A data display method

Abstract: In a graphic data processing system for CAD system for the design of LSI having a display screen (S), a storage (14,20) in which graphic data structured in the hierarchy of three levels, i.e. a functional block diagram level, a logical symbol level and a circuit component level, and a pointing device (22) for designating a window (W) within the display screen (S), the display method of the present invention is characterized in that the size of a designated window (W) is judged and a graphic data of the concept level corresponding to the judged size of the window (W) is read out and displayed within the window (W). According to this, during the design work of LSI, a general drawing of LSI of the appropriate concept level can be distinctly displayed within the window (W) so that it is easy to refer to the general drawing.

Description: The present invention relates to a data display method in a graphic data processing system of the kind which is known for example from US-A-4 574 364. Generally a display screen, for example, in a computer aided design (CAD) system for the design of large scale integration circuits (LSI), has the limitation that the available screen size is not sufficient as display and therefore it can not display a general drawing showing the whole structure of LSI to a convenient scale for the design work. Conventionally, to overcome this problem, there has been defined a window within the display screen. A drawing of a part of the LSI which is to be designed is displayed in a main area of the display screen to the convenient scale, while, in the area of the window, a general drawing of the whole structure of LSI is displayed to a reduced scale in order to indicate the relation between the part being designed and the whole structure A method and apparatus of this kind is disclosed in pp. 169 to 173 of the journal "PIXEL" No. 14, 1983, for example. Because the general drawing is not referred to so often during the design work a window defined within the display screen is preferably variable in size, such that the part being designed can be displayed to a convenient scale by reducing the size of the window, in case the present size of the window impedes the design work. In such a case, however, the rate of rescaling the general drawing is high and becomes possibly inconvenient. If the rate of scaling becomes too high, characters in a displayed drawing are defaced or closely adjacent lines become undistinguishable, so that the displayed drawing becomes very indistinct as a whole. It is to be noted that although the amount of data to be processed for the display does not change, the quality of the displayed graphic is degraded. The problem mentioned above results from the fact that the amount of data to be displayed does not change irrespectively of the reduction of the size of the designated window. Conversely, a certain amount of data is processed for the uninformative display. Accordingly the efficiency of the processing considerably deteriorates. In US-A-4 574 364 a method for controlling an image display apparatus is described. This method employs a window management table, comprising relevant data of each window such as size and location on the screen. The content of the window management table is updated in accordance with input commands in such a manner that superposition and scrolling of windows can be interactively controlled. In addition to the above mentioned prior art it is known in the field how to designate a window on the screen by means of a pointing device, how to set parameters of the window (size, scale), how to read data from a memory and how to display them in a window. Another method is known from Hewlett-Packard Journal, Vol. 32, No. 6, June 1981, pages 8 and 9, or pages 18-25, respectively. In the Hewlett-Packard publication a method in a graphic data processing system having a display screen on which predetermined data is displayed, a storage which stores graphic data representing the predetermined data, and a pointing device for designating a window of a selected size at a desired position within the display screen is described. SUMMARY OF THE INVENTION The object of the present invention is to provide a data display method in a graphic data processing system which is capable of distinctly displaying a drawing based on graphic data structured in the hierarchy of the plural concept levels and to improve the efficiency of the processing. This object is accomplished by a method as claimed in claim 1 and claim 2, respectively. Dependent claims are directed to features of preferred embodiments of the invention. In a CAD system for the design of LSI, for example, a storage stores graphic data structured in the hierarchy of plural concept levels, e.g. data for the highest concept level such as the functional block diagram level, data for the medium concept level such as the logical symbol arrangement level and data for the lowest concept level such as the circuit component arrangement level. One of the graphic data of the different concept level is selected in response to the predetermined parameter of a designated window, such as the size thereof or the rate or amount of scale-up and -down of the graphic data to be displayed within the designated window, and the data are then displayed in the window. If, therefore, a window of a small size is designated, for example, the graphic data of the highest concept level is selected and displayed. As a result, the minimum necessary information can be given to a user in the distinct form. BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1a to 1c show examples of a data display according to an embodiment of the present invention, in which the relationship between the size of a window and the concept level of a drawing to be displayed in the window is indicated; Fig. 2 is a block diagram of an apparatus for executing the data display method according to the present invention; Fig. 3 is an explanatory drawing of the relationship between a world coordinate system and a device coordinate system utilized in a graphic data processing system; Fig. 4 is a drawing for explaining a method of designating a window within a display screen; and Fig. 5 is an explanatory drawing of a table for determining the concept level of graphic data to be displayed in a designated window in response.to the size of the window. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring at first to Figs. 1a to 1c, the relationship between the size of a window W designated within a display screen S and the concept level of a graphic data to be displayed in the window W will be described, taking a data display in a CAD system for the design of LSI as an example. Fig. 1a shows the case where a small size of the window W is designated. Since in this case the size of the window area is small, the graphic data of the highest concept level is selected for the display; a functional block diagram of LSI in this example. In the remaining area of the display screen S, a part of LSI, which is now being designed, is displayed. Accordingly, a designer can carry out his design work on the display screen S, while referring to the general drawing of the whole structure of LSI displayed within the window W. Thereby, the designer can bear the general idea of the relationship of a part, which is now being designed by him, to the whole structure. If the medium size of the window W is designated as shown in Fig. 1b, the graphic data of the medium concept level is selected and displayed within the designated window. The graphic data of the medium concept level in this example are data for the arrangement of logical symbols. In this case, the designer can be given the more detailed information of the whole structure of LSI. As shown in Fig. 1c, if the further large size of the window W is allowed to be designated, there can be displayed in the designated window the most detailed drawing of the whole structure which is of the lowest concept level and is drawn by primitive circuit components. In this manner, according to the present invention, there is stored in an appropriate storage the graphic data of various concept levels, and the concept level of the graphic data to be displayed within the window are determined in response to a certain parameter of the window, i.e., the size of the window in the example shown. For example, if the circuit component arrangement as shown in Fig. lc were displayed within the window of the size as shown in Fig. la by reducing the scale of the drawing of the component arrangement, the designer could no longer read the exact information of the whole structure from the display in the window, since such a drawing had to be displayed to a considerably reduced scale and because very indistinct. Referring next to Fig. 2, an apparatus for carrying out the method according to the present invention will be described. Such an apparatus is generally known as a work station. The work station has a display screen 10, a central processing unit (CPU) 12, a main memory 14, a graphic processor 16, a frame memory 18, a disk memory 20, a pointing device 22 for designating a window, and an input device 24. Among these the CPU 12, the main memory 14, the graphic processor 16, the disk memory 20, the pointing device 22 and the input device 24 are connected to each other through a bus. The display screen 10 is connected to the graphic processor 16 through the frame memory 18. Since the configuration shown is that of a usual work station and respective components thereof as described above are all known, a further detailed description thereof will be omitted. When the design of a new LSI is carried out at this work station, a designer usually starts the design of the functional concept by using appropriate function and resources for the design work which are the same as in a usual work station. This design work is carried out within the memory space of the main memory 14 by the aid of CPU 12. Therefore, when the functional block diagram is completed, all the graphic data thereof are stored in the main memory 14, and thereafter the data of the main memory 14 are transferred to and stored in the disk memory 20. After that, the designer enters into the design of the logical arrangement, whereby data for the arrangement of logical symbols are formed and stored in the disk memory 20. During the design of the logical arrangement, the designer can designate a window of the desired size at the desired position within the display screen 10 by using the pointing device 22, and the data of the functional block diagram is read out from the disk memory 20 and displayed within the designated window. Therefore, the designer can refer to the window during the design work and have a general idea of the relationship of a part, which is now being designed by him, to the whole structure. After the completion of the logical arrangement, the designer sets about the design of the circuit component arrangement. Also in the course of this design work, the designer can designate a window of the desired size at the desired position within the display screen 10 by the pointing device 22 and display a graphic data read out from the disk memory 20. The graphic data displayed at this time can be either one of data for the functional block diagram or for the logical arrangement in response to the size of the window designated by the designer. Also, data of the circuit component arrangement obtained with the completion of the design of the circuit component arrangement are stored in the disk memory 20. In this manner, the graphic data structured in the hierarchy of the plural concept levels are successively stored in the disk memory 20 as the design of LSI is proceeding, and when the design of LSI has been completed, the graphic data for the design of LSI are stored in the disk memory 20 for every hierarchical level. Thereafter, when the design of LSI is proofread or becomes necessary to be changed, the graphic data stored in the disk memory 20 are corrected or edited. At that time, data of the necessary concept level are transferred from the disk memory 20 to the main memory 14. The designer carries out the processing such as the correction or edition of data transferred in the main memory 14 by the aid of CPU 12, referring to a drawing displayed on the display screen 10. The processed data are transferred to and stored in the disk memory 20 again. Also during this correction or edition, it is possible to designate a desired window and display a general drawing therein in order to bear the relationship of a part, which is now being designed, to the general drawing in mind. In this case, it is of course not necessary for the general drawing to be always transferred to the main memory 14, but it is sufficient to transfer the necessary part of data thereof to the main memory 14 at a time. Further, when data are transferred from the disk memory 20 to the main memory 14 and vice versa, the data can be subject to some processing by CPU 12. For example, data are stored in the main memory 14 in a data form such that the CPU 12 and the graphic processor 16 can easily refer to them, and when data in the main memory 14 are transferred to the disk memory 12, they are converted into the data form in which data to be stored occupy the smallest possible storage space of the disk memory 20. Next the processing in the display processor 16 will be described. The processor 16 executes instructions successively, which are read out from the main memory 14, when it receives from CPU 12 a start command and an entrance address in the main memory 14, at which a starting instruction is stored. Instructions for the graphic processor 16 are instructions for drawing basic figures such as a line and an arc, instructions for block transfer or arithmetic operation on data in the main memory 14 and data in the frame memory 18, various kinds of control instructions such as "jump" and "end", and so on. Each of the figure drawing instructions fetched by the graphic processor 16 has an operand which designates the location where a certain figure is to be drawn. The operand is given in the form of values in a coordinate system mentioned below. The coordinate system in which the operand is given is independent of the arrangement of pixels on the display screen 10 and can be arbitrarily defined by a user of the work station (this is generally called a world coordinate system). Therefore, the user can assume a given coordinate system as a world coordinate system and can carry out a series of figure drawing instructions in the world coordinate system by the aid of CPU 12. The graphic processor 16 carries out the transformation of the thus formed figure drawing instructions from the world coordinate system to a coordinate system in which one point of the coordinates physically corresponds to one pixel of the display screen 10 (the latter is generally called a device coordinate system). In this sense, the coordinate transformation carried out by the graphic processor 16 can be said to be a transformation of the graphic data stored in the main memory 14 (or the disk memory 20) for displaying them on the display screen 10. Fig. 3 is a diagram for explaining the coordinate transformation from the world coordinate system to the device coordinate system. In the figure, reference character U denotes world coordinates which are defined by two points (0, 0) and (32767, 32767) on the diagonal and reference character V denotes a window within the world coordinates, which is defined by two points (x₁, y₁) and (x₂, y₂) on the diagonal. Further, reference character S represents device coordinates which have the coordinate value 768 on the X axis and 1024 on the Y axis, which corresponds to the numbers of pixels on the X and Y axis of the display screen 10, respectively. In the device coordinates S of the display screen 10, a window W can be designated by two points (X₁, Y₁) and (X₂, Y₂) on the diagonal thereof. If the user designates the two points (x₁, y₁) and (x₂, y₂) on the world coordinate system and the two points (X₁, Y₁) and (X₂, Y₂) on the device coordinate system, the graphic processor 16 carries out the coordinate transformation in accordance with the following formula; P = A·p - B wherein p : a point in the world coordinates; P : a point in the device coordinates; and Referring next to Fig. 4, it will be explained how to designate a window W on a display screen S by the pointing device 22. In the figure, an arrow represents a graphic cursor. For the simplification, it is assumed that a general drawing of the whole structure of LSI is always displayed in the window W of the device coordinates S and that the window V in the world coordinates U of Fig. 3 is set so as to wholly cover the general drawing. Further, even if the size and location of the window W changes in the device coordinates S (display screen), the window V in the world coordinates U is always fixed. Under these circumstances, the window W in the device coordinates S can be altered by designating two points P₁ and P₂ by the cursor (a broken arrow and a solid arrow) which moves on the display screen in accordance with the instruction from the pointing device 22. If a button switch (not shown) of the pointing device 22 is pressed when the cursor is positioned at a desired location on the display screen 10, CPU 12 executes the processing by which the coordinate values are calculated and entered. In this manner, the user can designate the window at the desired location in the display screen freely. Upon the completion of designation of the desired window W, CPU 12 calculates the size (a x b) of the window by using the entered coordinate values and selects the graphic data of the appropriate concept level from among data stored in the disk memory 20 on the basis of the calculated size of the window W. The selected data are displayed in the window W by the aid of the graphic processor 16. Fig. 5 shows an example of a table which represents the relationship of the range of the parameters of the window, i.e., the size of the window in the example shown, to the pointers. According to this example, the lengths of respective sides of the designated rectangular window, which sides cross with each other at right angle, are compared with the predetermined ranges, which are set in advance in terms of the number of pixels in the display screen S. Respective ranges of size of the window have particular pointers, any one of which is selected in response to the calculated size of the window. The pointer is an indicator that indicates an entrance address of that location of the disk memory 20 in which graphic data of the corresponding concept level are stored. It as an example 0 < a ≦ 10 and 0 < b ≦ 10, a pointer, which indicates an address of the location in which data of the highest concept level are stored, is selected so that data for the functional block diagram are read from the disk memory 20. If 10 < a ≦ 100 and 10 < b ≦ 100, a pointer is selected, which indicates an address of the location in which data of the medium concept level are stored, i.e., the data for logical arrangement. Similarly, when 100 < a ≦ 768 and 100 < b ≦ 1024, a pointer, which indicates an address of the location in which data of the lowest concept level are stored, is selected so that data for the circuit component arrangement are read out. Further, the selection of the concept level of data to be displayed can be also executed on the basis of the number of pixels covered by the designated window, in place of the lengths of two sides of the window. This may be effective for such a case where a window is designated in the nonrectangular form, for example. Furthermore, the parameter of the window for the selection of the concept level of data to be displayed can be the scale in the coordinate transformation of data from the window V in the world coordinates U to the window W in the device coordinates S, as shown in Fig. 3. In this case the judging criteria are the x axis and the y axis separately, and the actual scale can be obtained on the basis of the values of elements (1, 1) and (2, 2) of a matrix of the coefficient A in the formula (1). As described above, according to the present invention, graphic data of the appropriate concept level are selected in response to an appropriate parameter of a window designated in a display screen such as the size thereof or the scale of graphic data to be displayed in the coordinate transformation, so that the efficiency of the data processing for the display and the easiness to see is much improved.

Claims: A data display method in a graphic data processing system having a display screen (5), on which predetermined data are displayed, a storage (14, 20), in which graphic data sets representing the predetermined data are stored, and a pointing device for designating a window (W) of a selected size at a desired position within the display screen, comprising the following steps: (a) storing one set of predetermined data in various graphic data sets in said storage (14, 20), each graphic data set representing a specific concept level corresponding to the predetermined data at a specific degree of details; (b) designating the window (W) on a part of the display screen (S) by means of the pointing device; (c) setting the size (a, b) of the window (W) by means of the pointing device; (d) detecting the range of the size and using said range to select the corresponding concept level; (e) reading out the graphic data, of which the concept level corresponds to the range of size determined in step (d) from the storage (14, 20); and (f) displaying on the display screen (S) the graphic data sets which are read out from the storage in step (e) in the window (W) as designated in step (c). A data display method in a graphic data processing system having a display screen (5), on which predetermined data are displayed, a storage (14, 20), in which graphic data sets representing the predetermined data are stored, and a pointing device for designating a window (W) of a desired size at a desired position within the display screen, comprising the following steps: (a) storing one set of predetermined data in various graphic data sets in said storage (14, 20), each graphic data set representing a specific concept level corresponding to the predetermined data at a specific degree of details; (b) designating the window (W) on a part of the display screen (S) by means of the pointing device; (c) setting the desired amount of scaling up and down the window (W) by means of the pointing device; (d) detecting the amount of scaling up or down in the coordinate transformation from the user-defined window to the window defined by the physical display pixel coordinates; (e) reading out the graphic data, of which the concept level corresponds to the range of size determined in step (d) from the storage (14, 20); and (f) displaying on the display screen (S) the graphic data sets which are read out from the storage in step (e) in the window (W) as designated in step (c). A data display method according to claim 1, wherein the relationship between window size and according concept level is stored in a table. A data display method according to claim 2, wherein the relationship between the amount of scaling up or down and according concept level is stored in a table. A data display method as defined in any of the preceeding claims, wherein the window (W) is designated in the rectangular form and the size of the window (W) is defined on the basis of the lengths of two sides of the rectangular window (W) which cross each other at right angle. A data display method as defined in any of claims 1 to 4, wherein the size of the window (W) is defined by the area of the window (W) in terms of the number of pixels in the display screen (S) covered by the area. A data display method as defined in any one of the preceeding claims, wherein the predetermined data are data of an LSI to be designed and the different concept levels include a concept level of a functional block diagram of the LSI, a concept level of a logical symbol arrangement of the LSI and a concept level of a circuit component arrangement of the LSI.

Inventors: KAWABATA ATSUSHI, NAKANISHI KUNIO, TANI MASAYUKI, TANIFUJI SHINYA, WATANABE NORITO, YOKOYAMA TAKANORI, KAWABATA, ATSUSHI, NAKANISHI, KUNIO, TANI, MASAYUKI, TANIFUJI, SHINYA, WATANABE, NORITO, YOKOYAMA, TAKANORI
Applicants: HITACHI LTD, HITACHI, LTD.
Application year: 1987
Main classification: G06T11
IPC codes: G06F17, G06F3, G09G5