The invention relates to a method and circuit for aligning a serial bit stream with a parallel output. The method comprises latching Q bits from the serial bit stream into a register, locating a position P of a first bit of a start of frame delimiter (SFD) in the register and discarding P-1 bits from the serial bit stream, before the position of the first bit of the SFD, thereby aligning the serial bit stream with the parallel output. The circuit comprises a latch, a fault tolerant analysis logic (FTAL) for locating a position P of a first bit of a start of frame delimiter (SFD) in the register and a shift register for discarding P-1 bits from the serial bit stream, before the position of the first bit of the SFD, thereby aligning the serial bit stream with the parallel output.