JPH096820A - Logical operation method and timing chart display method - Google Patents

Abstract

PURPOSE: To provide a logical operation method and timing chart display method which are easily used and suitable for efficient logic circuit designing. CONSTITUTION: Various data are inputted corresponding to sections expanded in two dimensions and stored in structured form, and arithmetic results obtained by referring to the data corresponding to those sections are displayed by a table calculating method. This table calculating method is utilized to allocate 1st section array directions to a time elapse direction and 2nd section directions by the kinds of binary logical data; and logical operation is performed by referring to the data corresponding to the input of a 2nd section direction and the result is displayed in specified display format to display a timing chart. Consequently, a display calculating method (program) is utilized to perform the logical operation for verifying logic circuit design and display the timing chart.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a logic operation method and a timing chart display method, and more particularly to a technique effective in designing a logic circuit.

[0002]

2. Description of the Related Art In designing logic circuits, various design tools have been developed and sold. These design tools have advanced functions that incorporate the requirements of professional engineers,
It is easy to use. In designing a logic circuit, there are functions such as a state transition creation diagram of a desired circuit, a timing chart creation, logic input editing, circuit simulation, and operation verification.

[0003]

As described above, although various conventional design tools are easy to use, they are very expensive. 8 and 9 show examples of timing charts. As shown in the figure, the timing chart expresses the time change of the signal as the horizontal axis time for each signal. In designing a logic circuit, it is very common to consider connections between circuits while using a timing chart. In the example of FIG. 8, the output is the logical product of the signal A and the signal B. In the example of FIG. 9, a 4-bit counter operates in accordance with the clock signal of the highest stage, and in each output, output 1 is the least significant bit and output 4 is the most significant bit. In addition, the numbers in decimal notation are shown below. It operates at the rising edge of the clock and counts up one by one from 0.

The timing chart of FIG. 8 is called an asynchronous logic circuit because there is no operation reference such as a clock. On the other hand, the timing chart of FIG.
Since it is a circuit that always operates in synchronization with the rising edge of the clock signal, it is called a synchronous logic circuit.
In a synchronous circuit, the output etc. does not change within one clock pattern, so when simulating,
Requires almost no resolution above the clock. Also,
Even with an asynchronous circuit, data input and calculation can be executed by assuming the necessary time step, as in a synchronous circuit that has no practical problems.

The inventor of the present application has realized that at the start of designing, a simple logic operation simulation function is sufficient at the time of proceeding while considering the overall operation. After completing the design at such a logic level, further detailed timing analysis (skew analysis) by actual element delay etc. can be performed to realize the actual circuit operation and LSI (large scale integrated circuit) on the board. Efficient circuit design can be performed by performing operation verification such as. When such a circuit design method is adopted, a simulation based on fine data such as signal propagation becomes unnecessary in the previous stage of circuit design, and it is a simple logical simulation level. The logical operation method and the timing chart display method suitable for dynamic simulation were examined.

An object of the present invention is to provide a logic operation method and a timing chart display method which can be easily used. Another object of the present invention is to provide a logic operation method and a timing chart display method suitable for efficient logic circuit design. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0007]

The following is a brief description of an outline of a typical invention among the inventions disclosed in the present application. That is, various kinds of data are input in correspondence with the two-dimensionally expanded sections, the input data is stored in a structured format, and the data corresponding to those sections are referred to for calculation and calculation. Using the spreadsheet method of displaying the calculation result, the first partition array direction is assigned to the time lapse direction and the second partition direction is assigned to the data type for the binary logic data as the above data. The data corresponding to the input in the section 2 direction is referred to, the logical operation is performed, and the result is displayed in the designated display format to display the timing chart.

[0008]

According to the above-mentioned means, it is possible to realize the logic operation and the timing chart display for verifying the logic circuit design by using the display calculation method (program).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a logical function including a clock signal, a shift operation synchronized with a clock signal, a counter operation, and the like is newly defined in addition to a binary logic operation defined by Boolean algebra. By displaying on a screen in a character information expression format associated with the value data, a logical operation for circuit design is executed using a simple spreadsheet system.

As the character information format used for display,
For example, by using a ruled line symbol such as “─” that represents a logic 1, for example, a “ Underline symbol of "," is expressed by a character that looks like a vertical bar such as a half-width "l" or "I" to express the transition between them. In this way, a combination of characters or ruled lines is used. By using the notation such as binary, octal, or hexadecimal, the required number of rows can be represented for functions such as a counter and a shift. Therefore, the data structure of each section is designed to have both binary data and information about the expression format for screen display.

FIG. 1 shows an overall configuration diagram of an embodiment of a logic simulation system used in the present invention. In the system of this embodiment, a normal personal computer is used as it is. That is, the computer 10 controls the entire system. Keyboard 13
Is used for inputting data and the like. The external storage device 11 such as a floppy disk memory or a hard disk memory is used for storing data. Then, the printer 12 is used to output the calculation result and the like. The computer body 10 includes a display device such as a CRT (cathode ray tube).

The spreadsheet system used in the present invention is
The spreadsheet software is stored in a storage medium such as a floppy disk for sale, and is realized by loading it into the main memory of the computer main body 10 or the internal hard disk memory via the external storage device 11.

FIG. 2 shows a screen state diagram at the time of activation for explaining the spreadsheet software, and FIG. 3 shows a state transition diagram for explaining transition states of the spreadsheet software as a whole. There is. In the figure, an ellipse indicates a state, and as illustrated in (a), an arrow portion indicates an event before the slash (/) and the processing content after the slash. Therefore, when an event input occurs, the processing content shown after the slash is executed and the state transits to the next state.

The general operation of the spreadsheet software will be described with reference to FIGS. 2 and 3. When the spreadsheet software is started, the two-dimensionally arranged sections are displayed as shown in FIG. 2 and the input waiting state as shown in FIG. 3 is entered. In order to input data or formula to any section, specify the section to be input by using the in-screen position specification input device with a mouse or keyboard. A frame or the like is highlighted in the designated section, and the section is in a data input waiting state. Here, when you enter and confirm the data, the display during calculation is displayed,
It becomes the calculation state of the related cell. When the calculation is completed, the result is displayed in the corresponding cell and the waiting state is resumed.

These spreadsheet systems have functions such as arithmetic function processing, character string processing, database processing function, and statistical financial function. However, the logical function is not suitable for circuit design because it is used for the control of calculation and the control at the time of searching a database.

FIG. 4 shows a data structure of the spreadsheet software. A structure for storing character string data is shown in (A). A pointer indicating the beginning of the area in which character examples are stored is stored.
In (C), a structure for expressing a numerical value is shown. Numerical values are expressed in a floating point format specified by IEEE. Then, (B) shows a structure expressing a logical value. Since the purpose is to control arithmetic operations, the logical values 1 and 0 are simply expressed and used.

FIG. 5 is a data structure diagram of an embodiment used in the logical operation method and the timing chart display method according to the present invention. In the present invention, in the newly provided data structure, the first word stores the data type, the following two words store a pointer indicating the start address of the character string storing the display character, one word data indicating the display format, and a logical value. It consists of one word to do.

The pointer of the display character string is set to the same word structure position in the pointer format as in the data structure of the character string shown in FIG. That is, the structure is made equal to the structure for storing the character string data of FIG. 4A, and the display format and the logical value data are allocated to the reserve (empty part). Therefore, by declaring the data type as a character string type, the calculation result can be displayed without hindering the function of the conventional spreadsheet system.

FIG. 6 is a data processing diagram for explaining the operation of the spreadsheet software in the logic operation method and the timing chart display method according to the present invention. The entire system is composed of a functional part of the spreadsheet software main body, an add-in front-end processor for determining the type of input data, and logical expression processing add-in software.

The data input from the spreadsheet software is sent to the add-in front-end processor to determine the type of data. If the determination result indicates that the processing is a logical expression, the data is sent to the logical expression processing add-in software to perform the processing of the logical expression. The result is filled in the corresponding cell in the above structure and sent to the spreadsheet software. In the present invention, since the spreadsheet software recognizes in the form of character example expression, nothing is done as an expression,
Display the result. If the input data is not a logical expression, the add-in front-end processor returns control to the spreadsheet software as it is. Standard processing is performed on the spreadsheet software side.

An example of the expression of the logical expression and a notation example using the expression will be shown below. (1) Logical product (AND): & A1 & A2 (2) Logical sum (OR): + A1 + A2 (3) Denial (NOT) :! ! (A1) (4) Exclusive OR (EOR): \ A1 \ A2 (5) Shift: SIFT (A1, n, 1 / r) A1 is the reference cell position, n is the number of bits, and 1 / r is the direction Represents (6) Count: CNT (A1, n) A1 represents the reference cell position, and n represents the count number.

FIG. 7 is a block diagram for explaining the present invention. The figure shows an example in which specific data is actually input. In the same figure (A),
The input data and the logical expression are shown. That is,
In the example of the figure, ABC indicates the name in the column direction, and the numbers 1 to 3 on the left side indicate the rows. In the first and second lines,
Only logical values are input, and logical expressions are input in the third line.

FIG. 3B shows an example of screen display after input. As shown in the figure, the above data is represented as a character string (symbol string) in which the timing chart includes the characters (symbols) as described above. That is, the logic 1 is replaced by the ruled line "-", and the logic 0 is changed to the ruled line "-". , And the transition part is represented by half-width characters such as "l".

The third line is obtained from the operation result of the logical expression. When the input values of the first line and the second line are changed, the logical operation process is performed and the successive result is obtained. It will be changed automatically. By using the insertion, deletion, and copying functions of cell units or row or column units of spreadsheet software, it is expected that the operability will be greatly improved in terms of man-machine interface such as repeating the same pattern and inputting the same logical expression. . In particular, there are many users who are already using spreadsheet software with the spread of it, so it is possible to create timing charts with a consistent operability.
Since editing and simulation are possible, it is possible to easily realize logic operation and timing chart display for verifying a logic circuit design with inexpensive equipment.

At the start of designing, a simple logic operation simulation function is sufficient at the time of proceeding while considering the overall operation. After completing the design at such a logic level, further detailed timing analysis (skew analysis) by actual element delay etc. can be performed to realize the actual circuit operation and LSI (large scale integrated circuit) on the board. Efficient circuit design can be performed by performing operation verification such as. In other words, expensive design tools can be used only for advanced simulation based on detailed data such as actual element delay and signal propagation as described above, without being occupied by simple logical operations and simulations. Can be made more efficient.

The operational effects obtained from the above embodiment are as follows. That is, (1) various data is input in correspondence with the two-dimensionally developed sections, the input data is stored in a structured format, and the data corresponding to those sections is referred to for calculation. Then, the table calculation method of displaying the calculation result is used, and the first target is binary logic data as the above data.
The partition arrangement direction of is allocated to the time passage direction, the second partition direction is allocated to the type of data, the data corresponding to the input of the second interval direction is referred to, the logical operation is performed, and the specified display format is used. By displaying the timing chart in accordance with (3), the display calculation method (program) can be used to easily realize the logic operation for verifying the logic circuit design and the timing chart display.

(2) As the binary logic data, a data type is set in the first word, a pointer indicating the start address of a character string for storing a display character in the next two words, one word of data indicating the display format, and a logical value. By constructing one word to be stored and having the same word configuration in the pointer format similar to the data structure of the character string, the effect that the existing spreadsheet software and system can be used as it is can be obtained.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention of the present application is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say. For example, as the spreadsheet software, existing spreadsheet software may be used as it is, or spreadsheet software including the logical operation method and the timing chart display method according to the present application may be newly developed by the same method. . Various types of spreadsheet software can be used in the present invention.

[0029]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows. That is, various kinds of data are input in correspondence with the two-dimensionally expanded sections, the input data is stored in a structured format, and the data corresponding to those sections are referred to for calculation and calculation. Using the spreadsheet method of displaying the calculation result, the first partition array direction is assigned to the time lapse direction and the second partition direction is assigned to the data type for the binary logic data as the above data. The logical operation is performed by referring to the data corresponding to the input in the section 2 direction and displaying the timing chart by displaying the logical operation in the specified display format, thereby using the display calculation method (program). It is possible to easily realize the logical operation for verifying the design and the timing chart display.

As the binary logical data, the data type is stored in the first word, the pointer indicating the first address of the character string storing the display character in the subsequent two words, and 1 representing the display format.
The existing spreadsheet software and system can be used as they are by constructing one word for storing the data and the logical value of the word to have the same word configuration in the pointer format similar to the data structure of the character string.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a logic simulation system used in the present invention.

FIG. 2 is a screen state diagram at the time of activation for explaining the spreadsheet software used in the present invention.

FIG. 3 is a state transition diagram for explaining transition states of the entire spreadsheet software used in the present invention.

FIG. 4 is a data structure diagram of spreadsheet software used in the present invention.

FIG. 5 is a data structure diagram of an embodiment used in the logical operation method and the timing chart display method according to the present invention.

FIG. 6 is a data processing diagram for explaining the operation of the spreadsheet software in the logical operation method and the timing chart display method according to the present invention.

FIG. 7 is a configuration diagram for explaining the present invention.

FIG. 8 is a timing chart of a logic circuit.

FIG. 9 is a timing chart of a counter.

[Explanation of symbols]

10 ... Computer main body, 11 ... External storage device, 12 ...
Printer, input device (keyboard).

Claims (3)

[Claims] 1. A means for inputting various data corresponding to a section developed in two dimensions, a means for storing the input data in a structured format, and a data corresponding to these sections. By using a spreadsheet method using a means for performing a reference operation and a means for displaying the operation result, the first partition array direction is assigned to the time lapse direction for the binary logical data as the data, Is assigned to the type of data, and the logical operation is performed by referring to the data corresponding to the input in the second section direction to display the operation of the logical circuit. 2. The binary logical data stores a data type in a leading word, a pointer indicating a leading address of a character string storing a display character in the following two words, one word of data representing a display format, and a logical value. 2. The same word structure of a pointer format similar to the data structure of a character string is composed of one word.
Logical operation method. 3. A means for inputting various data corresponding to a section developed in two dimensions, a means for storing the input data in a structured format, and data corresponding to these sections. By using a spreadsheet method using a means for performing a reference operation and a means for displaying the operation result, the first partition array direction is assigned to the time lapse direction for the binary logical data as the data, The partition direction is assigned to the type of data, the data corresponding to the input in the second section direction is referred to, the logical operation is performed to display the operation of the logic circuit, and the logical value itself is stored in the storing means. A method for displaying a timing chart, characterized in that a timing chart is displayed based on data of an area corresponding to the display format and an area for specifying the display format.