EP2SGX30C Datasheet, PDF (59/314 Pages) Altera Corporation – Stratix II GX Device

Stratix II GX Architecture
asynchronous clear, asynchronous preset/load, synchronous clear,
synchronous load, and clock enable control for the register. These LAB
wide signals are available in all ALM modes. Refer to “LAB Control
Signals” on page 2–46 for more information on the 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
The 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. The normal
mode allows two functions to be implemented in one Stratix II 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 2–37 shows the supported LUT combinations in normal mode.
Altera Corporation
October 2007
2–51
Stratix II GX Device Handbook, Volume 1