R
Functional Description
Switch Matrix
Interconnect
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.
For additional information, refer to the Using Interconnect
chapter in UG331.
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 identi-
cal 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
Switch
CLB
Matrix
Switch
Matrix
Switch
IOB
18Kb
Block
RAM
MULT
18 x 18
Matrix
Switch
Matrix
Switch
DCM
Matrix
Switch
Matrix
DS312_08_020905
Figure 48: Four Types of Interconnect Tiles (CLBs, IOBs, DCMs, and Block RAM/Multiplier)
64
www.xilinx.com
DS312-2 (v3.8) August 26, 2009
Product Specification