Patent Grant
7093240
1. Field of the Invention
This invention relates generally to the field of creation and use of timing charts and particularly to computer-assisted production of such charts.
2. Background Information
In designing most digital and some analog systems, designers and engineers have long relied upon the use of timing charts to identify signal dependencies, race conditions, and the like. In a complex chart, a slight change in the timing of one signal may have ripple effects throughout the system, and many signals may be in need of alteration to accommodate such a change.
Prior to this invention, the engineer or draftsman needed to modify the drawing of the signals by hand or at least signal line by signal line on a computer screen in a manual way. The cost in terms of potential errors and person-time was and remains very high.
This has been a significant problem since the advent of complex electronic systems. It only gets worse as clock signals get distributed among more and more components on chips and circuit boards, different kinds of devices with different response times get mixed into systems and alternative processing capabilities get switched in or out for power conservation, increased system throughput based on variable demand and other considerations.
While the components of the system taught by the inventor do exist and are readily available, it is not seen anywhere that this problem has been addressed in the straightforward manner that it has been handled by the inventor herein.
a and 3b are a timing chart created from the spreadsheet illustrated in
The short-hand name for this invention is T-Chart, because it helps simplify the drawing of timing charts used by electrical and electronic engineers. A user of the invention will compile a spreadsheet file with appropriately arranged data corresponding to drawing parameters for each line in a timing chart. Using this file, a program will manipulate a drawing program to produce a timing drawing from the drawing parameters in the spreadsheet file. Because the data from the spreadsheet file is used by the invention to direct the drawing program, a user can change data in the spreadsheet to change the drawing. Because of the iterative change capacity of the Excel spreadsheet program, a change in one data or formula cell can ripple through to other cells that are dependent on that cell. The result will be automatically used to update the timing chart drawn from the revised spreadsheet file. Thus, data dependencies that were embodied in the spreadsheet will ripple through and modify dependent data automatically.
The particular components of this system are commonly known. In the preferred embodiment, the inventor uses the Microsoft® Excel® program as the spreadsheet program, and has created templates for ease of organization of the data into the appropriate format that the controlling program will use. The controlling program is written in Visual Basic®, which provides a macro-like interface to the drawing program. The drawing program of the preferred embodiment is VISIO®, also a Microsoft product. The preferred embodiment avoids any likelihood of incompatibility by using products all from the same company, Microsoft, headquartered in Washington State. It is within the skill of the ordinary software writer to produce the invention in an alterative form using any drawing program that will respond to commands such as the ones used and described herein, with any programming language that can give such commands that can also pull data from a spreadsheet file.
Also, it should be noted that where within a timing diagram drawing, there are dependencies, if the user uses formulae instead of hard numbers in the spreadsheet file, the ripple-through recalculation process that the spreadsheet program performs will also cause a ripple-through re-jiggering of the drawing to comply with the new data.
Accordingly, the inventors have described the invention in detail in the next section, with reference to the figures, briefly described above.
Refer first to
The preferred embodiment uses the Microsoft® Excel® program as the spreadsheet program, and thus the spread sheet files are terminated with a “.xls” suffix. The preferred controlling program of the preferred embodiment is written in Visual Basic®, so the files it uses are terminated with a “.vbs” suffix. The drawing program of the preferred embodiment is VISIO®, so the files it uses are terminated with a “.vsd” suffix.
The operation of the invention can be seen through the
The User will initiate the operation of the visual basic program 26 when desired. The visual basic program will prompt the user or automatically, as the case may be, set up the required environment by opening the spreadsheet program, getting the name of the spreadsheet data file, and opening the drawing program. In the preferred embodiment the spreadsheet program is Excel 24, the drawing program is Visio 27, and the user specifies a spreadsheet data file 25 in the format “filename.xls.” After initialization the procedure called TPlot in the Visual Basic program 26 is called upon to get the data from the spreadsheet data file 25. It queries the spreadsheet program in the preferred embodiment, although one could have it obtain the data file and pull data directly from the data file with alternative systems. However, since access to .xls files is more easily obtained using the Excel program, that is preferred. After each line of the data file is reviewed, interpreted and the results sent to the drawing program 27, the procedure TPlot checks to see if it has found an END statement in the data file 26a. If not, it calls for the next line from the Excel data file 26b. Either when the last line has been reached or on a line-by-line basis, the result can be displayed on an associated display device 29 by the drawing program 27 by the TPlot procedure 26c. When complete, the user may save the plot file (.vsd if using VISIO) 28, and/or ask to have it printed by the drawing program on a printer device 29.
The user may modify this data by providing user modifications 21 after viewing either the display 29 or the print from 29.
a and 3b illustrates a sample drawing or plot of a timing chart 30 drawn from the spreadsheet file represented in
While most of this will be familiar to one of skill in the timing chart art, it is well to discuss the kinds of signals represented here, generally first before describing other details. Refer then to
The preferred embodiment command list is called TChart Commands and is reproduced as follows:
TChart Commands, General Comments.
Commands names and required option or variable fields are not case sensitive.
Except for the vectored label command only the first letter is used the rest of the field may be used for an internal comment. (Vectored label commands must begin with “L” and end with “V”.)
The following commands are available for controlling the construction of a timing chart. Text in BOLD CAPS is required, text in [square brackets] is optional. Text in italics indicates that command operation is reserved for future implementation.
Note: In all the command definitions that follow the commas “,” in the definition line indicate that the next variable is to be placed into the cell in the next column of your excel spreadsheet!
C[ycles], TIME, NUMBER, FIRST, CYCLES/PAGE, OPTIONAL TITLE [, BREAK , RESUME]
The cycle command is required to establish the scale factor of the timing chart.
The dotted transition command is the same as the Transition command shown below except that the lines are drawn as a series of dots. The command describes transition times for the traces.
The leading “D” and trailing “V” (case-insensitive) are required for this command.
The dotted transition command is the same as the Transition Vector command shown below except that the lines are drawn as a series of dots.
E[nd of plot]
TChart will plot traces from the first line to the last line of the source excel spreadsheet. If an End command is found processing will terminate even though there may be more entries beyond that point.
G[litch], T1, [Comment [, Type]]
The glitch command causes a transition to be plotted at the time specified without changing the current level of the trace. If timing values are being displayed they will be printed above the transition point.
—
H[eader], [Header Text], [Base]
The header command defines the page title and the time value for the left edge of the drawing.
The info command supplies various forms of information to be placed on the drawing other than timing trace information.
The label command is required to define the beginning of each trace of the drawing.
The vectored label command is similar to the label command except that it defines the beginning of a trace that is in vectored format.
A light dotted vertical line will be drawn across the page at the time[s] specified.
A light vertical line made up of varying patterns of dots and dashes will be drawn on the page at the times specified. Each of the times T1, t2, etc. will have a different pattern. All specified patterns will be repeated for each repeated cycle until the end of the cycle count, or the right margin is reach.
(Note: Use a single tick mark (′) to precede the + or − in your excel spreadsheets to prevent excel from attempting to interpret your entry as a number!)
Option commands that precede the first Label command will be included in the headers of the following pages.
The T and Z options may be changed as desired throughout the body of the page and will carry over into charts that follow on automatically generated new pages.
P[hase], WIDTH, OFFSET, [Level], [Name Text], [Cycle Time]
Phase commands generate a pulse for each cycle defined in the cycle command above. Only the initial transition of each phase will be labeled with the time value.
The repeat command is like a non-vectored label command except that the transition commands (T, D, & G) that follow it are repeated NUMBER times using TIME as the width of the repeat cycle.
The transition command describes the transition times for the traces; points where the trace switches from one logical level to another.
The vectored transition command describes the transition times for the traces; points where the trace switches from one logical level to another.
The first draft of a timing chart can easily be created through the use of graphic user interface static screens such as are illustrated in
Refer now to
The first column of the .xls file is used to indicate to the TChart program (the TPlot procedure therein) a command for drawing something, so the list of commands is reviewed and the appropriate one found by the TPlot procedure. Thus O or Options is first checked reading the first column in the first line (or row). A plus lower case “L” appears in the second column, which means set the drawing to LANDSCAPE mode. The minus capital “B” in the next column means to have no border. Then the next line is read by the TPlot procedure in the TChart Visual Basic program. The next line starts with “H” meaning header information will be in this row, and it will be printed in the first line of the display or print-out/plot. As a convenience, the authors have placed the pathname in this line automatically.
The next line is defining the cycle timing. IT provides the length of each cycle, the number (header or names) of each cycle (2–51, an indication where a break will be placed in the printed chart (between 50 and 450 time units), and specifies the length of a time unit.
The clock phases are defined in the next line. A minus “T” indicates no timing data to be displayed. The next line identifies the clock phases and displays a title as per the title given in the second column, starting at time=zero and repeating at 10 time units. The next rows define where the phases are to be reported within each cycle. Note that because we are using a spreadsheet, the 10 unit time cycle time can be broken easily into four congruent segments by using a formula in the second “T” (transition) row for this line where the formula is current column at row this minus 1+1.25, and rippling this formula down. The result will be a variable to be supplied by the user in the first row (here it's zero), followed by an incremental advance of 1.25 time units as one moves down the row. This and similar uses of formulae within spreadsheet cells is commonly understood, and can be put to good use anywhere some value should be dependent on another within the timing chart.
Vertical lines can be introduced into the chart lines using the Mark command, and here, in the next row after a blank row is a Mark command that writes all its marks into the cut between cycle 10 and cycle 48, so no display appears in
The visible signal line from the spreadsheet row starting “Label”, “First Signal” is a base level 1 (meaning it starts at “hi”). The first transition is at 10 time units, and comment 1 (C1) is placed at that transition. In
The rest of the operation is fairly straightforward and requires little further explanation, but there are a couple of items worth mentioning.
Toward the bottom of
Another feature worth noting is illustrated with reference to the bottom of
Finally, the appearance of the word “END” in a first column indicates that any data following that is to be ignored and that the TPlot routine has completed its work with respect to this .xls spreadsheet file. Data after that can be used for referenced formulae for calculations, holding drafts of lines, and the like as may be desired by the user.
The user can create any number of similar .xls files using commands like the ones described herein, and the principles just described can be used with other spreadsheet programs as may be desired and produced by the reader.
The TPlot routine that is the main subroutine or .vbs procedure in its currently preferred form is reproduced below:
This routine provides for the interpretation of the commands and the reading of the rows, line by line from the spreadsheet file and conversion to commands to be sent to the drawing program as was described more generally above it. The routine may of course be modified, in keeping with the teachings of this document, to provide additional features or modifications, as may be desired by the reader.
Thus we have described a program or set of programs that may guide a user through a creation of a spreadsheet file to be used by one of the programs procedures to create a timing diagram, plotable or printable by the user at will. Because of the use of the spreadsheet file, a user can easily manipulate any number of variables within the spreadsheet and rest assured that these changes will modify the resultant timing diagrams automatically and without any additional thought or effort on the user's part. In the preferred embodiment, off-the-shelf and related commercial software products are tied together to accomplish the result described, making construction of the end product quite straightforward.
It should be noted that the program will function within a computer memory system designed to run it, and may be moved from one computer system to another via electronic signaling or by being carried in a transportable medium such as a floppy disk or CD.
The only limit on the scope of the invention is set forth in the following appended claims.
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|---|---|---|---|
| 5033009 | Dubnoff | Jul 1991 | A |
| 5781190 | Gorbet et al. | Jul 1998 | A |
| 5790435 | Lewis et al. | Aug 1998 | A |
| 5983181 | Yamazaki | Nov 1999 | A |
| 6108661 | Caron et al. | Aug 2000 | A |
| 6115759 | Sugimura et al. | Sep 2000 | A |
