JP2000223578A - Interconnection of semiconductor circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for interconnection by evaluating a temporary precise interconnection route for interconnectivity and timing, predetermining a rough interconnection route while taking account of the evaluation results and then determining a precise interconnection route based on the rough interconnection route. SOLUTION: A rough interconnection route for connecting between respective elements and between the elements and external terminals is set by rough interconnection processing (S11) and then a temporary precise interconnection route is set based on the rough interconnection route thus set (S12). The temporary precise interconnection route is evaluated for interconnectivity and timing (S13). Rough interconnection processing is carried out again by feeding the congestion of the temporary precise interconnection back to the rough interconnection based on the evaluation results (S15). Finally, precise interconnection processing is carried out based on the rough interconnection route thus obtained (S16).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring method for designing a chip layout of a semiconductor integrated circuit, and more particularly to a wiring method which improves wiring characteristics and improves timing characteristics due to capacitance between wirings and wiring resistance. And a wiring method for performing the above.

[0002]

2. Description of the Related Art In a chip layout design of a semiconductor integrated circuit, after arranging a plurality of elements on a chip, a plurality of elements are arranged.
Then, wiring processing for connecting the element and the external terminal is performed. Conventionally, as this wiring processing, as shown in a flow chart of FIG. 10, first, a schematic wiring processing is performed in which a required wiring path is roughly designed and a schematic wiring path is obtained (S4).
01) Then, a detailed wiring process for obtaining a detailed wiring path based on the obtained schematic wiring path is performed (S40).
2). Then, regarding the detailed wiring path obtained in the detailed wiring processing, a wiring violation point such as presence / absence of a wiring short-circuited part or unwiring is verified, and a peeling re-wiring processing for repairing wiring in the wiring path of the wiring violation part is performed. (S
403). However, in this wiring processing method, if there is a wiring that could not be drawn or a wiring violation such as a short circuit, in order to re-route them, the already drawn wirings are peeled one by one so that those wirings can be drawn. Fix it. Therefore, if the number of wiring violations increases, it takes time for the peeling and rewiring process. In order to solve such a problem, according to the technology described in Japanese Patent Application Laid-Open No. 7-37985, when unwiring occurs in the detailed wiring, the wiring data is deleted from the data structure, and the general wiring is redone for the wiring. I have. Alternatively, the wiring congestion degree in the area is checked, a rewiring area in a high congestion area is determined, and then the wiring in that area is peeled off and rewiring is performed.

In order to form a wiring path in consideration of the delay time of a signal transmitted through a wiring, that is, a wiring path with high timing, the signal delay time in the provided wiring path is determined in the wiring evaluation processing. Processing is performed while estimating and verifying whether the required operating frequency can be satisfied. In the conventional schematic wiring, the estimation is performed based on information on a schematic wiring path that is currently being generated. As a method of improving the timing of such wiring, Japanese Patent Application Laid-Open No. 10-3225
There is a technique described in Japanese Patent Application Laid-Open No. 4 (Kokai) 4

[0004]

However, the technique described in Japanese Patent Application Laid-Open No. 7-37985 described above is improved by removing and rewiring the wiring once wired, so that there are many congested points. In a high-density chip, the rewiring process takes time. Further, in the technology described in Japanese Patent Application Laid-Open No. 10-32254, since the timing property is evaluated based on the information of the schematic wiring path, the accuracy of the estimated value of the delay calculation in a semiconductor using a fine process is reduced. being insufficient. To estimate the delay time of a semiconductor using a fine process, it is necessary to consider not only the shape of the wiring path of interest, but also the situation where other wiring paths are adjacent to or intersect around the wiring path There is. Also, if two wiring paths run in parallel over a long distance, crosstalk occurs, and one of the adverse effects is a deterioration in the delay time, which should be taken into consideration. Was difficult to handle.

[0005] The present invention provides a wiring method having a high wiring property and a reduced wiring processing time. Another object of the present invention is to provide a wiring method for obtaining a wiring path having excellent timing.

[0006]

According to the wiring method of the present invention, after determining the arrangement position of elements to be mounted on a semiconductor integrated circuit, a general wiring path for connecting the elements is determined, and then the general wiring path is provisionally determined. The detailed wiring route is determined, the wiring property and the timing property are evaluated with respect to the temporary detailed wiring route, and the evaluation result is added to the constraint conditions, the rough wiring is performed again, and the rough wiring route is calculated again. It is characterized in that a detailed wiring route is obtained based on the corrected general wiring route. Here, the second schematic wiring may be omitted based on the evaluation result. Further, a peeling and rewiring process for restoring a part of the obtained detailed wiring route may be included.

FIG. 1 is a flow chart of the wiring method according to the present invention. First, after determining the arrangement positions of the elements mounted on the semiconductor integrated circuit, a general wiring process for setting a general wiring path between the elements and between the elements and external terminals is performed (S11). Next, based on the schematic wiring path obtained by the schematic wiring processing, a temporary detailed wiring path is set by a temporary detailed wiring processing (S12). Then, wiring evaluation is performed on the provisional detailed wiring route by wiring evaluation processing (S1).
3). In this wiring evaluation processing, the wiring property and the timing property are evaluated based on the congestion degree of the wiring in the temporary detailed wiring path, the wiring length, and the like. It is determined whether or not execution is possible. If it is determined that the detailed wiring is difficult, the congestion degree of the evaluation result of the provisional detailed wiring is fed back to the schematic wiring, and the general wiring processing is performed again, that is, the schematic wiring processing is performed again (S15). Note that the temporary detailed wiring route obtained at this time is subjected to temporary detailed wiring discarding processing (S1
Discard in 4). In the re-schematic routing process, since the schematic routing is modified based on the routing information, the possibility of occurrence of a routing violation route is extremely low. Then, detailed wiring is performed by detailed wiring processing based on the improved schematic wiring path obtained by the re-schematic wiring processing (S16). When it is determined in the wiring evaluation processing that the detailed wiring processing can be executed, detailed wiring is performed by the detailed wiring processing based on the obtained first schematic wiring path (S16). Further, with respect to the obtained detailed wiring path, a part of the wiring violation path is peeled off and re-routed (S17). At this time, since the degree of congestion is taken into account in the re-schematic wiring processing, the probability that a wiring violation can occur becomes low,
The accompanying wiring peeling and rewiring processing are reduced.

Here, in each of the above-described processes in the wiring method of the present invention, it is preferable to perform the following processes. The general wiring process divides a wiring region of the semiconductor integrated circuit into a plurality of divided regions, sets a general wiring path based on wiring information such as a predetermined wiring capacity and a priority order, and further sets each of the divided regions. Set the boundary terminal on the boundary. Also,
In the re-routing process, at least a part of the rough wiring path is improved based on the wiring information improved in the wiring evaluation, and the position of the boundary terminal is appropriately set accordingly.

In the temporary detailed wiring process, a temporary detailed wiring path is set by using a simplified wiring pattern such as a straight line, a right-angled bent line, a crank-shaped bent line, or the like, alone or in combination.

Further, in the wiring evaluation processing, at least one of the wiring property and the timing based on the temporary detailed wiring path is evaluated, and based on a result of the evaluation, the detailed wiring is executed in the current detailed wiring path in the detailed wiring processing. It is determined whether or not it is possible, and if it is determined that the detailed wiring is difficult, the process shifts to the schematic wiring again using the congestion degree obtained in the wiring evaluation processing, and the detailed wiring processing can be executed. When it is determined that the wiring is the same, the process proceeds to the detailed wiring based on the wiring information in the general wiring processing.

Here, the evaluation of the wiring property in the wiring evaluation processing is performed, for example, by calculating the congestion degree of the temporary detailed wiring path in each of the plurality of divided areas, and determining the congestion degree of the divided area where the congestion degree is remarkable The wiring information is obtained as the wiring capacitance for improving the congestion degree set by the general wiring so as to reduce the wiring. Further, as a preferred mode, the divided area having a congested degree is set as a divided area whose congestion degree is significantly larger than a simple average of the congestion degrees of all divided areas,
The wiring information for improving the congestion degree obtains a moving average including a divided area around the divided area where the congestion degree is remarkable, and determines the congestion degree based on a difference between the moving average and the simple average. This is information for reducing the wiring capacitance set in a remarkable divided area.

On the other hand, the evaluation of the timing property in the wiring evaluation processing includes, for example, calculating a delay time using the path information of the tentative detailed wiring, and setting a higher priority to a net having a higher timing violation. Features.

According to the wiring method of the present invention, after performing temporary detailed wiring capable of performing high-speed processing and creating a wiring path close to the actual detailed wiring path, wiring evaluation is performed, and schematic wiring is performed in re-schematic wiring. By improving the route, it is extremely unlikely that an error route will occur in the detailed wiring route created in the subsequent detailed wiring process,
After that, the design of a desired wiring route can be realized only by performing a slight peeling and rewiring process. For this reason, the number of times of the peeling and rewiring process after the detailed wiring process can be reduced, the processing time is shortened, and the wiring property is improved.

Further, since the timing is evaluated based on the tentative detailed wiring route created in the tentative detailed wiring process, highly accurate evaluation can be realized.

[0015]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a flowchart for explaining a specific embodiment of the wiring method of the present invention described above. FIGS. 4 to 7 are reference diagrams showing examples of wiring paths for explaining the flow. Here, for simplicity, the line is shown in a plane. In FIG. 2, first, after arranging necessary elements and external terminals on a chip, general wiring processing is performed (S11). In this rough wiring step, the chip is divided into a large number of divided regions by a rough rough wiring grid (S1).
11). For example, in FIG. 4A, the chip CH is 6 × 6
Is divided into the divided areas DIV.
Is divided, for example, into a rectangle such that one side can pass 10 to 20 wirings per wiring layer. Next, a target chip circuit and an element EL arranged on the chip
Then, the number of wirings that can pass through the boundary of each divided area DIV is estimated based on the divided area DIV, and set as the wiring capacity (S112). Then, based on the wiring capacitance, a rough wiring process for connecting the elements and between the elements and the external terminals is performed, and a rough wiring path GC is created as shown in FIG. 4B (S113). As the formation of the general wiring route GC, for example, a method of searching for a wiring route by a conventional maze method or the like is used. Based on this schematic wiring path GC, as shown in FIG. 4C, in each divided area DIV, it is determined at which part of the boundary with the adjacent divided area the wiring passes, and the boundary terminal T is determined. Is performed (S114). This general routing process generally has a mechanism that takes into account the global congestion degree. There are several implementation methods. Here, the estimated value of the number of wires that can pass through the boundary of the divided area is defined as the capacity of the boundary, and the number of wires that pass through a certain boundary is
The following description will be made on the assumption that the wiring path is adjusted so that the capacitance at the boundary is not exceeded as much as possible. There are several ways to realize the timing in the rough routing process. Here, we estimate the delay time and preferentially shorten the nets that are unlikely to meet the timing or reduce the wiring capacity. The following description is made assuming that the wiring method is used.

After the approximate wiring paths have been obtained for all the wirings, provisional detailed wiring processing (S12) is performed. In the temporary detailed wiring process (S12), a wire that passes through the boundary terminal T at the boundary between the divided regions obtained in the general wiring process (S11) is set. In this temporary detailed wiring processing (S12), a high-speed wiring method using a conventionally proposed switch box router or the like is used. This switch box router is a method of setting a wiring route by using a wiring pattern that is relatively simplified, for example, a wiring pattern such as a straight line, a right-angled bent line, and a crank-shaped bent line, alone or in combination. It is possible to set a temporary detailed wiring route in a very short time and at a high speed as compared with the wiring processing.
For example, IEEE TRANSACTIONS ON COMPUTER-AIDED DESIG
One example has been reported in N, VOL. 7, NO. 6, JUNE 1988, P684-697. In this tentative detailed wiring processing, even if a short-circuit wiring has occurred during the wiring path search, the wiring processing is ignored. With this temporary detailed wiring path, a temporary detailed wiring path is created in a very short time for each divided region through the boundary terminal determined in the general wiring processing.

Next, wiring evaluation processing (S13) is performed on the temporary detailed wiring path. This wiring evaluation processing (S1
In 3), a wiring property evaluation process (S) for improving the wiring property is performed.
131) and the timing evaluation process (S132) for improving the timing for improving the characteristics are selectively performed.
Or it is done in parallel. Wiring property evaluation processing (S13
In 1), a density of the temporary detailed wiring, that is, a divided area having a high congestion degree is searched, and a preparation process for reducing the congestion degree of the divided area is performed. In addition, the timing evaluation processing (S13)
2) calculating the delay time in the wiring route based on the wiring length of the temporary detailed wiring, adjacent wiring, crossing wiring, and the like,
Preparation processing for reducing the delay time is performed. Then, in the wiring evaluation process (S13), a process (S133) for improving the wiring information including the estimated setting and the priority order of the wiring capacity estimated for each divided region in the general wiring process (S11) is performed. I have.

Here, first, the wiring property evaluation processing (S1)
31) and its wiring information improvement processing (S133) will be described. FIG. 3 is a flowchart in which the wiring property evaluation processing (S131) and the wiring information improvement processing (S133) are integrated. The number of errors is determined for each divided region for the temporary detailed wiring route created in the temporary detailed wiring process (S12). The number of errors is, for example, the number of nets including wiring paths that are short-circuited in a certain divided area or other inappropriate wiring paths. When a net extending over a plurality of divided regions is detected as an error in some divided regions, the number of errors is individually added in each region. Then, the total number of errors for the entire chip is obtained, and this is divided by the number of divided regions to obtain a simple average E (S20).
1). Next, the number of errors in each divided area is calculated by the simple average E
Then, a divided region having an error number larger than the simple average is obtained as a set R (S202). In addition, an empty set M for determining a divided area to be determined to be congested is prepared and is set to an empty state (S203). Then, among the divided areas included in the set R, the number of errors is a simple average E
A divided region r larger by a predetermined multiple than that is obtained. For example, a divided region having an error number larger than 2 · E obtained by doubling E is obtained as a divided region r. Then, this divided area r
Is moved to the set M (S204). Further, with respect to the divided region r, an average em is calculated for the divided region r and the number of errors in each of the eight divided regions around the divided region r, and this is set as a moving average. Then, the divided area m satisfying em> E is set M
(S204). Next, the state of the set M is verified (S205). If there is no divided area in the set M, the wiring route does not need to be improved, and the process proceeds to the detailed wiring process S16. There is often a region m. Next, for the divided area m included in the set M, the moving average em exceeds the simple average E by a value pm (p
m = em−E) is calculated (S207). Also, this p
Based on m, the number of wiring paths am that is preferably reduced in the divided area m is obtained from an empirical rule. That is, am is obtained from the function f (pm) obtained from the rule of thumb (S207). Next, with respect to the four sides (boundaries) of the divided region m included in the set M, am is assigned to each side while substantially maintaining the ratio of the number of wiring paths of each side. And
The allocated am is subtracted from the wiring capacity allocated to each divided area in the general wiring processing (S11), and the wiring capacity is updated by updating the estimated wiring capacity (S20).
8).

The flows S201 to S208 of the wiring property evaluation processing or wiring information improvement processing will be described based on specific examples. With respect to the created temporary detailed wiring route, it is verified whether or not an appropriate temporary detailed wiring route is created in each divided region based on the set boundary terminal, and a short-circuited wiring route or other faulty wiring route is determined. An appropriate wiring path is detected, and the error number is detected using the wiring path as an error path. Then, the number of detected errors is totaled for each divided area, and as shown in FIG.
Create a map of IV error counts. Then, the total number of errors for the entire chip is obtained, and this is divided by the number of divided areas to obtain a simple average E. In the example of FIG. 5A, the simple average E is 3.14. Then, a difference between the number of errors in each divided region and the simple average is obtained, and a divided region having a larger number of errors than the simple average is obtained. These divided regions constitute the set R. Here, when the number of errors is larger than, for example, twice the simple average E, it is highly necessary to reduce the congestion degree of the divided area, and thus the number of errors in the divided area is not changed. On the other hand, in a divided area where the number of errors is a simple average E <the number of errors ≦ 2E, as shown by hatching in FIG. 5A, the movement is performed between one divided area and each error number of eight divided areas around the divided area. An average em is obtained, and is set as a moving average em of the divided area. As shown in FIG. 5B, by taking the moving average em and setting the value as the value of the divided region, the deviation of the error number of the neighboring divided region including the divided region is obtained, and the congestion degree is determined. Is a candidate for improvement. Then, as shown in FIG. 5 (c), the difference between the obtained moving average em and the simple average E is calculated, and a divided area having a moving average larger than the simple average is detected. The excess number pm obtained by subtracting the value of the simple average from is set in the divided area.

Next, a reduced number am of the wiring paths is obtained from the excess error number pm by using a function f (pm). The function f (p
For m), standard settings can be determined in advance by experiments or the like separately from the above-mentioned flow, and a more appropriate function can be selected from several functions depending on the structure of the element and the number of wiring layers. it can. This function f (pm)
What is the number of excess errors, if the number of wiring paths that enter the divided area (through the boundary of the divided area) is reduced,
This indicates whether it can be expected that a detailed wiring path can be created without causing an error in the subsequent detailed wiring processing. FIG. 6A is a graph of one example. By applying the excess number of errors in each of the divided areas to this graph, the reduced number am of the wiring paths that need to be reduced in each divided area is obtained as shown in FIG. 6B. Then, the reduced number am is allocated in proportion to each of the wiring capacitances set on the four sides of the divided area. In the example of FIG. 7A, the upper side, the left side, the lower side, and the right side
For each wiring capacitance of 7, 10, 5, 10 on one side,
In order to reduce the wiring capacity of 6.0 wires, 6.0 is proportionally distributed by the wiring capacity and subtracted from the wiring capacity of each side, thereby obtaining the wiring capacity of each side as shown in FIG. Are 5.7, 8.1, 4.1, and 8.1. If an integer value is used as a boundary capacity in the schematic wiring path, an integer conversion process such as rounding is performed. When two divided regions that require a reduction in the wiring capacitance at the reduced number am are adjacent to each other, a larger value of the reduced number am is assigned to an adjacent boundary with respect to a side serving as the boundary. Will be deducted. In the example of FIG. 7C, since the divided areas of the reduction numbers 4.1 and 3.8 are adjacent to each other, the larger 4.1 is subtracted to update the wiring capacitance.

As described above, the wiring property evaluation processing (S13)
Is performed, the error path in the temporary detailed wiring path formed based on the wiring capacity estimated and set in the rough wiring processing (S11) is evaluated, and as a result, the error path can be eliminated. A new wiring capacity is estimated. Therefore, the temporary detail wiring is discarded (S14).
Then, the wiring information of the rough wiring in the rough wiring processing (S11), that is, the information of the element position, the divided area, etc., excluding the previous wiring capacity estimation, and the information of the updated wiring capacity are held. On the other hand, the tentative detailed wiring route is not required any more since it is not necessary thereafter. After obtaining a new wiring capacity, the information of the temporary detailed wiring path is not necessary,
It is discarded in temporary detail wiring discarding (S14).

Next, in FIG. 2, the retained wiring information of the schematic wiring is reused, and the schematic wiring processing is performed again based on the updated wiring information of the wiring capacitance (S15). Is executed to improve the schematic wiring path (S151) and reset the boundary terminal (S152). In this case, the wiring path is improved and the boundary terminals are reduced for the location where the wiring capacity is updated, that is, for the divided area where the congestion degree needs to be reduced in the wiring evaluation processing (S13). With the above, the boundary terminal is allocated and set to an adjacent divided region or a nearby divided region. Or change all the previous boundary terminals,
A boundary terminal is set again from the beginning based on the updated wiring capacitance. In any case, in the re-routing process (S15), the rough routing is performed again according to the wiring capacity updated based on the obtained wiring congestion degree information, so that the rough routing can be improved over a wide range of the divided region. In addition, it is possible to set a boundary terminal whose congestion degree is reduced.

Then, the re-schematic wiring processing (S1
Based on the boundary terminal improved in 5), detailed wiring (S1
Execute 6). In the wiring evaluation process (S13), if the set M of regions to be improved is empty,
After the wiring evaluation processing (S14) without performing the re-schematic wiring processing (S15), the tentative detailed wiring path is discarded in the tentative detailed wiring discarding (S14), and the first rough wiring processing (S11) is performed. Perform detailed wiring based on the boundary terminals. In the detailed wiring processing (S16), the degree of congestion in each divided area is reduced by the wiring evaluation processing (S13) and the re-schematic wiring processing (S15), and a detailed wiring path is created based on the improved boundary terminals. Error paths rarely occur. Also, even when an error path occurs, it occurs only in a very small part, and can be easily repaired by the next peeling and rewiring process (S17). This makes it possible to reduce the delay time, reduce the number of intersections with other wiring paths, reduce the parasitic capacitance, and also reduce the parallel length with other wiring to reduce crosstalk. .

On the other hand, the timing evaluation processing (S132) and the wiring information improvement processing (S133) in the wiring evaluation processing (S13) will be described. FIG. 8 is a flowchart of the timing evaluation processing and the wiring information improvement processing.
Based on the tentative detailed wiring path created in the tentative detailed wiring processing, the delay time in each wiring path is calculated (S301). This calculation considers the wiring length of the wiring path, another wiring path adjacent to the wiring path, another wiring path intersecting with the wiring path, and the like, and determines the wiring resistance and the distance between the wiring path and other wiring paths. It is calculated by integrating the wiring capacitance including the generated parasitic capacitance. Next, it is verified whether or not the operating frequency required by the specification is satisfied for each path to which design constraints are given (S302). In synchronous circuit design, a path is generally given as a series of nets and elements from a flip-flop element via some combinational circuit elements to the next flip-flop element. If the delay time of the signal propagating through the path is longer than the allowable delay time of the path given as a constraint, it is determined that there is a timing violation, and the process proceeds to S303. In S303, a more detailed allowable delay time for each net is determined again based on the current delay time for each net calculated from the provisional detailed wiring route. Finally, the priority of the net is reset to a higher value for the net whose current delay time is longer than the allowable delay time (S304).

As described above, by performing the flow S301 to S305 of the timing evaluation processing and the wiring information improvement processing, the provisional detailed wiring path created based on the priority set and estimated in the general wiring processing (S11). Is evaluated, and as a result, a new priority order is set so that the error path can be eliminated. After the new priority order is obtained, the temporary detailed wiring route information is not required, so the temporary detailed wiring is discarded (S1).
Discard in 4).

The subsequent processing is the same as the above-described re-routing process (S15) based on the evaluation of the wiring property. In this case, however, the rough routing path is improved based on the priority of the net in consideration of the timing. And change its boundary terminals. Alternatively, the previous boundary terminals are all changed, and the boundary terminals are set again from the beginning based on the updated priority. In any case, since the temporary detailed wiring information created in the temporary detailed wiring processing (S12) is discarded, it is possible to improve the schematic wiring over a wide range of the divided area. A method to improve the timing by setting priorities to nets and routing shorter high-priority nets is AEDunlop et al. "Chip Layout Optimization Usi
ng Critical Path Weighting "21st Design Automation
Conference. Pp.133-136 (1984) and many other technologies based on it. Also, by controlling the wiring of another net so as not to be adjacent to the net having a higher priority, the wiring capacity can be reduced, and the delay time can be improved. In the re-schematic wiring process (S15), at least one of a process of reducing the wiring length and a process of reducing the wiring capacity is used. Then, the re-schematic wiring processing (S1)
Detailed wiring processing (S) based on the boundary terminal improved in (5)
16) is the same as the case of improving the wiring property,
Thereafter, the peeling and rewiring process (S17) is performed in the same manner.

The detailed wiring route created in the detailed wiring processing (S16) is similar to the conventional wiring method shown in FIG. 10 because the temporary detailed wiring information is discarded in the general wiring processing. As compared with the case where the peeling and rewiring process is performed while retaining the detailed wiring information, a wiring path with less detour wiring and bent wiring can be created. For example, in the example of FIG. 9, another wiring path is formed in a part of the detailed wiring C0 formed over a plurality of divided areas DIV as shown in FIG. In this case, a new wiring path is a bent wiring path C1 in order to create a wiring path avoiding the already set wiring path C0 in the conventional method of FIG. On the other hand, in the present invention in which the temporary detailed wiring route is discarded, as shown in FIG. 3C, the boundary terminal of another wiring route C0 is moved to give priority to the new wiring route. A straight wiring path C2 can be created for a simple wiring.

Here, in the above-described embodiment, an example in which the evaluation of the wiring property and the evaluation of the timing property are independently evaluated in the wiring evaluation processing has been described. It is preferable to perform re-schematic wiring processing after evaluating wiring properties in parallel and obtaining wiring information that combines wiring capacity and priority obtained from each evaluation. In this case, a priority may be set between the wiring capacity based on the wiring property and the priority based on the timing property, and the rough wiring processing may be performed again.

[0029]

As described above, according to the present invention, the temporary detailed wiring is performed after the schematic wiring, and the wiring evaluation processing is performed on the temporary detailed wiring path created by the temporary detailed wiring. Since the wiring information is improved based on the evaluation result of the above and the re-schematic wiring is performed, and then the detailed wiring is performed, it is extremely unlikely that an error path will occur in the detailed wiring path created in the detailed wiring processing performed thereafter. Less, less subsequent rewiring and rewiring,
The improvement of the wiring property shortens the total wiring processing time.
In addition, since the temporary detailed wiring is evaluated and the re-schematic wiring process is performed, the accuracy of the evaluation of the timing can be improved as compared with the case of evaluating the schematic wiring route, and the timing is improved.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the entire process of a wiring method according to the present invention.

FIG. 2 is a flowchart of an embodiment of a wiring method according to the present invention.

FIG. 3 is a schematic diagram for explaining a schematic wiring process.

FIG. 4 is a flowchart for explaining wiring property evaluation in a wiring evaluation process;

FIG. 5 is a first schematic diagram for explaining improvement of wiring information by evaluation of wiring properties.

FIG. 6 is a second schematic diagram for explaining the improvement of the wiring information by the wiring property evaluation.

FIG. 7 is a third schematic diagram for explaining an improvement in wiring capacitance based on wiring property evaluation.

FIG. 8 is a flowchart for explaining timing evaluation in a wiring evaluation process;

FIG. 9 is a schematic diagram showing an example of improvement of a wiring route according to the present invention.

FIG. 10 is a flowchart of an example of a conventional wiring method.

[Explanation of symbols]

 S11 Schematic wiring processing S12 Temporary detailed wiring processing S13 Wiring evaluation processing S14 Temporary detailed wiring discard S15 Re-schematic wiring processing S16 Detailed wiring processing S17 Peel-off rewiring processing CH chip DIV divided area EL element GC Schematic wiring path T Boundary terminal C0 Detailed wiring Route C1, C2 Wiring route to be added

Claims (9)

[Claims] After deciding an arrangement position of elements to be mounted on a semiconductor integrated circuit, a general wiring path for connecting the elements is obtained, and then a temporary detailed wiring path is obtained for the general wiring path, and the temporary details are obtained. Evaluate the wiring property and timing with respect to the wiring path, perform the rough wiring again in consideration of the evaluation result in the constraint condition, re-calculate the rough wiring path, and then determine the detailed wiring path based on the calculated rough wiring path. A wiring method for a semiconductor integrated circuit, comprising: 2. A schematic wiring process for setting a general wiring path for connecting between the elements after determining an arrangement position of an element to be mounted on a semiconductor integrated circuit, and setting a temporary detailed wiring path based on the general wiring path. A temporary detailed wiring process, a wiring evaluation process of performing wiring evaluation on the temporary detailed wiring route, and a re-schematic wiring process of resetting the schematic wiring route as necessary based on the evaluation result in the wiring evaluation process. And a detailed wiring process for setting a detailed wiring route based on the rough wiring route set in the rough wiring process or the re-schematic wiring process. 3. The wiring method for a semiconductor integrated circuit according to claim 2, further comprising a peeling and rewiring process for restoring a part of the detailed wiring path. 4. The general routing process divides a wiring region of a semiconductor integrated circuit into a plurality of divided regions and sets each of the divided regions based on wiring information such as a predetermined boundary capacity of the divided regions and a priority of a net. A unit schematic wiring path is set, and a boundary terminal is set on a boundary on a divided area through which the set general wiring path passes, and the re-schematic wiring processing is performed based on wiring information improved in the wiring evaluation. 4. The wiring method for a semiconductor integrated circuit according to claim 2, wherein at least a part of a schematic wiring path and a boundary terminal position are improved. 5. The temporary detailed wiring process is a process of setting a temporary detailed wiring route by using a simplified wiring pattern such as a straight line, a right-angled curved line, a crank-shaped curved line, or the like, alone or in combination. 5. The wiring method for a semiconductor integrated circuit according to claim 2, wherein 6. The wiring evaluation processing evaluates at least one of a wiring property and a timing property based on the tentative detailed wiring path, and based on a result of the evaluation, executes detailed wiring in the current general wiring path in the detailed wiring processing. It is determined whether or not it is possible, and if it is determined that detailed wiring is difficult,
The improved wiring information obtained in the wiring evaluation processing is retained and the process proceeds to the re-schematic wiring processing, and when it is determined that the detailed wiring processing is executable, based on the wiring information in the schematic wiring processing, 6. The wiring method for a semiconductor integrated circuit according to claim 2, wherein the processing shifts to the detailed wiring processing. 7. The evaluation of the wiring property in the wiring evaluation processing includes calculating a congestion degree of the temporary detailed wiring path in each of the plurality of divided areas, and determining a congestion degree of the divided area where the congestion degree is remarkable. 7. The wiring method for a semiconductor integrated circuit according to claim 6, wherein wiring information is obtained as a wiring capacitance for improving the congestion degree set in the rough wiring processing so as to reduce the wiring capacity. 8. The divided area having a remarkable congestion degree is set as a divided area having a remarkably large congestion degree with respect to a simple average of the congestion degrees of all the divided areas, and wiring information for improving the congestion degree is set. Calculates a moving average including the divided regions around the divided region where the congestion degree is remarkable, and sets the divided region where the congestion degree is remarkable based on a difference between the moving average and the simple average. 8. The wiring method for a semiconductor integrated circuit according to claim 7, wherein the information is information for reducing a wiring capacitance. 9. The evaluation of the timing in the wiring evaluation processing includes estimating a delay time of a circuit, and obtaining wiring information in which a priority of a net is corrected based on the estimation. The wiring method for a semiconductor integrated circuit according to any one of the above.