R
Functional Description
FXINB
FXINA
F8
F5
X
F5
FXINB
FXINA
FX
F6
F5
F5
FXINB
FXINA
FX
F7
F5
F5
FXINB
FXINA
F6
F5
FX
F5
DS312-2_38_021305
Figure 17: Muxes and Dedicated Feedback in
Spartan-3E CLB
Table 8: Mux Capabilities
Total Number of Inputs per Function
For Any
Function
For Limited
Functions
Mux
Usage
F5MUX
F6MUX
F7MUX
F8MUX
Input Source
LUTs
For Mux
F5MUX
FiMUX
5
6
7
8
6 (4:1 mux)
9
F5MUX
11 (8:1 mux)
20 (16:1 mux)
37 (32:1 mux)
19
39
79
F6MUX
F7MUX
DS312-2 (v1.1) March 21, 2005
www.xilinx.com
19
Advance Product Specification