slice, and CL5 The most basic element of the Spartan-3 device is a logic
cell (LC), which contains a four-input LUT and a D FF, similar to that in Figure 2.2.
In addition, a logic cell contains a carry circuit, which is used to implement arithmetic
functions, and a multiplexing circuit, which is used to implement wide multiplexers. The
LUT can also be configured as a 16-by-1 static random