11.4.1 Multiplexors

Using case statements with the multiplexor based Microchip architecture provides area and speed efficient solutions and is more efficient than inference of priority encoders using if-then-else statements. Microchip recommends that you use case statements instead of long, nested if-then-else statements to force mapping to multiplexors in the Microchip architecture.

VHDL synthesis tools automatically assume parallel operation without priority in case statements. However, some Verilog tools assume priority, and you may need to add a directive to your case statement to ensure that no priority is assumed. Refer to the documentation provided with your synthesis tool for information about creating case statements without priority.