Applications - 1.0 English

PCI Express PHY LogiCORE IP Product Guide (PG239)

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The following table summarizes the recommended default features supported for different line rates.

Table 1. Default Features Supported
Features Gen1 Gen2 Gen3 Gen4
Line Rate 2.5 GT/s 5 GT/s 8 GT/s 16 GT/s
PCLK Frequency 125 MHz 250 MHz    
2-Byte Data Width Yes Yes    
4-Byte Data Width     Yes  
8-Byte Data Width       Yes
CPLL Yes      
QPLL1   Yes 1 Yes  
QPLL0       Yes
RX Elastic Buffer with Clock Correction Yes Yes Yes Yes
8b/10b Encoder and Decoder Yes Yes    
128b/130b Encoder and Decoder     Yes Yes
N_FTS 255 255 255 255
UltraScale Device GT Support GTH GTH GTH N/A
UltraScale+ Device GT Support GTH/GTY GTH/GTY GTH/GTY GTH/GTY
  1. For the Gen2 speed, the default PLL option is QPLL1 in the customization GUI; you can choose either CPLL or QPLL1 also. In case of speed training down, the chosen PLL will still be active.
  2. By default, DFE is enabled. You can change the value with the Form factor driven Insertion loss adjustment option in the customization GUI. For more information, see the Advanced Settings Tab.
  3. A Gen4 configuration requires a -2, -2L, or -3 speed grade UltraScale+ device.