JP2620005B2 - Placement and wiring decision method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the arrangement of elements on an integrated circuit or a printed circuit board and the arrangement and wiring for determining the wiring between these elements and terminals connected to the outside. etc., relating to placement and routing method for determining the optimum circuit patterns of interconnection that satisfy the wiring condition requiring can be sure obtained indeed.

[0002]

2. Description of the Related Art Almost all operations, such as the use of CAD (Computer Aided Design), for arranging elements such as integrated circuits and printed circuit boards and for determining wiring between these elements and terminals connected to the outside are automated. .

In a conventional placement and routing determination method, for example, elements are first placed using an evaluation function with a minimum Manhattan distance, and then a wiring set in advance using an evaluation function with a minimum congestion degree is used. Wiring between the elements is performed in a region.

[0004]

However, in the prior art such as the above-described method for determining the arrangement and wiring, the elements are first arranged by using an evaluation function for this purpose, and then the wiring is established by using another evaluation function. In some cases, it may be difficult to control the wiring length.

In a semiconductor integrated circuit, as the process becomes finer, the influence of a wiring length delay on chip operation is increasing. However, in the conventional placement and routing determination method, the arrangement of elements has been determined first, so that
There was a limit in trying to shorten certain wiring. For example, the length of the wiring cannot be reduced below the distance between the arranged elements.

Furthermore, in the conventional placement and routing determination method, since the evaluation function used for placement and the evaluation function used for wiring are different, the wiring conditions required to achieve the characteristics of the electronic circuit to be built are set. There was something I could not fill.

For example, even if the evaluation function used for the wiring is changed in order to achieve the characteristics of the electronic circuit to be built, the change cannot be reflected on the evaluation function of the arrangement. In some cases, it is not possible to obtain a circuit pattern of a wiring satisfying the required wiring conditions.

The present invention, wherein those solve such conventional problems, etc. to a minimum delay and a predetermined value or more, the wiring to satisfy the wiring condition requiring including the wiring length top
The optimal circuit patterns and to provide a specific hand <br/> methods that can be sure obtained indeed.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a plurality of arrangements and wirings for determining the arrangement of elements on an integrated circuit or a printed circuit board and the wiring between these elements and terminals connected to the outside are determined .
Is first divided placement and routing area including the elements, placement and routing decisions pairs
In the divided area of the set of elements and terminals of the elephant circuit
A set of elements and terminals connected by each wiring included (element
Pairs), and for each extracted element pair,
In each case, the relative position of each element
Of all possible combinations that can be the relative position of
Identify the candidates and use a common evaluation function to determine whether
Procedure to select one candidate from all elements
By repeating for each division until it is placed in the divided area of
Thus , the above-described object is achieved by determining a divided region in which each element is arranged and determining a wiring path between terminals of the element over a plurality of divided regions.
Further, the evaluation function is a function of the size of each element, the number of wiring paths that can pass through the boundary between the divided regions, and the estimated wiring length in each divided region and between divided regions.

[0010]

The present invention has been made based on the finding that it is extremely important to consider the wiring between the elements and the terminals connected to the outside when arranging the elements.

Therefore, in the present invention, such an arrangement and wiring are determined in the same process using the same evaluation function. This makes it possible to more reliably obtain a circuit pattern of wiring satisfying the wiring conditions necessary for achieving the characteristics of the electronic circuit to be manufactured.

[0012] In the present invention, the same process used to determine the placement and wiring and, according to fabricate an electronic circuit, and first divides the placement and routing area including a plurality of elements, arrangement
Of the set of elements and terminals of the circuit for which wiring
Elements and terminals connected by each wiring included in the specified area
Is extracted (element pairs), and for all the extracted element pairs
Therefore, for each element pair, for each element pair,
Everything that can be the relative position of the layout and the relative position of each wiring route
Identify the candidate combinations and use a common evaluation function to
The procedure to select one candidate from all candidates
Repeat for each division until each is placed in one division area
This is a series of procedures for determining a divided region in which each element is arranged and determining a wiring path between terminals of the element over a plurality of divided regions. Further, in the present invention, the same evaluation function used for the layout and wiring used in the same process is a function serving as an evaluation criterion for the layout and wiring according to the characteristics of the electronic circuit to be built. This is a function of, for example, the size of each element, the number of wiring paths that can pass through the boundary between the divided areas, and the estimated wiring length in each divided area and between the divided areas.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a flowchart of an embodiment of the present invention.

FIG. 1 shows a layout and wiring determination method according to the present embodiment for determining the layout of elements and wiring between these elements and terminals connected to the outside in an integrated circuit or a printed circuit board.

In FIG. 1, first, at step 104, the arrangement of elements to be performed in the subsequent processing and the area for wiring between these elements and terminals connected to the outside are set. For example, if the layout and wiring decision made below is for an electronic circuit to be built into an integrated circuit, the layout of the current element and the wiring between these elements and the terminals connected to the outside are applied to the entire integrated circuit chip. Is set. Alternatively, if the layout and wiring decision to be made below is for an electronic circuit built on a printed circuit board, the layout and wiring area is set for the entire printed circuit board. The setting of the placement and wiring area in step 104 will be described later in detail with reference to FIG.

A series of subsequent steps 106, 108, 11
2, the relative positional relationship of the wiring between the terminals for connecting to the relative positional relationship and the elements or external arrangement of the elements is repeatedly executed until it determined or.

The relative position is an arrangement of each element and a route of each wiring in a unit of a divided area described later. That is, the relative position of the element arrangement does not determine a fine position in each divided area, but indicates a divided area where each element is arranged. Further, the relative position of each wiring path does not indicate a fine wiring path in each divided area, but means each divided area that is a path of each wiring.

These series of steps 106, 108, 1
In step 12, first, in step 106, the placement and wiring area set in step 104 is sequentially divided into two. The division of the placement and wiring area in step 106 will be described later with reference to FIG.

Each of the divided areas is hereinafter referred to as a divided area.

Next, at step 108, it is determined which divided region is to be used for disposing each element, and which divided region is to be used for the route of each wiring between each element and the terminal connected to the outside. The processing performed in step 108 is as follows.
Details will be described later with reference to the flowchart of FIG.

Such steps 106, 108, 11
If it is determined in step 112 that the determination of the relative positional relationship between the respective arrangements and the respective wirings has been completed by the series of processing in step 2, the absolute position of the arrangement of the respective elements is determined in step 114 according to the determination.

In step 116, the absolute positions of the wiring paths between the elements and the terminals connected to the outside are determined in accordance with the above determination.

The determination of the absolute position performed in steps 114 and 116 will be described later in detail with reference to FIG.

FIG. 2 is a flowchart of the placement / wiring divided region determination processing performed in the above embodiment.

The series of processing shown in FIG. 2 is the processing performed in step 108 of FIG.

First, in step 134 of FIG. 2, of the set of elements and terminals of the electronic circuit to be placed and determined, the set of terminals and elements included in the divided area divided in step 106 of FIG. Is extracted. This set of terminals and elements is a set of a pair of terminals and elements connected by each wiring (hereinafter, referred to as an element pair).

Subsequently, in step 136, for all the element pairs extracted in step 134, the relative position of the arrangement of each element is determined for each of these element pairs with respect to the divided area divided this time in step 106 of FIG. Identify all combinations that can be the relative positions of each wiring path.

In step 136, such an element arrangement candidate and a wiring path candidate are determined in accordance with a condition which does not depend on the division into the divided regions in step 106, such as arrangement and wiring conditions 1 to 3 described later. You may wash it out. For example, when wiring is performed in two layers, that is, a wiring layer having a main wiring in the vertical direction and a wiring layer having a main wiring in the horizontal direction, such a condition is satisfied according to the condition that the number of through holes extending over these two layers is two or less. May be washed out.

In step 138, the following arrangement and wiring conditions are obtained for the divided area divided in step 106 in FIG.

Arrangement and wiring condition 1: Total value of the sizes of elements that can be arranged in each divided area Arrangement and wiring condition 2: Number of paths that can pass through boundaries between divided areas Arrangement and wiring condition 3: Each division in which the element pair is arranged Estimated wiring length within the region or estimated wiring length between two divided regions where the element pairs are arranged

In step 140, step 138 is performed.
Out of all the candidates identified in step 136 according to the placement and routing conditions 1 to 3 set in the above, one candidate, that is, a combination of the relative positional relationship of the arrangement of each element and the relative positional relationship of each wiring Is selected.

Hereinafter, the processing of this embodiment will be described in detail using a specific circuit example.

FIG. 3 is a circuit diagram showing a specific example of a circuit in which placement and wiring are determined in this embodiment.

As shown in FIG. 3, a specific circuit example used in the following description of the processing of the arrangement and wiring determination method of the present embodiment is an electronic circuit using a total of eight elements A to H. These elements are connected by wirings W1 to W8.

Of the above connections, the connection between the element A and the element B is via the wiring W1. The element B and the element E depend on the wiring W2. The connection between the element C and the element D is via a wiring W3. Element B
Is connected to the element D by the wiring W4. The connection between the element D and the element F is via a wiring W5. The connection between the element F and the element G is via a wiring W6. The connection between the element D and the element G is via a wiring W7. The connection between the element G and the element H is via a wiring W8.

In this example, the specific example of the circuit shown in FIG. 3 is incorporated into a printed circuit board of a desired size. The layout and wiring determination method of the present embodiment described below is a layout and wiring determination method on a printed circuit board.

In FIG. 3, elements A, C,
The area of E, F, and H is 400 mm ² (= 20 mm × 20 mm), and the area of the elements B, D, and G is 600 mm ² (= 20 mm ×
30 mm). In order to satisfy the characteristics of this specific circuit example, the wiring length of the wiring W6 and the wiring length of the wiring W8 are each set to 40 mm.

FIG. 4 is a layout diagram showing the setting of the placement and wiring area in this embodiment.

Reference numeral 10 in FIG. 4 denotes a printed circuit board (area for arranging and wiring elements) for determining layout and wiring. L0 indicates an area set as a placement and wiring area. The layout wiring area L0 is 100 mm long × 140 mm wide.
It is a size of mm.

The setting of the layout area L0 corresponds to step 104 in FIG. The setting of the arrangement and wiring area L0 is a setting that is virtually performed when deciding the arrangement and wiring when it is desired to limit the arrangement of the elements and the area in which wiring is performed.

In this specific example, the arrangement and wiring of the printed circuit board is determined. The unit of the setting of the arrangement and wiring area is millimeters. Circuit, printed circuit board, etc.)
Is determined according to the following.

FIG. 5 is a diagram showing a first example of the arrangement and wiring area in this embodiment.
It is a layout diagram showing division.

Due to the vertical division into two shown by the one-dot chain line in FIG.
And a divided region R1.

The two divisions indicated by the dashed line in FIG. 5 correspond to the division performed in step 106 in FIG. Note that the division performed in step 106 is performed each time a series of processing in steps 106, 108, and 112 is performed. Hereinafter, the division illustrated in FIG. 13 and FIGS. 18 to 21 is performed. .

When such division is completed, extraction of the element pairs arranged in the range of the currently divided regions L1 and R1 corresponding to step 134 in FIG. 2 is performed.

The two divisions indicated by the dashed line in FIG.
Since the entire layout wiring area L0 is divided, a total of eight element pairs are extracted. That is, an element pair of the element A and the element B connected by the wiring W1, an element pair of the element B and the element E connected by the wiring W2, and an element C and an element D connected by the wiring W3 A pair, an element pair of an element B and an element D connected by a wiring W4, an element pair of an element D and an element F connected by a wiring W5, and an element pair of an element F and an element G connected by a wiring W6. Element D and Element D Connected by Wiring W7
And the element pair of the element G and the element pair of the element G and the element H connected by the wiring W8 are extracted.

FIGS. 6 and 7 show an element arrangement candidate and a wiring path candidate for an element pair of elements A and B or an element pair of elements B and E in two adjacent divided regions L1 and R1, respectively. It is a layout diagram shown.

That is, FIG. 6 shows element arrangement candidates and wiring path candidates for the element pairs (elements A and B) extracted corresponding to the two divisions shown in FIG. On the other hand, FIG. 7 shows an element arrangement candidate and a wiring path candidate of an element pair (elements B and E) extracted corresponding to the two divisions in FIG.

The element arrangements and wiring paths shown in FIGS. 6 and 7 are relative positions. That is, the element arrangements and wiring paths shown in FIGS.
It indicates in which divided region L1 or R1 each element is arranged, or which divided region L1 or R1 each wiring passes through, and does not indicate a detailed position in each divided region L1 or R1. Absent.

Such a relative element arrangement and wiring path are hereinafter referred to as a relative element arrangement or relative wiring path.

In the layout diagrams of FIGS. 6 and 7 and the layout diagrams to be described later, each of the elements A to H is indicated by a circle with an alphabetical letter of each element. In addition, the wiring between the elements marked with a circle is indicated by solid lines, double lines, or broken lines. The solid lines indicate the divided areas L1 and R1.
2 shows a wiring of a wiring layer having a main wiring in the horizontal direction passing through both. The double line indicates the divided area L1 or the divided area R
1 indicates a wiring passing through only one of them, and it is determined whether to use the main wiring layer in the vertical direction or the horizontal direction. The broken line indicates a wiring whose main direction is the vertical direction.

First, in FIG. 6 showing the element pair (elements A and B), a total of six types of wiring path candidates are shown. This is because a total of two divided areas L1 and R1
The reason is that there are six types of wiring paths.

In FIG. 6, the wiring route candidate r _AB1 passes only through the divided region R1. The wiring route candidate r _AB2 passes only through the divided area L1. The wiring route candidate r _AB3 passes through the divided areas L1 and R1, which connects the element A arranged in the divided area L1 and the element B arranged in the divided area R1. The wiring route candidate r _AB4 passes through the divided areas L1 and R1, which connects the element B arranged in the divided area L1 and the element A arranged in the divided area R1. The wiring route candidate r _AB5 is one in which the elements A and B arranged in the divided region L1 pass through the divided region L1 again from the divided region L1 via the divided region R1. The wiring route candidate r _AB6 connects the element A and the element B arranged in the divided region R1, and passes through the divided region L1 from the divided region R1 via the divided region L1.

[0055] Incidentally, element pairs (element B, E) wiring path candidate r _BE1 ~r _BE6 shown in Figure 7 for also, FIG. 6
This is the same as the wiring route candidates r _AB1 to r _AB6 .

Also, with respect to the element pairs corresponding to the wirings W3 to W8 extracted corresponding to the two divisions in FIG. 5, the element arrangement candidates and the wiring path candidates are similarly identified.

The wiring W corresponding to the two divisions shown in FIG.
Identification of the element arrangement candidates and the wiring path candidates for all the element pairs corresponding to 1 to W8 respectively corresponds to the step 136 in FIG.

Thereafter, corresponding to the step 138 in FIG. 2, in the two divisions of the layout wiring area L0 in FIG.
The setting of the arrangement and wiring conditions of each divided area is performed as follows.

Placement and Wiring Condition 1: Total Area of Elements Placeable in Divided Region L1 ≦ 3500 (= 70 × 100 × K1; K1 = 0.5) (1) Area of Elements Placeable in Divided Region R1 Total ≦ 3500 (= 70 × 100 × K1; K1 = 0.5) (2)

[0060] Incidentally, where, K1 is the ratio of the area available for placement in each divided region is set in advance. Here, K1 is set to “0.5” as an example.
Can be set for each step of the division.

Placement and wiring condition 2: Number of wiring paths that can pass through the boundary between divided region R1 and divided region L1 <K2 (= 4) (3)

Note that K2 is set as an example to "4", and may be determined according to, for example, the length of the boundary.

The layout and wiring conditions 3a to 3c will be described with reference to the estimated wiring lengths shown in FIGS.

Arrangement and wiring condition 3a: Estimated wiring length of wiring path candidates r _XY1 and r _XY2 shown in FIG. 8 <170 (= 100 + 70) (4)

Note that the estimated wiring length is an estimated wiring length when both elements of an element pair are in the same divided area, and is determined according to the size of the divided area. And the horizontal length. Here, X = A, B, C,..., And Y = A, B,
C,.

[0066] placement and routing Conditions 3b: estimate the wiring length of the wiring path candidates r _XY4 shown in the wiring path candidate r _XY3 and 10 shown in FIG. 9 <240 (= 100 + 140) ... (5)

The estimated wiring length is obtained when the elements of the element pair are located in different adjacent divided regions, and is in accordance with the entire size of these adjacent divided regions. All vertical length and lateral regions may be specified by a length. Here, X = A, B,
, And Y = A, B, C,.

Placement and wiring condition 3 c: wiring route candidate r _XY5 > 240 (6)

The estimated wiring length in this case is a wiring length in a case where both elements of the element pair are not in the same divided region and each element of the element pair is not in each of the adjacent divided regions. is there.

When the placement and wiring conditions 1, 2, 3a to 3c corresponding to the two divisions in FIG. 5 are determined in this way, the wirings W1 to W1 determined by the electrical required characteristics of the specific circuit example and the like are determined. According to the condition of the length of W8 and the like, candidates are selected (narrowed down) from the element placement candidates and the wiring path candidates that have been extracted as described with reference to FIGS.

For example, according to the electrical characteristics required of the specific circuit example, the wiring length of the wiring W6 is set to 40 mm,
When the wiring length of the wiring W8 is 40 mm, the following wiring path candidates are selected according to the layout wiring conditions 3a to 3c among the layout wiring conditions 1, 2, 3a to 3c.

A wiring path candidate for the wiring W6: a wiring path candidate r _FG1 or r _FG2 is selected. Note that these wiring route candidates r _FG1 and r _FG2 correspond to the above-mentioned placement and routing conditions 3 respectively.
It corresponds to the wiring route candidate r _XY1 and r _XY2 of a.

A wiring path candidate selected corresponding to the wiring W8: a wiring path candidate r _GH1 or r _GH2 . Incidentally, the wiring path candidate r _GH1, r _GH2, respectively, corresponding to the wiring path of the placement and routing condition 3a candidate r _XY1, r _{XY two.}

Here, in order to satisfy all of the conditions for the wirings W6 and W8, the elements F, G and H must all be arranged in the same divided area L1 or R1. Therefore, as the wiring W6, the wiring route candidate r
_{If FG1} is selected, r _GH1 must be selected as the wiring route candidate for the wiring W8. Alternatively, if the wiring route candidate _rFG2 is selected as the wiring W6, _rGH2 must be selected as the wiring route candidate for the wiring W8.

Here, as shown in FIG. 11, wiring route candidates r _FG1 and r _GH1 are employed.

When the relative element arrangement of the elements F, G, and H is determined in the divided area R1, the wiring path candidates for the wiring W5 between the elements D and F are the wiring path candidates _rDF1 , _rDF .
_DF3 , r _DF6 will be selected. The wiring path candidate lines W7 connecting the device D and G would be selected from among the wiring path candidate _{r DG1, r DG3, r DG6} .

The selection of the wiring route candidates for the wirings W5 and W7 and the relative element arrangement of the elements A to E are performed according to the arrangement and wiring condition 1 (the condition regarding the total area) and the arrangement and wiring condition 2 (the condition of passing through the boundary). Conditions for the number of possible wiring paths).

As a result, the elements A, B and E are divided into the divided areas L1
And the elements C, D, F, G, and H are arranged in the divided region R1, and the wiring route candidates r _AB2 , r _BE2 , r _CD1 , r _BD3 , r as the wiring route candidates for the wires _{W1 to W8} , respectively.
Select _DF1 , _rFG1 , _rDG1 , _rGH1 .

This is as shown in FIG.

[0080] In this selection result, element A in the divided regions L1, B, the total area of E 1 400 (= 400 ×
2 + 600), and element C is arranged in the divided region R1, D, F, G, the total area of the H is 2 400 (= 400 ×
3 + 600 × 2 ), and all of the above-mentioned placement and wiring conditions 1
To be satisfied. Also, as a result of this selection, the divided areas L1 and R
Since only the wiring route candidate _rBD3 corresponding to the wiring W4 passes through the boundary between the wiring route _{W1 and} the wiring route _W1 , the above-described layout and wiring condition 2 is also satisfied.

In the relative element arrangement and the relative wiring path described above with respect to the divided areas L1 and R1, the distance between the elements A, B and E or the distance between the elements C, D and F
The relative element arrangement and the relative wiring route between G and H are undecided.

Therefore, as shown in FIG. 13, the layout wiring area L0 is divided. Hereinafter, this is referred to as a second division.

According to the two divisions shown in FIG. 13, divided region L1 is divided into divided regions UL1 and DL1, and divided region R1 is divided into divided regions UR1 and DR1, for a total of four divided regions. Area. The total size of these four divided regions UL1, DL1, UR1, and DR1 is all 50 mm × 70 mm. The division in FIG. 13 corresponds to the division in step 106 in FIG.

Thereafter, step 108 in FIG.
(Steps 134, 136, 138, 14 in FIG. 2)
0) and 112 are performed.

First, corresponding to step 134 in FIG. 2, an element pair whose relative element arrangement and relative wiring path are not determined is extracted. At this stage, an element pair corresponding to the wiring W1 (elements A and B), an element pair corresponding to the wiring W2 (elements B and E), and an element pair corresponding to the wiring W3 (elements C and D)
The element pair (elements B and D) corresponding to the wiring W4, the element pair (elements D and F) corresponding to the wiring W5, the element pair (elements F and G) corresponding to the wiring W6, and the wiring W7. A corresponding element pair (elements D and G) and an element pair (elements G and H) corresponding to the wiring W8 are extracted.

Subsequently, corresponding to step 136 in FIG. 2, candidate element arrangements and wiring paths for each element pair extracted in this way are identified. At this time, the wiring route candidates between the element pairs of the elements whose relative element arrangement has been determined in the same divided area L1 or the same divided area R1 before the second division this time are respectively set in the divided area L1 or the divided area R1. Only via That is, in the element pair in which both elements are in the divided region L1,
The wiring route candidate is only the divided region UL1 or DL1. Alternatively, it is assumed that the wiring route candidate of the element pair in any of the elements in the division region R1 passes only through the division region UR1 or the division region DR1.

When the element arrangement candidates and the wiring route candidates are identified in this manner, the number of wiring route candidates corresponding to the wiring W1 is six in total, as shown in FIG. 14 by the wiring route candidates r _AB1 to r _AB6. .

Further, the layout candidates and wiring route candidates for the element pair corresponding to the wiring W3 are the wiring route candidates r _CD1 to r _{CD1 in} FIG.
_As shown in _CD6 , the total is six.

The arrangement candidates and the wiring route candidates corresponding to the wiring W4 are the wiring route candidates r _BD1 to r _BD1 shown in FIG.
_As shown in _BD8 , the total is eight.

After the second division of FIG. 13, setting of the arrangement and wiring conditions of each divided region corresponding to step 138 of FIG. 2 is as follows.

Placement and Wiring Condition 1: Total Area of Elements Placeable in Each of Divided Areas UL1, DL1, UR1, and DR1 <1750 = (50 × 70 × K1; K1 = 0.5) (7)

Placement and wiring condition 2: Number of wiring paths that can pass through the boundary between divided areas UL1 and UR1, or the boundary between divided areas DL1 and DR1 ≦ K2 / 2 (= 2; K2 = 4) (8) The number of wiring paths that can pass through the boundary between the regions UL1 and DL1 or the divided regions UR1 and DR1 ≦ K3 (= 3 is set) (9)

Arrangement and wiring condition 3 (Estimated wiring length of each): r _AB1 and r _AB2 ≦ 120 (= 50 + 70) (10) r _AB3 and r _AB4 ≦ 170 (= 100 + 70) (11) r _AB5 and r _AB6 > 170 (12) _rCD1 and _rCD2 ≦ 120 (= 50 + 70) (13) _rCD3 and _rCD4 ≦ 170 (= 100 + 70) (14) _rCD5 and _rCD6 > 170 (15) _rBD1 and _{r BD2 ≦ 190 (= 140 +} 50) ... (16) r BD3, r BD4, r BD5 and _{r BD6 ≦ 240 (= 100 +} 140) ... (17) r BD7 and _{r BD8> 240 ... (18)} ··· ···・ ・ ・ ・ ・ ・

When the selection of the element arrangement candidate (divided area) corresponding to step 140 in FIG. 2 is performed while determining the arrangement and wiring conditions 1 to 3 for the wiring W6 and the wiring W7, the element E Is a divided area UL1, elements A and B are divided areas DL1, elements F, G, and H are divided areas UR1, and elements C and D are divided areas DR1. Such a selection result is as shown in FIG.

In such a selection result, the relative element arrangement of the element E is substantially determined, but the other elements A to
The relative element arrangement of D, F to H and the relative wiring path between them are not determined. Therefore, step 1 in FIG.
The determination corresponding to 12 is a determination that branches forward in step 106 of FIG.

Thereafter, steps 106 and 108 in FIG. 1 (steps 134 and 1 in FIG. 2) are performed until the relative element arrangements and relative wiring paths for all the elements A to H are determined.
36, 138, 140), the processing shown in step 112 is divided into a third division shown by a dashed line in FIG. 18, a fourth division shown by a dashed line in FIG. 19, and a fifth division shown by a dashed line in FIG. And is executed every time the sixth division shown by the one-dot chain line in FIG. 21 is performed.

In the third division indicated by the one-dot chain line in FIG. 18, the layout wiring area L0 is divided into a total of six division areas. After the processing for the third division, the element G
Is the left side of the elements H and F, the element D is the left side of the element C, and when the main wiring is viewed in the horizontal wiring layer, the wiring path candidates r _GH and r _GF are the wiring path candidates r _DF6 , R
Confirm that it is above the _CD .

In the fourth division shown by the one-dot chain line in FIG. 19, the layout wiring area L0 is divided into a total of eight division areas. After the processing for the fourth division is completed,
The relative element arrangement and the relative wiring path for the elements A, B, and E are determined.

In the fifth division indicated by the one-dot chain line in FIG. 20, the arrangement and wiring area L0 is a total of twelve division areas. After the processing for the fifth division is completed, the relative element arrangements of all the elements A to H are determined.

According to the sixth division shown by the one-dot chain line in FIG. 21, the layout wiring area L0 is divided into a total of 16 division areas. After the processing for the sixth division is completed, the relative element arrangements and relative wiring paths of all the elements A to H are determined.

FIG. 22 is a layout diagram in which the layout and wiring of the specific circuit example have been determined.

FIG. 22 shows a layout diagram in which the absolute position of each arrangement and the absolute position of each wiring are determined according to the relative element arrangement and the relative wiring path determined in FIG. Note that the determination of the absolute position of each arrangement according to the determined relative element arrangement and the determined relative wiring path corresponds to step 114 in FIG. In addition, the determination of the absolute position of each wiring according to the determined relative element arrangement and relative wiring path is performed in Step 11 of FIG.
Equivalent to 6.

In FIG. 22, the shaded area on the lower left is a wiring prohibited area set at the time of determining the absolute position of each arrangement and the absolute position of each wiring.

As described above, according to this embodiment, the arrangement of elements on a printed circuit board and the wiring between these elements can be determined in the same process using the same evaluation function. Therefore, in the specific circuit example described above, it is possible to determine the arrangement and wiring satisfying the condition that the wiring length of the wirings W6 and W8 is 40 mm. For example, it is possible to reliably obtain the circuit pattern of the wiring satisfying the necessary wiring conditions. Can be.

In the above specific circuit example, the terminal to be connected to the outside is not mentioned, but the arrangement and wiring can be determined in the same manner. Although the above specific circuit example is directed to a printed circuit board, it goes without saying that it can be used for layout design of an integrated circuit.

[0106]

As described above, according to the present invention, an optimum circuit pattern of a wiring satisfying necessary wiring conditions including a wiring length, such as setting a minimum delay to a predetermined value or more, is confirmed. An excellent effect that it can be obtained can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart of an embodiment of the present invention.

FIG. 2 is a flowchart of a placement and wiring division region determination process performed in the embodiment.

FIG. 3 is one circuit diagram of a specific example of a circuit in which arrangement and wiring are determined in the embodiment.

FIG. 4 is a layout diagram illustrating setting of a placement and wiring area in the embodiment.

FIG. 5 is a layout diagram showing a first division of a placement and wiring area in the embodiment.

FIG. 6 is a layout diagram showing element arrangement candidates and wiring path candidates for an element pair of elements A and B in two adjacent divided regions.

FIG. 7 is a layout diagram showing element arrangement candidates and wiring path candidates for an element pair of elements B and E in two adjacent divided regions.

FIG. 8 is a layout diagram showing an estimated wiring length corresponding to a placement and wiring condition 3a defined in the embodiment.

FIG. 9 is a layout diagram showing estimated wiring lengths corresponding to placement and wiring conditions 3b defined in the embodiment.

FIG. 10 is a layout diagram showing estimated wiring lengths corresponding to placement and wiring conditions 3c defined in the embodiment.

FIG. 11 is a layout diagram relating to the selection of the layout candidates of the elements F to H and the selection of the wiring path candidates for the elements F to H in the embodiment.

FIG. 12 is a layout diagram relating to selection of arrangement candidates of elements A to H and selection of wiring route candidates for these elements A to H in the embodiment.

FIG. 13 is a layout diagram showing a second division of the placement and wiring area in the embodiment.

FIG. 14 is a layout diagram showing element arrangement candidates and wiring path candidates relating to an element pair of elements A and B in a divided region obtained by the second division.

FIG. 15 is a layout diagram showing an element arrangement candidate and a wiring path candidate for an element pair of elements C and D in a divided area by the second division.

FIG. 16 is a layout diagram showing an element arrangement candidate and a wiring path candidate regarding an element pair of elements B and D in a divided area by the second division.

FIG. 17 is a layout diagram illustrating selection of arrangement candidates of the elements A to H after the second division and selection of wiring path candidates for the elements A to H in the embodiment.

FIG. 18 is a layout diagram relating to a third division of the placement and routing area in the embodiment.

FIG. 19 is a layout diagram relating to a fourth division of the placement and routing area in the embodiment.

FIG. 20 is a layout diagram relating to a fifth division of the placement and routing area in the embodiment.

FIG. 21 is a layout diagram relating to a sixth division of the placement and routing area in the embodiment.

FIG. 22 is a layout diagram in which arrangement and wiring determination of the specific circuit example is completed.

[Explanation of symbols]

10 ... printed circuit board, L0 ... area, L1, R1, UL1, DL1 , UR1, DR1 ... divided regions, A to H ... elements, W1 to W8 ... _{wiring, r XY1 ~ r XY6, r} AB1 ~ r AB6, r BE1 ~ R _BE6 , r
_{CD1 ~ r CD6, r BD1 ~} r BD8, r EB, r DF, r DG,
r _CD , r _DF6 , r _GH , r _GF ... wiring route candidate.

Claims (2)

(57) [Claims] Upon 1. A placement of elements of the integrated circuit or a printed circuit board and the placement and routing decision which determines the wiring between terminals connected to these elements or external, is first divided into a placement and routing area including a plurality of elements, the placement and routing decisions Of the set of elements and terminals of the target circuit,
Elements and terminals connected by each wiring included in the divided area
A child set (element pair) is extracted, and for each of the extracted element pairs,
Regarding the split area, the relative position of each element arrangement and each wiring route
Identify all combinations of candidates that can be relative positions of, and use a common evaluation function to select one candidate from all candidates.
The procedure for selecting all elements must be arranged in one divided area.
Iteratively, for each division, until it is arranged, the divided area for arranging each element is determined, and the wiring path between the terminals of the elements over a plurality of divided areas is also determined. Method. (2) 2. The method according to claim 1, wherein the evaluation function is
The size of the child and the wiring route that can pass through the boundary between the divided areas
And the estimated wiring length in each divided area and between divided areas
Placement and wiring determination method characterized by being a function of
Law.