JP2536189B2 - Automatic wiring method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic wiring system for an integrated circuit and a printed circuit board.

[Conventional technology]

In the conventional automatic wiring method, the wiring area is treated as a grid, all the grids are secured in the storage area, each grid is labeled based on the wavefront propagation from the grid corresponding to the terminal to be wired, and the wavefront is When you reach the target terminal, follow the label backwards to complete the path "Maze method"
There is a well-known method in which the wavefront propagation is performed in parallel by the processors constituting the parallel computer in the wiring area.

This conventional technique is described in detail in the 1986 IPSJ journal "Parallel Routing Processor Prototype Research".

Also, although not parallel processing, as a conventional sequential automatic wiring system, lines (called search lines) are output from both the terminal S and the terminal D that perform wiring, and the search line and the terminal D output from the terminal S are output. If the generated search line does not intersect, the operation of generating a line orthogonal to those search lines as a new search line is repeated, and the search line derived from the terminal S and the terminal D
A well-known "line segment search method" is to find a route when the search lines derived from (Cross line) are found (D W High Tower, 'A Solution to Line Routing, Problem on The Continuous Plane'Procedure Sixth Day Automation Workshop, pages 1-24,1969 '(DWHightower,' A Solution to L
ine−Routing Problem on the Continuous Plane, 'Pro
c. 6th Design Automation Workshop, pp.1-24, 1969).

In addition, "Improved line search method" which improved "Line search method"
Is also well known. This generates a corner point at a distance from the corner of the obstacle that satisfies the design rule of the integrated circuit, and generates an escape line passing through the corner point. When generating an escape line, its length is determined so that the escape line satisfies the design rules. That is, extend the escape line from the corner point, and when you reach the allowable range to approach the obstacle, stop the extension there. Next, a line (referred to as a search line) is generated from both the terminal S and the terminal D for wiring. Then, an operation of enumerating escape lines intersecting with the search line generated from the terminal S and setting it as a new search line is repeated until the search line derived from the terminal S reaches the search line derived from the terminal D, When the route is reached, the search line is traced in the opposite direction to complete the wiring route.

This conventional technique is described in detail in the 1988 Technical Report of the Institute of Electronics, Information and Communication Engineers, "Improved line segment search method using heap search tree".

[Problems to be Solved by the Invention]

In the method in which the "maze method" is parallelized, in order to secure all the grids of the wiring area in the storage area, the consumption of the storage area is large, and it is necessary to cope with the large scale of the integrated circuit to be wired. Have difficulty. It is also difficult to respond to detailed design rules.

The "line segment search method" has no problem in terms of storage area consumption and design rule correspondence, but there is no example of parallel processing by a parallel computer, and in the wiring of a large-scale integrated circuit, It takes a huge amount of wiring time.

The "improved line segment search method" has no problem with regard to the amount of storage area consumption, but it does not support multilayer wiring,
Also, similar to the "line segment search method", there is no example of parallel processing by a parallel computer, and in the wiring of a large-scale integrated circuit,
It takes a huge amount of wiring time.

On the other hand, an object of the present invention is to improve the wiring speed by adapting the "improved line segment search method" to multilayer wiring and enabling parallel processing.

[Means for solving the problem]

The structure of the automatic wiring method of the present invention is such that, in an automatic wiring process of an integrated circuit having a multi-layered structure and a printed circuit board, a corner is placed at a distance from a corner of an obstacle and a distance satisfying a design rule and at the same position of an adjacent layer.・ To generate points, generate escape lines that avoid obstacles according to the wiring direction of the layer to which the corner points belong, and connect the terminals from these escape lines. In addition, when a computer connected to each other by an interconnection network performs parallel processing for automatic wiring processing of integrated circuits and printed circuit boards, the wiring area is divided and received by each computer. Each computer has an obstacle included in the wiring area that it is in charge of, and the obstacle itself in the adjacent area. Memorize the attributes and positions of obstacles where the influence of obstacles reaches your own area, generate a corner point at a distance from the corners of those obstacles that satisfies the design rule, and then use that corner. -Each computer performs parallel processing to generate an escape line that avoids the obstacle based on the point and search for a route for connecting terminals between these escape lines And

[Operation] In the present invention, assuming that the number of computers for parallel processing is N, the wiring area is divided into N equal parts according to the wiring direction for each wiring layer, and each computer is included in its own wiring area. The obstacles and the obstacles themselves exist in the adjacent area,
Memorize the attribute / position of the obstacle where the influence that the obstacle gives to your area according to the design rule.

Then, the respective computers perform the generation of the corner points accompanying the obstacles and the escape lines in parallel. Next, the computer in charge of the area including the terminals to be connected (terminal S, terminal D) generates search lines from those terminals, and determines the position and length of the search line generated from terminal S to all other positions. Send to the calculator. The search line generated from the terminal D is added to a set of escape lines of the computer that generated the search line.

Each computer, on the basis of the information about the search line sent to it, finds out if there is an escape line that intersects with the search line in its area and enumerates them as a new search line. , And the process of sending those positions and lengths to all other computers is repeated. Then, if the search line generated from the terminal 2 is included in the listed escape lines, it means that the wiring route has been found.

Further, the path is completed by tracing the crossing escape lines from the terminal D side to the terminal S side in the reverse direction (referred to as back trace). This back tracing is performed by a computer that handles each escape line.

〔Example〕

 Next, examples of the present invention will be described.

FIG. 1 is a diagram showing the distribution of wiring areas by a plurality of computers according to an embodiment of the present invention. The wiring area has two layers, the first layer is wiring in the X-axis direction, and the second layer is Y. It is a layer for wiring in the axial direction. A computer that performs parallel processing (P
E) is n units, and each is PE0, PE1 ... PE _n-1 .

FIG. 2 is a diagram showing a state of preprocessing. Calculator PE0
Performs the input processing of the information on the wiring area,
Based on the position of the terminals 24, transfer them to the computer PE in charge of them.

Next, each computer PE, based on the information about the obstacle 21 sent from the computer PE0, places a corner at a position away from the corner of the obstacle 21 by the design rule allowable range.
Generate point CP (22). At that time, a corner point CP (22) is also generated at the layer having the obstacle 21 and the points having the same coordinates (upper and lower) adjacent thereto. And
Each computer PE checks whether the generated corner point CP (22) is at a position that is more than the allowable range of the design rule from the obstacle, and the corner point CP (22) that does not follow it is checked.
Remove point CP (22). Next, each computer PE goes from the corner point CP (22) to the escape line EL.
Generate (23). This is the corner point CP (2
When the line is extended from 2) along the wiring direction of the layer, the obstacle that first hits is extended to a position separated by the design rule allowable range.

The processing of generating the corner points CP (22) and the escape line EL (23) can be performed by each computer PE using only the information regarding the area in charge of each computer PE. Communication between computers is completely unnecessary, and when all computers PE have finished processing, each computer PE
Synchronize between

Next, the terminals to be wired (terminal S (31), terminal D)
The corner point CP and escape line EL caused by (32)) are removed by the computer PE in charge of the terminal (Fig. 3). Then, the search line 41 is generated from the terminal S (31) and the terminal D (32) (FIG. 4). This is from the point of the same coordinates of the layer where the terminal exists and the layer next to it (upper, lower),
A line is extended along the wiring direction of the layer to a point separated from the obstacle by the allowable range of the design rule to form a search line 41. This processing is also performed by the computer PE in charge of the wiring area, the search line 41 generated from the terminal S (31) is sent to the computer PE0, and the search line 41 generated from the terminal D (32) is Escape line of computer PE in charge of
Added to the EL set.

Next, the position of the search line 41 generated from the terminal S (31),
The computer PE0 of length information transfers it to all other computers PE, and causes each computer PE to search for an escape line EL intersecting with it. Each computer PE0 checks whether or not there is one generated from the terminal D (32) in the set of escape lines EL (set A) sent from each computer PE, and if it does not exist. , The set A is transferred to each computer PE again, and the task of letting each computer PL search for the escape line EL intersecting with it is repeated until the escape line EL (23) generated from the terminal D is reached.

When the computer PE0 finds the escape line EL generated from the terminal D in the set A, it then follows the escape line EL which intersects the escape line EL in the opposite direction to complete the path 51 (FIG. 5). At the time of the above-mentioned search, a pointer is provided for tracing back in the opposite direction.

Since the newly generated route 51 becomes a new obstacle, it is necessary to update the escape line EL and the corner point CP around the route 51 (Fig. 6). The computer PE0 sends the newly generated route 51 to the computer PE in charge of the area in which the route 51 exists, and the computer PE to which the information of the route 51 is sent is included in the wiring prohibited area around the route 51. Remove the corner point CP and the escape line EL generated from that corner point CP,
The escape line EL is included in the wiring prohibited area (area not separated by the distance satisfying the design rule), but if the corner point CP that is the basis of the escape line EL is outside the wiring prohibited area, that corner Regenerate escape line EL from point CP. It also creates corner point CP and escape line EL around the route. This operation has the maximum parallelism of the number of bends in the route.

When the escape line EL and corner point CP in the wiring area have been updated, the next wiring is repeated.

〔The invention's effect〕

In the present invention, since the wiring area is divided and handled by each computer, the processing of "escape line generation" and "escape line crossing check" processing that occupy a considerable part of the processing time in the "improved line segment search method" Can be parallelized, which enables faster wiring processing.
Information about obstacles existing in the wiring area is calculated by each computer.
Since the data is shared and stored, the storage area is unlikely to run short even if the wiring area is enlarged. Further, since it is adapted to the multi-layer wiring, there is an effect that it is more suitable for practical use.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a wiring area is shared by a plurality of computers according to an embodiment of the present invention, in which a two-layer wiring area is divided into PEs, and FIG. Fig. 3 is a diagram showing how corner points CP and escape lines EL are generated around objects and terminals. Fig. 3 shows a state in which corner points CP and escape lines EL caused by terminals to be wired are removed. 4A and 4B are diagrams showing a state in which a search line is generated from terminals to be wired, FIG. 5 is a diagram showing a state in which a wiring route is completed, and FIG. 6 is a diagram showing a newly generated route. It is a figure which shows a mode that the peripheral corner point CP and escape line EL were updated. 21 ... Obstacle, 22 ... Corner point, 23 ... Escape line, 24 ... Terminal, 31 ... Terminal S, 32 ... Terminal D, 41 ... Search line, 51 ... Route.

Claims (2)

(57) [Claims] 1. A corner point is generated at a position separated from a corner of an obstacle by a distance satisfying a design rule and at the same position on an adjacent layer during automatic wiring processing of an integrated circuit having a multi-layer structure and a printed circuit board. , Generate an escape line that avoids obstacles according to the wiring direction of the layer to which the corner point belongs, based on that corner point, and from the point of the same coordinates of the layer where the terminal to be wired exists and its adjacent layer, A search line that avoids an obstacle is generated according to the wiring direction of each layer, an escape line that intersects with the search line is searched for in a wiring layer different from the layer in which the search line exists, and a layer in which this escape line exists Repeat the search operation to find the escape line that intersects on different wiring layers until the searched escape line reaches the search line. An automatic wiring method characterized by applying. 2. When the automatic wiring processing of the integrated circuit and the printed circuit board is processed in parallel by the computers connected to each other by the interconnection network, each computer divides the wiring area and takes charge of each computer. Memorize the attributes and positions of obstacles that are included in the wiring area that you are in charge of and obstacles that exist in the adjacent area, but where the influence of the obstacles affects your area due to design rules Then, a corner point is generated at a position away from the corners of those obstacles by a distance satisfying the design rule, and an escape line that avoids the obstacle is generated based on the corner point as a reference. From the point of the same coordinates of the layer where the terminal exists and the layer adjacent to the layer, the computer in charge of the point generates a search line for avoiding an obstacle according to the wiring direction of each layer, and the search Each computer in parallel searches for an escape line that intersects with the search line in a wiring layer different from the layer in which is present, from the escape line in its own area, and a wiring layer different from the layer in which this escape line exists. An automatic wiring method, wherein each computer repeatedly performs a search operation for searching for an escape line intersecting with each other until the searched escape line reaches the search line.