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How to make Cyclone V GX receiving and transmitting data at two different rates


User have 2 cables with 2 different speed and amounts of data transmitting throw them, one cable work at 1Gbps another at 2Gbps and I want to save receiving data at DDR and translate it to same GX transmitter at same speed, or translate predefined data from DDR to GX transmitter at speed (1G or 2G) chosen by command from NiosII.


I have Cyclone 5CGXFC7B6F31 and I never work with GX transceivers before and so far I only read a 676AN and some pages in handbooks and user guides.


I still don't understand re configurable GX part how can I make such system.


As I suggest I need:


1) 2 PLLs for 1G and 2G rates;


(don't sure why in AN676 use fPLL and Channel PLL, as I understand fPLL work at rated up to 3.125Gb, Channel PLL work above but only for transmitting (CMU) or receiving (CDR) data? I my case what I need to use?)


2) Transceiver Native PHY where i must specify this two external PLLs and their data rates.


3) one transceiver reconfiguration controller to connect transceiver native PHY and transceiver PLLs(if I use it)? And to work with mif ?


4) one reset controller


5) add two mif files for 1G and 2G Native PHY settings in original project.


As I understand for receiving part I need channel PLL in CDR mode, who work in LockToReference and LockToData modes to understand at which speed data comes to transceiver? For transmitting part I can select speed via setting registers in streamer module?


Maybe someone have step-by-step tutorial for my case?

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As I understand it, you have some inquiries related to reconfiguring the CV XCVR between 1G and 2G. For your information, you can make use of the TX local divider and RX channel reconfiguration to switch between these two data rates since one is x2 of the other. I have shared with you a simulation example previously from wiki on CV dynamic reconfiguration between 800Mbps and 1600Mbps for your reference. This simulation uses embedded streamer to ease the rate change.


Please let me know if there is any concern. Thank you.



Best regards,

Chee Pin

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