Pitch Constraint in a Floorplan Pin Constraints File
A pin constraints file is a SKILL file with constraints entered in a SKILL list. The constraints are entered in a tabular format so that they are readable and editable.
The pitch constraint in a Floorplan pin constraints file defines the minimum edge-to-edge spacing between pins and other components. The format for specifying the pitch is as follows:
Unsigned Number > mfgGridResolution | -1
Pitch values greater than the manufacturing grid resolution are valid. If you do not want to specify any pitch value, enter -1 in the table. This will be treated as the pitch value not being set. During pin optimization, "floating" and "placed" pins are positioned such that the pitch of fixed/locked pins is honored. If different pitch values are defined for a pin and its pinFig, then the pinFig pitch value is respected.
The following examples illustrate how the pitch value is calculated in different situations.
Adjacent Pins or Objects separated by a Minimum Distance
In the following design, the pitch of pin A is 0.3. A pitch can have value zero. Assumption is that the pitch for the neighboring pins or objects is zero. Pins are placed such that adjacent pins or objects are separated by a minimum distance of 0.3, which is the pin pitch value.
Objects placed at a Minimum Distance from Pin
Consider pins A and B. The pitch for pin A is 0.3, whereas the pitch for pin B is 0.5. Here, objects are placed at a minimum distance of 0.3 from pin A and 0.5 from pin B. However, when determining the distance between these two pins, the higher pitch is honored.
Pins A and B are placed at a distance of 0.5, which is the higher pin pitch value.
Pins spaced to achieve Minimum Net Length
Consider pins in two separate blocks, Block A and Block B. The pitch for pins in these blocks is different. During pin optimization, the pins are placed such that:
In the following image, notice that after pin optimization, the pins in Block B are separated by a minimum distance of 0.3, which is the pitch value. The spacing is further increased to ensure that the minimum net length is achieved.
Related Topics
Pin Name in a Floorplan Pin Constraints File
Edge Constraint in a Floorplan Pin Constraints File
Pitch Constraint in a Floorplan Pin Constraints File
Return to top