JP2836434B2 - Multi-layer channel wiring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer channel wiring device for an integrated circuit.

[0002]

2. Description of the Related Art A channel wiring method, which is one of the wiring methods of an integrated circuit, is a method in which, as shown in FIG. This is a method in which a wiring request for wiring between terminals having the same number (net number) in which each terminal is given a number is provided by using an area between two terminal rows. A set of terminals having the same number is called a net, and the net is wired by a line segment (horizontal line segment) parallel to the terminal row and a vertical line segment (vertical line segment). The wiring area has a fixed number of wiring layers of two or more, and when focusing on one layer, wiring with only parallel lines or wiring with only vertical lines is performed.
The layer where the horizontal line is wired is called a horizontal wiring layer, and the layer where the vertical line is wired is called a vertical wiring layer. The horizontal and vertical line segments are connected by vias. A grid is cut in the wiring area, horizontal and vertical line segments are wired on grid lines, and vias are placed at grid points. Grid lines parallel to the terminal rows are called tracks, and vertical grid lines are called columns. The column always passes where the terminal is located. Further, the terminals are placed on a vertical wiring layer, and there are cases where a plurality of terminals are present on the same column by changing layers, such as a terminal on the second layer and a terminal on the fourth layer. The wiring request is given as a set of nets (a set of terminals having the same net number).

As shown in FIG. 13, the wiring of a net between two terminals is performed by one horizontal line segment and two vertical line segments. It is conceivable that the wiring of each net is performed by a plurality of horizontal line segments and a plurality of vertical line segments. However, in this case, the wiring becomes very complicated, and it takes an enormous amount of time to complete the entire wiring. By limiting the wiring of each net to one horizontal line segment and two vertical line segments, the entire wiring can be performed relatively easily.

A conventional multi-layer channel wiring device will be described with reference to FIG. FIG. 3 is a flowchart showing a wiring procedure in the multilayer channel wiring device.

[0005] The horizontal line segment generation device 102 generates a wiring request 10
With 1 as an input, a horizontal line segment is created from each net of the wiring request. The work content is such that when the net contains only two terminals, the starting point is the x coordinate of the terminal on the left on the x coordinate, and the end point is the x coordinate of the terminal on the right on the x coordinate Generate minutes. When the net includes three or more terminals and the x-coordinate of each terminal is x1, x2, x3, x4,... From the left, horizontal line segments [x1, x2], [x2, x3], [x3, x
4],..., A plurality of horizontal line segments are generated.

Wiring is performed between one end point and a terminal of the horizontal line segment and between the other end point and the terminal using one vertical line segment.
It cannot exist in layers separated by more than one layer. for that reason,
Each of the previously generated horizontal components has a limited wiring layer that can be wired. For example, in the case of a net connecting the terminals of the second layer and the terminals of the second layer, both of the two vertical segments are the second lines.
Both end points are wired in the layer, and both end points also appear in the second layer, and a horizontal line connecting the two end points can be wired in the first layer or the third layer. However, in the case of a net connecting the terminal of the second layer and the terminal of the fourth layer, the end points of two vertical line segments appear on the second and fourth layers, respectively, so that the horizontal line segment is wired only to the third layer. Can not.

In the horizontal line segment generator 102, at the same time as the generation of the horizontal line segment, the number of the horizontal wiring layer that can be wired for each horizontal line segment is added to the horizontal line segment as its attribute.
Wiringable horizontal generated by the horizontal line generator 102
The set of horizontal line segments to which the wiring layer number is added is the vertical constraint group.
Output to the rough management device 103.

It is not allowed that horizontal line segments overlap in the same track and the same layer, and vertical line segments are not allowed to overlap in the same column and the same layer. As shown in FIG.
When two nets require vertical line segments that are wired in the same column and the same layer, there is a restriction on the vertical relationship between the horizontal line segments of those nets. In the example of FIG. 14, the horizontal line segment of the net 2 must be routed to a track above the horizontal line segment of the net 1. Therefore, the constraint of the vertical relationship between the horizontal line segments is expressed using a vertical constraint graph. With a vertical constraint graph, each vertex corresponds to a horizontal line segment,
5 is a graph in which a directed edge from a vertex corresponding to the horizontal line segment A to a vertex corresponding to the horizontal line segment B is provided when the horizontal line segment A must be wired to a track above the horizontal line segment B.

The vertical constraint graph management device 103 receives a set of horizontal line segments as input, and examines the vertical constraint relationship between horizontal line segments having the x-coordinate of the column as an end point in all layers of all columns. A constraint graph is generated. The generated vertical constraint graph is held by the vertical constraint graph holding unit 104. Also, vertical system
About the graph management device 103, the vertical constraint graph holding means 10
4. Read the vertical constraint graph stored in
The graph is deformed by the operation described below, and the vertical
The direct constraint graph is output to the vertical constraint graph holding means 104 again.
Force and hold.

When a directed cycle exists on a vertical constraint graph, a wiring requirement cannot be satisfied unless horizontal lines of some nets are divided. For example, a directed cycle A → B → C → D → A means that A must be wired to a track above itself.

When a directed cycle exists on the graph after the vertical constraint graph is generated, the vertical constraint graph management device 103 divides a horizontal line segment corresponding to an arbitrary vertex on the directed cycle into two horizontal line segments. . After the horizontal line segment is divided into two, if the vertical constraint graph is updated by dividing the horizontal line segment, one directed cycle is eliminated. The vertical constraint graph management device 103 performs an operation of dividing a horizontal line segment until a directed cycle no longer exists on the vertical constraint graph.

When there is a directed path from vertex A to vertex B on the vertical constraint graph, vertex A is called an ancestor of vertex B, and vertex B is called a descendant of vertex A. The horizontal line segment that can be wired to the highest track (the track closest to the upper terminal row) is limited to a horizontal line segment corresponding to a vertex having no ancestor on the vertical constraint graph. Similarly, a horizontal line segment that can be wired to the lowest track (the track closest to the lower terminal row) is limited to a horizontal line segment corresponding to a vertex having no descendants on the vertical constraint graph.

The wiring operation is performed in the order of the first track, the second track, and the third track. First, focusing on the first track, the horizontal line candidates that can be wired in the horizontal wiring layer of the first track are a set of horizontal line segments corresponding to vertices having no ancestors on the vertical constraint graph. Vertical constraint graph tube
The processing device 103 extracts a set of horizontal line segments by a method described later.
Then, it is output to the track wiring device 105. truck
The wiring device 105 receives a set of horizontal line segments as input and performs wiring.
Only the horizontal line segment is returned to the vertical constraint graph management device 103.

The vertical constraint graph management device 103 extracts a set of horizontal line segments corresponding to vertices having no ancestors on the vertical constraint graph (306). Since the horizontal line segments must not overlap in the same wiring layer on the same track, not all candidate horizontal line segments can be simultaneously wired to one track. The extracted horizontal line segment candidates are transferred to the track wiring device 105. Track wiring device 10
In step 5, which horizontal line segment is to be wired to the track is selected, and at the same time, which horizontal wiring layer is to be wired is also determined.
Details of the track wiring device will be described later.

The track wiring device 105 performs wiring on one track (307), and then notifies the vertical constraint graph management device 103 of a set of wired horizontal lines. The vertical constraint graph management device 103 deletes vertices corresponding to the wired horizontal line segments from the vertical constraint graph held by the vertical constraint graph holding unit 104 (308).

Referring back to 304 in FIG. 3, if the vertical constraint graph is not empty (ie, there is a horizontal line segment that has not been wired yet), wiring to the next track is performed. For example, in the case of the second track, on the vertical constraint graph in which the vertices corresponding to the horizontal line segment wired to the first track are deleted from the vertical constraint graph, a set of horizontal line segments corresponding to the vertices having no ancestor is formed on the second track. Is a candidate for a horizontal line segment to be wired in the horizontal wiring layer.

The operation in the loop of FIG. 3 is repeated until the vertical constraint graph becomes empty, that is, until all the horizontal segments are wired. This means that tracks are required as many times as the number of repetitions.

Next, the track wiring device 105 will be described. FIG. 11 is a diagram showing a configuration of a conventional track wiring device, and FIG. 12 is a flowchart showing a wiring procedure of the conventional track wiring device.

The wiring to each track is formed by a first horizontal wiring layer,
The process is performed in the order of the second horizontal wiring layer and the third horizontal wiring layer. A set of horizontal line segments passed to the track wiring apparatus as wiring candidates is denoted by V. Each horizontal line segment has limited horizontal wiring layers on which they can be wired. For each horizontal wiring layers i, is denoted by V _i the set of horizontal segments that can be wired to the i-th horizontal wiring layer among V. Since the number of horizontal wiring layers to which one horizontal line can be routed is not limited to one,

[0020]

(Equation 1)

This is not necessarily the case. The set V _{1 of} horizontal line segments that are wiring candidates to the first horizontal wiring layer are all
Wiring to the horizontal wiring layer is not always possible.

First, the horizontal line segment management device 1101 holds a set V of horizontal line segments passed to the track wiring device by the horizontal line segment holding means 1102, and from among them, a horizontal line segment that can be wired to the first horizontal wiring layer. extracts the partial set V ₁ (1203), and passes the row wire selection apparatus 1103. The one-line wiring selection device 1103 selects which horizontal line is to be wired to the horizontal wiring layer of the track, and a set of the selected horizontal lines is passed to the one-line wiring device 1104. In the one-row wiring device 1104, the set of passed horizontal lines is
Wiring is performed on one track and one horizontal wiring layer. After the horizontal line is wired, the vertical line is wired.However, since the horizontal line of the net is wired, the coordinates of the end points of the vertical line are determined. Can be done easily. The wiring work of the vertical line is also performed by the single-row wiring device 1104. Details of the one-row wiring selection device 1103 will be described later.

A candidate for a horizontal line segment wired to the second horizontal wiring layer is obtained from a set V _{2 of} horizontal line segments that can be wired to the second horizontal wiring layer from the horizontal line segment originally wired to the first horizontal wiring layer. in which removal of the set U _1.

The one-line wiring selecting device 1103 not only transfers the selected horizontal line set to the one-line wiring device 1104 but also
The horizontal line segment management device 1101 is also notified. The horizontal line segment management device 1101 removes the horizontal line segment notified from the one-line wiring selection device 1103 from the horizontal line segment set held by the horizontal line segment holding unit 1102.

Then, returning to 1202 in FIG. 12, the operation for wiring to the next horizontal wiring layer is started. In the next horizontal wiring layer,
From the set of horizontal segments currently held in the horizontal segment holding means 1102, a set of horizontal segments that can be wired to the horizontal wiring layer is extracted by the horizontal segment management device 1101.
A set of horizontal lines to be wired to the next horizontal wiring layer is selected by the one-row wiring selection device 1103. The operation in the loop of FIG. 12 is repeated by the number of horizontal wiring layers.

In the track wiring device, one row wiring selection device 1103 is used by the number of horizontal wiring layers.

Next, a one-line wiring selection device will be described. The one-line wiring line selection device receives a set of horizontal line segments as input,
A set of horizontal lines that can be wired on one track and one horizontal wiring layer is output. Let S be a set of input horizontal segments.
Each horizontal line segment belonging to S

[0028]

It is assumed that a weighting function w (s) is given to. The weight function w (s) represents the desirability that the horizontal line segment s is wired to the track where the current wiring is performed. The weighting function w (s) is represented by the length l of the horizontal line segment s, the path length of the longest route among the directed paths starting from the vertex corresponding to the horizontal line segment s on the vertical constraint graph m, and the vertex thereof. Let c be the number of directed sides leading to, and α, β, γ be given by w (s) = αl + βm + γc. The significance of giving weight to horizontal line segments is that by wiring a certain horizontal line segment, the number of vertices that have no ancestors on the vertical constraint graph is increased as much as possible, and the next track will have more horizontal line segments that are wiring candidates. The purpose is to prioritize the horizontal line. This leads to a reduction in the number of tracks required for wiring. The collection of horizontal lines output by the one-line wiring selection device is a horizontal line having the maximum sum of the weight functions of the selected horizontal lines among a set of horizontal lines that can be wired without overlapping each other on one track and one horizontal wiring layer. Set of minutes. This means that as many horizontal line segments as possible are wired in one track and one horizontal wiring layer, with priority given to horizontal line segments having a large weighting function. Regarding a method for selecting a horizontal line segment in which a total sum of weight functions of selected horizontal line segments is maximum among a set of horizontal line segments that can be wired without overlapping each other on one track and one horizontal wiring layer by a one-row wiring selection device, [Ta
keshi Yoshimura, AnEfficie
nt Channel Router ", Proc.
21st DA conf. pp. 38-44, (198
4)].

[0030]

The track wiring device of the conventional multi-layer channel wiring device repeatedly uses a one-line wiring selection device. It is assumed that a horizontal line segment as shown in FIG. 7 is a wiring candidate to a certain track. FIG. 8 shows a set of horizontal lines when the first horizontal wiring layer, the second horizontal wiring layer, and the third horizontal wiring layer are sequentially selected by the one-row wiring selection device. The horizontal line segment wired in the first horizontal wiring layer has the largest sum of the weighting functions among the horizontal line segments that can be wired without overlapping the first horizontal wiring layer. Similarly, a horizontal line segment wired in the second horizontal wiring layer is a horizontal line segment obtained by removing the horizontal line segment wired in the first horizontal wiring layer as a wiring candidate, and a horizontal line segment that can be wired without overlapping the second horizontal wiring layer. Among them, the sum of the weight functions is the largest. The same applies to the horizontal line segment wired in the third horizontal wiring layer. Here, the sum of the weighting functions of the horizontal line segments wired in the three horizontal wiring layers is 28. However, when a horizontal line segment to be wired to the first horizontal wiring layer, the second horizontal wiring layer, and the third horizontal wiring layer is selected as shown in FIG. 9, the sum of the weight functions of the horizontal line segments is 32. As shown in this example, even if a horizontal line segment that maximizes the sum of the weighting functions is sequentially selected for one track and one horizontal wiring layer, the weight function is determined by a set of horizontal line segments that can be wired to one track. That is, it is not always possible to select the one that maximizes the sum of

Since the conventional track wiring device repeatedly uses the one-line wiring selection device, the horizontal line segment wired in one track is not necessarily a set of horizontal line segments in which the sum of the weighting functions is maximum. There is. Also,
The conventional multilayer channel wiring device having this track wiring device has a disadvantage that the number of required tracks is not always minimum in the final wiring result.

An object of the present invention is to provide a multi-layer channel wiring apparatus for performing wiring such that the required number of tracks is minimized.

[0033]

According to the present invention, there is provided a multi-layer channel wiring apparatus which receives a wiring request as a set of nets and generates a horizontal line segment set from each net of the wiring request. , A vertical constraint graph management device having a function of updating the vertical constraint graph, a vertical constraint graph holding means for holding the vertical constraint graph, and a horizontal line segment that can be wired on one track. It is characterized by having a track wiring device for selecting a set that maximizes the sum of the weight functions in the set and wiring the selected horizontal line segment.

Further, the multilayer channel wiring device of the present invention
A weighting function calculating device that receives a set of horizontal line segments as input, and calculates a weighting function w (s) representing the desirability that each horizontal line segment s is wired to the track currently being wired; Weight function holding means for storing the function w (s), and a horizontal line having the largest x-coordinate of the right end point among the horizontal line segments which can be wired to the i-th horizontal wiring layer having a right end point to the left of the left end point of each horizontal line segment s shows a map L _i indicating the minutes (s), the most size horizontal line segment x coordinate of the rightmost point of the horizontal line segments can be wired to the i-th horizontal wiring layer having a rightmost point to the left of the right end point of each horizontal line s a mapping computing device for determining a mapping R _i (s), mapping L _i (s), and mapping the holding means for storing R _i (s), the calculated weighting function w (s) and the mapping L _i
(S) and R _i (s), a partial section maximum weight calculation device for calculating the maximum value M of the sum of weight functions of a set of horizontal line segments that can be wired in partial sections of the track, and each part of the track Means for storing a maximum value of a partial section, which stores the calculated value of M for the section, a weighting function w (s), mappings L _i (s), R _i (s), and a horizontal line segment that can be wired to all sections of the track A horizontal line search device for obtaining a set of horizontal line segments having the maximum sum of weight functions that can be wired to the track from the maximum value M of the sum of the weight functions of the sets of the set, and wiring the set of horizontal line segments obtained by the horizontal line search device And a vertical line wiring device for wiring a vertical line connected to the horizontal line obtained by the horizontal line search device.

[0035]

The track wiring device according to the present invention will be described.

It is assumed that a set of horizontal line segments passed as wiring candidates to the track wiring device is V, and the number of horizontal line portions is n. Further, it is assumed that there are k horizontal wiring layers in one track. Put and V _i the set of horizontal segments that can be wired to the i-th horizontal wiring layer among V. The horizontal line segments belonging to V are represented by s ₁ , s ₂ ,
s _3, ..., give a s _n and name. For convenience, a horizontal line segment s ₀ = [0,0] that can be wired to any horizontal wiring layer is provided.
In the horizontal line segment s belonging to V, two types of mapping from the horizontal line segment to the horizontal line segment are defined. Mapping L _i (s), of the horizontal segments in V _i with the right edge points to the left than the left end point of the horizontal line segment s, represents the x coordinate of the rightmost point largest horizontal segments.
Mapping R _i (s), of the horizontal segments in V _i with the right edge points to the left than the right end point of the horizontal line segment s, represents the x coordinate of the rightmost point largest horizontal segments. The x coordinate of the right end point of the horizontal line segment s is represented by s ⁺ . In the case of a set of horizontal line segments as shown in FIG. 7, the mappings L and R of the second horizontal wiring layer of the horizontal line segment s ₁₁ are shown in FIG.
, R ₂ (s ₁₁ ) = s ₁₀ , L ₂ (s
_{1 1} ) = s ₈ .

When v ₁ , v ₂ ,..., V _k are each a horizontal line segment, M (v ₁ , v ₂ ,..., V _k ) is _defined as a section [0, v ₁ ⁺ ], the section [0, v ₂ ⁺ ] of the second horizontal wiring layer,..., of the set of horizontal segments that can be wired in the section [0, v _k ⁺ ] of the k-th horizontal wiring layer, It is defined as the sum of the weighting functions of the set of horizontal line segments where the sum of the functions is the largest.

A set of horizontal line segments in which the sum of the weighting functions is maximum is called a maximum weight horizontal line segment set.

For example, M (s ₁ , s ₀ , s ₀ ,..., S ₀ )
, The section [0, s ₁ ⁺ ] of the first horizontal wiring layer, the section [0, 0] of the second horizontal wiring layer,..., The section [0, 0] of the k-th horizontal wiring layer include the first Since only the horizontal line segment s ₁ can be wired to the horizontal wiring layer, M (s ₁ , s ₀ , s ₀ ,
.., S ₀ ) = w (s ₁ ). Also, for the most x-coordinate of the rightmost point greater horizontal segments v _n in V, the interval [0, v
_n ⁺ ] represents the entire section of one track, and M (v _n , v _n ,
.., V _n ) represent weight values of the maximum weight horizontal line set that can be wired in one track. Horizontal segments s ₀ is a _{[0,0], M (s 0} , s 0, ..., s 0) For, since corresponds to a section of length _{0 M (s 0, s 0} , ..., s 0) = It becomes 0.

When v ₁ , v ₂ ,..., V _k are each a horizontal line segment, the following equation holds for M (...).

[0041]

(Equation 2)

For example, in the case of a collection V of horizontal lines to which horizontal lines are input as shown in FIG. 7, when one track has three horizontal wiring layers, Becomes M (s ₁₂ , s ₁₂ , s ₁₂ ) = 32. _{M (s n, s n,} ..., s n) but is merely representative of the value of the weight of the maximum weight horizontal segments set can be routed to one _{track, M (s n, s n} , ..., s n) From the value of
By using (...) and the values of R _i (s) and L _i (s), the maximum weight horizontal line set can be obtained by wiring in one actual track.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, an embodiment of a multilayer channel wiring device according to the present invention will be described. FIG. 3 is a flowchart showing a wiring procedure in the multilayer channel wiring device.

The horizontal line segment generator 102 generates the wiring request 10
With 1 as an input, a horizontal line segment is created from each net of the wiring request. When the net includes only two terminals, the starting point is the x coordinate of the terminal on the left side on the x coordinate, and x
A horizontal line segment is generated such that the end point is the x coordinate of the terminal on the right side on the coordinates. When the net includes three or more terminals, the x-coordinate of each terminal is x1, x from the left.
2, x3, x4, ..., a horizontal line segment [x1,
x2], [x2, x3], [x3, x4],... At the same time as the generation of the horizontal line segment, the number of the horizontal wiring layer that can be wired to each horizontal line segment is added to the horizontal line segment as an attribute.

The vertical constraint graph management device 103 receives a set of horizontal line segments as input, and in all layers of all columns,
A vertical constraint graph is generated by examining the vertical constraint relationship between horizontal line segments having the x coordinate of the column as an end point. If a directed cycle exists on the graph after generating the vertical constraint graph, the horizontal line segment corresponding to any vertex on the directed cycle is divided into two horizontal line segments, and the directed cycle on the vertical constraint graph is removed. I do. The generated vertical constraint graph is
It is held by the vertical constraint graph holding unit 104.

The vertical constraint graph management device 103 has a function of extracting a set of horizontal line segments corresponding to vertices having no ancestors on the vertical constraint graph (306), and deletes vertices corresponding to horizontal line segments from the vertical constraint graph. It has a function (308).

The track wiring device 105 is different from the track wiring device described above in that the set of horizontal segments extracted by the vertical constraint graph management device 103 is input,
A set of horizontal line segments that can be wired in one track is wired such that the sum of the weighting functions is maximum, and the set of wired horizontal line segments is notified to the vertical constraint graph management device 103.

As shown in the flowchart of FIG. 3, wiring is performed using the track wiring device 105 for each track. The wiring operation is repeated while increasing the number of tracks until the vertical constraint graph held by the vertical constraint graph holding unit 104 becomes empty, that is, until all the horizontal line segments are wired to the tracks. Tracks for the number of repetitions are required to satisfy the wiring requirements.

FIG. 2 is a diagram for explaining an embodiment of the track wiring apparatus of the present invention. FIG. 4 is a flowchart showing a wiring procedure in the track wiring device.

The track wiring device is a device that receives a set of horizontal line segments as input and routes a set of maximum weighted horizontal line segments that can be wired in one track to one track. A set of horizontal line segments that are input to the track wiring device is denoted by S, and the horizontal line segments of S include s ₁ , s ₂ ,.
_{s 3,} ..., s _n and are named. FIG. 4, FIG. 5 and FIG.
In 6, the name of the horizontal line is referred to as an integer. Sand
Chi, integer 1 indicates the horizontal segments s _1, integer 2 horizontal line s
₂ shows the integer k is an horizontal segments _{s k.} Subscript i
Is an integer indicating a horizontal line segment. The mappings R _i ( _ik ) and
L _{i (i k)} inputs the integer _{i k} indicating the horizontal line,
Output an integer indicating the horizontal line segment. Weight function w ( _ik )
Outputs the real inputs the integer i _k that indicates the horizontal line.
The function M (i ₁ , i ₂ ,..., _Ik ) is an integer indicating a horizontal line segment.
The number _{i 1, i 2, ...,} function value as input _{i k} is taken a real value
You.

Step 401 in the flowchart of FIG .
Is a weight function calculator that receives a set 201 of horizontal segments as an input.
The calculation result is calculated by the weight function calculator 202.
Is output to the weight function holding means 203. The weighting function calculation device 202 receives a set of horizontal line segments as input, and
Calculates a weighting function w (s) that represents the desirability of being wired to the track currently being wired. Weight function w
(S) indicates that the length of the horizontal line segment s is l, the path length of the longest one of the directed paths starting from the vertex corresponding to the horizontal line segment s on the vertical constraint graph is m, and is connected to the vertex. When the number of sides is c and three constants are α, β, and γ, w (s) = αl + βm + γc.
The calculated weight function w (s) is stored in the weight function holding unit 20.
3 is stored.

Process 402 in the flowchart of FIG .
Is a mapping calculation device 2 which receives a set 201 of horizontal line segments as an input.
04, and the result of the calculation by the mapping calculation device 204 is a mapping.
It is output to the holding means 205. The mapping calculation device 204
For each horizontal wiring layers i and the horizontal line segment s, of the horizontal segments in V _i with the right edge points to the left than the left end point of the horizontal line segment s, mapping L representing the x coordinate of the rightmost point has the largest horizontal segments
_i and _(s), of the horizontal segments in V _i with the right edge points to the left than the right end point of the horizontal line segment s, obtaining the mapping R _{i (s)} that the x coordinate of the rightmost point represents the highest horizontal segments. The obtained mappings R _i (s) and L _i (s) are stored by the mapping holding means 205.

In the flowchart of FIG .
The processing of No. 3 is held in the weight function holding means 203.
Weight function and mapping held in mapping holding means 205
And held in the partial section maximum weight holding means 207.
Partial section maximum with partial section maximum weight value M (...) as input
This is performed by the weight calculation device 206,
The result of the calculation in the unit 206 is the
07. Subsection maximum weight calculator 206
Is the calculated weight function w (s) and the mapping L
_{Using i} (s) and R _i (s), the weight M of the maximum weight horizontal line segment set that can be wired in a partial section of the track is calculated. When v ₁ , v ₂ ,..., v _k are each a horizontal line segment and the x coordinate of the right end point of the horizontal line segment v is represented by v (recruitment), the section [0, v] of the first horizontal wiring layer in one track ₁ ⁺ ], the section [0, v ₂ ⁺ ] of the second horizontal wiring layer,..., The maximum that can be wired in a partial section of the track including the section [0, v _k ⁺ ] of the k-th horizontal wiring layer. The weight M (v ₁ , v ₂ ,... V _k ) of the weight horizontal line set is calculated. M (v ₁ , v
_2, ..., _{v k)} is calculated by the following formula.

[0054]

(Equation 3)

Using the partial section maximum weight calculator 206, the sets {v ₁ , v ₂ ,.
.., V _k } for all possible combinations of M
The value of (v ₁ , v ₂ ,..., V _k ) is calculated. By calculating M (...) In the order of the flowchart of FIG.
_{1, v 2, ..., v} k) Another required to calculate the value of M (...) would have already been computed. Once calculated, the value of M (...)
07 is stored. Subsection maximum weight holding device 20
The value of M (...) stored in 7 is referred to when the partial section maximum weight calculation device calculates another value of M (...). The flowchart of FIG. 5 shows a procedure for calculating the above-described equation.

Step 414 in the flowchart of FIG .
Is the weight function held in the weight function holding means 203
And the mapping held by the mapping holding means 205
Partial section held in section maximum weight holding means 207
Horizontal line segment search device 20 that receives maximum weight value M (...) as input
8 performed by the horizontal line segment search device 208.
The set of line segments is output to the horizontal line segment wiring device 209.
The horizontal line segment search device 208 calculates the weight function w (s) and the mapping L
_{From i} (s), R _i (s) and the weight M of the maximum weight horizontal line set that can be wired in a subsection of the track, the maximum weight horizontal line set that can be wired to that track is itself obtained.

The flowchart of FIG.
Reference numeral 08 denotes an operation procedure for obtaining a maximum weight horizontal line segment set that can be wired in one track. This work is performed by the partial section maximum weight calculation unit 206 using the last calculated M (s
_n, s _n, ..., from the _{s n), M (s n} , s n, ...,
s _n ) is performed by following the calculation process in reverse order. FIG. 6 of an operation procedure in the horizontal line segment search unit 208
The operation 608 is a regression corresponding to the case where the operations 503 and 506 in FIG. 5 of the operation procedure of the partial section maximum weight calculating apparatus are performed. Hereinafter, the operations 503 and 507 are described in 609.
612 corresponds to the operations 504 and 506, and 613 corresponds to the operations 504 and 507, respectively. The fact that the operations 503 and 506 are performed in the flowchart of FIG. 5 means that a set of maximum weighted horizontal line segments that includes the horizontal line segment which became the argument of the weight function at that time exists.
The horizontal line is marked at 607 before 608 in FIG. 6, corresponding to the operations of 503 and 506. When the operation of following the reverse order is completed, the horizontal line segment search device 208 outputs a set of marked horizontal line segments as a maximum weighted horizontal line segment set.

The horizontal line segment wiring device 209 receives the maximum weighted horizontal line segment set output from the horizontal line segment search device 208 as an input, and routes them.

The vertical segment wiring device 210 wires a vertical segment connected to the horizontal segment wired by the horizontal segment wiring device 209.

[0060]

According to the multilayer channel wiring apparatus of the present invention, the maximum weight horizontal line set is wired for each track, so that the most desirable horizontal line set is wired to each track. For this reason, a track with the smallest number of tracks used in the final wiring result can be obtained. In addition, a set of horizontal line segments that can be wired in one track can be found with the largest sum of weight functions.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a multilayer channel wiring device of the present invention.

FIG. 2 is a configuration diagram of an embodiment of a track wiring device of the present invention.

FIG. 3 is a diagram showing a wiring procedure in the multilayer channel wiring device of the present invention.

FIG. 4 is a diagram showing a wiring procedure in the track wiring device of the present invention.

FIG. 5 is a diagram showing a procedure of calculating a partial section maximum weight.

FIG. 6 is a diagram showing a procedure for searching for a set of maximum weighted horizontal line segments;

FIG. 7 is a diagram showing an example of a set of horizontal line segments;

FIG. 8 is a diagram showing a wiring result of a conventional track wiring device.

FIG. 9 is a diagram showing a result of an optimum track wiring;

FIG. 10 is a diagram illustrating mappings L and R.

FIG. 11 is a configuration diagram of a conventional track wiring device.

FIG. 12 is a diagram showing a wiring procedure in a conventional track wiring device.

FIG. 13 is a diagram of a channel wiring region.

FIG. 14 is a diagram for explaining a vertical constraint on a horizontal line segment;

[Description of sign]

 Reference Signs List 102 horizontal line segment generator 103 vertical constraint graph management device 104 vertical constraint graph holding means 105 track wiring device 202 weight function calculation device 203 weight function holding device 204 mapping calculation device 205 mapping holding device 206 partial section maximum weight calculation device 207 partial section maximum Weight holding means 208 Horizontal line segment search device 209 Horizontal line segment wiring device 210 Vertical line segment wiring device 1101 Horizontal line segment management device 1102 Horizontal line segment holding device 1103 Single line selection device 1104 Single line wiring device

Claims (1)

(57) [Claims] 1. A wiring request as a set of nets is inputted.
A horizontal line segment generating device that generates a set of horizontal line segments from each net of the wiring request, a function of creating a vertical constraint graph from the set of horizontal line segments, and a vertical constraint graph management device having a function of updating the vertical constraint graph, A vertical constraint graph holding means for holding a vertical constraint graph, and a track wiring device for selecting a set of horizontal segments that can be wired in one track and having a maximum sum of weighting functions and wiring the selected horizontal segment , The track wiring device receives a set of horizontal line segments as input,
Each horizontal line segment s is routed to the track currently being routed.
A weighting function w (s) representing the desirability of
A weight function calculating device, and the calculated weight function w (s)
And a left end point of each horizontal line segment s
Water that can be wired to the i-th horizontal wiring layer having the right end point to the left of
The x coordinate of the right end point of the flat line segment indicates the largest horizontal line segment
The mapping L _i (s) and the right to the left of the right end point of each horizontal line segment s
Of the horizontal line segments that can be wired to the i-th horizontal wiring layer having an end point
Mapping R _i where x coordinate of the rightmost point shows the most size horizontal segments
A mapping calculation device for calculating (s) and mappings L _i (s) and R _i
Mapping holding means for storing (s), and the calculated weights
Using the function w (s) and the mappings L _i (s), R _i (s)
Collection of horizontal lines that can be routed in partial sections of the truck
Of the sub-interval for calculating the maximum value M of the sum of the weight functions
A weight calculation device, and for each partial section of the track,
Subsection maximum weight holding means for storing the calculated value of M
And weighting function w (s) and mappings L _i (s), R _i (s)
Weight function of a set of horizontal line segments that can be routed to all sections of the track
Weight that can be wired to the track from the maximum value M of the sum of numbers
A horizontal line search for finding the set of horizontal lines with the largest sum of functions
Horizons and the horizon determined by the horizon searcher
Line segment wiring device to wire a set of minutes and horizontal line segment search
Vertical line connected to the horizontal line determined by the device
Having a vertical line segment wiring device for wiring segments.
Multi-layer channel wiring device.