JP5125791B2 - Design support program, design support apparatus, and design support method - Google Patents

Description

  The present invention relates to a technique for supporting wiring design of a printed circuit board or LSI (Large Scale Integration).

  In wiring design of printed circuit boards and LSIs, it is necessary to perform wiring in accordance with wiring restrictions to satisfy the specified circuit characteristics. 2. Description of the Related Art Conventionally, a technique for automating wiring in accordance with wiring constraints has been disclosed in order to reduce a designer's work load related to wiring design (see, for example, Patent Documents 1 to 3 below).

  In recent years, the number of wiring layers required for wiring design has increased with the increase in scale and integration of printed circuit boards and LSIs, and manufacturing costs have increased. For this reason, it is important to realize the specified circuit characteristics with fewer wiring layers in order to reduce manufacturing costs.

JP 2000-331038 A Japanese Patent Laid-Open No. 5-143692 JP-A-8-263539

  However, in the above-described prior art, since it is difficult to automate the assignment of the wiring layer in accordance with the complicated wiring restrictions, the wiring layer is manually assigned. As a result, there is a problem in that the work load on the designer for the design work increases, and as a result, the design period is prolonged.

  Furthermore, allocating an enormous number of wires to the wiring layer manually is not only a very complicated task, but also requires designers' knowledge and experience. Regardless, there is a problem that the optimum result may not be obtained.

  In order to eliminate the above-described problems caused by the prior art, the present invention automatically performs each net group obtained by grouping nets to be wired in the same wiring layer among nets connecting a pair of components in a circuit to be designed. The purpose is to improve the reliability of circuit operation and shorten the design period by performing optimal wiring layer assignment.

  In this disclosed technique, for each pair of components having a connection relationship in a circuit to be designed, the net group specific start / end coordinates and wiring in which nets to be wired to the same wiring layer among nets connecting the components are grouped Access to a table for storing the width, search the wiring path of the wiring width from the start point coordinates to the end point coordinates in the wiring area of the circuit to be designed for each net group, and search for the searched wiring A combination of net groups having a cross relationship with each other between paths is detected, and each net group of the detected combination is assigned to a different wiring layer. The wiring layer to be assigned to the net group is determined, and the determined determination result is output.

  According to this disclosed technique, by automatically and optimally assigning wiring layers for each net group in which nets to be wired to the same wiring layer are grouped among the nets connecting a pair of components in the circuit to be designed. As a result, the reliability of the circuit operation can be improved and the design period can be shortened.

  Exemplary embodiments of a design support program, a design support apparatus, and a design support method will be described below in detail with reference to the accompanying drawings. In the design support program, the design support apparatus, and the design support method, nets to be wired to the same wiring layer among the nets connecting a pair of components in the circuit to be designed are grouped, and a wiring route search and a net are searched for each net group. The design period is shortened by automating the wiring layer assignment.

(Outline of the embodiment)
First, an outline of the present embodiment will be described. Here, first, a net group obtained by grouping a plurality of nets connecting parts in a circuit to be designed will be described. FIG. 1 is an explanatory diagram illustrating an example of a net group. In FIG. 1, a pair of components 110 and 120 having a connection relationship is shown. The component 110 and the component 120 are connected by four nets 130 to 160.

  The nets 130 to 160 are paths (paths) for connecting the terminals T1 to T4 of the component 110 and the terminals T5 to T8 of the component 120, respectively. Here, it is assumed that the nets 130 to 160 are paths that should all be wired in the same wiring layer due to a characteristic problem. In the present embodiment, a plurality of nets 130 to 160 to be wired in the same wiring layer are grouped and handled as a net group 170.

  The wiring width of the net group 170 is, for example, 4 W obtained by adding the wiring widths of the nets 130 to 160 when the wiring width of the nets 130 to 160 is W. Although details will be described later, the start point coordinates A and end point coordinates B of the net group 170 are set to arbitrary coordinate positions in the area occupied by the parts P1 and P2.

  Conventionally, when deciding on which wiring layer a wiring path that connects parts in a circuit to be designed should be formed, first, each wiring path that connects the parts is searched, and then manually The wiring layer to be assigned to the wiring route was determined. As a result, the work load on the designer becomes enormous, leading to an increase in work time.

  Therefore, in the present embodiment, nets (for example, nets 130 to 160) to be wired in the same wiring layer are grouped, and for each net group (for example, net group 170), a wiring route search and wiring layer allocation are performed. We propose a method to automate the process. As a result, the work load for wiring design is reduced and the work time is shortened.

(Example of circuit to be designed)
Next, the wiring area of the circuit to be designed according to the present embodiment will be described. FIG. 2 is an explanatory diagram illustrating an example of a wiring area of a circuit to be designed. In FIG. 2, a wiring area 200 of the circuit to be designed is shown. Here, the wiring grid size of the wiring region 200 is “0 ≦ X ≦ X _max ” in the X-axis direction and “0 ≦ Y ≦ Y _max ” in the Y-axis direction.

  Components P1 to P6 are arranged on the wiring region 200. In the wiring area 210, reference numerals F1 to F4 are wiring prohibited areas where obstacles are arranged. In the present embodiment, nets to be wired to the same wiring layer among nets connecting a pair of components (for example, component P1 and component P5) arranged in wiring region 200 are handled as a net group.

  Of the multiple wiring layers of the circuit to be designed, the wiring layer where each obstacle is formed is determined, but here all the obstacles are formed in the wiring area of a certain wiring layer. Is described as the wiring region 200 of the circuit to be designed.

(Hardware configuration of design support device)
Next, a hardware configuration of the design support apparatus according to the embodiment will be described. FIG. 3 is a block diagram illustrating a hardware configuration of the design support apparatus. In FIG. 3, a design support apparatus 300 includes a CPU (Central Processing Unit) 301, a ROM (Read-Only Memory) 302, a RAM (Random Access Memory) 303, a magnetic disk drive 304, a magnetic disk 305, and an optical disk. A drive 306, an optical disk 307, a display 308, an I / F (Interface) 309, a keyboard 310, a mouse 311, a scanner 312, and a printer 313 are provided. Each component is connected by a bus 320.

  Here, the CPU 301 governs overall control of the design support apparatus 300. The ROM 302 stores a program such as a boot program. The RAM 303 is used as a work area for the CPU 301. The magnetic disk drive 304 controls the reading / writing of the data with respect to the magnetic disk 305 according to control of CPU301. The magnetic disk 305 stores data written under the control of the magnetic disk drive 304.

  The optical disk drive 306 controls the reading / writing of the data with respect to the optical disk 307 according to control of CPU301. The optical disk 307 stores data written under the control of the optical disk drive 306, and causes the computer to read data stored on the optical disk 307.

  The display 308 displays data such as a document, an image, and function information as well as a cursor, an icon, or a tool box. As this display 308, for example, a CRT, a TFT liquid crystal display, a plasma display, or the like can be adopted.

  An interface (hereinafter abbreviated as “I / F”) 309 is connected to a network 314 such as a LAN (Local Area Network), a WAN (Wide Area Network), and the Internet through a communication line, and the other via the network 314. Connected to other devices. The I / F 309 serves as an internal interface with the network 314 and controls data input / output from an external device. For example, a modem or a LAN adapter can be adopted as the I / F 309.

  The keyboard 310 includes keys for inputting characters, numbers, various instructions, and the like, and inputs data. Moreover, a touch panel type input pad or a numeric keypad may be used. The mouse 311 performs cursor movement, range selection, window movement, size change, and the like. A trackball or a joystick may be used as long as they have the same function as a pointing device.

  The scanner 312 optically reads an image and takes in the image data into the design support apparatus 300. The scanner 312 may have an OCR (Optical Character Reader) function. The printer 313 prints image data and document data. As the printer 313, for example, a laser printer or an ink jet printer can be employed.

(Functional configuration of design support device)
Next, a functional configuration of the design support apparatus 300 will be described. FIG. 4 is a block diagram illustrating a functional configuration of the design support apparatus. 4, the design support apparatus 300 includes an acquisition unit 401, a search unit 402, a detection unit 403, a creation unit 404, a determination unit 405, an output unit 406, and a determination unit 407. .

  Specifically, the functions (acquisition unit 401 to determination unit 407) serving as the control unit are, for example, a program stored in a storage area such as the ROM 302, RAM 303, magnetic disk 305, and optical disk 307 shown in FIG. The function is realized by executing the function or by the I / F 309.

  Output data from each function (acquisition unit 401 to determination unit 407) is held in the storage area. Further, the connection destination function indicated by the arrow in FIG. 4 reads output data from the connection source function from the storage area and causes the CPU 301 to execute a program related to the function.

  First, the acquisition unit 401 has a function of acquiring circuit information related to a design target circuit. The circuit information is electronic data including wiring area information related to a design target circuit and net group information related to a net group for each pair of components having a connection relationship in the design target circuit. The acquired circuit information is stored in a storage area such as the RAM 303, the magnetic disk 305, and the optical disk 307 shown in FIG.

  This circuit information may be directly input to the design support apparatus 300 by the user operating the keyboard 310 and the mouse 311 shown in FIG. 3, or may be acquired from an external apparatus (not shown). Good. Furthermore, circuit information may be acquired by extraction from a database or library (not shown) provided in the design support apparatus 300.

  Here, the wiring area information and net group information included in the circuit information will be described. First, a specific example of wiring area information will be described. 5 and 6 are explanatory diagrams showing specific examples of the wiring area information. In FIG. 5, the wiring area information 500 indicates information for specifying the wiring grid size of the wiring area 200 of the circuit to be designed.

According to the wiring area information 500, the wiring grid size “0−X _max ” in the X-axis direction and the wiring grid size “0−Y _max ” in the Y-axis direction of the wiring area 200 and the wiring layer of the circuit to be designed are included. The number of layers “30” can be specified. Each wiring layer is assigned a number “1-30” in order from the lowermost wiring layer. Thereby, each wiring layer can be recognized.

  In FIG. 6, the wiring area information 600 includes wiring prohibition information 600-1 to 600-4 representing the wiring prohibition area on the wiring area 200. Here, the wiring prohibition region is a region where obstacles such as transistors, wirings, and vias are arranged and a new wiring cannot be formed.

  Specifically, the wiring prohibition information 600-1 to 600-4 includes information regarding a wiring prohibition ID, a start coordinate, an end coordinate, a start layer, and an end layer. The wiring prohibition ID is an identifier for identifying a wiring prohibited area. The start coordinate is a coordinate position that specifies the start position of the wiring prohibited area. The end coordinates are coordinate positions that specify the end position of the wiring prohibited area. The start layer / end layer is a number that identifies the start layer and the end layer of the wiring prohibited area formed over a plurality of layers.

Here, taking the wiring prohibited area F1 as an example, it is a rectangular area specified by the start coordinates (X _F 1, Y _F 1) and the end coordinates (X _F 2, Y _F 2) (see FIG. 2). These are obstacles (vias connecting different wiring layers) formed from the first layer to the 30th layer of the circuit to be designed.

  Next, a specific example of net group information will be described. FIG. 7 is an explanatory diagram of a specific example of net group information. In FIG. 7, the net group table 700 stores net group information 700-1 to 700-4 for each pair of components having a connection relationship in the design target circuit. Here, the component is an electronic component such as a resistor, a capacitor, a transistor, or an IC (Integrated Circuit).

  Specifically, the net group information 700-1 to 700-4 includes information on the net group ID, start point coordinates, end point coordinates, bit width, and use layer. The net group ID is an identifier for identifying a net group. The start point coordinates / end point coordinates are coordinate positions that specify the start point and end point of the wiring path of the net group.

The bit width is information for specifying the wiring width unique to the net group. The use layer is information for specifying a usable wiring layer limited by the via type. Here, taking the net group NG1 as an example, the start point coordinates (X _N 1, Y _N 1), the end point coordinates (X _N 2, Y _N 2), the bit width “32 bits”, the use layer “first” Layer to 5th layer ".

  When the bit width is “32 bits”, for example, if one wiring is used to transmit 1-bit information, the total number of nets included in the net group NG1 is 32. For this reason, for example, when the wiring width of the circuit to be designed is 60 [nm], the wiring width unique to the net group NG1 is 1920 [nm] (= 32 × 60).

  Returning to the description of FIG. 4, the search unit 402 searches each net group for a wiring route having a wiring width unique to the net group from the start point coordinates specific to the net group in the wiring region of the design target circuit to the end point coordinates. It has a function. Specifically, for example, search unit 402 searches for a wiring route for each of net groups NG1 to NG4 based on wiring region information 500 and 600 and net group information 700-1 to 700-4 stored in the storage region. To do.

  More specifically, for example, the search unit 402 uses the entire wiring area 200 as a routable area, and determines the shortest wiring path (virtual wiring path) from the start point coordinates specific to the net groups NG1 to NG4 to the end point coordinates. It is good also as searching. That is, the wiring route of each net group NG1 to NG4 is searched without considering the wiring prohibition regions F1 to F4 on the wiring region 200.

  Here, a search result by the search unit 402 will be described. FIG. 8 is an explanatory diagram (part 1) of a specific example of a search result. In FIG. 8, the wiring area 200 shows wiring routes 810 to 840 from the start point coordinates unique to the net groups NG1 to NG4 to the end point coordinates. Here, each of the wiring paths 810 to 840 is a straight line connecting the start point coordinates and the end point coordinates unique to the net groups NG1 to NG4.

  The detection unit 403 has a function of detecting a combination of net groups having a cross relationship with each other between the wiring routes searched by the search unit 402. Specifically, for example, the detection unit 403 selects a combination of net groups having a cross relationship between the wiring paths based on the wiring area information 500 and 600 and the wiring path information representing the wiring paths 810 to 840. To detect.

  In the example shown in FIG. 8, the wiring grid size of the wiring area 200 is specified from the wiring area information 500, and the intersection between the straight lines connecting the start point coordinates and the end point coordinates unique to each net group NG1 to NG4 in the wiring area 200 is determined. By detecting, a combination of net groups having an intersection relationship can be detected.

  More specifically, for example, an intersection between an arbitrary net group selected from the net groups NG1 to NG4 and another net group is detected and registered in an intersection information table described later. This is repeated until there is no unselected net group selected from the net groups NG1 to NG4. However, duplicate registration is not performed for intersections that have already been registered.

  Here, a detection result (intersection information) by the detection unit 403 will be described. FIG. 9 is an explanatory diagram (part 1) of a specific example of intersection information. In FIG. 9, the intersection information table 900 shows intersection information 900-1 to 900-4 representing combinations of net groups having a mutual intersection relationship.

  Specifically, the intersection information 900-1 to 900-4 includes information on the edge ID, the start point, and the end point. The edge ID is an identifier for identifying an edge connecting between nodes of a net group having an intersection relationship in an undirected graph described later. The start point / end point is information for identifying a combination of net groups having an intersection relationship.

  For example, according to the intersection information 900-1, the intersection relationship can be recognized between the wiring route 810 of the net group NG1 and the wiring route 830 of the net group NG3. The intersection information table 900 is realized by storage areas such as the RAM 303, the magnetic disk 305, and the optical disk 307 shown in FIG.

  The determination unit 405 has a function of determining a wiring layer to be assigned to each net group from among a plurality of wiring layers of the design target circuit so that the combination of net groups detected by the detection unit 403 is assigned to different wiring layers. Have For this determination processing, for example, it is possible to apply a coloring problem in which coloring is performed so that colors are different between directly connected nodes with respect to nodes of a given undirected graph.

  By solving the coloring problem of the undirected graph, the nodes in the undirected graph can be colored with the minimum number of colors. That is, by applying this coloring problem to the optimization of the wiring layer assignment (the color in the coloring problem is applied to the wiring layer number), the minimum number of wiring layers required for the wiring design is obtained. Hereinafter, specific processing contents of the determination processing by the determination unit 405 will be described.

  First, the creation unit 404 creates a node for each pair of net groups having a connection relationship in the design target circuit, and connects the nodes of the net group combination having the cross relationship detected by the detection unit 403. It has a function to create a graph. Specifically, for example, the net groups NG1 to NG4 are first made into nodes with reference to the net group information 700-1 to 700-4.

  Thereafter, with reference to the intersection information 900-1 to 900-4, an undirected graph is created in which the nodes E1 to E4 connect the nodes representing the net groups having an intersection relationship with each other. FIG. 10 is an explanatory diagram (part 1) of a specific example of an undirected graph. In FIG. 10, an undirected graph 1000 is composed of nodes NG1 to NG4 representing net groups NG1 to NG4, and nodes having an intersecting relationship are connected by edges E1 to E4.

  The determination unit 405 solves the coloring problem of the undirected graph 1000 created by the creation unit 404 so that the wiring layers are different between the directly connected nodes in the undirected graph 1000. The wiring layer to be assigned to is determined. Specifically, for example, colors not assigned to the adjacent nodes are sequentially assigned to the nodes NG1 to NG4 in the undirected graph 1000 by using SEQ (Sequential Heuristic).

  Here, the maximum value of the number of edges connected to each of the nodes NG1 to NG4 is “Δ”. By applying the coloring problem to the wiring layer assignment, it is possible to determine the wiring layer to be assigned to each of the net groups NG1 to NG4 using the maximum number of wiring layers of “Δ + 1”. In the example of the undirected graph 1000, the required wiring layers are at most three layers.

  Here, a specific example of the determination result by the determination unit 405 will be described. FIG. 11 is an explanatory diagram (part 1) of a specific example of the determination result. In FIG. 11, the determination result 1100 shows the wiring layer to which the net groups NG1 to NG4 are assigned. Specifically, net groups NG1 and NG2 are assigned to the first layer, and net groups NG3 and NG4 are assigned to the second layer.

  According to the determination result 1100, the net group NG1 and the net groups NG3 and NG4 that are in a cross relationship with each other are assigned to different wiring layers, and the net group NG2 and the net group NG3 that are in a cross relationship with each other. , NG4 are assigned to different wiring layers.

  Further, the net group NG1 and net group NG2 and the net group NG3 and net group NG4 that are not in an intersecting relationship are assigned to the same wiring layer. That is, the number of wiring layers required for the wiring design of the net groups NG1 to NG4 is “2”. In this way, by applying the coloring problem of the undirected graph to the wiring layer assignment, the number of wiring layers required for wiring design can be minimized.

  The output unit 406 has a function of outputting the determination result determined by the determination unit 405 (for example, the determination result 1100). The output format by the output unit 406 includes, for example, display on the display 308, print output to the printer 313, and transmission to an external device by the I / F 309. Alternatively, the data may be stored in a storage area such as the RAM 303, the magnetic disk 305, and the optical disk 307.

  In the above-described example, the virtual wiring route (810 to 840) that does not consider the wiring prohibition area in the wiring area is searched. However, physically considering the wiring prohibition area in the wiring area, It is good also as searching for the wiring route (outline wiring route) which can be wired.

  Specifically, for example, the search unit 402 traces from the start point coordinates unique to the net groups NG1 to NG4 to the end point coordinates using the remaining wiring areas 200 other than the wiring prohibition areas F1 to F4 in the wiring area 200 as routable areas. It is good also as searching for the wiring route until it arrives. Here, specific processing contents of the search processing by the search unit 402 will be described.

  First, in the routable area, a wiring route is searched by allowing one turn before reaching the end point coordinates from the start point coordinates unique to the net groups NG1 to NG4. Here, when the wiring route is not searched, the wiring route is similarly searched by allowing two bends. If the wiring route is not searched for even after this, the search process is terminated because the wiring is impossible, or the wiring area size of the wiring area 200 is expanded to search again.

  Here, a search result by the search unit 402 will be described. FIG. 12 is an explanatory diagram (part 2) of a specific example of a search result. In FIG. 12, in the wiring area 200, wiring routes 1210 to 1240 from the start point coordinates unique to the net groups NG1 to NG4 to the end point coordinates are shown. These wiring paths 1210 to 1240 are schematic wiring paths that bypass the wiring prohibited areas F1 to F4 in the wiring area 200 and connect the start point coordinates and the end point coordinates unique to each net group NG1 to NG4.

  Next, a data structure representing a search result (wiring route information) by the search unit 402 will be described. 13 and 14 are explanatory diagrams showing specific examples of wiring route information. 13, the search result table 1300 stores wiring route information 1300-1 to 1300-4 regarding the wiring routes 1210 to 1240 (see FIG. 12) for each of the net groups NG1 to NG4.

  Specifically, the wiring route information 1300-1 to 1300-4 has the start index and the number of patterns of each net group NG1 to NG. The index is an index number that identifies the storage location of the wiring route information (wiring route information 1400-1 to 1400-12 shown in FIG. 14) of each pattern constituting the wiring routes 1210 to 1240.

  The start index is an index number that identifies the storage location of the wiring path information of the start pattern of each wiring path 1210 to 1240 (a pattern including the start point coordinates unique to each net group NG1 to NG4). The number of patterns is the total number of patterns constituting each of the wiring paths 1210 to 1240.

  In FIG. 14, the search result table 1400 stores wiring path information 1400-1 to 1400-12 regarding the pattern ID and start / end coordinates for each index 0-11. The pattern ID is an identifier for identifying the patterns PT1 to PT12 constituting the wiring paths 1210 to 1240.

  By referring to these search result tables 1300 and 1400, each of the wiring paths 1210 to 1240 in the wiring area 200 can be specified. Here, taking the wiring route 1230 of the net group NG3 as an example, the start index “3” and the number of patterns “3” are specified from the wiring route information 1300-3. Then, the start / end coordinates of the patterns PT4, PT5, and PT6 are specified from the three pieces of wiring route information 1400-4 to 1400-6 including the index 3.

  Thereby, the wiring path 1230 including the patterns PT4, PT5, PT6 in the wiring region 200 can be specified. The search result tables 1300 and 1400 are realized by storage areas such as the RAM 303, the magnetic disk 305, and the optical disk 307 shown in FIG.

  In this case, the detection unit 403 refers to the search result tables 1300 and 1400 to detect a combination of net groups that have a mutual crossing relationship between the wiring routes 1210 to 1240. Specifically, referring to the search result tables 1300 and 1400, the respective wiring routes 1210 to 1240 in the wiring region 200 are specified, and the crossing relationship between the wiring routes 1210 to 1240 is detected.

  Here, a detection result by the detection unit 403 will be described. FIG. 15 is an explanatory diagram (part 2) of a specific example of intersection information. In FIG. 15, the intersection information table 1500 stores intersection information 1500-1 to 1500-5 representing combinations of net groups having a mutual intersection relationship.

  According to this, compared with the case where the wiring routes 810 to 840 are searched using the entire wiring region 200 as a routable region (intersection information table 900 shown in FIG. 9), the intersection between the wiring route 1230 and the wiring route 1240 is performed. The number of combinations (intersection information 1500-5) of the net group NG3 and the net group NG4 representing the relationship is increasing.

  Next, an undirected graph based on the intersection information 1500-1 to 1500-5 will be described. FIG. 16 is an explanatory diagram (part 2) of a specific example of an undirected graph. In FIG. 16, an undirected graph 1600 is composed of nodes NG1 to NG4 representing net groups NG1 to NG4, and nodes having an intersecting relationship are connected by edges E1 to E5.

  The undirected graph 1600 has more edges E5 connecting the nodes NG3 and NG4 than the undirected graph 1000 shown in FIG. In this case, the determination unit 405 solves the coloring problem of the undirected graph 1600 so that the allocation destination wiring layers are different between the directly connected nodes in the undirected graph 1600. Determine the wiring layer to be assigned.

  Here, a specific example of the determination result by the determination unit 405 will be described. FIG. 17 is an explanatory diagram (part 2) of a specific example of the determination result. In FIG. 17, the determination result 1700 shows the wiring layer to which the net groups NG1 to NG4 are assigned. Specifically, the net groups NG1 and NG2 are assigned to the first layer. The net group NG3 is assigned to the second layer, and the net group NG4 is assigned to the third layer.

  According to the determination result 1700, as a result of searching for the physically routable wiring routes 1210 to 1240, the cross relationship between the net group NG3 and the net group NG4 is greater than when searching for a virtual wiring route. Newly occurring. For this reason, the net group NG3 and the net group NG4 are assigned to different wiring layers.

  The acquisition unit 401 may acquire a constraint condition that defines a combination of a plurality of net groups to be assigned to the same wiring layer. Here, a specific example of the constraint condition will be described. FIG. 18 is an explanatory diagram (part 1) of a specific example of the constraint condition. In FIG. 18, a constraint condition 1800 defines a constraint condition ID and a combination of net groups NG1 to NG4 to be assigned to the same wiring layer.

  The constraint condition ID is an identifier for identifying the constraint condition. Here, a combination of net groups NG1 and NG2 to be assigned to the same wiring layer is defined as the constraint condition C1. The constraint condition 1700 may be input directly to the design support apparatus by the user operating the keyboard 310 and the mouse 311 shown in FIG. 3, or may be acquired from an external apparatus (not shown). Good.

  In this case, the determination unit 405 may determine a wiring layer to be assigned to each net group from a plurality of wiring layers included in the design target circuit based on the constraint condition acquired by the acquisition unit 401. Specifically, in the coloring problem, it is realized by adding a restriction that colors nodes representing a net group to be assigned to the same wiring layer with the same color. In the example shown in FIG. 17, first, the net groups NG1 and NG2 are assigned to the same wiring layer (same color), and then the assignment destinations of the net groups NG3 and NG4 are determined.

  In addition, when the detection unit 403 detects a combination of the first and second net groups as a result of searching for a wiring route of each net group that can be physically wired, the search unit 402 selects the second net group. The wiring path of the first net group may be re-searched using the wiring path as the wiring prohibited area.

  Specifically, based on the wiring area information (for example, wiring area information 500, 600) of the circuit to be designed and the wiring path information on the searched wiring paths (for example, search result tables 1300, 1400), the wiring area is determined. The wiring path of the first net group is re-searched using the obstacles inside (for example, the wiring prohibited areas F1 to F4) and the wiring path of the second net group as the wiring prohibited area (see Example 1 described later). ).

  Further, when the detection unit 403 detects a combination of the first and second net groups, the search unit 402 is based on the wiring width specific to the third and fourth net groups divided from the first net group. Thus, it is also possible to search for the wiring paths of the third and fourth net groups that connect the start point coordinates and end point coordinates unique to the first net group (see Example 2 described later).

  The wiring width specific to the third and fourth net groups may be calculated from, for example, the ratio of dividing the first net group described later. Moreover, it is good also as specifying from the net group information regarding the 3rd and 4th net group divided | segmented from a 1st net group. Note that the net group information regarding the third and fourth net groups is included in the circuit information of the circuit to be designed, for example.

  Here, the ratio of the number of nets for dividing the first net group obtained by grouping N nets into the third and fourth net groups can be arbitrarily set. For example, when the ratio of the number of nets is set to “1: 1”, the first net group is divided into a third net group obtained by grouping N / 2 nets and N / 2 nets. This is divided into a grouped fourth net group.

  For example, if the net group 170 shown in FIG. 1 is the first net group, each of the two nets (= 4/2) is divided into third and fourth net groups. If the number of nets is not divisible, one fraction may be rounded up and the other fraction rounded down.

  Note that the ratio of dividing the first net group is arbitrarily set by the user operating the keyboard 310 and the mouse 311 shown in FIG. 3, for example, in a storage area such as the RAM 303, the magnetic disk 305, and the optical disk 307. Remembered.

  Further, by dividing the wiring width specific to the first net group according to the ratio of dividing the first net group, the wiring width specific to the third and fourth net groups can be calculated. For example, when the ratio is “1: 1” and the wiring width specific to the first net group is 240 [nm], the wiring width specific to the third and fourth net groups is 120 [nm]. .

  The determination unit 407 has a function of determining whether or not the allocation destinations of the first and second net groups having a cross relationship with each other violate the constraint condition as a result of the determination of the allocation destination by the determination unit 405. . Specifically, for example, by comparing the detection result detected by the detection unit 403 with the constraint condition acquired by the acquisition unit 401, it is determined whether or not the constraint condition is violated.

  When the determination unit 407 determines that the constraint condition is violated, the search unit 402 can wire the remaining wiring region excluding the wiring prohibited region and the wiring path of the second net group in the wiring region. As another example, the wiring route of the first net group may be searched again (see Example 3 described later).

(Design support procedure of design support device)
Next, a design support processing procedure of the design support apparatus 300 according to the present embodiment will be described. FIG. 19 is a flowchart illustrating an example of a design support processing procedure of the design support apparatus.

  In the design support process described below, for example, when the user operates the keyboard 310 or the mouse 311 shown in FIG. 3, wiring area information and net group information related to the design target circuit are input to the design support apparatus 300. Then, a series of processing in steps S1901 to 1906 is automatically executed by the computer.

  In the flowchart of FIG. 19, first, the acquisition unit 401 determines whether or not the wiring area information and net group information related to the design target circuit have been acquired (step S1901). Here, after waiting for the acquisition of the wiring area information and the net group information (step S1901: No), if acquired (step S1901: Yes), the search unit 402 adds the acquired wiring area information and net group information. Based on the net group, a wiring route having a wiring width specific to the net group from the start point coordinates specific to the net group in the wiring region of the design target circuit to the end point coordinates is searched for each net group (step S1902).

  After that, the detection unit 403 detects a combination of net groups that intersect each other between the searched wiring routes (step S1903), the creation unit 404 makes the net group into a node, and the detection unit 403 detects the net group. An undirected graph connecting the nodes of the combination of net groups having the intersected relationship is created (step S1904).

  Then, the determination unit 405 solves the coloring problem of the created undirected graph, so that the wiring layers of the design target circuit are different between the directly connected nodes in the undirected graph. A wiring layer to be assigned to each net group is determined from among the network groups (step S1905), and finally, the output unit 406 outputs the determination result determined by the determination unit 405 (step S1906). Exit.

  In step S1902, it is assumed that whether the virtual wiring route or the schematic wiring route is to be searched is set in advance by the user.

  As described above, according to the present embodiment, nets to be wired to the same wiring layer among nets connecting a pair of components in the circuit to be designed are grouped, and a wiring route search and wiring layer for each net group are performed. Assignment can be automated. As a result, it is possible to reduce the work load and work time required for the wiring design, and to shorten the design period.

  Further, net groups having a cross relationship with each other can be assigned to different wiring layers, and net groups not having a cross relationship with each other can be assigned to the same wiring layer. Thereby, the number of wiring layers required for wiring design can be optimized without reducing the reliability of circuit operation, and the manufacturing cost can be reduced.

  Next, Example 1 of the present embodiment will be described. In the first embodiment, if a combination of the first and second net groups having a crossing relationship with each other is detected as a result of searching for a physically routable wiring route, the wiring route of the second net group is routed. As the prohibited area, the wiring route of the first net group is searched again.

  As a result, when the wiring route from the start point coordinates unique to the first net group to the end point coordinates is searched, bypassing the wiring route of the second net group, the first net group and the second net group are searched. Cross relationship is canceled. In addition, illustration and description are abbreviate | omitted about the location same as the location demonstrated in embodiment.

  Specifically, as a result of detecting a combination of net groups having a cross relationship with each other by the detection unit 403, the net group having the maximum number of other net groups in the cross relationship among the net groups NG1 to NG4. Is detected. Specifically, for example, the number of edges of each node NG1 to NG4 is counted with reference to the undirected graph 1600 (or the intersection information table 1500) created by the creation unit 404.

  More specifically, for example, by counting each net group ID that appears in the intersection information table 1500, the number of edges of each node NG1 to NG4 can be counted. Note that the net group represented by the node having the largest number of edges corresponds to the net group having the largest number of other net groups in an intersecting relationship.

  FIG. 20 is an explanatory diagram showing a specific example of the counting result. In FIG. 20, the counting result 2000 shows the number of edges for each of the net groups NG1 to NG4. By referring to the counting result 2000, the nodes NG3 and NG4 having the maximum number of edges (three) can be detected.

  Thereafter, the search unit 402 uses the net group NG3 (or net group NG4) among the net groups NG3 and NG4 having the maximum number of edges as a wiring prohibited area, and the net group NG4 (or net group NG3). Re-search for the wiring route.

  Here, the search result by the search part 402 in Example 1 is demonstrated. Here, as a result of searching for the wiring routes 1210 to 1240 by the search unit 402, a search result obtained by re-searching the wiring route of the net group NG4 using the wiring route 1230 of the net group NG3 as a wiring prohibited area will be described.

  FIG. 21 is an explanatory diagram (part 3) of a specific example of a search result. In FIG. 21, the wiring area 200 shows wiring routes 1210 to 1230 and 2110 from the start point coordinates unique to the net groups NG1 to NG4 to the end point coordinates.

  The wiring path 2110 uses the wiring prohibited areas F1 to F4 in the wiring area 200 and the wiring path 1230 of the net group NG3 as a wiring prohibited area, and re-routes the wiring path from the start point coordinates specific to the net group NG4 to the end point coordinates. It is the search result searched. Here, as a result of searching for the wiring route 2110, the cross relationship between the net group NG3 and the net group NG4 is eliminated.

  FIG. 22 is an explanatory diagram (part 3) of a specific example of the determination result. In FIG. 22, the determination result 2200 shows the wiring layer to which the net groups NG1 to NG4 are assigned. Specifically, net groups NG1 and NG2 are assigned to the first layer, and net groups NG3 and NG4 are assigned to the second layer.

  According to this, the cross relationship between the net group NG3 and the net group NG4 is canceled, and the net groups NG3 and NG4 are assigned to the same wiring layer. For this reason, the number of wiring layers required for the wiring design of the circuit to be designed is “1” less than the determination result 1700 shown in FIG.

  Note that the re-search of the wiring path by the search unit 402 may be repeated until the number of wiring layers required for wiring design is equal to or less than a preset threshold value. For example, when “5” is set as the threshold value, re-searching of the wiring path is repeated until the number of wiring layers required for wiring design becomes 5 or less. Note that the threshold value can be arbitrarily set by the user operating the keyboard 310 and the mouse 311 shown in FIG. 3, for example.

(Design support processing procedure of Example 1)
Next, a design support processing procedure in the first embodiment will be described. FIG. 23 is a flowchart illustrating an example of a design support processing procedure according to the first embodiment. First, it is determined whether the acquisition unit 401 has acquired the wiring area information 500, 600 and the net group information 700-1 to 700-4 (step S2301).

  Here, it waits for the acquisition of the wiring area information 500, 600 and the net group information 700-1 to 700-4 (step S2301: No), and when acquired (step S2301: Yes), the search unit 402 performs wiring. Based on the area information 500, 600 and the net group information 700-1 to 700-4, the net groups NG1 to NG4 from the start point coordinates specific to the net groups NG1 to NG4 in the wiring area 200 to the end point coordinates are determined. A wiring route having a wiring width is searched (step S2302).

  Thereafter, the detection unit 403 detects a combination of net groups having a crossing relationship with each other between the searched wiring routes 1210 to 1240 (step S2303), and the creation unit 404 makes the net groups NG1 to NG4 into nodes. Then, an undirected graph 1600 that connects the nodes of the combination of net groups having an intersection relationship is created (step S2304).

  Then, the determination unit 405 solves the coloring problem of the undirected graph 1600, so that the wiring layers are different among the directly connected nodes in the undirected graph 1600. To determine a wiring layer to be assigned to each of the net groups NG1 to NG4 (step S2305).

  Next, based on the determination result determined by the determination unit 405, it is determined whether or not the number of wiring layers required for the wiring design of the circuit to be designed is equal to or less than a preset threshold value (step S2306). If it is not equal to or less than the threshold value (step S2306: NO), the detection unit 403 detects the net groups NG3 and NG4 representing the node with the maximum number of edges from the net groups NG1 to NG4 (step S2307). .

  Then, of the detected net groups NG3 and NG4, the wiring path 1230 of the net group NG3 is set as a wiring prohibited area (step S2308), the process returns to step S2302, and the search unit 402 reconfigures the wiring path of the net group NG4. Explore.

  In step S2306, if it is equal to or less than the threshold value (step S2306: Yes), finally, the output unit 406 outputs the determination result determined in step S2305 (step S2309), and a series of processes according to this flowchart. Exit.

  In consideration of the case where a wiring route that eliminates the crossing relationship is not searched, if the number of re-searches exceeds a predetermined number in step S2307, the number of wiring layers required for wiring design Even if is not less than or equal to the threshold value, the process may proceed to step S2309.

  According to the first embodiment, the wiring path 1230 is used as a wiring prohibited area, and a new search is performed for the wiring path 2110 from the start point coordinates unique to the net group NG4 to the end point coordinates, whereby the net groups NG3 and NG4 are connected to the same wiring layer. Allocation is possible, and the number of wiring layers required for wiring design can be reduced.

  Next, Example 2 of the present embodiment will be described. In the second embodiment, if a combination of the first and second net groups having a crossing relationship with each other is detected as a result of searching for a physically routeable wiring route, the second divided from the first net group is detected. Based on the wiring width specific to the third and fourth net groups, the wiring paths of the third and fourth net groups that connect the start point coordinates and the end point coordinates specific to the first net group are searched.

  As a result, when the wiring route of the third and fourth net groups is searched until the wiring route of the second net group is bypassed and the starting point coordinates specific to the first net group reach the end point coordinates, The cross relationship between the first and second net groups is eliminated.

  Specifically, the detection unit 403 detects the nodes NG3 and NG4 having the maximum number of edges with reference to the counting result 2000 shown in FIG. Here, the net group 3 will be described as a division target. Thereafter, the wiring width specific to the net groups NG5 and NG6 divided from the net group NG3 is specified.

  Then, the search unit 402 searches for the wiring paths of the net groups NG5 and NG6 that connect the start point coordinates and the end point coordinates specific to the net group NG3 based on the wiring widths specific to the net groups NG5 and NG6.

  Here, the search result by the search part 402 in Example 2 is demonstrated. Here, as a result of searching for the wiring routes 1210 to 1240, a search result obtained by searching the wiring routes of the net groups NG5 and NG6 divided from the net group NG3 using the wiring route 1240 of the net group NG4 as the wiring prohibited area will be described. .

  FIG. 24 is an explanatory diagram (part 4) of a specific example of a search result. For the sake of explanation, the start point / end point coordinates specific to the net groups NG5 and NG6 are shifted from the start point / end point coordinates specific to the net group NG3. In FIG. 24, the wiring region 200 shows wiring paths 1210, 1220, 1240, 2310, and 2320 from the start point coordinates unique to each net group NG1, NG2, NG4, NG5, NG6 to the end point coordinates. .

  The wiring paths 2310 and 2320 are search results obtained by searching the wiring paths of the net groups NG5 and NG6 using the wiring prohibited areas F1 to F4 in the wiring area 200 and the wiring path 1240 of the net group NG4 as the wiring prohibited areas. Here, as a result of searching for these wiring paths 2310 and 2320, the cross relationship between the net group NG3 (net groups NG5 and NG6) and the net group NG4 is eliminated.

  When the wiring route of the net groups NG5 and NG6 is not searched, the ratio of the number of nets dividing the third net group is automatically changed (for example, “5: 5” → “6: 4”). The wiring paths of the net groups NG5 and NG6 may be searched again.

  According to the second embodiment, by using the wiring path 1240 as a wiring prohibition area and newly searching for the wiring paths 2310 and 2320 from the start point coordinates unique to the net group NG3 to the end point coordinates, the same wiring layer of the net groups NG4 to NG6. The number of wiring layers required for the wiring design of the circuit to be designed can be reduced.

  Next, Example 3 of the present embodiment will be described. In the third embodiment, as a result of the assignment of the wiring layer to each net group, if the assignment result of the first and second net groups having a cross relationship with each other violates the constraint condition, The wiring path of the first net group is searched again using the wiring path as a wiring prohibited area.

  As a result, when the wiring route from the start point coordinates unique to the first net group to the end point coordinates is searched, bypassing the wiring route of the second net group, the first net group and the second net group are searched. Cross relationship is canceled. Here, the constraint condition of Example 3 is demonstrated. FIG. 25 is an explanatory diagram (part 2) of a specific example of the constraint condition.

  In FIG. 25, the constraint condition 2500 defines a combination of net groups NG1 and NG3 to be assigned to the same wiring layer as the constraint condition C2. Here, the determination unit 407 determines whether or not the allocation result of the first and second net groups having a cross relationship with each other violates the constraint condition 2500.

  Specifically, the determination unit 407 determines the allocation destination by the determination unit 405 (determination result 1700 shown in FIG. 17), the combination of net groups that are detected by the detection unit 403 and have a cross relationship with each other. By comparing the combinations of the net group NG1 and the net group NG3 defined in the constraint condition 2500, it is determined whether or not the constraint condition 2500 is violated.

  Here, the combination of net group NG1 and net group NG3 exists among the combinations of net groups that intersect each other (refer to intersection information table 1500 and undirected graph 1600), and therefore violates constraint condition 2500. Judge that you are doing.

  In this case, the search unit 402 routes the remaining wiring area 200 except the wiring prohibited areas F1 to F4 in the wiring area 200 and the wiring path 1230 (or wiring path 1210) of the net group NG1 (or net group NG3). As a possible area, the wiring path 1210 (or wiring path 1230) of the net group NG3 (or net group NG1) is searched again.

  Here, the search result by the search part 402 in Example 3 is demonstrated. Here, as a result of the determination unit 407 determining that the restriction condition 2500 for forming the net groups NG1 and NG3 in the same wiring layer is violated, the wiring path 1210 of the net group NG1 is set as a wiring prohibited area, and the net group NG3 A search result obtained by re-searching the wiring route will be described.

  FIG. 26 is an explanatory diagram (part 5) illustrating a specific example of the search result. In FIG. 26, the wiring area 200 shows wiring routes 1210 to 1230 and 2610 from the start point coordinates unique to the net groups NG1 to NG4 to the end point coordinates.

  The wiring path 2610 uses the wiring prohibited areas F1 to F4 in the wiring area 200 and the wiring path 1210 of the net group NG1 as a wiring prohibited area, and re-routes the wiring path from the start point coordinates specific to the net group NG3 to the end point coordinates. It is the search result searched. Here, as a result of searching for the wiring route 2510, the crossing relationship between the net group NG1 and the net group NG3 is eliminated.

(Design support processing procedure of Example 3)
Next, a design support processing procedure in the third embodiment will be described. FIG. 27 is a flowchart illustrating an example of a design support processing procedure according to the third embodiment. In the flowchart of FIG. 27, first, the acquisition unit 401 determines whether the wiring area information 500, 600, the net group information 700-1 to 700-4, and the constraint condition 2500 have been acquired (step S2701).

  Here, after waiting for the acquisition of the wiring area information 500, 600, the net group information 700-1 to 700-4, and the constraint condition 2500 (step S2701: No), and when acquired (step S2701: Yes), the search unit Based on the wiring area information 500 and 600 and the net group information 700-1 to 700-4, each net group from the start point coordinates unique to each net group NG1 to NG4 in the wiring area 200 to the end point coordinates is obtained by 402. A wiring route having a wiring width of NG1 to NG4 is searched (step S2702).

  Thereafter, the detection unit 403 detects a combination of net groups having a cross relationship with each other between the searched wiring routes 1210 to 1240 (step S2703), and the creation unit 404 converts the net groups NG1 to NG4 into nodes. Then, an undirected graph 1600 that connects the nodes of the combination of net groups having an intersecting relationship is created (step S2704).

  Then, the determination unit 405 solves the coloring problem of the undirected graph 1600, so that the wiring layers are different among the directly connected nodes in the undirected graph 1600. To determine a wiring layer to be assigned to each of the net groups NG1 to NG4 (step S2705).

  Next, the determination unit 407 determines whether or not the combination of net groups having a cross relationship detected by the detection unit 403 violates the constraint condition 2500 acquired in step S2701 (step S2706). .

  If the constraint condition 2500 is violated (step S2706: YES), the wiring path 1210 of the net group NG1 is set as a wiring prohibited area (step S2707), the process returns to step S2702, and the starting point unique to the net group NG3. Re-search the wiring route from the coordinates to the end point coordinates.

  On the other hand, if the constraint condition 2500 is not violated (step S2706: No), finally, the output unit 406 outputs the determination result determined in step S2705 (step S2708), and the series of processing according to this flowchart is performed. finish.

  According to the third embodiment, the wiring path 1210 of the net group NG1 in violation of the constraint condition 2500 is used as a wiring prohibited area, and a new search is performed for the wiring path 2610 from the start point coordinates unique to the net group NG3 to the end point coordinates. The net groups NG1 and NG3 can be assigned to the same wiring layer, and the constraint condition 2500 violation can be eliminated.

  The design support method described in the present embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. Further, this program may be a medium that can be distributed via a network such as the Internet.

  Further, the design support apparatus 300 described in the present embodiment is a PLD (Programmable) such as a standard cell or an application specific IC (hereinafter simply referred to as “ASIC”) such as a structured ASIC (Application Specific Integrated Circuit). It can also be realized by Logic Device). Specifically, for example, the function of the design support apparatus 300 (acquisition unit 401 to determination unit 407) is defined by HDL description, and the HDL description is logically synthesized and given to the ASIC or PLD, thereby supporting the design. The apparatus 300 can be manufactured.

  The following additional notes are disclosed with respect to the embodiment described above.

(Supplementary note 1) For each pair of components having a connection relationship in the circuit to be designed, net group specific start / end coordinates and wiring width in which nets to be wired to the same wiring layer among nets connecting the components are grouped A computer accessible to storage means for storing
Search means for accessing the storage means and searching for a wiring route of the wiring width from the start point coordinates to the end point coordinates in the wiring region of the design target circuit for each net group;
Detecting means for detecting a combination of net groups having a mutual crossing relationship between the wiring paths searched by the searching means;
Determining means for deciding a wiring layer to be assigned to each net group from among a plurality of wiring layers of the circuit to be designed so that a combination of net groups detected by the detecting means is assigned to different wiring layers;
Output means for outputting the determination result determined by the determination means;
Design support program characterized by functioning as

(Appendix 2)
Creation means for creating an undirected graph that connects nodes of a combination of net groups having a cross relationship detected by the detection means in which a net group for each pair of components having a connection relationship in the circuit to be designed is noded Function as
The determining means includes
By solving the coloring problem of the undirected graph created by the creating means, each net group is selected from the plurality of wiring layers so that the wiring layers are different between directly connected nodes in the undirected graph. The design support program as set forth in appendix 1, wherein a wiring layer to be assigned is determined.

(Supplementary note 3) The search means includes
The design support program according to appendix 1 or 2, wherein the shortest wiring path from the start point coordinates to the end point coordinates is searched for using the wiring area as a routable area.

(Supplementary Note 4) The search means includes:
The design according to appendix 1 or 2, wherein a search is made for a wiring route from the start point coordinates to the end point coordinates, with the remaining wiring area excluding the wiring prohibition area in the wiring area as a routable area. Support program.

(Supplementary Note 5) The search means includes:
When the combination of the first and second net groups is detected by the detecting means, the wiring path of the first net group is re-searched using the wiring path of the second net group as a wiring prohibited area. The design support program according to appendix 4, which is characterized.

(Appendix 6) The search means includes:
When a combination of the first and second net groups is detected by the detection means, the first net group is based on the wiring width specific to the third and fourth net groups divided from the first net group. The design support program according to appendix 4 or 5, wherein a wiring route of the third and fourth net groups connecting the start point coordinates and end point coordinates specific to the net group is searched.

(Appendix 7) The search means includes:
Supplementary note 6: The wiring paths of the third and fourth net groups are searched by calculating the wiring width specific to the third and fourth net groups divided from the first net group. The design support program described in 1.

(Appendix 8) The storage means
Stores constraints that specify combinations of multiple net groups that should be assigned to the same wiring layer.
The computer,
As a determination means for accessing the storage means and determining whether the assignment destinations of the first and second netgroups violate the constraint condition as a result of the assignment destination being determined by the determination means. Make it work
The search means includes
If it is determined by the determining means that the constraint condition is violated, the wiring prohibition area in the wiring area and the remaining wiring area excluding the wiring path of the second net group are set as routable areas. The design support program according to any one of appendices 5 to 7, wherein the search is performed again for a wiring route of one net group.

(Supplementary note 9) The search means includes:
If it is determined by the determining means that the constraint condition is violated, the first net group is based on the wiring widths specific to the third and fourth net groups divided from the first net group. 9. The design support program according to appendix 8, wherein a wiring route of the third and fourth net groups connecting the unique start point coordinates and end point coordinates is searched.

(Supplementary Note 10) The storage means
Stores constraints that specify combinations of multiple net groups that should be assigned to the same wiring layer.
The determining means includes
The design according to any one of appendices 1 to 9, wherein a wiring layer to be assigned to each net group is determined from the plurality of wiring layers based on the constraint condition stored by the storage unit. Support program.

(Additional remark 11) The computer-readable recording medium which recorded the design assistance program as described in any one of Additional remark 1-10.

(Supplementary note 12) For each pair of components having a connection relationship in the circuit to be designed, the net group specific start / end coordinates and wiring width in which nets to be wired to the same wiring layer among the nets connecting the components are grouped Storage means for storing
Search means for accessing the storage means and searching for a wiring route of the wiring width from the start point coordinates to the end point coordinates in the wiring area of the design target circuit for each net group;
Detecting means for detecting a combination of net groups having a mutual crossing relationship between the wiring paths searched by the searching means;
Determining means for deciding a wiring layer to be assigned to each net group from among a plurality of wiring layers of the circuit to be designed so that a combination of net groups detected by the detecting means is assigned to different wiring layers;
Output means for outputting the determination result determined by the determination means;
A design support apparatus comprising:

(Supplementary note 13) A net group specific group comprising a control unit and a storage unit, and groups of nets to be wired to the same wiring layer among the nets connecting the components for each pair of components having a connection relationship in the circuit to be designed A computer that can access a table that stores the start / end coordinates and the wiring width of
A search step of accessing the table by the control means and searching for a wiring route of the wiring width from the start point coordinate to the end point coordinate in the wiring region of the design target circuit for each net group; ,
A detection step of detecting a combination of net groups having a mutual crossing relationship between the wiring paths searched by the search step by the control means;
The control means determines a wiring layer to be assigned to each net group from among a plurality of wiring layers of the design target circuit so that the combination of net groups detected in the detection step is assigned to different wiring layers. A decision process to
An output step of outputting the determination result determined by the determination step by the control means;
A design support method characterized by executing

It is explanatory drawing which shows an example of a net group. It is explanatory drawing which shows an example of the wiring area | region of a design object circuit. It is a block diagram which shows the hardware constitutions of a design support apparatus. It is a block diagram which shows the functional structure of a design support apparatus. It is explanatory drawing (the 1) which shows the specific example of wiring area | region information. It is explanatory drawing (the 2) which shows the specific example of wiring area | region information. It is explanatory drawing which shows the specific example of net group information. It is explanatory drawing (the 1) which shows the specific example of a search result. It is explanatory drawing (the 1) which shows the specific example of intersection information. It is explanatory drawing (the 1) which shows the specific example of an undirected graph. It is explanatory drawing (the 1) which shows the specific example of a determination result. It is explanatory drawing (the 2) which shows the specific example of a search result. It is explanatory drawing (the 1) which shows the specific example of wiring route information. It is explanatory drawing (the 2) which shows the specific example of wiring route information. It is explanatory drawing (the 2) which shows the specific example of intersection information. It is explanatory drawing (the 2) which shows the specific example of an undirected graph. It is explanatory drawing (the 2) which shows the specific example of a determination result. It is explanatory drawing (the 1) which shows the specific example of a constraint condition. It is a flowchart which shows an example of the design support process sequence of a design support apparatus. It is explanatory drawing which shows the specific example of a count result. It is explanatory drawing (the 3) which shows the specific example of a search result. It is explanatory drawing (the 3) which shows the specific example of a determination result. 6 is a flowchart illustrating an example of a design support processing procedure according to the first exemplary embodiment. It is explanatory drawing (the 4) which shows the specific example of a search result. It is explanatory drawing (the 2) which shows the specific example of a constraint condition. It is explanatory drawing (the 5) which shows the specific example of a search result. 12 is a flowchart illustrating an example of a design support processing procedure according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 200 Wiring area 300 Design support apparatus 401 Acquisition part 402 Search part 403 Detection part 404 Creation part 405 Determination part 406 Output part 407 Judgment part

Claims (6)

A memory for storing a start / end point coordinate and a wiring width specific to a net group obtained by grouping nets to be wired to the same wiring layer among nets connecting the parts for each pair of parts having a connection relationship in a design target circuit A computer accessible to the means,
Search means for accessing the storage means and searching for a wiring route of the wiring width from the start point coordinates to the end point coordinates in the wiring region of the design target circuit for each net group;
Detecting means for detecting a combination of net groups having a mutual crossing relationship between the wiring paths searched by the searching means;
Creation means for creating an undirected graph that connects nodes of a combination of net groups having a cross relationship detected by the detection means in which a net group for each pair of components having a connection relationship in the circuit to be designed is noded ,
By solving the coloring problem of the undirected graph created by the creation means, the wiring layers of the design target circuit are different so that the wiring layers are different between directly connected nodes in the undirected graph. Determining means for determining a wiring layer to be assigned to each net group from
Output means for outputting the determination result determined by the determination means;
Design support program characterized by functioning as   The search means includes
  2. The design support according to claim 1, wherein a wiring route from the start point coordinates to the end point coordinates is searched for using a remaining wiring area excluding a wiring prohibited area in the wiring area as a routable area. program.   The search means includes
  When the combination of the first and second net groups is detected by the detecting means, the wiring path of the first net group is re-searched using the wiring path of the second net group as a wiring prohibited area. The design support program according to claim 2, wherein:   The search means includes
  When a combination of the first and second net groups is detected by the detection means, the first net group is based on the wiring width specific to the third and fourth net groups divided from the first net group. The design support program according to claim 2 or 3, wherein a wiring route of the third and fourth net groups connecting the start point coordinates and end point coordinates specific to the net group is searched.   A memory for storing a start / end point coordinate and a wiring width specific to a net group obtained by grouping nets to be wired to the same wiring layer among nets connecting the parts for each pair of parts having a connection relationship in a design target circuit Means,
  Search means for accessing the storage means and searching for a wiring route of the wiring width from the start point coordinates to the end point coordinates in the wiring area of the design target circuit for each net group;
  Detecting means for detecting a combination of net groups having a mutual crossing relationship between the wiring paths searched by the searching means;
  Creation means for creating an undirected graph that connects nodes of a combination of net groups having a cross relationship detected by the detection means in which a net group for each pair of components having a connection relationship in the circuit to be designed is noded When,
  By solving the coloring problem of the undirected graph created by the creation means, the wiring layers of the design target circuit are different so that the wiring layers are different between directly connected nodes in the undirected graph. Determining means for determining a wiring layer to be assigned to each net group from:
  Output means for outputting the determination result determined by the determination means;
  A design support apparatus comprising:   A net group specific start point / end point that includes a control unit and a storage unit and groups nets to be wired to the same wiring layer among a pair of components having a connection relationship in the design target circuit. A computer with access to a table that stores coordinates and wire width
  A search step of accessing the table by the control means and searching for a wiring route of the wiring width from the start point coordinate to the end point coordinate in the wiring region of the design target circuit for each net group; ,
  A detection step of detecting a combination of net groups having a mutual crossing relationship between the wiring paths searched by the search step by the control means;
  A net group for each pair of components having a connection relationship in the design target circuit is noded by the control means, and an undirected graph that connects nodes of a combination of net groups having a cross relationship detected by the detection step. Creating process to create
  A plurality of the design target circuits have different wiring layers between directly connected nodes in the undirected graph by solving the coloring problem of the undirected graph created by the creating step by the control means. A determination step of determining a wiring layer to be assigned to each net group from among the wiring layers of
  An output step of outputting the determination result determined by the determination step by the control means;
  A design support method characterized by executing

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