JPH06163690A - Placement and routing apparatus for electronic device - Google Patents

Abstract

PURPOSE:To make it possible to lay out wirings more easily in the case when a PLD is included in electronic devices wires on a circuit board by providing a pin function conversion means which changes the functions of an input pin or an output pin of a programmable logic device laid out by a device layout means. CONSTITUTION:A before-wiring to be processed is assumed to be a wiring 1. As for a source terminal A of the unlaid out wiring 1, there is found a source terminal changeable to this source terminal A with the same PLD. The found source terminal B is exchanged with the source terminal A and the wiring 1 is connected to the source terminal B where a wiring 2 is connected to the source terminal A. When all wiring, which are not laid out yet, are processed, the whole processing will be ended. If there remains any wiring which is not laid out yet, the process will return to the original process as an uncompleted wiring. In the case when a PLD is included as an electronic device, it will be possible to lay out wirings more smoothly in automatic mode with no attendance of an operator who directs replacement of devices by himself or herself. What differs from the prior art process, is in the point that a step (i) is inserted between steps (f) and (g).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device placement / wiring apparatus for designing placement / wiring of a plurality of electronic devices on a circuit board.

[0002]

2. Description of the Related Art Conventionally, a circuit board (PCB;
I placed on the t-Circuit Board)
An electronic device equipped with an algorithm that automatically determines the placement positions of electronic devices such as C, transistors, resistors, and capacitors on the circuit board, and automatically determines the connection between the terminals of each electronic device according to the determined positions. A device placement and wiring device is used.

FIG. 3 is a flow chart showing an example of a layout and wiring design procedure in a conventional electronic device layout and wiring apparatus. When the arrangement positions of the input pins and output pins of a plurality of electronic devices to be arranged and wired on the circuit board and the wiring diagram between the plurality of electronic devices are input, first, the plurality of electronic devices are arranged on the circuit board. The arrangement order is determined (step (a)), and the electronic device that receives an input to the circuit board or the electronic device that takes an output from the circuit board to the outside according to the determined order is the The electronic device is arranged on the circuit board according to a constraint condition such as arrangement in the vicinity of the terminal of the circuit board (step (b)). It should be noted that the term “arrangement” here does not mean that the electronic device is physically arranged on the circuit board, but means that the electronic device is arranged on a virtual plane, that is, the layout is designed. ing.

Next, the wiring order is given to each terminal (hereinafter referred to as "source terminal") for transmitting signals of a plurality of electronic devices arranged on the circuit board (step (c)), and the order is given. Wiring is carried out according to. It should be noted that the term "wiring" as used herein means wiring on a virtual plane, that is, wiring design, like the above-mentioned "arrangement". Next, in step (e), it is judged whether or not a large number of wirings can be arranged without intersecting each other, and if the wiring pitch is not too small, etc., and all the wirings satisfy the criteria. Then, the layout and wiring design is completed. If even one wire does not meet the criteria, for example, if wiring is not allowed to intersect, if wiring cannot be performed unless it intersects with another wiring, the process proceeds to step (f), and wiring is performed for all wiring orders. It is determined whether or not, and if the wiring order that has not been tried remains, the process returns to step (c) to change the wiring order of the source terminal,
The wiring is tried again. When none of the wiring orders satisfy the criteria as a result of attempting the wiring in this way, the process proceeds to step (g), where it is determined whether the wiring has been attempted for all the placement orders. If there is an arrangement order in which wiring is not attempted, the arrangement order of a plurality of electronic devices is changed (step (a)) and wiring is performed (step (b)). Further, if wiring is attempted for all the arrangements in step (g), it is output that the standard cannot be satisfied for all the wirings of all the arrangements (step (h)).

Conventionally, for example, the above-described algorithm has been adopted as an example of arrangement and wiring of electronic devices on a circuit board.

[0006]

In the prior art, for example, the placement and routing algorithm described above is employed to place and route electronic devices on a circuit board, so that wiring can be performed without straddling other wiring. However, there is a problem that the wiring is often congested especially when trying to shorten the wiring length.

In view of the above circumstances, the present invention is a so-called PLD having a plurality of pins whose functions can be freely converted.
(Programmable Logic Device
It is an object of the present invention to provide an electronic device placement and routing apparatus effective for placement and routing design of an electronic device when e) (including FPGA, PAL, etc.) is included as an electronic device to be placed on a circuit board.

[0008]

An electronic device placement and routing apparatus of the present invention which achieves the above object includes a plurality of programmable logic devices which are electronic devices having a plurality of input pins or output pins whose functions are changed. In an electronic device placement and routing apparatus for designing placement and routing of electronic devices on a circuit board, device placement means for designing placement of a plurality of electronic devices on a circuit board, and a plurality of electronic devices placed by the device placement means The inter-device wiring means for designing the wiring between the devices and the pin function conversion means for changing the function of the input pin or the output pin of the programmable logic device arranged by the device arranging means are provided.

Here, "changing the function of the input pin or the output pin" means exchanging the functions of a plurality of pins P1 and P2 with each other as shown in FIG. 1 (A), and FIG. 1 (B). ) Has a pin with a predetermined function as shown in 1)
Both include moving from one pin P1 to another pin P2.

[0010]

The electronic device placement / wiring apparatus of the present invention includes the same device placement means and inter-device wiring means as in the prior art,
Since the pin function changing means is provided, wiring congestion is alleviated when a programmable logic device (PLD; including FPGA, PAL, etc.) is provided as an electronic device arranged and wired on a circuit board, and it is easier and more necessary than before. Placement and routing satisfying the requirement of is performed.

[0011]

EXAMPLES Examples of the present invention will be described below. FIG. 2 is a flowchart showing a processing procedure in the electronic device placement and routing apparatus according to the embodiment of the present invention. The steps having the same contents as those in the flowchart shown in FIG. 3 are designated by the same numbers as those given in FIG. 3, and only the differences will be described.

The difference between the flowchart shown in FIG. 2 and the flowchart shown in FIG. 3 is that the step (i) for terminal exchange is inserted between the steps (f) and (g). . The terminal exchange algorithm of step (i) will be described in detail below. This terminal exchange algorithm is performed by the following procedure. (I) The following processing for all unwired wiring (ii)
Repeat ~ (xi). The unwiring to be processed is called wiring 1. (Ii) Regarding the source terminal A of the unwired 1, find the source terminal B that can be exchanged with the source terminal A in the same PLD. If the replaceable source terminal B cannot be found, the process proceeds to the process (vi). When a wire is already connected to the found terminal B, the wire will be referred to as a wire 2 hereinafter. (Iii) Replace the found source terminal B with the source terminal A. In this case, the wiring 1 is connected to the source terminal B, and the wiring 2
Will be connected to the source terminal A. (Iv) Wiring the wiring 1 and the wiring 2 respectively. (V) If both of them are wired, the processing for that wiring is terminated, and the processing proceeds to processing (xi). If either one of them is not wired, the process returns to the process (ii) to find a terminal other than B. (Vi) The following processes (vii) to (x) are performed on all the load terminals (referred to as load side terminals connected to the source terminals) A ′ of the unwired 1. (Vii) On the same PLD as the load terminal A ', find the load terminal B'which is replaceable with the load terminal A'. If the replaceable terminal B ′ cannot be found, the process (xi) proceeds. If a wire is already connected to the found terminal B ', the wire will be referred to as a wire 3 hereinafter. (Viii) Replace the found load terminal A'with the load terminal B '. In this case, the wiring 1 is connected to the load terminal B'and the wiring 3 is connected to the load terminal A '. (Ix) Wire 1 and wire 3 respectively. (Each of the wirings 1 and 3 has been wired if it is wired between all the loads and sources.) (X) If both of them are wired, the processing is completed for the unwired. Proceed to processing (xi). If either is not wired, return (vii) to find another replaceable load terminal. (Xi) If the processing (including the case where the wiring could not be completed finally) is performed for all the unwired, the entire processing is ended. If there are no unwired wires at the end of the entire processing, "normal termination" is performed, and if unwired wires remain, "wiring unfinished" is returned to the flow shown in FIG. If there are unprocessed wires that have not been processed,
Return to i).

In this embodiment, the terminals are exchanged as described above. Therefore, when a PLD is included as an electronic device, a smoother automatic arrangement can be performed without the operator's instruction to exchange the terminals. Wiring is done.
In the above embodiment, if the wiring is not completed in step (i) shown in FIG. 2, the electronic device layout is changed. However, if the wiring is not completed, the wiring order may be changed. Alternatively, whether to proceed to the step of changing the wiring order or the step of changing the arrangement order may be divided depending on the degree of uncompleted wiring and other circumstances.

The above embodiment is merely an example, and it goes without saying that the terminal conversion may be performed by an algorithm other than the terminal conversion algorithm described above.

[0015]

As described above, the electronic device placement / wiring apparatus of the present invention includes the same device placement means and inter-device wiring means as in the prior art, and the pin function changing means. When the PLD is included in the electronic device to be placed and routed above, the placement and routing is performed more easily than before.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing conversion (A) and pin movement (B) of a PLD pin function.

FIG. 2 is a flow chart showing a processing procedure in an electronic device placement and routing apparatus according to an embodiment of the present invention.

FIG. 3 is a flowchart showing an example of a procedure for layout and wiring design in a conventional electronic device layout and wiring apparatus.

Claims (1)

[Claims] 1. An electronic device placement and routing apparatus for designing placement and routing of a plurality of electronic devices including a programmable logic device, which is an electronic device having a plurality of input pins or output pins whose functions are changed, on a circuit board. A device placement means for designing placement of the plurality of electronic devices on a circuit board; an inter-device wiring means for designing wiring between the plurality of electronic devices placed by the device placement means; and the device placement means. And a pin function changing means for changing a function of an input pin or an output pin of the programmable logic device arranged by the electronic device placement and routing apparatus.