VHDL 101

Chapter 2. Overview of the Process of Implementing an FPGA Design

There's more to designing an FPGA than just typing in the VHDL program. An entire process exists for turning what you just typed into an image suitable for loading into an FPGA. The code that you enter determines both the behavior and performance of the design.

Specifying the performance standards, that is, how fast the design should operate, is an art in and of itself and is well outside the scope of this text. ¹ These performance standards are specified in a User Constraint File (UCF). Suffice it to say that the code that you write determines what gets created²– that is, how it behaves, ³ but how it is placed within the fabric of an FPGA is determined by the implementation phase ...