JPH09251472A - Method and device for synthesizing logic circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the description quantity of a logic circuit and to synthesize the logic circuit of good quality by synthesizing the logic circuit though the use of a circuit object definition description where the feature of the operation of a part of a logical element is described and an operator definition description where an operation rule and an operator are set. SOLUTION: A description analysis part inputs and analyzes object description 100 and divides it into circuit object definition description 101 where the feature of the operation of a part of the logical element provided for the logic circuit is described, operator definition description 102 where the operation rule and the operator for a defined object are set and circuit operation definition description 103. Then, circuit object definition description 101 is synthesized into the logic circuit by an object synthesis part. The synthesized logic circuit is stored in a library database while the relation is held. At last, circuit operation definition description 103 is synthesized into the logic circuit by the synthesis part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of synthesizing a logic circuit and its device, and more particularly, to easily describe a logic circuit,
The present invention relates to a logic circuit synthesizing method and device capable of synthesizing.

[0002]

2. Description of the Related Art Conventionally, to express a logic circuit, a language called a register transfer level language that abstracts and expresses the circuit element is used to express the connection between the circuit elements, A description of behavior of a logic circuit, which is called a behavior description, is used to represent the logic circuit by the specification of only the behavior.

The logic circuits represented by the respective descriptions have been realized by using the corresponding logic synthesis system. Hereinafter, a conventional method of synthesizing a logic circuit will be described with reference to FIG.

FIG. 8 is a diagram for explaining a conventional method of synthesizing a logic circuit. The behavioral description 1 representing the behavior of the logic circuit is input to the high-level synthesis section 2, and the high-level synthesis section 2 synthesizes the description representing the behavior into an abstracted circuit element,
Outputs register transfer level (RTL) language 3.

In this way, conventionally, the logic circuit is synthesized by using the behavior description for the logic synthesis.

[0006]

However, in the conventional register transfer level description, since the logic circuit is represented by the connection of the logic elements, the description increases in proportion to the logic circuit, and the large scale logic circuit is described. It required a huge amount of description to do so. On the other hand, in the behavioral description, only the operation of the logic circuit is described, so the amount of description can be reduced, but since it is abstracted, the connection with the logic element is diluted and it is very difficult to synthesize the logic circuit. It was

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the description amount of a logic circuit and express the logic circuit with a description that is easy for a designer to understand. It is an object of the present invention to provide a logic circuit synthesizing method and device capable of synthesizing a high-quality logic circuit.

[0008]

In order to achieve the above object, a feature of the first invention is a method for synthesizing a logic circuit using a description showing an operation of the logic circuit, the logic circuit being provided in the logic circuit. To synthesize a logic circuit using a circuit object definition description that describes the operation characteristics of some logic elements and an operator definition description in which the operation rules and operators for the defined objects are set. Is.

A feature of the second invention is that, in a method of synthesizing a logic circuit by using a description representing an operation of the logic circuit, a block representing a feature of each logic element included in the logic circuit is an object. Is defined as follows, a calculation rule and an operator are newly set for the object to represent a logic circuit, and logic synthesis is performed on the expressed logic circuit.

Here, it is preferable that a logic circuit is created for each of the defined object and the set operator, and these are logically synthesized as a functional block to synthesize the entire logic circuit.

A feature of the third invention is that, in the method of synthesizing a logic circuit by using the description representing the operation of the logic circuit, the feature of the operation of some of the logic elements included in the logic circuit is described. Circuit object definition description, operator definition description in which operation rules and operators for the defined object are set, and the operation of the entire logic circuit is described using the object definition description and the operator definition description. This is to express the logic circuit using the circuit operation definition description and the provided object description, and synthesize the logic circuit using the object description.

Here, when synthesizing the logic circuits,
It is preferable to perform composition for each of the circuit object definition descriptions.

The operator definition description preferably sets the operation rule and the operator for a part of the object when setting the operation rule and the operator for the object.

Further, although it can be generally used in a synchronous logic circuit, it can also be used in an asynchronous logic circuit. In designing an asynchronous logic circuit, it is necessary to design and synthesize in consideration of the timing of a normal logic circuit. However, according to the present invention, when considering a block as a unit of processing in an asynchronous logic circuit, the timing should be considered. It is possible to perform logic synthesis without doing so.

In order to achieve the above-mentioned object, the features of the fourth invention are: a circuit object definition description which describes the operation characteristics of a part of logic elements included in a logic circuit; and an operation rule for this defined object. A device for synthesizing a predetermined logic circuit by using an operator definition description in which an operator is set, and inputting the circuit object definition description, and synthesizing for each circuit object definition description Department,

An operator synthesizing section for inputting the operator definition description and synthesizing for each operation definition description, the object synthesizing section, and the result synthesized by the operator synthesizing section are associated with each object expression. And a library database for storing the logic circuit, and the synthesis of the entire logic circuit is performed using the library database.

The fifth aspect of the present invention is characterized in that a circuit object definition description which describes the operation characteristics of a part of logic elements included in a logic circuit, and an operation rule and an operator for the defined object are set. Operator definition description,
The logical circuit is expressed by using an object description including the circuit operation definition description that describes the operation of the entire logic circuit using the object definition description and the operator definition description, and the logical circuit is expressed by using this object description. Which is a device for synthesizing the object description, interprets the description, divides the description into each definition description, and the circuit object definition description, and inputs each circuit object definition description. An object synthesizing unit for synthesizing, an operator synthesizing unit for inputting the operator definition description and synthesizing for each operation definition description, an object synthesizing unit, and a result synthesized by the operator synthesizing unit. A library database that is stored in association with each object representation, and the above-mentioned theory using the library database and the circuit operation definition description It is to and a synthesis unit for synthesizing the entire circuit.

Here, generally, it can be used in a synchronous logic circuit, but it can also be used in an asynchronous logic circuit. In designing an asynchronous logic circuit, it is necessary to design and synthesize in consideration of the timing of a normal logic circuit, but according to the present invention, considering a block as a unit of processing in an asynchronous logic circuit, the timing is considered. It is possible to perform logic synthesis without doing so.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a logic synthesis method and an apparatus therefor according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining the object description used in this embodiment. As shown in the figure, the object description 100 is a circuit object definition description 10 that describes the operational characteristics of some of the logic elements included in the logic circuit.
1, an operator definition description 102 in which operation rules and operators for the defined objects are set, and a circuit operation definition that describes the operation of the entire logic circuit using the object definition description 101 and the operator definition description 102. Description 103
And

Here, the concept of the object definition description will be described with reference to FIG. First, the object A20
1. Assume that the object B202 is defined. Of these, the object D20 of the function including the object A
3 can be defined. Similarly, object A2
Although it is the same as including 01, an object D'204 having a different function from the object D203 can be defined.

Object D203 and object D '
Regarding the part of the object A201 of 204, it may be possible to share it when implementing it in a logic circuit, but if it does not exist as an object, it is necessary to perform a circuit comparison and determine that it is the same value. That is virtually impossible. Further, an object C including a circuit excluding a part of the objects A and B can be defined similarly. Also in this case, the parts of the objects A and B can be combined with the parts of the other objects A and B in consideration of sharing.

As described above, each object can be derived by inheritance, and a block having almost the same function but partially different function can be easily defined. This makes it easier for the designer to understand the operation of the functional blocks, and it is clear that explicit equivalent circuits are used during automatic synthesis. The work of searching for a block having the same function is significantly reduced, not only the processing time is shortened, but also the designed logic circuit becomes an easy-to-read logic circuit organized by function.

FIG. 3 is a diagram for explaining an example of the circuit object definition description 101 and the operator definition description 102. There are various methods of expressing a logic circuit, such as a method of expressing with a diagram, a method of expressing with a description, a method of expressing with a logical expression, etc., but in this embodiment, the method expressed with a description is used. There are two different circuit object definitions in FIG. One is dat
e and the other is day. date is an object that represents a date, and date is an object that represents time. The operation of adding 1 to the number of days is defined by the operator "++" for date. Similarly, d
Also for ay, the operation of adding 1 to the second is defined by the operator "++". In this way, the operator is defined for each object and may have the same name and the same symbol. The former operation takes into account the month represented by the current object and changes the value of the object one day ahead. In the latter calculation, the time one second ahead is calculated. In this way, the contents that operate for each object are different, but it is now possible to define an operator that has the same meaning in the global sense of addition for the designer, and it is possible to express only the operation more clearly. Like

As described above, the operation of the circuit can be described by using the operator defined as the object definition, and the object can be declared so as to correspond to the actual logic circuit block in a one-to-one correspondence. This means that if the designer already has an image of a logic circuit, it can be expressed, and if not, only the operation specification can be expressed.

Next, an apparatus for synthesizing a logic circuit using the above object description will be described. FIG. 4 is a block diagram showing a logic circuit synthesis device. The logic circuit synthesis device inputs an object description 100, interprets the object description 100 and divides it into each definition description, and a circuit object definition description 101, and inputs each circuit object definition description. The object synthesizing unit 114 for synthesizing and the operator definition description 102 are input, and the operator synthesizing unit 115 for synthesizing for each operation definition description, the object synthesizing unit 114, and the operator synthesizing unit 115 are synthesized. Library database 116 for storing the results of the association in association with each object representation
And the synthesis unit 11 that synthesizes the entire logic circuit using the library database 116 and the circuit operation definition description 103.
7 is provided.

Next, the operation of this logic circuit synthesizer will be described. First, the description interpretation unit 111 inputs the object description 100, interprets the object description 100, and divides it into a circuit object definition description 101, an operator definition description 102, and a circuit operation definition description 103. Here, the circuit object definition description 101 is defined with the functional block unit of the logic circuit designed as described above as an object. Operator definition description 1
02 may define an operator defined by each designer for each object. Circuit operation definition description part 1
Reference numeral 03 describes the operation of the entire logic circuit using the defined objects and operators.

Subsequently, the circuit object definition description 101
Is synthesized into a logic circuit by the object synthesizer 114. Then, the operator definition description 102 is the operator synthesizing unit 11
At 5 the logic circuit is synthesized. The logic circuits synthesized by each are stored in the library database 116 while maintaining the relationship.

Finally, the circuit operation definition description 103 is combined with the logic circuit by the combining unit 117 while referring to the library database.

Next, FIG. 5 shows an example in which a scheduler is built using the objects shown in FIG. First, the object representing the clock in the scheduler is defined as clock. The objects of date and day are used in the clock. Here, a clock that adds one second by the input clk signal is shown. The definition of the scheduler itself is that when a clk signal is input from the outside and the internal clock is advanced, and a preset time comes, ala
It is designed to output an rm signal. Since objects can be handled as parts, first, a clock object that has been synthesized in advance is used as an internal clock and the clk signals are connected together. Then, each time is compared with a preset time time, and if they match, the alarm signal is set to 1.

First, the object synthesizing unit 114 synthesizes the objects date, day, and clock. Although it is not possible to determine whether or not to assign a variable to a storage element even at the time of synthesizing, a temporary storage element is assigned to the variable and the logic circuit is synthesized.
Although date and day have only this temporary storage element,
Since the clock has a portion for performing an arithmetic operation in addition to this, a logic circuit is actually created for that portion. Regarding the user-defined arithmetic unit among them, only the argument and the type are stored and combined. When this clock object is combined, it is configured as shown in FIG. First, c
Connect lk to DAY ++ 605 so that DAY ++ is activated for clk input. DAY ++ is DA
Advance the time of Y603. Next, DAYEQ604 is DA
It is compared whether the time of Y is 0, 0, 0, and if it is 0, 0, 0, DATE ++ 602 is started. DATE ++
Advances the date of DATE 601.

In the operator synthesizing unit 115, the operator definition description 10 is specified as the specification between the temporary storage element in the object and the argument.
Input 2 to synthesize the logic circuit. Here, DATE
The contents of ++, DAY ++, and DAYEQ are combined as a logic circuit.

Next, the synthesized object and operator are stored in the library database 116 while preserving the mutual relationship as shown in FIG. Finally, the high-level synthesis unit synthesizes the logic circuit by using these components stored in the library database 116.

As described above, by using the logic circuit synthesizer described in this embodiment, the circuit operation can be expressed by a unique operator. For this reason, it is very easy for the designer to understand and can greatly contribute to the reduction of the description amount.

Further, when synthesizing a target logic circuit from the description, it becomes clear that each object and operator represent a common operation of the logic circuit, and thus it is easy to reuse as a component. Since the circuit elements can be easily shared, it becomes possible to synthesize a logic circuit having a smaller area than in the past in a short time.

[0036]

As described above, according to the logic circuit synthesizing method and apparatus according to the present invention, the description amount of the logic circuit can be reduced and the logic circuit can be easily understood by the designer. Can be expressed to synthesize a high-quality logic circuit.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a logic circuit synthesis method according to the present invention.

FIG. 2 is a diagram showing a circuit object definition example used in the logic circuit synthesis method according to the present invention.

FIG. 3 is a program showing an example of definition of a circuit object and an operator used in the logic circuit synthesis method according to the present invention.

FIG. 4 is a block diagram showing a configuration of a logic circuit synthesis device according to the present invention.

FIG. 5 is a diagram showing a circuit object and an operator definition example used in the logic circuit synthesis device according to the present invention.

FIG. 6 is a diagram showing an object description type RTL output in the embodiment of the present invention.

FIG. 7 is a diagram showing a configuration example of an object library used in the embodiment of the present invention.

FIG. 8 is a diagram for explaining a conventional method of synthesizing a logic circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Behavior description 2 High-level synthesis part 3,120 Object description type RTL 100 Object description 101 Circuit object definition description 102 Operator definition description 103 Circuit behavior definition description 110 High-level synthesis part (logic synthesis device) 111 Description interpretation part 114 Object synthesis part 115 Operator composition section 116 Library database 117 Composition section 201 Object A 202 Object B 203 Object D 204 Object D ′ 205 Object C 601 Object DATE 602 Object DATE ++ 603 Object DAY 604 Object DAYEQ 605 Object DAY ++

Claims (10)

[Claims] 1. Using a description representing the operation of a logic circuit,
In a method for synthesizing a logic circuit, a circuit object definition description that describes characteristics of operation of some logic elements included in the logic circuit, and an operator in which an operation rule and an operator for the defined object are set A logic circuit synthesizing method characterized in that a logic circuit is synthesized using the definition description and. 2. Using a description representing the operation of the logic circuit,
In a method of synthesizing a logic circuit, a block representing the characteristics of each logic element included in the logic circuit is defined as an object, and a calculation rule and an operator are newly set for the object to represent the logic circuit. , A logic circuit synthesis method characterized by performing logic synthesis on the expressed logic circuit. 3. The entire logic circuit is synthesized by creating a logic circuit for each of the defined object and the set operator and logically synthesizing them as a functional block. Item 2. A logic circuit synthesis method according to item 2. 4. Using a description showing the operation of the logic circuit,
In a method for synthesizing a logic circuit, a circuit object definition description that describes characteristics of operation of some logic elements included in the logic circuit, and an operator in which an operation rule and an operator for the defined object are set A definition description, a circuit operation definition description that describes the operation of the entire logic circuit using the object definition description and the operator definition description,
A logic circuit synthesizing method, characterized in that the logic circuit is expressed by using an object description provided with, and the logic circuit is synthesized by using the object description. 5. The logic circuit synthesizing method according to claim 4, wherein when synthesizing the logic circuit, synthesis is performed for each of the circuit object definition descriptions. 6. The operator definition description sets an operation rule and an operator for a part of the object when setting an operation rule and an operator for the object. The described logic circuit synthesis method. 7. The logic circuit synthesizing method according to claim 2, wherein the logic circuit is an asynchronous logic circuit. 8. A circuit object definition description, which describes characteristics of operation of a part of logic elements included in a logic circuit, and an operator definition description, in which an operation rule and an operator for the defined object are set. A device for synthesizing a predetermined logic circuit by using the circuit object definition description, and an object synthesizing unit for synthesizing each circuit object definition description, and the operator definition description for inputting each operation. An operator synthesizing unit for synthesizing for each definition description, a library database for storing the object synthesizing unit and the result synthesized by the operator synthesizing unit in association with each object expression, and storing the library database. A logic circuit synthesizing device, characterized in that the whole logic circuit is synthesized using the same. 9. A circuit object definition description that describes characteristics of operation of a part of logic elements included in a logic circuit, an operator definition description in which an operation rule and an operator for the defined object are set, A circuit operation definition description that describes the operation of the entire logic circuit using the object definition description and the operator definition description, and expresses the logic circuit using an object description, and uses the object description to describe the logic circuit A device for synthesizing the object description, which interprets the description and divides it into each definition description; and the circuit object definition description, which is input for each circuit object definition description. An object composition section for composition, an operator composition section for inputting the operator definition description, and composition for each operation definition description; A library synthesizing unit for storing the result synthesized by the object synthesizing unit and the operator synthesizing unit in association with each object expression, and a synthesizing unit for synthesizing the entire logic circuit using the library database and the circuit operation definition And a logic circuit synthesizing device comprising: 10. The logic circuit synthesizer according to claim 8, wherein the logic circuit is an asynchronous logic circuit.