5.27.2 Physical Constraints

Designer software enables you to specify the physical constraints to define the size, shape, utilization, and pin/pad placement of a design. You can specify these constraints based on the utilization, aspect ratio, and dimensions of the die. The pin/pad placement depends on the external physical environment of the design, such as the placement of the device on the board.

There are three types of physical constraints:

• I/O assignments

• Set location, attributes, and technologies for I/O ports
• Specify special assignments, such as VREF pins and I/O banks
  • Location and region assignments
• Set the location of Core, RAM, and FIFO macros
• Create Regions for I/O and Core macros as well as modify those regions
  • Clock assignments
• Assign nets to clocks
• Assign global clock constraints to global, quadrant, and local clock resources