4.3 Clocking Structure

In this design, there are two clock-domains. The on-board 125 MHz crystal oscillator drives the XCVR reference clock. XCVR REFCLK sources the transceivers and global clock network in this design. The on-chip 160 MHz RC oscillator drives CoreABC, Flag_for_RXPLL_lock, PF_XCVR_DRI block, and the ERM module of XCVR. The following figure shows the clocking structure in this design.