UCD3138: What mean HS Loop in ADC Control Register.

Part Number: UCD3138

Hello.

I want to make a ADC timing in a DPWM edge.

For example, if I want to synchronize ADC12 with DPWM0, how should I set the register?

And, what does "HS Loop" mean ? 

A below picture is in sniu028a.pdf

Regards,