XC3S100E_06 Datasheet, PDF (64/231 Pages) Xilinx, Inc – Configurable Logic Block (CLB)

Functional Description
R
Interconnect
Interconnect is the programmable network of signal path-
ways between the inputs and outputs of functional elements
within the FPGA, such as IOBs, CLBs, DCMs, and block
RAM.
Overview
Interconnect, also called routing, is segmented for optimal
connectivity. Functionally, interconnect resources are iden-
tical to that of the Spartan-3 architecture. There are four
kinds of interconnects: long lines, hex lines, double lines,
and direct lines. The Xilinx Place and Route (PAR) software
exploits the rich interconnect array to deliver optimal system
performance and the fastest compile times.
Switch Matrix
The switch matrix connects to the different kinds of intercon-
nects across the device. An interconnect tile, shown in
Figure 48, is defined as a single switch matrix connected to
a functional element, such as a CLB, IOB, or DCM. If a func-
tional element spans across multiple switch matrices such
as the block RAM or multipliers, then an interconnect tile is
defined by the number of switch matrices connected to that
functional element. A Spartan-3E device can be repre-
sented as an array of interconnect tiles where interconnect
resources are for the channel between any two adjacent
interconnect tile rows or columns as shown in Figure 49.
Switch
Matrix
CLB
Switch
Matrix
Switch
Matrix
IOB
Switch
Matrix
DCM
Switch
Matrix
Switch
Matrix
Switch
Matrix
18Kb
Block
RAM
MULT
18 x 18
DS312_08_020905
Figure 48: Four Types of Interconnect Tiles (CLBs, IOBs, DCMs, and Block RAM/Multiplier)
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DS312-2 (v3.4) November 9, 2006
Product Specification