A method for relative pin placement guidance, comprising the steps of placing a plurality of pins to form a pinout in response to a first design, a second design and an attribute and determining one or more placement constraints, one or more groups of the pins, and routing of the pins in response to the attribute. The bad-road control section includes a braking-force applying section configured to apply a braking force to a drive-wheel, and a driving-force applying section configured to apply a driving force to the drive-wheel which is receiving the braking force from the braking-force applying section, as the bad-road control. The DFB laser also includes a secondary etch stop layer located either above or below the grating layer, and a spacer layer interposed between the grating layer and the active region.