Logic Elements - Altera Cyclone IV Device Handbook

November 2009
CYIV-51002-1.0
CYIV-51002-1.0
This chapter contains feature definitions for logic elements (LEs) and logic array
blocks (LABs). Details are provided on how LEs work, how LABs contain groups of
LEs, and how LABs interface with the other blocks in Cyclone

Logic Elements

Logic elements (LEs) are the smallest units of logic in the Cyclone IV device
architecture. LEs are compact and provide advanced features with efficient logic
usage. Each LE has the following features:
■ A four-input look-up table (LUT), which can implement any function of four
variables
■ A programmable register
■ A carry chain connection
■ A register chain connection
■ The ability to drive the following interconnects:
■
■
■
■
■
■ Register packing support
■ Register feedback support
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Cyclone IV Device Handbook,
Volume 1
November 2009
2. Logic Elements and Logic Array Blocks
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