MUXCY_D

2-to-1 Multiplexer for Carry Logic with Dual Output

MUXCY_D is used to implement a 1-bit high-speed carry propagate function. One such function can be implemented per logic cell (LC), for a total of 4-bits per configurable logic block (CLB). The direct input (DI) of an LC is connected to the DI input of the MUXCY_D. The carry in (CI) input of an LC is connected to the CI input of the MUXCY_D. The select input (S) of the MUX is driven by the output of the lookup table (LUT) and configured as an XOR function. The carry out (O and LO) of the MUXCY_D reflects the state of the selected input and implements the carry out function of each LC. When Low, S selects DI; when High, S selects CI.

Outputs O and LO are functionally identical. The O output is a general interconnect. The LO output is used to connect to other inputs within the same CLB slice.

See also “MUXCY” and “MUXCY_L.”