtained after the binding means 102 and the FSM generating means 103 is illustrated. The example of FIG. 17 is expressed in Verilog-HDL. The module is synthesized as a pipeline circuit. All stages from STAGE 1 to STAGE 4 are operated so as to be executed every clock in synchronization with the clock.

  Next, the input application / output observation timing recording unit 108 refers to the control data flow graph, and determines the number of clocks from when reset is released until the input value is applied, and the cycle of input application, for each input signal. Record about. In addition, the number of clocks from when reset is released until the output value becomes valid, and the period of output observation are recorded for each output signal. Referring to FIG. 18, the module main in which these pieces of information are recorded is illustrated in the module main in FIG.

  The input signals a and b of the module main are described in order to apply the input every cycle from the next clock after the reset is released. That is, as shown in FIG. 18A, the comment lines 1 and 1 of the input signals a and b of the declaration part become valid one clock after the reset is released, and the cycle is one clock cycle. Is shown.

  The input signals c and d are described in order to apply the input every cycle after the reset is released and two clocks later. That is, as shown in FIG. 18A, the comment lines 2 and 1 of the input signals c and d in the declaration part become valid two clocks after the reset is released, and the period is one clock cycle. Is shown.

  Since the output value of the output signal o1 becomes valid every cycle three clocks after the reset is released, the information is described. That is, as shown in FIG. 18A, the comment lines 3 and 1 of the output signal o1 of the declaration part become effective three clocks after the reset is released, and indicate that the cycle is one clock cycle. Yes.

  Since the output value of the output signal o2 becomes valid every cycle from 4 clocks after the reset is released, the information is described. That is, as shown in FIG. 18A, the comment lines 4 and 1 of the output signal o2 of the declaration part become valid four clocks after the reset is released, indicating that the period is one clock cycle. Yes.

  Next, an RTL and a test bench are created by the RTL generation unit 105 and the test bench generation unit 109 of FIG. 14 and stored in the storage device 110, respectively.

  Referring to FIG. 19, a test bench created by the test bench generation means 109 of FIG. 14 is illustrated. The example of FIG. 19 is expressed by pseudo code similar to Verilog-HDL.

  The generated test bench generally operates as follows. The values of the input signals a and b are applied to the input terminals a and b one clock cycle after the reset is released and in one clock cycle, respectively.

  Two clock cycles after the reset is released, and the values of the input signals c and d are applied to the input terminals c and d, respectively, in one clock cycle.

  Further, the value of the output terminal o1 is observed three clock cycles after the reset is released and in one clock cycle, and collated with the expected value of the output signal o1.

  Four clock cycles after the reset is released, and the value of the output terminal o2 is observed in one clock cycle and collated with the expected value of the output signal o2.

<Example 4>
Next, a fourth embodiment of the present invention will be described. The fourth example of the present invention corresponds to the fourth embodiment. Referring to FIG. 20, an example of a test bench created by the test bench generating means 106 according to the fourth embodiment of the present invention is shown.

  As shown in FIG. 20, the generated test bench generally operates as follows.

  When the value of the input application timing signal a_e is an active value (1 (High)) and the reset is not valid, it is assumed that the value of the input signal a is acquired from the input terminal iport1, and the input terminal iport1 The input value of the input signal a is applied. When the value of the input application timing signal b_e is an active value (1 (High)) and the reset is not valid, it is assumed that the value of the input signal b is acquired from the input terminal iport1, and the input terminal iport1 The input value of the input signal b is applied. When the value of the input application timing signal c_e is an active value (1 (High)) and the reset is not valid, it is assumed that the value of the input signal c is acquired from the input terminal iport2, and the input terminal iport2 The input value of the input signal c is applied. When the value of the input application timing signal d_e is an active value (1 (High)) and the reset is not valid, it is assumed that the value of the input signal d is acquired from the input terminal iport2, and the input terminal iport2 The input value of the input signal d is applied.

  When the value of the output observation timing signal o_e is the active value (1 (High)) and the reset is not valid, the output terminal o1 is assumed to output the value of the output signal o. The value of port1 is observed and compared with the expected value of the output signal o.

  FIG. 21 shows another example of a test bench created by the test bench generation unit 106 of the fourth embodiment.

  The values of the input signals a and b are applied to the input terminals a and b, respectively, one clock cycle after the reset is released, one clock cycle, and when the stall signal is not valid. Further, two clock cycles after the reset is released, one clock cycle, and when the stall signal is not valid, the values of the input signals c and d are applied to the input terminals c and d, respectively.

  In addition, when the reset signal is released, after 3 clock cycles, 4 clock cycles, 1 clock cycle, and when the stall signal is not valid, the values of the output terminals o1 and o2 are observed and compared with the expected values. To do.

<Example 5>
Next, a fifth embodiment of the present invention will be described. The fifth example of the present invention corresponds to the fifth embodiment. Referring to FIG. 22, an example of behavioral description is shown. This behavioral description generally specifies the following behavior.

  First, values are read from the input signals a and b, and the value of the input signal b is written at the address of the value of the input signal a in the array ary [].

  Next, a value is read from the input signal c, and the value of the address of the input signal c in the array ary [] is read and output to the output signal o1.

  Referring to FIG. 23, there is shown an example of RTL obtained through the scheduling unit 101, the binding unit 102, the FSM generation unit 103, and the RTL generation unit 105 according to the fifth embodiment of the present invention. In the description of FIG. 23, a memory interface circuit for accessing the array ary [] is created. Signals ad, rd, wd, and we respectively correspond to an address, read data, write data, and a write valid flag.

  The module main operates as follows. The following operations are performed at the rising event of the clock signal clk. When the input of the reset terminal rst is 1, the value of the state register state is set to T_STATE1, and the registers v0, v1, and o_t are initialized to 0.

  When the input of the reset terminal rst is not 1 at the rising event of the clock signal clk, the following operation is performed. When the value of the state register state is T_STATE1, the input signals a and b are read, the respective values are stored in the registers ad_t and wd_t, 1 is stored in the we_t, and the value of the state register state is updated to T_STATE2.

  When the value of the state register state is T_STATE2, the input signal c is read, the value is stored in ad_t, 0 is stored in we_t, and the value of the state register state is updated to T_STATE3.

  When the value of the state register state is T_STATE3, the value of the state register state is updated to T_STATE4. When the value of the state register state is T_STATE4, the read data rd is stored in the register o_t, and the value of the state register state is updated to T_STATE1. The value of the status register state is updated in the order of T_STATE1, T_STATE2,.

  Referring to FIG. 24, the test bench generated by the test bench generating means 106 is shown. In this test bench, in addition to the test target module (main dut (...)), a memory simulation model m1 (memory m1 (...)) corresponding to the array ary [] is created, and necessary connections are made. Has been.

  According to the present invention, the present invention can be applied to a purpose of confirming that the behavioral description and the RTL after behavioral synthesis are equivalent. Further, the present invention can also be applied to uses such as confirming whether the performance of RTL after behavioral synthesis is sufficient.

  Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the configurations of the above-described embodiments, and various modifications that can be made by those skilled in the art within the scope of the present invention. Of course, including modifications.

100 computer (central processing unit; processor; data processing unit)
101 Scheduling means 102 Binding means 103 FSM generation means 104 Input application / output observation timing signal generation means 105 RTL generation means 106 Test bench generation means 107 Test bench generation means
108 Input application / output observation timing recording means 109 Test bench generation means 110 Storage device 111 Operation description storage section 112 RTL storage section 113 Test bench storage section 500 Recording medium

Claims (4)

A behavioral synthesis device that converts behavioral description into RTL (Register Transfer Level) using behavioral synthesis,
Regarding the input and output signals of the circuit, the number of clocks from when reset is released until the input value and output value become valid, and timing information indicating the period of input application and output observation, respectively, are described in the operation description of the circuit. An input application output observation timing recording means for adding to the annotation field of the input signal and output signal of the declaration part of each and storing in the storage device,
Read RTL information from the RTL storage unit storing RTL information for the behavioral description, refer to the input signal and output signal annotation fields in the declaration part of the circuit behavioral description from the storage device,
Tests that measure the number of clocks from reset release and perform application of input to the circuit and observation of the output of the circuit when the number of clocks matches the timing information of the input signal and the output signal. A test bench generating means for generating a bench and storing it in a test bench storage unit ;
With a behavioral synthesis apparatus characterized by. The input application / output observation timing recording means refers to the control data flow graph of the circuit, the number of clocks until the input value is applied after the reset is released, and the next time after the input is applied once. Record timing information consisting of the period until the input is applied for each input signal,
Record the number of clocks from when reset is released until the output value becomes valid, and the period from when the output value becomes valid until the next output value becomes valid, for each output signal .
The test bench generating means includes
Read the timing information of input and output recorded by the input application / output timing recording means,
The number of clocks after the reset signal input to the circuit is released is measured, and when the number of clocks matches the number of clocks to which the input is applied or when the number of clocks matches the period of applying the input Apply
When the number of clocks after the reset signal is canceled and the number of clocks until the output becomes valid, or when the period until the output becomes valid, the output is observed and the expected value Like matching,
Create a test bench and store it in the test bench storage unit ,
The behavioral synthesis device according to claim 1. A behavioral synthesis method by a behavioral synthesis apparatus that includes an input application output observation timing recording unit and a test bench generation unit, and converts behavioral descriptions into RTL (Register Transfer Level) using behavioral synthesis,
The input application output observation timing recording means, for the input signal and output signal of the circuit, the number of clocks until the input value and the output value become valid after the reset is released, and the period of input application and output observation, respectively. The timing information shown is added to the input signal and output signal annotation fields in the declaration part of the operation description of the circuit, respectively, and stored in the storage device,
The test bench generation means reads RTL information from an RTL storage unit that stores RTL information for the behavioral description, and refers to an annotation field of an input signal and an output signal of a declaration unit of the circuit behavioral description from the storage device,
Tests that measure the number of clocks from reset release and perform application of input to the circuit and observation of the output of the circuit when the number of clocks matches the timing information of the input signal and the output signal. A behavioral synthesis method characterized in that a bench is generated and stored in a test bench storage unit . In a computer constituting a behavioral synthesis device that converts behavioral description into RTL (Register Transfer Level) using behavioral synthesis,
Regarding the input and output signals of the circuit, the number of clocks from when reset is released until the input value and output value become valid, and timing information indicating the period of input application and output observation, respectively, are described in the operation description of the circuit. An input application output observation timing recording process to be added to the annotation field of the input signal and the output signal of the declaration part of each and stored in the storage device,
Read RTL information from the RTL storage unit storing RTL information for the behavioral description, refer to the input signal and output signal annotation fields in the declaration part of the circuit behavioral description from the storage device,
Tests that measure the number of clocks from reset release and perform application of input to the circuit and observation of the output of the circuit when the number of clocks matches the timing information of the input signal and the output signal. A program that executes a test bench generation process that generates a bench and stores it in the test bench storage unit .

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