How does 3D over DVI work on s23a700d?

[abddbz]

I would like to know how amd graphics cards achieve eye sync with this monitor while doing frame/field sequential over DVI-DL. I have searched through google for a couple of days but haven't found anything detailed enough. All I managed to find was that there is something special with this monitor that allows tridef to do 120hz field sequential 1080p through DVI-DL unlike monitors with 3D over display port. I also found that the EDID Detailed Timing Descriptor block contains the information of stereo sync which says the monitor has field sequential and sync=1 during left. How is this information used?

Please help me understand.