Specifications
400 www.xilinx.com Development System Reference Guide
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combinatorial logic
Combinatorial logic refers to any primitives with the exception of 
storage elements such as flip-flops.
compiler
A compiler is a language interpreter. The Synopsys compiler 
interprets HDL and makes concurrent process implementations for 
target architectures. 
component
A component is an instantiation or symbol reference from a library of 
logic elements that can be placed on a schematic.
configuration
Configuration is the process of loading design-specific bitstreams into 
one or more FPGA devices to define the functional operation of the 
logical blocks, their interconnections, and the chip I/O. 
This concept also refers to the configuration of a design directory for a 
particular design library.
constraints
Constraints are specifications for the implementation process. There 
are several categories of constraints: routing, timing, area, mapping, 
and placement constraints. 
Using attributes, you can force the placement of logic (macros) in 
CLBs, the location of CLBs on the chip, and the maximum delay 
between flip-flops. PAR does not attempt to change the location of 
constrained logic.
constraints file
A constraints file specifies constraints (location and path delay) 
information in a textual form. An alternate method is to place 
constraints on a schematic.
contention
Contention is the state in which multiple conflicting outputs drive the 
same net.
counter
A counter is a circuit, composed of registers, that counts pulses, often 
reacting or causing a reaction to a predetermined pulse or series of 
pulses. Also called a divider, sometimes accumulator.










