is the type of register with combinatorial logic used for stage st j through st n fig5 register stages 63 are the same as register 62 with the addition to register function 62 of a logic block 614 the output of mux 612 on line 613 selects inputs from either the previous stage s l 1 on line 625 or from the next stage s l 1 on line 611 depending on control updn on line 89 other inputs to the fig6 logic circuit are the inputs 79 from the phase shift range calibrator 70 fig1 and fig5 both for the current stage c l on line 617 and for the previous stage on line 616 and input from stage one s 1 on line 606 the function of the logic becomes easier to understand by also referring to fig7 a equations and fig7 b truth table for the function for each register unit st l there are two outputs s l and wa l s l provides the corresponding digital control input 68 to the digital adjustable delay 50 fig2 wa l 608 is the feedback signal to stage one st 1 in the fig7 b truth table shown.