Adaptive Logic Modules
LAB-wide signals are available in all ALM modes. Refer to “LAB Control
Signals” on page 2–37 for more information about LAB-wide control
signals.
The Quartus II software and supported third-party synthesis tools, in
conjunction with parameterized functions such as library of
parameterized modules (LPM) functions, automatically choose the
appropriate mode for common functions such as counters, adders,
subtractors, and arithmetic functions. If required, you can also create
special-purpose functions that specify which ALM operating mode to use
for optimal performance.
Normal Mode
Normal mode is suitable for general logic applications and combinational
functions. In this mode, up to eight data inputs from the LAB local
interconnect are inputs to the combinational logic. Normal mode allows
two functions to be implemented in one Arria GX ALM, or an ALM to
implement a single function of up to six inputs. The ALM can support
certain combinations of completely independent functions and various
combinations of functions which have common inputs. Figure 2–30
shows the supported LUT combinations in normal mode.
2–42
Arria GX Device Handbook, Volume 1
Altera Corporation
May 2008
ALTERA [ ALTERA CORPORATION ]
