Harvard biphase

[1] It is one of the formats employed in forming the digital bits of logic one and logic zero, along with non-return-to-zero (NRZ) and bipolar-return-to-zero (RZ) formats.

[2] Harvard biphase has previously been used for digital flight data recorder (FDR) where 12-bit words per second are recorded onto magnetic tape using Harvard biphase code.

[3] The data are encoded in frames and each of these contains a snapshot of the avionics system in the aircraft.

There is also a phase transition at the start of each bit cell.

[5] The ARINC 573 serves as a standard for FDRs that feature continuous data stream encoded in Harvard biphase.