1.1.5. ALM Resources
With up to eight inputs for the two combinational ALUTs, one ALM can implement various combinations of two functions. This adaptability allows an ALM to be completely backward-compatible with four-input LUT architectures. One ALM can also implement any function with up to six inputs and certain seven-input functions.
One ALM contains four programmable registers. Each register has the following ports:
- Synchronous and asynchronous clear
- Synchronous load
Global signals, general purpose I/O (GPIO) pins, or any internal logic can drive the clock enable signal and the clock and clear control signals of an ALM register.
For combinational functions, the registers are bypassed and the output of the look-up table (LUT) drives directly to the outputs of an ALM.