I think that we can use si,sq ,siq to control the phase move.In my understanding,in the Fig. 5. Phase rotator ,si, sq correspond to the values on the horizontal and vertical lines.siq corresponds to the value on the diagonal line.For example,when si=0,sq=0,siq=0 the phase should be 20.2°。when si=0，sq=0,siq=1,the phase should be 25.3°。I calculated this by phase=arctan Q/I. I（si，siq）=（7-2·si）·UI+(1-2·poli)·(9-siq）UIQ. Q（sq，siq）=（7-2·sq）·UI+(1-2polq)·siq·UIQ. The original formula is Q（sq，siq）=（7-2·sq）·UI+(1-2·polq)·（9-siq）·UIQ.If my understanding is wrong, could you explain it to me?
when poli =0，polq=0，I think siq does not work.Should I add an inverter to one input of poli and polq to ensure that siq can work?
Pier Andrea Francese et al., “A 16Gb/s 3.7mW/Gb/s 8-tap DFE receiver and baud rate CDR with 30kppm tracking bandwidth,” IEEE J. Solid-State Circuits, vol. 49,no. 11, pp. 2490–2502, Nov.. 2014. –