In methods of forming a trench, first patterns separated from each other by a first width and second patterns separated from each other by a second width are formed on a substrate. Wherein a buckle base, in which a buckling cavity is formed, may be arranged on the hanging buckle main body, and an opening of the buckling cavity is divided into an inserting segment and a buckling segment that are connected with each other. A universal-serial-bus-to-serial signal may be detected at a USB interface and converted by a USB-to-serial converter circuit to the serial communication format and directed, via the same multiplexer, to the universal-asynchronous-receiver-transmitter instead of the serial signals from the primary serial configuration interface. The first level shifters can concurrently receive two double-precision mantissas under the double-precision mode or two single-precision mantissas under the single-precision mode.