We tried the manual approach without using openlane. We could get caravel.gds with the PLL placed and routed inside with this connection of pins: REF -> wb_clk_i CLK -> io_out ENb_VCO -> wb_sel_i[0] ENb_CP -> wb_sel_i[1] VCO_IN -> analog_io[30] VDD -> VCCD GND -> VSSD1