Adaptive Logic Module (ALM) Definition

The Adaptive Logic Module (ALM) is the basic building block of supported device (Arria series, Cyclone V, Stratix IV, and Stratix V) families and is designed to maximize performance and resource usage. Each ALM can support up to eight inputs and eight outputs, contains two or four register logic cells (lc_ff) and two combinational logic cells (lc_comb), two dedicated full adders, a carry chain, a register chain, and a 64-bit LUT mask. In Stratix IV, and StratixV family devices, you can implement the two combinational logic cells ( mp _comb) as register, combinational, or MLAB logic cells. In ArriaV, CycloneV, and StratixV family devices, you can implement the two combinational logic cells ( mp _comb) as combinational, or MLAB logic cells

Each LAB in Arria V, Cyclone V, Stratix IV, and Stratix V family devices contains ten ALMs. Each ALM drives the local, row, column, carry chain, register chain, and direct link interconnects.

You can implement the following types of functions in a single ALM:

• Two independent 4-input functions
• An independent 5-input function and an independent 3-input function
• A 5-input function and a 4-input function, if they share one input
• Two 5-input functions, if they share two inputs
• An independent 6-input function
• Two 6-input functions, if they share four inputs and share function
• Some 7-input functions

The ALM operates in adaptive combinational logic mode (normal mode), extended LUT mode (7-input function mode), arithmetic mode, and shared arithmetic mode.