Adaptive Logic Module (ALM) Definition

The Adaptive Logic Module (ALM) is the basic building block of supported device families ( Arria^® series, Cyclone^® V, Stratix^® IV, and Stratix^® V) 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 Stratix^® V family devices, you can implement the two combinational logic cells (mp_comb) as register, combinational, or MLAB logic cells. In Arria^® V, Cyclone^® V, and Stratix^® V 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.