Is DSD signed or unsigned?

[MarcelvdG]

Does anyone know whether the single bit stream of a DSD signal is to be interpreted as:

A. Just a simple unsigned bit, so 1 > 0

or

B. The sign bit of a very short two's complement word, so 1 means negative and 0 means not negative?

I've always assumed A, but that's not based on anything.

 

[xx3stksm]

I usually regard DSD as the signed expression. When I designed decimation filter from DSD to 24 bits PCM, 0 of DSD converts to 0x7fffff, 1 of DSD is 0x800001. 0x7fffff and 0x800001 are the input data to decimation filter. 0 of DSD isn't 0 of PCM in this case.

1 bit DSM also has the same problem. Positive input value to the quantizer outputs 0(positive), negative one does 1(negative). That's why I regard DSD as the shortest 2'complement from the viewpoint of compatibility between another bit resolutions.