Verilog: what does begin followed by colon and a variable mean

问题

What does data_mux mean here? Is it just a name for the block?

if ((PORT_CONFIG == "32") && (P0 == 1'b1))
begin : data_mux
...
end

回答1:

These are block names. Especially useful with generate blocks. For example you can define a generate block such as

genvar i;
generate (for i = 0; i<10; i++)
begin : structures
    reg my_reg;
    // ...
    .. other block descriptions
    // ...
end
endgenerate

Then you can access the block elements later like

structures[3].my_reg <= 1'b1;

回答2:

Yes, it is just the name for the begin/end block. Refer to the free IEEE Std 1800-2012 (section 9.3.4 Block names). In most cases the block label is optional.

来源：https://stackoverflow.com/questions/41990552/verilog-what-does-begin-followed-by-colon-and-a-variable-mean