Multiplexing more than 2 signals using Altera's LPM

Question

How can I use busmux more than two input in Quartus? It seems I can use LPM_MUX instead, but I can't understand how to use it. Is there any easier way?

Answer 1

While using lpm_mux, you need to drive 3 signals (+ clock for pipelined usage):

• data port, which consists of LPM_SIZE buses, each LPM_WIDTH wide,
• sel signal, which selects one of the input buses, LPM_WIDTHS wide,
• result port, which is LPM_WIDTH wide.

data and sel are both inputs, result is output port. Values of LPM_SIZE, LPM_WIDTH and LPM_WIDTHS can be set using defparam clause.