JPH04165471A - Parts arrangement design support system - Google Patents

Abstract

PURPOSE:To make the length of a wiring to be within a designated line length by designating the arrangement of the part between a source pin and a final load pin within the length of a main spindle line, setting a temporary line on both sides of the main spindle line at a distance of a branch line length away from it, and arranging and designating an unarranged part so that the load pin comes on the temporary line. CONSTITUTION:A signal line designation part 3 which designates a critical signal line, a main spindle line designation part 4 which designates the length of the main spindle line, and a branch line designation part 5 which designates the length of the branch line, are provided. A signal name is designated, the part with the line source pin and the final load pin from the parts to be connected are placed within an arrangable range, the main spindle line with the source pin and the final load pin connected at the designated line length is provided, the temporary lines are provided on both sides of the main spindle line at a distance of the designated branch line length away from the main spindle line, and the parts are arranged so that the load pins of the remaining parts are designated on the above temporary line. Thus, a part arrangement information with the wiring length less than or equal to the designated line length, which as the branch line length that is approximately fixed to the main spindle line, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a component placement design support system, and particularly to component placement design support for printed wiring boards of electronic devices.

[Conventional technology]

In conventional component placement design support systems, parts are arranged so that the virtual wiring length between them is shortened, or the number of wirings that cross cut lines placed between parts is reduced.

[Problem to be solved by the invention]

The conventional component placement design support method described above has the disadvantage that when branch wiring is allowed in wiring processing, the branch line length of each load pin with respect to the main axis line is not constant, and when wiring processing is performed, the wiring length is not the same as the specified line. There is a drawback that there is no guarantee that it will be within the long term.

[Means to solve the problem]

A component placement design support method of the present invention is a component placement design support method for a printed wiring board, comprising: a logical connection information storage means storing logical connection information of components mounted on the printed wiring board and signal lines between the components; signal line designation means for designating the signal line and its main axis length and one branch line length; determining a component to be connected to the signal line designated via the signal line designation means with reference to the logical connection information storage means; , select a component with a source bin and a component with a final load pin from among the components connected to the specified signal line, designate the component to be placed in the placeable area, and set the main axis between the source bin and the final load pin of these two components. Wiring is specified as a line within the main axis line length specified via the signal line specifying means, and temporary lines are set on both sides of the main axis line separated by the branch line length specified via the signal line specifying means. , a component placement processing means for specifying the placement of unplaced components connected to the specified signal line so that their load pins are placed on the temporary line, and outputting placement information of these components.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. The component placement design support method of this embodiment is based on the logical connection information file 1.
Logical connection information storage unit 1 that stores logical connection information starting from 0
, a signal line specification section 3 for specifying a critical signal line such as a clock signal line, a main axis line specification section 4 for specifying the length of the main axis line, and a branch line specification section 5 for specifying the length of the branch line. , a signal line connection component name storage unit 6 that stores the names of components connected to critical signal lines, a signal line connection component number counter 7 that counts the number of components connected to critical signal lines, and a number of components that have been placed. a processed parts counter 8 for counting the number of parts, a wiring area map storage part 9 for storing the parts placement status within the routeable area, and a wiring area map storage section 9 for storing the parts placement status within the routeable area; It has a component placement processing section 2 that outputs information to a component placement information file 11 and outputs error information when a component placement is impossible to an error file 12.

Next, the operation will be explained. Flowcharts are shown in FIGS. 2(a) and 2(b), and an example of arrangement of parts is shown in FIG.

The following processing is performed under the control of the component placement processing section 2. The signal line specifying unit 3 specifies a signal line Wα for a clock signal or the like whose branch line length is desired to be constant (step 81). Components connected to the signal line α are extracted from the logical connection information in the logical connection information storage unit 1, each is designated as ai, and stored in the signal line connection component name storage unit 6 (step S2). A component P having a source bin for the signal line α and a component Q having the final load pin for the signal line α are selected from the components ai (step S3). The total number of parts ai is set as a count value j in the signal line connected parts number counter 7 (step 84). Based on the information in the wiring area map storage section 9, parts P and Q are arranged within the wiring possible area (step S5). 2 of parts P and Q from the count value j of the signal line connected parts counter 7
The amount for each item is subtracted (step S6). The source bin of the part P and the final load pin of the part Q are wired within the line length specified by the main axis line specifying section 4 based on the theoretical delay calculation, and this pattern is used as the main axis line (step S7).

Temporary lines N1 and N2 for placement are set on both sides of the main axis line, separated by the branch line length m specified by the branch line specifying section 5 (step S8).

Next, placement processing is performed for all remaining components ai stored in the signal line connection component name storage section 6. First, the count value i of the processed parts counter 8 is set to II OIT (step S9), and "1" is added to the count value i every time placement processing is performed (step S510).
). Temporary line N.

In the above, let the point 01 be an arbitrary distance d away from the part P (
Step 511). The component at is arranged so that the load pin of the component ai, which is connected to the signal line α by a branch line, is placed on the point o1 (step 512). If part ai overlaps with another part in the process of step 812 (Y of step S13)
ES), move the point 01 to a position a minute distance Δd away on the temporary line N1 (step 514), and repeat the processes from step 812 to step S14 until the point O□ reaches the end point (part Q) of the temporary line N1. . When the point 01 reaches the end point of the temporary line N (YES in step S15), set the point 02 on the temporary line N2 from the part P by a distance d in step 81.
B), in the same way as above, place part ai on point 02 (step 517), if it overlaps with another part (step 8
18), while moving the point 02 by a minute distance Δd until it reaches the end point of the temporary line N2 (step 519).
, repeats the processing from step 817 to step S19.

When point 02 reaches the end point of temporary line N2 (step S2
0 (YES), the component at is determined to be unplaceable, and error information is output and written to the error file 12 (step 21).

For parts ai that did not overlap with other parts in step S13 or step 818, component placement information is extracted and written in the component placement information file 11 (step 522).

While the count value i of the processed parts number counter 8 is less than the count value j of the signal line connected parts number counter 7, the processes from step 810 to step S22 are repeated (step 52
3).

〔Effect of the invention〕

As explained above, the present invention specifies a signal line name, places a component having a source pin and a final load pin from among the components to be connected in a placeable area, and connects the source pin and final load pin with a specified line length to a main shaft. The wiring length can be changed to the specified line length by setting a temporary line on both sides of the main axis line and placing a temporary line on both sides of the main axis line, at a distance of the specified branch line length, and placing the components so that the load pins of the remaining components rest on the previous temporary line. It is possible to obtain component placement information such that the branch line length is approximately constant with respect to the main axis.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a flow chart of the present invention, and FIG. 3 is a diagram showing an example of arrangement of parts according to the present invention. DESCRIPTION OF SYMBOLS 1... Logical connection information storage section, 2... Component placement processing section, Trigastric signal line specification section, 4... Main axis line specification section, 5...
Branch line specification section, 6...Signal line connection part name storage section, 7.
... Signal line connected parts number counter, 8... Processed parts number counter, 9... Wiring area map storage section, 10...
Logical connection information file, 11...Component placement information file, 12...Error file.

Claims (1)

[Claims] In a component placement design support system for a printed wiring board, a logical connection information storage means storing logical connection information such as components mounted on the printed wiring board and signal lines between the components; the signal lines, their main axis line lengths, and branches; a signal line designating means for designating a line length; determining a component to be connected to the signal line designated by the signal line designating means with reference to the logical connection information storage means, and connecting it to the designated signal line; A component having a source pin and a component having a final load pin are selected from among the components and designated to be placed in a placeable area, and the signal line designation means is set as a main axis between the source pin and the final load pin of these two components. Specify the wiring within the specified main axis line length through the signal line specifying means, set temporary lines on both sides of the main axis line separated by the branch line length specified via the signal line specifying means, and connect the specified signal line to the specified signal line. A component placement design support system comprising a component placement processing means for specifying placement of unplaced components to be connected so that their load pins are placed on the temporary line, and outputting placement information of these components.