JP2908201B2 - Waveform data conversion method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for converting waveform data in a logic simulation, and more particularly to a method for automatically compressing and converting waveform data.

[0002]

2. Description of the Related Art When simulating a logic circuit,
A waveform pattern for simulation is required, but this waveform pattern must be created each time the re-simulation is performed after calculating the actual wiring delay time after layout. It was a time-consuming operation.

For this reason, conventionally, output waveforms of other logic simulators or waveform data generated by other personal computers or terminals are converted by a waveform data converter and used by the simulator.

If the format of the waveform data is simply changed, the file capacity of a large waveform pattern becomes extremely large.
As shown in the specification, when format conversion is performed by a waveform data conversion apparatus, a method of manually designating a repetition pattern in advance and compressing waveform data has been used.

[0005]

In the above-described conventional waveform data converter, if the format is simply changed as it is, the file becomes extremely large, the disk capacity is reduced, and the conversion speed is increased by performing many slow I / O accesses. Has a disadvantage that the simulation speed is reduced by performing the simulation with a large number of waveform patterns, while the method of compressing the waveform data has a disadvantage.
It is necessary to manually specify the repetition pattern in advance, and there is a disadvantage that efficiency is low.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. Even a large waveform pattern can be processed as a relatively small file without relying on humans, saving disk space and reducing the number of I / O accesses. It is an object of the present invention to provide a waveform data conversion method capable of increasing the waveform data conversion speed and the simulation speed by reducing the number.

[0007]

A first aspect of the present invention is a simulation device.
Logic simulator for circuit diagram
Output waveform data or second personal computer
Logic simulation of the first waveform data generated by the
Waveform used as input of macro gate and macro symbol
In the waveform data conversion method when converting to data,
Read from pre-converted waveform data file
The waveform pattern indicated by the first waveform data
Analyze the columns from the beginning and the waveform pattern is predetermined
Until the number of times it changes
If the same character continues,
In this case, the same character is converted to another character.
The converted character data file
It is characterized by having a waveform conversion device for storing in a file.

[0008]

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2A is an AND circuit diagram in this embodiment, and FIG.
2B is a waveform pattern diagram for testing the circuit of FIG. 2A, FIG. 3A is a waveform pattern diagram before conversion generated by the waveform editor, and FIG. 3B is a waveform pattern after conversion in the present embodiment. FIG. 3C is a diagram illustrating an example of a compressed converted waveform pattern according to the present embodiment, FIG. 4 is a flowchart illustrating an example of a waveform pattern conversion process according to the present embodiment, and FIG. FIG. 4 is an operation explanatory diagram of the present embodiment.

In FIG. 1, reference numeral 1 denotes a CAD on a personal computer, or a circuit diagram or netlist output file for inputting a logic simulator created on another workstation, and 2 denotes a circuit diagram data file 1 for testing. A pre-conversion waveform data file created by a CAD or simulator on another personal computer or another workstation, 3 stores the waveform data conversion device of the present invention, and 4 stores the waveform pattern data converted by the waveform data conversion device. Converted waveform data file, 5
Is a logic simulator.

FIG. 2A shows an example of one 2-input AND circuit, in which 6 is an AND gate, and INA and INB are each an AND circuit.
Input terminal of D circuit, OUT is an output terminal, INB and AN
One buffer 7 is placed between the D gates.

FIG. 2B is a waveform pattern for testing the circuit diagram of FIG. 2A with a logic simulator. The upper part of the figure shows the number of patterns, and the lower part shows each of the circuit diagrams of FIG. The waveform patterns corresponding to the terminals INA and I are shown.
7 shows a test waveform pattern for an input terminal of NB and a waveform pattern of an expected value output to an OUT terminal. The waveform pattern indicates that the time elapses to the right, and the number of patterns indicates the simulation reference time (for example, 20 m).
The value multiplied by s) is the real time in the simulation.

FIG. 3A shows an example of the format of the pre-conversion waveform pattern data shown in FIG. 2B. The TERM line is a row of terminals, and the lines # 0 to # 28 are the terminals at the elapsed simulator time. #FINISH
Indicates an identifier indicating the end of data. For example, in simulation time # 4, INA is 1, INB
Is 1 and OUT is 1.

FIG. 3B shows an example of the converted waveform pattern format, in which the terminal name and the value at which the terminal has changed are listed after the terminal name. Assuming that the value obtained by multiplying the simulator time by 80 is the real time in the simulation, the initial value of the INA terminal is 0 and 80 ns.
Later changes to 1, 0 at 160ns, 1,3 at 240ns
0 for 20 ns, 1,400 ns for 1,480 ns for 0,56
This indicates that the value has changed to 0 ns.

FIG. 3 (c) shows a case where the format shown in FIG. 3 (b) has a repeat pattern.
3C shows the same waveform pattern of FIG. 3B in compressed form, followed by uppercase letters up to V followed by a recursive pattern.

Next, referring to the flowchart of FIG.
The flow of processing for converting the waveform pattern of FIG. 3A to the waveform pattern of FIG. 3C will be described in detail. FIG. 4A shows a large flow of the processing of the waveform pattern conversion apparatus 3, starting from the start, and reading the waveform pattern / table creation unit 20.
The processing ends with the waveform pattern reading / table creation processing (Step 45), the waveform compression processing by the waveform compression unit 202 (Step 46), and the output processing by the waveform output unit 203 (Step 47). Read waveform pattern
In the table creation process, a file open process and a table creation process are performed. The table is created in a list structure with the terminal name at the head and the changed time and value connected by a pointer on a terminal basis. In this embodiment, the table exists in the memory of the computer, and the table is represented by a list structure based on the terminal. However, depending on the type of the waveform format and the size of the data, the table data is used as a temporary file. The data may be written to an external storage device, or may have a time-based list structure.

FIG. 4B is a detailed flowchart of the waveform compression processing (step 46) by the waveform compression section 202. The data on the table is developed in simulation unit time in the waveform pattern development process (step 49), and then the waveform pattern is processed in the pattern recording process (step 50).
The change is recorded as one repetition pattern, and it is collated in a collation / registration process (step 52) whether or not this pattern has been recorded before. If not, the repetition pattern is registered as a character (step 5).
3) Further, the arrangement of the character patterns is recursively registered (steps 52 to 55). That is, at the INA terminal, the time change pattern “000” from time # 0 to # 7.
01111 "as the first pattern A, and as positions where the character arrangement changes, # 8 to # 15, # 16 to # 23, and # 24 to # 32 are the same pattern A, respectively, and further recursively the character pattern Record “AAAAA” as B.

Although the number of signal changes is two here, this value is not particularly determined, and may be changed as appropriate depending on the type of data and the contents of the simulation. Alternatively, the pattern may be registered as a fixed simulation time unit.

Next, the processing for the terminal INB will be described with reference to FIGS. 3, 4B and 5. FIG. # 0 to # 5 in FIG.
Are converted as C (step 51) and D from # 6 to # 13 (step 52). Since the repeated pattern is registered as A in # 14 to # 21, the pattern is a registered character. Replacement (Step 5
3) Finally, # 22 to # 32 are replaced with E (step 55). The reason why a two-character change such as CD, DA, or AE is not registered is to prevent a decrease in efficiency. Hereinafter, the same processing is repeated until the end of the data of the table.

The last converted table is output as a converted waveform pattern. Before this output, the table in which numbers and characters are mixed is compressed by a character string compression algorithm such as a slide dictionary method. A process of replacing the pattern with a repetitive pattern and outputting the pattern may be performed.

After performing the waveform compression processing, FIG.
As shown in (1), first, patterns A to G are output as repetitive patterns, and then the compressed waveform format of each terminal is output.

[0023]

According to the present invention, since the waveform data of the logic simulation is compressed and output by the automatically detected repetition pattern, even a large waveform pattern can be processed as a relatively small file without relying on humans. This can save disk space and reduce the number of slow I / O accesses, which is effective in increasing the waveform conversion speed and the simulation speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2A is an AND circuit diagram in the present embodiment,
(B) is a waveform pattern diagram for testing the circuit of (a).

3A is a diagram showing an example of a pre-conversion waveform pattern generated by a waveform editor, FIG. 3B is a diagram showing an example of a post-conversion waveform pattern in the present embodiment, and FIG. FIG. 4 is a diagram illustrating an example of a waveform pattern.

FIG. 4 is a flowchart illustrating an example of a waveform pattern conversion process according to the embodiment;

FIG. 5 is an operation explanatory diagram showing a compression process according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit diagram data file 2 Waveform data file before conversion 3 Waveform data converter 4 Waveform data file after conversion 5 Logic simulator 6 AND gate 7 Buffer 201 Pattern reading / table creation unit 202 Waveform compression unit 203 Waveform output unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-180973 (JP, A) JP-A-1-295345 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G06F 17/50 G06F 5/00

Claims (1)

(57) [Claims] 1. A simulation method for a circuit diagram to be simulated.
The output waveform data of the first logic simulator or the second
First waveform data generated by a personal computer
Third logic simulator gate and macro symbol
Waveform data when converting to input second waveform data
In the data conversion method, waveform data before conversion prepared in advance
Indicated by the first waveform data read from the file
From the beginning in time series,
One turn until the turn changes a predetermined number of times
Convert to a predetermined character as a return pattern,
If the same character continues, replace the consecutive same character with another
The character is converted to one character and the converted character is
It has a waveform conversion device that stores the converted waveform data file.
Waveform data conversion method characterized by the fact that: