Computer aided design apparatus for aiding design of a printed wiring board to effectively reduce noise

A Computer Aided Design apparatus for a printed wiring board for placing a component belonging to a second type of components in a vicinity of a component belonging to a first type of components, comprising:

• first determining means for determining a pin order in order of seriousness of noise that can occur in a current that flows through a power pin, for a power pin of each of the components belonging to the first type of components,
• second determining means for determining a component order in ascending order of impedance for each component belonging to the second type of components;
• and
• assigning means for assigning a second type component which is highest amongst the components in the component order that are not assigned, to a first type component having a power pin which is highest amongst the power pins in the pin priority that are not assigned.

A Computer Aided Design apparatus for displaying at least one component placement on a wiring board, and aiding an evaluation by a user of whether a placement of a position dependent component, whose effectiveness differs according to a placement position, is appropriate, the CAD apparatus comprising:

• design information storage means for storing sets of position information which show the position of each component on the wiring board,
• relationship information storage means for storing sets of relationship information of the placement dependent component in relation with an effected component which is effected by the placement dependent component;
• and
• display means for displaying, according to one set of placement information, the position dependent component and the effected component which is in relation therewith in the relationship information in correspondence, in a user-recognizable state.

A Computer Aided Design apparatus for aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate, comprising:

• position information storage means for storing a set of position information which is made up of information showing a position on a wiring board of
• (a) a position dependent component, or a pin thereof, and
• (b) one or more effected components, or pins thereof, which are potentially effected by the position dependent component,
• retrieval means for retrieving from the position dependent component or the pin thereof, based on the sets of position information stored by the position information storage means, for each effected component or the pins thereof, whether the effected component or the pin thereof is within a predetermined distance from the placement dependent component or the pin thereof, or for retrieving a predetermined number of effected components or pins thereof in a predetermined order;
• and
• relationship information storage means for storing the effected component or the pin of the effected component retrieved by the retrieval means in relation with the position dependent component or the pin thereof from which the retrieval was performed, as relationship information.

A Computer Aided Design apparatus for aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate, comprising:

• position information storage means for storing a set of position information which is made up of information showing a position on a wiring board of
• (a) a position dependent component, or a pin thereof, and
• (b) one or more effected components, or pins thereof, which are potentially effected by the position dependent component,
• retrieval means for retrieving from the effected component or the pin thereof, based on the sets of position information stored by the position information storage means, for each position dependent component or the pins thereof, whether the position dependent component or the pin thereof is within a predetermined distance from the effected component or the pin thereof, or for retrieving a predetermined number of position dependent components or pins thereof in a predetermined order;
• and
• relationship information storage means for storing the position dependent component or the pin of the position dependent component retrieved by the retrieval means in relation with the effected component or the pin thereof from which the retrieval was performed, as relationship information.

A computer program embodied on a computer readable medium for use with a computer for aiding a design of a printed wiring board for placing a component belonging to a second type of components in a vicinity of a component belonging to a first type of component, on the printed wiring board, the program realizing on the computer:

• first determining means for determining a pin order in order of seriousness of noise that can occur in a current that flows through a power pin, for a power pin of each of the components belonging to the first type of components,
• second determining means for determining a component order in ascending order of impedance for each component belonging to the second type of components;
• and
• assigning means for assigning a second type component which is highest amongst the components in the component order that are not assigned, to a first type component having a power pin which is highest amongst the power pins in the pin priority that are not assigned.

A component placement evaluation aiding computer program embodied on a computer readable medium for displaying a placement of components that are on a wiring board and aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate, the program realizing on a computer:

• a position information storage step for storing a set of position information which is made up of information showing a position on a wiring board of
• (a) a position dependent component, or a pin thereof, and
• (b) one or more effected components, or pins thereof, which are potentially effected by the position dependent component,
• a retrieval step for retrieving from the position dependent component or the pin thereof, based on the sets of position information stored in the position information storage step, for each effected component or the pins thereof, whether the effected component or the pin thereof is within a predetermined distance from the placement dependent component or the pin thereof, or for retrieving a predetermined number of effected components or pins thereof in a predetermined order;
• and
• a relationship information storage step for storing the effected component or the pin of the effected component retrieved in the retrieval step in relation with the position dependent component or the pin thereof from which the retrieval was performed, as relationship information.

A component placement evaluation aiding computer program embodied on a computer readable medium for aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate, the program realizing on a computer:

• a position information storage step for storing a set of position information which is made up of information showing a position on a wiring board of
• (a) a position dependent component, or a pin thereof, and
• (b) one or more effected components, or pins thereof, which are potentially effected by the position dependent component,
• a retrieval step for retrieving from the position dependent component or the pin thereof, based on the sets of position information stored in the position information storage step, for each effected component or the pins thereof, whether the effected component or the pin thereof is within a predetermined distance from the placement dependent component or the pin thereof, or for retrieving a predetermined number of effected components or pins thereof in a predetermined order;
• and
• a relationship information storage step for storing the effected component or the pin of the effected component retrieved in the retrieval step in relation with the position dependent component or the pin thereof from which the retrieval was performed, as relationship information.

A component placement evaluation aiding computer program embodied on a computer readable medium for aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate, the program realizing on a computer:

• a position information storage step for storing a set of position information which is made up of information showing a position on a wiring board of
• (a) a position dependent component, or a pin thereof, and
• (b) one or more effected components, or pins thereof, which are potentially effected by the position dependent component,
• a retrieval step for retrieving from the effected component or the pin thereof, based on the sets of position information stored in the position information storage step, for each position dependent component or the pins thereof, whether the position dependent component or the pin thereof is within a predetermined distance from the effected component or the pin thereof, or for retrieving a predetermined number of position dependent components or pins thereof in a predetermined order;
• and
• a relationship information storage step for storing the position dependent component or the pin of the position dependent component retrieved in the retrieval step in relation with the effected component or the pin thereof from which the retrieval was performed, as relationship information.

A program implemented on a computer for aiding a design of a printed wiring board for placing a component belonging to a second type of components in a vicinity of a component belonging to a first type of component, on the printed wiring board, the program realizing on the computer:

• first determining means for determining a pin order in order of seriousness of noise that can occur in a current that flows through a power pin, for a power pin of each of the components belonging to the first type of components,
• second determining means for determining a component order in ascending order of impedance for each component belonging to the second type of components;
• and
• assigning means for assigning a second type component which is highest amongst the components in the component order that are not assigned, to a first type component having a power pin which is highest amongst the power pins in the pin priority that are not assigned.

A program implemented on a computer for aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate by displaying a placement of components on a wiring board, the program realizing on a computer:

• a design information storage step for storing a set of position information which is made up of (a) information showing a position on a wiring board of a position dependent component, or a pin thereof, and
• (b) information showing one or more effected components, or pins thereof, which are potentially effected by the position dependent component, and
• a relationship information storage means for storing in correspondence relationship information about the position dependent component or the pin thereof and the placement dependent component or the pin thereof within a predetermined distance from the placement dependent component or the pin thereof;
• and
• a display step for displaying the position dependent component or the pin thereof and the effected component or the pin thereof in correspondence in the relationship information stored in the relationship information storage step, in a user-recognizable state.

A program implemented on a computer for aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate, the program realizing on a computer:

• a position information storage step for storing a set of position information which is made up of information showing a position on a wiring board of
• (a) a position dependent component, or a pin thereof, and
• (b) one or more effected components, or pins thereof, which are potentially effected by the position dependent component,
• a retrieval step for retrieving from the position dependent component or the pin thereof, based on the sets of position information stored in the position information storage step, for each effected component or the pins thereof, whether the effected component or the pin thereof is within a predetermined distance from the placement dependent component or the pin thereof, or for retrieving a predetermined number of effected components or pins thereof in a predetermined order;
• and
• a relationship information storage step for storing the effected component or the pin of the effected component retrieved in the retrieval step in relation with the position dependent component or the pin thereof from which the retrieval was performed, as relationship information.

A program implemented on a computer for aiding an evaluation by a user of whether a placement of a position dependent component whose effectiveness differs according to a placement position is appropriate, the program realizing on a computer:

• a position information storage step for storing a set of position information which is made up of information showing a position on a wiring board of
• (a) a position dependent component, or a pin thereof, and
• (b) one or more effected components, or pins thereof, which are potentially effected by the position dependent component,
• a retrieval step for retrieving from the effected component or the pin thereof, based on the sets of position information stored in the position information storage step, for each position dependent component or the pins thereof, whether the position dependent component or the pin thereof is within a predetermined distance from the effected component or the pin thereof, or for retrieving a predetermined number of position dependent components or pins thereof in a predetermined order;
• and
• a relationship information storage step for storing the position dependent component or the pin of the position dependent component retrieved in the retrieval step in relation with the effected component or the pin thereof from which the retrieval was performed, as relationship information.