Using binary number as replicator in the replication operator

[fragnen]

Can m be binary numbers in the replication operator which is shown below? Here m is the replicator.

{m{variable for replicating}}

For example, in the below example a is replicated by 4'b0100. So m in below example is 4'b0100. Is it valid to write synrhesizble rtl code with the m in binary as shown below?

wire [3:0] x;
wire a;
assign x = { 4'b0100{a}};

Normally we see m to be in decimal in synthsizable rtl code that uses replication operator. So this question being asked.

 

[FvM]

In case of doubt review Verilog language reference manual. It requires a "non-negative, non-x, and non-z constant expression" for the concatenation constant but no specific number format.

The answer is yes.

 

[fragnen]

In case of doubt review Verilog language reference manual. It requires a "non-negative, non-x, and non-z constant expression" for the concatenation constant but no specific number format.

The answer is yes.

Does it mean that even an expression can work as replicator?

 

[FvM]

That's what the language reference says. It has to be a constant expression.