JP2580984B2 - Netlist splitter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital device design support technology, and more particularly to a netlist dividing device which is a kind of CAD device suitable for designing an upstream design process such as a schematic design.

[0002]

2. Description of the Related Art Digital devices are designed in a hierarchical design system of "device (unit) -package-LSI chip (block) -sub-block". In the schematic design stage, the schematic specifications of these layers are
The design data is expressed by a description method such as a state transition diagram and a flowchart, and is represented by a netlist. Then, the netlist is converted into design data described in a hardware description language, and is taken over to a detailed design stage, which is a midstream design process. As a document related to such a technique, for example, there is JP-A-1-309185.

[0003]

Conventionally, it has been practiced to input a description such as a block diagram, a state transition diagram, or a flow chart and convert it into a netlist. No consideration was given to means for dividing the given netlist into appropriate units. For this reason, it is difficult to divide the design into appropriate sizes so that the designer can easily design at the design stage downstream from the upstream design. There is a problem that the connection of the design data to the stage is poor and the design cannot be efficiently advanced.

The present invention has been proposed in view of the above circumstances, and has as its object to divide an entire netlist of a designed digital device into an appropriate size by an interactive method. It is an object of the present invention to provide a netlist dividing device capable of performing such operations.

[0005]

According to the present invention, there is provided a digital device comprising a symbol, a net and images of input / output terminals based on an entire netlist of a designed digital device. Block diagram display control means for displaying a block diagram of the above on a display device, group selection control means for assisting a user to divide the block diagram displayed on the display device using a pointing device, Extracting means for extracting, from the overall netlist, netlists belonging to individual groups obtained by being divided with the support of the control means.

[0006]

In the netlist dividing apparatus according to the present invention, the block diagram display control means includes a symbol, a net, and an image of input / output terminals based on the entire netlist of the designed digital device. The block diagram is displayed on the display device, and the group selection control means assists the user in dividing the block diagram displayed on the display device using a pointing device, and the extraction means supports the work by the group selection control means. Then, the netlists belonging to the individual groups obtained by being divided under are extracted from the entire netlist.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of a CAD for supporting upstream design provided with a netlist dividing apparatus according to the present invention. The schematic specification 1 and detailed specification 2 of a digital device to be designed and a general-purpose library 4 are shown. An editor device 3 for creating an entire netlist of a digital device based on the above, data holding means 5 for holding the entire netlist created by the editor device 3 and the group netlist after division, a netlist dividing device 6, And a conversion unit 7 for converting the group netlist into design data 8 described in a hardware description language.

The general specification 1 of a digital device may include a block diagram showing a structure of the device, a state transition diagram showing a transition of a state of the device, and a flowchart showing a relationship between control conditions and operation of the device. Generally, in order to advance the device design hierarchically, a schematic block diagram of the entire device is created, a part of the device is shown as a state transition diagram, another portion is shown as a flowchart, and another portion is shown as a more detailed diagram. It is described in a mixture of three expressions, such as a detailed block diagram.

[0010] The detailed specification 2 may include a hardware description language representing the function and operation of the device, a truth table, and a gate-level logic circuit diagram. Here also, in general, a part of the device is described in a hardware description language, another part is described in a truth table, and another part is diverted from an existing gate-level logic circuit diagram. The three expressions are described in a mixed manner.

The library 4 has information describing the shape of the symbol, the external interface of the symbol, and the internal function of the symbol in a hardware description language.

The editor device 3 includes a drawing editor 31 for drawing a block diagram, a state transition diagram, a flowchart, and a gate level logic circuit diagram by the same operation, and a text editor 3 for inputting a hardware description language.
2 and a truth table editor 33 for inputting a truth table
It is composed of In particular, the drawing editor 31 has basic editing functions for drawing creation, such as arrangement of block symbols registered in the library 4, wiring between block symbols, and copying, moving, and deleting of the arranged and wired objects. It has logic design support functions such as naming the arranged block symbols and wired lines, inputting additional information, and inputting the correspondence of signals between layers when designing in layers.

The editor device 3 includes these editors 31
33 assists the designer in designing the digital device. Finally, an overall netlist for the digital device to be designed is generated and output to the data holding means 5.

Here, the netlist is composed of symbols, which are basic elements representing the structure of the device to be designed, input / output terminals, and nets representing connections between symbols or connections between symbols and input / output terminals.

Each symbol has a symbol identification name, symbol input / output port names, detailed data, and information on display coordinates on a block diagram. The detailed data is a description of the logic of the symbol in a hardware description language. FIG. 2A shows an example of a symbol, and FIG. 2B shows an example of detailed data of the symbol.

The net has information on the identification name of the net and the display coordinates on the block diagram, in addition to the information on which symbol and the input / output terminal are to be connected. The information of the display coordinates is also added to the information of the input / output terminals.

The netlist dividing device 6 allows the designer to interactively divide the entire netlist held in the data holding means 5 into an appropriate size, ie, a unit suitable for operating the downstream CAD system. This is a supporting device, and each netlist obtained by division is re-stored in the data holding unit 5 as a group netlist.

The conversion means 7 is a means for converting each group netlist stored in the data holding means 5 into a hardware description language and outputting it as design data 8. When the group netlist is described in the hardware description language, the conversion means 7 corrects the signal names so that the signals included in the individual detailed design data are unique when viewed as a group as a whole. Then, the design data of each group described in the hardware description language is output.

The netlist dividing device 6 according to one embodiment of the present invention is used in the CAD for upstream design support under the above-mentioned position.

Referring to FIG. 3, the netlist dividing device 6 includes a block diagram display control means 61, a group selection control means 62, an extraction means 63, and a display device such as a CR.
T64, an input device such as a keyboard 65, and a pointing device such as a mouse 66.

The block diagram display control means 61 displays, on the CRT 64, a block diagram of a digital device composed of images of symbols, nets, and input / output terminals, based on the entire net list 51 stored in the data holding means 5. FIG. 4 shows an example of the processing.

The group selection control means 62 includes a CRT 64
Is a means for assisting the user in dividing the block diagram displayed in the above into groups using the mouse 66.
FIG. 5 shows an example of the processing.

The extracting means 63 includes a group selection controlling means 6
2 is a means for extracting the netlists 52-1 to 52-n belonging to the individual groups obtained by being divided under the support of the group 2 from the entire netlist 51 and outputting the extracted netlists to the data holding means 5. Is shown in FIG.

Hereinafter, the operation of the netlist dividing device 6 according to the present embodiment configured as described above will be described.

When dividing the entire netlist 51 stored in the data holding means 5, the user first operates the keyboard 65 to activate the block diagram display control means 61.

When the block diagram display control means 61 is activated, as shown in FIG. 4, symbol information is inputted one by one from the whole netlist 51, and the inputted symbol image is displayed on the CRT 64 at the display coordinates set on the CRT 64. In the system, it is displayed at the position indicated by the display coordinate information on the block diagram specified for the symbol (steps 401 to 403).

Next, input / output terminal information is input one by one from the entire netlist 51, and the input / output terminal image is designated as the input / output terminal in the display coordinate system set on the CRT 64. It is displayed at the position indicated by the display coordinate information on the block diagram (steps 404 to 40).
6).

Next, net information is input one by one from the entire net list 51, and the input net image is
The display is performed at the position indicated by the display coordinate information on the block diagram specified for the net in the display coordinate system set to RT64 (steps 407 to 409).

By executing the above processing by the block diagram display control means 61, a block diagram as shown in FIG. 7 is displayed on the CRT 64, for example. In FIG. 7, the figures with reference numerals S1 to S6 represent the symbol images, the figure with the reference IN represents the image of the input terminal, the figure with the reference OUT represents the image of the output terminal,
The lines with the reference characters NT indicate the nets.

A block diagram as shown in FIG.
4, when the user inputs an instruction to start division from the keyboard 65, the group selection control means 62 starts the processing shown in FIG.

First, the group selection control means 62 includes, as shown in FIG. 8, a group list 80 having columns for a display color 81, a group name 82, the number of symbols 83, the number of input signals 84, and the number of output signals 85. Is displayed in an empty area of the CRT 64 (step 501). In the group list 80 of FIG. 8, reference numerals 86-1, 86-2,... Denote display lines for each group, which are all blank at this time.

Next, the user enters the group name 82 in the first display row 86-1 of the displayed group list 80,
For example, when a group name "GROUP1" is input from the keyboard 65, the group selection control means 62 inputs the input group name, displays it on the display line 86-1 of the group list 80, and displays it on the display line 86-1. , A picture indicating a predetermined display color is displayed in the display color 81 column, and the number of symbols 83 and the number of input signals 8 in the display row 86-1 are displayed.
4, the initial value of 0 is displayed in the column of the number of output signals 85 (step 502).

Next, when the user selects one of the symbols to be included in the group of the group name GROUP1 by operating the mouse 66, the group selection control means 62 changes the identification name of the selected symbol to the group name GROUP1.
And internally as belonging to the group of
The display color of the selected symbol is changed to the display color displayed in the column of the display color 81 of the display line 86-1 (step 50).
3). Further, since the number of symbols belonging to the group having the group name GROUP1 has increased by 1, the group list 8
Change the number of symbols in the display line 86-1 of 0 from 0 to 1;
And the number of input signals related to the symbol selected this time,
The number of output signals is added to the number of input signals and the number of output signals up to the present (both initially 0), and the number of input signals and the number of output signals after the addition are displayed in the number of input signals 84 and 85 in the display row 86-1. (Step 504).

The group selection control means 62 performs the same operation as described above every time a symbol is selected for the group name GROUP1 (steps 503 to 505). Therefore, when the user selects the symbol S in the block diagram of FIG.
Assuming that 1, S2, and S3 are selected, the display colors of the symbols S1, S2, and S3 are changed to specific colors on the CRT 64 as shown in FIG. 9, and the selected symbols are clearly displayed. The display row 86-1 of the group list 80 includes
As shown in FIG. 8, the number of symbols = 3, the number of input signals 4, and the number of output signals 2 are displayed.

The user finishes selecting the symbol for the group name GROUP1, and then selects the group name GROUP1.
When the group name of GROUP2 is input, the same operation as described above is repeated for each group (steps 502 to 506). Therefore, when the user selects, for example, the symbols S4 and S5 as the symbols to be included in the group name GROUP2, the display colors of the symbols S4 and S5 are changed on the CRT 64 as shown in FIG. Display row 86 of list 80
8, the number of symbols = 2, the number of input signals 2, and the number of output signals 2 are displayed as shown in FIG. When the symbol S6 is subsequently selected as a symbol to be included in the group name GROUP3, the display color of the symbol S6 is changed to a display color specific to the group on the CRT 64 as shown in FIG. 86-3, the number of symbols = 1, the number of input signals, and the number of output signals 1 are displayed as shown in FIG.

As described above, in the netlist dividing device 6 of the present embodiment, while checking the size (the number of symbols and the number of input / output signals) of each group by the group list 80, the symbols belonging to each group are displayed in the display colors. The user can proceed with the division while confirming.

Now, the group selection control means 62 will be described with reference to FIG.
In step 506, when it is determined that an instruction to end the division work has been issued instead of inputting a new group name,
The information of each group stored therein (the group name of the group and the identifiers of the symbols belonging to the group) is notified to the extracting means 63 (step 507), and the processing in FIG. 5 ends.

The extracting means 63 includes the group selection controlling means 6
When the information of each group is notified from 2, the processing shown in FIG. 6 is started.

First, attention is paid to information of one group (step 601), and all information of symbols belonging to the group is extracted from the entire netlist 51 (step 6).
03).

Next, for each of the extracted symbols, information on the nets and input / output terminals connected to the symbols is extracted from the entire net list 51 (steps 604 to 60).
6). When the input or output of a symbol is connected to the output or input of a symbol belonging to another group, a temporary input terminal or output terminal is generated. Then, for all the symbols belonging to one group extracted in step 603, the information of the nets connected to the symbols and the input / output terminals is completely extracted from the entire netlist 51 (YES in step 605). The input / output terminal information and the symbol information extracted in step 603 are handled as a unit and output to the data holding unit 5 as one group netlist 52-1 to 52-n (step 607).

The above processing is executed for all the remaining groups, and when it is determined in step 602 that the execution has been completed for all the groups, the processing in FIG. 6 is ended.

[0042]

As described above, by using the netlist dividing apparatus of the present invention, the designer can divide the entire netlist concerning the digital device into each group while referring to the block diagram of the digital device. By an interactive method of sequentially selecting belonging symbols using a pointing device such as a mouse, it becomes possible to divide the symbol into an appropriate size desired by the designer, and it is possible to improve the efficiency of a later design stage.

Further, while checking the size of each group (the number of symbols and the number of input / output signals) with a group list,
Further, the division work can be advanced while confirming the symbols belonging to each group by the display colors.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an upstream design support CAD provided with a netlist dividing device according to the present invention.

FIG. 2 is a diagram illustrating an example of a symbol and an example of detailed data of the symbol.

FIG. 3 is a block diagram of an embodiment of a netlist dividing device according to the present invention.

FIG. 4 is a flowchart illustrating a processing example of a block diagram display control unit.

FIG. 5 is a flowchart illustrating a processing example of a group selection control unit.

FIG. 6 is a flowchart illustrating a processing example of an extraction unit.

FIG. 7 is a diagram showing an example of a block diagram corresponding to a division target net list displayed on a CRT at the time of division work.

FIG. 8 is a diagram showing an example of a group list displayed on a CRT at the time of division work.

FIG. 9 is a diagram showing an example of a block diagram corresponding to a division target netlist displayed on a CRT when a first group is selected.

FIG. 10 is a diagram showing an example of a block diagram corresponding to a division target netlist displayed on a CRT when a second group is selected.

FIG. 11 is a diagram showing an example of a block diagram corresponding to a division target netlist displayed on a CRT when a third group is selected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Outline specification 2 ... Detailed specification 3 ... Editor device 31 ... Drawing editor 32 ... Text editor 33 ... Truth table editor 4 ... Library 5 ... Data holding means 51 ... Overall net list 52-1 to 52-n ... Group net list 6 Netlist dividing device 61 Block diagram display control means 62 Group selection control means 63 Extraction means 64 CRT 65 Keyboard 66 Mouse 7 Conversion means 8 Design data in hardware description language

Claims (3)

(57) [Claims] 1. A block diagram display control means for displaying, on a display device, a block diagram of the digital device constituted by symbols, nets, and images of input / output terminals, based on an entire netlist of the designed digital device; Group selection control means for assisting a user to divide the block diagram displayed on the display device using a pointing device; and individual groups obtained by division under the support of the group selection control means. Extracting means for extracting a netlist belonging to the entire netlist from the netlist. 2. The method according to claim 1, wherein the group selection control means includes a display color,
A group list for presenting the group name, the number of symbols, the number of input signals and the number of output signals to the user for each group is displayed on the display device, and for each group, the group name input from the user is displayed. Each time a symbol is designated by the pointing device, the display color of the symbol is changed to a display color unique to the group, and the number of symbols, the number of input signals, and the number of output signals belonging to the group at the present time are displayed on the group list. 2. The netlist dividing device according to claim 1, wherein the number is calculated and displayed on the group list. 3. The netlist dividing device according to claim 2, wherein the pointing device is a mouse.