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Altera_Forum's avatar
Altera_Forum
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15 years ago

10 Base ethernet Transmitter issues

Hey,

I know that is not the most proper area to place this question but i think there are many who can give me a tip on this matter.

When i have to design the circuit , i have to implement anything more than a RJ45 Filtered Jack (with transformers) ?

Like this : http://uk.farnell.com/amphenol/rjmg163118101nr/jack-10-100-base-t-rohs5/dp/1357436

http://uk.farnell.com/productimages/farnell/standard/135743307-40.jpg

Ps. The ethernet packets (UDP) will pass through hub.

I am really curious if i will face any collisions.

Thank you for your interest.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    The driver electrical specification and requirements of collision avoidance in half-duplex operation of 10BASE-T twisted-pair ethernet medium can be found in IEEE Std. 802-3, Section One, Clause 14.

    In a short, the interface has to listen on the receiving channel for colliding packets during transmission.

    The standard can be downloaded for free within the Get IEEE 802 program: http://standards.ieee.org/getieee802/portfolio.html
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Thanks for the reference FVM, i got some vital specifications about my needs.

    But i have a question, i had been concitrated on the fpga4fun.com 10base ethernet project (http://www.fpga4fun.com/10base-t0.html) and i am asking: It will be any clock issue if I use this project (20Mhz) combined with a Phy Chip (25Mhz) ?

    I am cornered on this matter and i dont know what to decide.

    1.Follow the fpga4fun project without PHY and face collisions, or

    2.Modify the source code and add a PHY chip to solve these problems.

    Ref: http://www.fpga4fun.com/10base-t0.html (http://www.fpga4fun.com/10base-t0.html)

    PS. I will only implement the Transmittion part ( Half Duplex)

    Thank you for your time. :)

    Friendly Giannis