JPS63273169A - Function design diagram production aid equipment - Google Patents

Abstract

PURPOSE:To efficiently obtain a function design diagram including a circuit for control system by inputting the logic specifications in a form of a truth table. CONSTITUTION:The titled equipment is provided with an element information storage means 3 stored with element information of a function design diagram, an input means 2 inputting the logic specification in a form of truth table, a logic equation producing means 5 producing the logic equation while expanding the logic specification, and a net list producing means 4 combining the element information stored in the element information storage means 3 and the logic equation produced by the logic equation producing means 4 to produce a net list. Inputting the logic specifications in the form of truth table by the input means 2, the logic equation generating means 5 expands the logic specifications to produce the logic equation, and the net list producing means 4 couples the logic equation with the element information to produce the net list. Thus, in case of the design of the circuit of the control system, the operator has only to input the logic specification in the form of truth table, and it is not required to input a pattern representing a gate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a functional design diagram creation support device used when creating a functional design diagram at the design stage of an integrated circuit.

(Prior art) In general, logic design occupies most of the design of integrated circuits, etc., and traditionally, the creation of logic design diagrams has been carried out using design support equipment.
This was done by placing figures representing circuit components on the display screen of i (CAD system) and connecting them.

However, as the integrated circuits to be designed become larger and more complex, it becomes necessary to perform design at a higher level than logical design.

Due to these circumstances, in recent years, it has become common to create functional design diagrams using boxes that indicate functional modules, and devices have been developed to create functional design diagrams on a display screen.

According to this device, an a-function design can be created by simply connecting boxes one after another while defining the functions of the boxes.

(Problem to be Solved by the Invention) However, in such a device, when inputting element information (information indicating each part in a functional design drawing), for example, as shown in FIG. circuits (registers and ALUs)
For circuits that do not involve logical operations (such as circuits that do not involve logical operations) S+, all you need to do is place boxes and connect them, but the control system circuit S2 must be configured by combining figures that indicate gates, which is very time-consuming. was there.

The present invention was made under these circumstances, and an object of the present invention is to provide a functional design drawing creation support device that can extremely efficiently create a functional design diagram including a control system circuit.

[Configuration of the Invention (Means for Solving Problems) The functional design diagram creation support device of the present invention includes an element information storage means in which element information of a functional design diagram is stored, and a logical specification in the form of a truth table. an input means for inputting a logical formula, a logical formula creating means for expanding the logical specification to create a logical formula, and a logical formula created by the logical formula creating means and the element information stored in the element information storage means. and netlist creation means for creating a netlist by combining the netlists.

(Function) In the functional design drawing creation support device of the present invention, when a logical specification in the form of a truth table is inputted by the input means, the logical formula creating means expands the logical specification to create a logical formula, and creates a netlist. The means combines this logic formula with the element information to create a netlist, so even when designing a control system circuit, the operator only needs to input the logic specifications in the form of a truth table. There is no need to input.

(Example) Hereinafter, details of an example of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of an apparatus according to an embodiment of the present invention.

In the figure, 1 is a screen editor that has the function of combining element information to draw a functional design diagram on the screen of a display device such as a CRT display, and 2 is a logical specification in the form of a truth table (hereinafter simply referred to as truth) that is input by the operator. A truth table creation module 3 stores a truth table storage area 3a of a function diagram database 3 (abbreviated as a value table) to be described later; function diagram database, 4 is function diagram database 3
Read the element information from , combine it with the logical formula described later,
A netlist creation module that creates a netlist (connection information); 5 a logical formula creation module that reads a truth table from the truth table storage area 3a and creates a logical formula by minimum term expansion to be described later; 6 a whole system C that controls
PU, 7 is a keyboard.

In this embodiment, in the truth table storage area 3a of the functional diagram database 3, as shown in FIG. Bin names and their corresponding truth tables are written.

For example, the truth table TN shows that both signals A and B are Lebel,
Alternatively, it represents a logical specification in which pin CN of component YN becomes active when signals A and C are both at 0 level, or when signals B and C are both at 0 level.

The screen editor 1 also controls the display while the functional design drawing is being input on the screen.

As shown in FIG. 3, the data bus system circuit S1
When the truth table input mode is selected once the input has been completed, the CPU 6 transfers control to the truth table creation module 2.

Then, a window for inputting the truth table appears, and from then on, the truth table 83 corresponding to the input from the keyboard 7 is displayed in this window.

FIG. 4 is a flowchart showing the operation when inputting a truth table in the system of this embodiment.

First, in step A), when the truth table input mode is selected, the truth table creation module 2 tells the operator the unique names and bin names of the parts connecting the control system circuits to be represented by the truth table. prompts for a specification and then prompts for truth table input.

Then, when the operator follows these requests by operating a pointing device such as a mouse (not shown) or the keyboard 7, in steps B and C), the proper name of the part, Its bin name and truth table are written (step D).

The truth table creation module 2 repeats this process until another mode is designated.

FIG. 5 is a flowchart showing the operation when creating a netlist in the apparatus of this embodiment.

First, when the netlist creation mode is selected, in step A), the CPU 6 transfers control to the netlist creation module 4.

Netlist creation module 4 is functional diagram database 3
Read out and create a netlist for each component.

At this time, if there is a component whose input is not connected, the CPU
6 transfers control to the logical formula creation module 5.

The logical formula creation module 5 reads out the input of unconnected bins from the truth table storage area 3a using the unique names of parts, pin names, etc. as keywords (step B), and returns control to the netlist creation module 4.

The netlist creation module 4 creates a netlist by combining the logical formula obtained in the logical formula creation module 5 with element information stored in other areas of the functional diagram database 3 (step C). List creation processing is performed for all parts.

FIG. 6 is a diagram showing the operation when creating a logical formula in the apparatus of this embodiment.

As can be seen from this figure, the logical formula creation module 5 first extracts terms (minimum terms) that satisfy each case from the truth table TN, calculates the logical product of each case, and calculates the logical sum of the logical products. .

For example, in case 1, when signal 11 is level, signal 12 is level, and signal I3 is O level, it indicates that the bin of the target component becomes active, so the logic of signals I, , I2, and 13 is Take the product. The same applies to cases 2 and 2.

On the other hand, in case 3, when signal 11 is indeterminate, signal 2 is 0 level, and signal I3 is level, this indicates that the bin of the target component becomes active. Take a logical product.

In this way, for all cases, we extract only the terms whose logic is not indeterminate and perform the logical product calculation (AN
), and finally find the logical sum of each logical product (BN
).

Thus, in the system of this embodiment, when inputting a control system circuit, the operator places a figure indicating a gate,
There is no need to make connections between gates, just input a simple truth table.

It is preferable that the apparatus of this embodiment is also provided with a mode for inputting a figure representing a gate, as in the conventional apparatus, so that input using a figure representing a gate or input using a truth table format can be arbitrarily selected.

[Effects of the Invention] As explained above, the functional design diagram creation support device of the present invention can input logic specifications in the form of a truth table, so it can extremely efficiently create functional design diagrams including control system circuits. can be created.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a device according to an embodiment of the present invention, FIG. 2 is a diagram showing the contents of information stored in the truth table storage area in the device according to the embodiment, and FIG. 3 is a diagram showing the same embodiment. A diagram showing the display state when inputting the control system circuit in the device,
FIG. 4 is a flowchart showing the operation of the device of the embodiment when inputting a truth table, FIG. 5 is a flowchart showing the operation of the device of the embodiment when creating a netlist, and FIG. 6 is a flowchart showing the operation of the device of the embodiment when creating a logical formula. FIG. 7, a flowchart showing the operation of the example device, is a diagram showing a display state when inputting a control system circuit in a conventional functional design drawing creation support device. 1...Screen editor 2...Truth table creation module 3...
...Functional diagram database 3a...Truth table storage area 4...Netlist creation module 5.
......Logical formula creation module 6...
・・・CPU 7・・・・・・・・・Keyboard Applicant Toshiba Corporation Patent Attorney Sa Suyama - Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) Element information storage means that stores element information of a functional design diagram, input means that inputs logical specifications in truth table format, and logical expression creation means that develops the logical specifications and creates logical expressions. and netlist creation means for creating a netlist by combining the element information stored in the element information storage means and the logical formula created by the logical formula creation means. Blueprint creation support device.