Printing signed integer value stored in a variable of type reg

Question

How do I print a signed integer value stored in an 8-bit register declared as:

reg [7:0] acc;

Using:

$display("acc : %d", acc)

It prints the unsigned value.

What's the correct syntax for the $display function?

Answer 1

If you declare the reg as signed, $display will show the minus sign:

module tb;

reg signed [7:0] acc;

initial begin
    acc = 8'hf0;
    $display("acc : %d", acc);
end

endmodule

Prints out:

acc :         -16