SDI II Intel® Stratix 10 FPGA IP Design Example User Guide
                    
                        ID
                        683368
                    
                
                
                    Date
                    12/09/2022
                
                
                    Public
                
            2.1. Parallel Loopback Design Examples
   Note: For parallel loopback designs, do not share the TX PLL reference clock with the RX transceiver reference clock. The design logic tunes the TX PLL clock to match the RX recovered clock frequency. For the parallel loopback with external VCXO designs (single-rate and triple-rate), use the only 148.5 MHz on-board oscillator as the TX PLL reference clock. For the RX reference clock, use a 148.5 MHz clock from another on-board oscillator. 
  
 
  
    Figure 9. Parallel Loopback with Simplex Mode Block Diagram
     
      
   
 
   
    Figure 10. Parallel Loopback with Simplex Mode Clocking Scheme
     
      
   
 
  
    Figure 11. Parallel Loopback with Duplex Mode Block Diagram
     
      
   
 
   
    Figure 12. Parallel Loopback with Duplex Mode Clocking Scheme