module top; parameter A = 3; parameter B = 4; logic [A*B-1:0] arr; initial begin arr = 0; for (integer i = 0; i < A; ++i) begin // yes this is silly but it captures an interesting edge case arr[i * B +: B] = $bits(arr[i * B +: B])'(i); end $display("%b", arr); end endmodule