Preliminary Information
Cyclone FPGA Family Data Sheet
Cyclone devices include an enhanced interconnect structure within LABs
for routing LE output to LE input connections faster using LUT chain
connections and register chain connections. The LUT chain connection
allows the combinatorial output of an LE to directly drive the fast input of
the LE right below it, bypassing the local interconnect. These resources
can be used as a high-speed connection for wide fan-in functions from LE
1 to LE 10 in the same LAB. The register chain connection allows the
register output of one LE to connect directly to the register input of the
next LE in the LAB for fast shift registers. The Quartus II Compiler
automatically takes advantage of these resources to improve utilization
and performance. Figure 10 shows the LUT chain and register chain
interconnects.
Altera Corporation
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ALTERA [ ALTERA CORPORATION ]
