Schematic diagram generator and schematic diagram generating method

Claim 3

A method according to Claim 1 wherein in said third step, when a plurality of candidates of disconnec­tion points are found, for each of nodes at the points, either one of the following selection rules or a combination thereof is employed to determine a location disconnection point of the loop (68, 69); a first selection rule for preferentially selecting one of said nodes associated with a smaller number of nodes as start points of arcs (i.e. connecting lines) having said one node as an end point; a second selection rule for preferentially selecting one of said nodes associated with a greater number of nodes assigned with levels among the nodes as the start points of arcs; and A third selection rule for preferentially selecting one of said nodes associated with a smaller value of the maximum level of nodes assigned with levels among the nodes as the start points of said arcs.

Claim 4

A method according to Claim 1 or 2 wherein said first step includes a processing step (101) for extracting loops each comprising only two nodes so as to set the two nodes constituting the loop to a level.

Claim 5

A placement method in which nodes of a net diagram are assigned with levels so as to determine positional relationships for each said level in a direction vertical to a direction of the level comprising: a fourth step (144) for effecting a maximum matching on a bipartite graph comprising a set of nodes for which positional relationships are already determined, a set of nodes for which positional relationships are not determined, and connective relationships between the sets so as to determine positional relationships such that nodes associated with each other as a result of the maximum matching are placed on a position; and a fifth step (145) operative when nodes not saturated in the maximum matching exist as a result of said fourth step, for determining positional relationships of the nodes based on direct or indirect connective relationships with the nodes having the determined positional relationships so as to sequentially determine positional relationships of all the nodes, thereby determining the placements in the direction vertical to the level direction based on the positional relationships.

Claim 6

A placement method in which nodes of a net diagram are assigned with levels so as to determine positional relationships for each said level in a direction vertical to a direction of the level comprising: a fourth step (144) for effecting a maximum matching on a bipartite graph comprising a set of nodes for which positional relationships are already determined, a set of nodes for which positional relationships are not determined, and connective relationships between the sets so as to determine positional relationships such that nodes associated with each other as a result of the maximum matching are placed on a position; and a fifth step (145) operative when nodes not saturated in the maximum matching exist as a result of said fourth step, for determining positional relationships of the nodes based on direct or indirect connective relationships with the nodes having the determined positional relationships so as to sequentially determine positional relationships of all the nodes, thereby determining the placements in the direction vertical to the level direction based on the positional relationships.

Claim 7

A placement method according to Claim 4 wherein in the maximum matching of the bipartite graph in the fourth step, a matching between nodes having a larger level difference therebetween takes precedence.

Claim 8

A placement method of determining node positions of a network wherein the following steps are executed when determining positional relationships between a plurality of nodes not directly connected with each other in the network: a sixth step (102-104) in which for all pairs of said nodes, a common descendant (or ancestor) is detected for the pairs so as to obtain a total number of arcs from said nodes of said each pair to the common descendant (or ancestor) and a level difference between said two nodes and the common descendant (or ancestor), thereby setting a priority sequence of each said pair such that a higher priority sequence is assigned to said pair with a smaller value of the total number of arcs or with a smaller minimum value of the level difference; and a seventh step (105) for determining positional relationship such that the pair having a higher priority is located at a nearer position.

Claim 9

A placement method of determining node positions of a network wherein the following steps are executed when determining positional relationships between a plurality of nodes not directly connected with each other in the network: a sixth step (102-104) in which for all pairs of said nodes, a common descendant (or ancestor) is detected for the pairs so as to obtain a total number of arcs from said nodes of said each pair to the common descendant (or ancestor) and a level difference between said two nodes and the common descendant (or ancestor), thereby setting a priority sequence of each said pair such that a higher priority sequence is assigned to said pair with a smaller value of the total number of arcs or with a smaller minimum value of the level difference; and a seventh step (105) for determining positional relationship such that the pair having a higher priority is located at a nearer position.

Claim 10

A schematic generating method of automatically generating a net diagram comprising: an eleventh step (11) for assigning levels to nodes by use of the method of assigning levels to nodes of a network according to Claim 1, 2 or 3: a twelfth step (12) for determining or for beforehand specifying positional relationships between nodes at a reference level or as reference of placement by use of the placement method according to Claim 6; a thirteenth step (13) for sequentially determining positional relationships of all the nodes based on the positional relationships obtained in said twelfth step by use of the placement method according to Claim 4 or 5; and a step (15) operative after the placements of the nodes are determined in said steps above for routing connecting lines between said nodes.

Claim 11

A routing method of routing connecting lines between nodes of a network diagram comprising: an eighth step (261) operative when a plurality of connecting lines path a routing route for determining for each said connecting line in the routing route a virtual routing length from a position of a bending point thereof; and a ninth step (262, 263) for routing the respective connecting lines in the routing route in a sequence of the virtual routing length.

Claim 12

A routing method of routing connecting lines between nodes of a network diagram comprising: an eighth step (261) operative when a plurality of connecting lines path a routing route for determining for each said connecting line in the routing route a virtual routing length from a position of a bending point thereof; and a ninth step (262, 263) for routing the respective connecting lines in the routing route in a sequence of the virtual routing length.

Claim 13

A routing method of sequentially routing connecting lines between nodes of a network diagram for each region including a column (or a row) of nodes comprising: a tenth step (242) for determining a routing route based on a positional relationship between a node of a start point and a node of an end point respectively of the connecting line; and a step for (243-246) achieving a routing operation for each routing pattern determined by positions of the start and end points of each said connecting line in the region in a routing sequence predetermined for the pattern by use of said eighth and ninth steps according to Claim 8.

Claim 14

A schematic generating method of automatically generating a logic diagram comprising: a step A (11-13) for executing said eleventh, twelfth, and thirteenth steps according to Claim 7 for determining a first global coordinate from the levels assigned to the respective placement elements in said eleventh step and a second global coordinate (orthogonal to the first global coordinate) from the positional relationsnips of the respective placement elements attained in said thirteen step; a step B (14) operative based on global placements of the respective placement elements obtained in said step A and connective relationship therebetween and contours of the respective placement elements for effecting a physical placement determination of local coordinates and orientations of the respective placement elements and including placements of pin positions of the respective placement elements; a step C (15) for routing connecting lines based on the routing method according to Claim 9 by use of the global and local coordinates for each said first global coordinate; and a step D (16) for determining absolute coordinates of positions and routings of the respective placement elements based on the global and local coordinates.

Claim 15

A schematic generator for automatically generating a logic circuit comprising: first means (1) for inputting connective information of a logic circuit; second means (2) for keeping therein information on contours of the placement elements; third means (3) for keeping therein information associated with placements and routing of the logic circuit; fourth means (4) for keeping therein information on graphic symbols of the respective placement elements, said information preserving integrity with respect to the information kept in said second means; fifth means (5) for drawing a logic circuit diagram by use of the information kept in said third means and the information kept in said fourth means; and processing means (11-16) for sequentially executing: a step A (11-13) for executing said eleventh, twelfth, and thirteenth steps according to Claim 7 for determining a first global coordinate from the levels assigned to the respective placement elements in said eleventh step and a second global coordinate (orthogonal to the first global coordinate) from the positional relationships of the respective placement elements attained in said thirteen step; a step B (14) operative based on global placements of the respective placement elements obtained in said step A and connective relationship therebetween and contours of the respective placement elements for effecting a physical placement determination of local coordinates and orientations of the respective placement elements and including placements of pin positions of the respective placement elements; a step C (15) for routing connecting lines based on the routing method according to Claim 9 by use of the global and local coordinates for each said first global coordinate; and a step D (16) for determining absolute coordinates of positions and routings of the respective placement elements based on the global and local coordinates so as to attain information associated with placements and routings of the logic circuit diagram, said information associated with placements and routings being kept in said third means, thereby said fifth means draws a logic circuit diagram of a logic circuit supplied from said first means.