If的表达:
module mux4to1(input [1:0]d0,d1,d2,d3,input s1,s0,output [1:0] out);
reg [1:0] out_t ;
always @(*) begin
if ({s1,s0} == 2'b00)
out_t = d0 ;
else if ({s1,s0} == 2'b01)
out_t = d1 ;
else if ({s1,s0} == 2'b10)
out_t = d2 ;
else
out_t = d3 ;
end
assign out = out_t ;
endmodule
Case的表达:
module mux4to1(input [1:0]d0,d1,d2,d3,input s1,s0,output [1:0] out);
reg [1:0] out_t ;
always @(*) begin
case({s1,s0})
2'b00:out_t=d0;
2'b01:out_t&#