assign ena[1] = q[3:0] == 4'h9 ? 1'b1 : 1'b0; assign ena[2] = q[7:0] == 8'h99 ? 1'b1 : 1'b0; assign ena[3] = q[11:0] == 12'h999 ? 1'b1 : 1'b0; q[7:4] <= ena == 3'b001 ...

assign ena = {q[11:8] == 4'd9 && q[7:4] == 4'd9 && q[3:0] == 4'd9, q[7:4] == 4'd9 && q[3:0] == 4'd9, q[3:0] == 4'd9}; ...