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    [moved] External Ethernet Microcontroller or ZYNQ

    Hi,

    I need to implement 1 GigE with either FPGA or ZYNQ. I am wondering performance wise which Ethernet option is more promising.

    1- FPGA with external Ethernet Microcontroller (MAC and PHY) on external chip
    2- ZYNQ 7020 having MAC inside the chip but it need external PHY

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    Re: External Ethernet Microcontroller or ZYNQ

    ZYNQ IS an FPGA.

    There are cores that implement 1G MAC in an FPGA, and chips that do it externally. Both methods meet the requirements of 1Gig Ethernet. How are YOU defining performance?



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    Re: External Ethernet Microcontroller or ZYNQ

    Hi,

    By performance I mean the overall system speed. I am wondering which option will make the system speed maintain at good level.



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    Re: External Ethernet Microcontroller or ZYNQ

    Obviously, the question can't be answered without considering the intended system purpose, data paths and processing.

    You are presuming a FPGA, hence the data path is apparently between FPGA fabric and ethernet. For the"external microcontroller" variant, how's the data transported between FPGA and processor? The SoC (e.g. ZYNQ) advantage is the fast interface between FPGA fabric, processor core and hardwired peripherals.



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    Re: External Ethernet Microcontroller or ZYNQ

    Yes, I understand that ZYNQ only provide MAC, it need External Ethernet PHY for example in ZedBoard. How about if my design in PL fabric in ZYNQ need both core of ARM process to run the design in PL then how would this effect the 1 Gbps Ethernet communication ? Would the Ethernet bandwidth be reduced ?



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    Re: External Ethernet Microcontroller or ZYNQ

    Quote Originally Posted by joniengr View Post
    Yes, I understand that ZYNQ only provide MAC, it need External Ethernet PHY for example in ZedBoard. How about if my design in PL fabric in ZYNQ need both core of ARM process to run the design in PL then how would this effect the 1 Gbps Ethernet communication ? Would the Ethernet bandwidth be reduced ?
    Doesn't matter, which way you do it. Either way the performance (i.e. the maximum payload bps you can transfer) is dependent on whether or not you can keep up with the data transfer to the MAC (either internal to the Zynq or external through an interface to an external MAC). If you can't keep up with the data rate due to either too much code running on the processor or dead time in a FSM in an FPGA sending data to the MAC, then you will have reduced performance.

    if you equate performance with payload sent, then If you send minimum sized Ethernet packets your payload rate (hence performance) will be significantly reduced, if you send jumbo packets your payload rate will be maximized, regardless of which end of the packet size spectrum you chose to send the Ethernet link will still be a 1 Gbps link.


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