18.104.22.168. Arithmetic Mode
The ALM in arithmetic mode uses two sets of two 4-input LUTs along with two dedicated full adders. The dedicated adders allow the LUTs to perform pre-adder logic. Therefore, each adder can add the output of two 4-input functions.
Arithmetic mode also offers clock enable, counter enable, synchronous up and down control, add and subtract control, and synchronous clear.
The clear and clock enable options are LAB-wide signals that affect all registers in the LAB. You can individually disable or enable these signals for each register . The Intel® Quartus® Prime software automatically places any registers that are not used by the counter into other LABs.