Arria 10: Native Phy CDR in Manual Mode LTD

HI,

Pls see my reply below

1. I am littlie confused about CDR at10G Manual Mode LTD and CDR at 10G Automode

• The difference is in CDR auto mode, it will automatically detect incoming Rx data rate and lock the CDR accordingly
  • For CDR manual mode, user is expected to manually control CDR lock operation.
  • Detail explanation is available in user guide doc (page 471, chapter 5.1.6.3. CDR Lock Modes)
  • https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/arria-10/ug_arria10_xcvr_phy.pdf
  • If you are unsure then my recommendation is to just use CDR automatic mode

1. When receiver receive other than 10G rate what will be rxdata and rx_clk in both case?

• I don't understand your question as the both rxdata and rx_clk is incoming data transfer from external system to FPGA transceiver Rx channel
  • You should understand what your system is sending to FPGA Rx channel, right ?
  • From FPGA Rx channel side, below is the expectation example
    • If NativePHY is configured to 10G setting and incoming Rx data transfer is 10G with no signal integrity concern, then CDR should locked
    • If NativePHY is configured to 10G setting and incoming Rx data transfer is 8G, then CDR will likely loose lock as this is not expected data transfer that match with 10G setting

Thanks.

Regards,

dlim