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Ready-made Ethernet controller module for MII PHY interface

Discussion in 'Electronic Design' started by Ant_Magma, Mar 15, 2006.

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  1. Ant_Magma

    Ant_Magma Guest

    Does anyone know of any ethernet modules that would be able to
    communcate with this:

    It can be configured for MII/GPSI PHY or MII Host/DTE host interface.
    I've found some on Google, i just want to know if any of you have any
    experience with such modules and would recommend any?
  2. Ant_Magma

    Ant_Magma Guest

    Most of i found has SPI interface. Do any of you know any with MII
  3. Guest

    What you're looking for is an "ethernet phy evaluation" board.

    A google search turned up a bunch. The ones from the chip makers can
    be expensive, but the ones for things like the DSTINI are reasonably
  4. Ant_Magma

    Ant_Magma Guest

    Thanks, but in alot of these i do not see the word MII mentioned in
    their descriptions. Is it compatible with my Belfuse module?
  5. Ant_Magma

    Ant_Magma Guest

    Thanks, but in alot of these i do not see the word MII mentioned in
    their descriptions. I don't think it's compatible with my Belfuse

    There this website they have an array of ethernet
    modules. However they uses SPI to communicate to the uC. I'm not very
    knowleageble in these kind of things, but is there a way to convert SPI
    to MII?
  6. Richard H.

    Richard H. Guest

    You will find that some Ethernet controllers have an MII output on them.
    For example, the ASIX AX88796L on the EDTP website. You still need to
    interface the MCU with the Ethernet controller, but instead of using the
    built-in PHY for the copper Ethernet connection you can use the MII
    output for an alternate media (e.g., fiber).

    In other words, you need to check the data sheets of the Ethernet

  7. Guest

    Look again.

    99.9% of the ethernet phy-only chips are MII on the digital side. SPI
    is actually the rare case.
  8. Ant_Magma

    Ant_Magma Guest

    Fred Eady's boards on looks great.

    I've emailed him and he has confirmed that only the NICholas version
    with the AX88796L has MII connection. However, based on AX88796L 's
    datasheet and the picture of the board on the website, it seems that
    the MII connection pins are not used.

    I've tried googling looking for boards similar to Fred's but to no
    avail. I used terms such as MII PHY transceiver, Ethernet PHY module
    etc. Any ideas?
  9. Richard H.

    Richard H. Guest

    Aha. Yes, I concur, the MII pins are not extended on that board.

    You should ask Fred nicely if he still has any of his original ASIX
    proto boards. They wire (nearly) every pin to a contact pad. That
    board will do what you want. (The pads are on the left side, and are
    labeled with their alternate printer port function.)

    If not, you could persuade him to do a mod for you on NICholas and
    hand-solder a few "flying wires" to the MII pins. I convinced him to do
    that a couple times on the old board (for an address line that was

    The original ASIX proto board was tied to an article he wrote on it for
    Circuit Cellar 3-4 years ago, and he's got AVR drivers on the website
    for it. Again, maybe by request now.

    The ASIX has a register to select the integrated PHY or the external
    MII. Once that selector's switched you can talk to the MII powerline
    module through the ASIX to set its options before activating the ASIX

  10. Ant_Magma

    Ant_Magma Guest

    Thanks Richard. But he haven't replied my previous email, so i don't
    know how he thinks about my request. Can i mention your name in my next
    email to him?

    I have actually ordered parts to build my own Ethernet module based on
    Micrel's KS8721B PHY transceivers, single layer only. However i was
    told that to build a Ethernet module with only single layer is
    impossible. Thus, with my limited knowledge and pressing deadline i
    don't think i can make it, that's why i'm looking for ready-made
    Ethernet MII modules.

    If you know any other company that produces the similar thing as Fred
    Eady's with MII connection i would appreaciate if you let me know.
  11. Richard H.

    Richard H. Guest

    :) I'm flattered, but it wouldn't do any good. I'd be impressed if he
    even remembered my order.

    Have you asked Belfuse if they have a dev kit for the powerline PHY?
    I'd agree that making a single-layer Ethernet proto board will be nearly
    impossible. It's hard enough to get working (not just laid out) with 2
    layers. And if you're pressed for time you don't want to be trying to
    figure out hardware problems on Ethernet. I had a bugger of a problem
    and ended up having to blindly re-spin the board hoping I'd fixed the
    problem. (Got lucky.)

    I'm not aware of anyone else offering boards like Fred's. ASIX is one
    of only 3-4 non-PCI controllers, and I'm fairly certain the others don't
    have MII. Then, the liklihood of finding someone offering that chip on
    a proto board with the MII pins extended is practically nil.

    However... if you have the capability to make your own board, presumably
    you can solder fine-pitch chips? If so, why not add the flying wires to
    the MII pins on NICholas yourself?

    Mostly I've seen MII interfaces as outputs on MCU's with integrated
    Ethernet, such as the Freescale Coldfire. If you haven't picked an MCU
    yet, that could be an option. But if you haven't picked an MCU or
    Ethernet controller yet (or started writing drivers, etc.), you're a
    long way from a working proto.

    What kind of a deadline are you up against? Maybe someone here could do
    the mod for you if Fred's not available.

  12. Ant_Magma

    Ant_Magma Guest

    No, they say they do not even have any reference designs or application
    notes available.
    I'm very hard pressed for time, around 3 weeks. I did not know building
    an ethernet module is so hard.

    I think extending the NICholas pins could be possible.
  13. Ant_Magma

    Ant_Magma Guest

    While i try to pursuade Fred, in the mean time does anyone know how to
    build an ethernet module with just top n bottom 2 layers?
  14. Richard H.

    Richard H. Guest

    Going back to this comment, what does this PHY have to do with your
    project, and what were you going to connect this part to? It's a 10/100
    copper PHY, and seems out of place unless you're trying to tie the two
    PHYs together through MII to make a converter. I don't know if this is
    possible (maybe; if so, this could be technically much simpler).

    Perhaps you could explain what you're trying to achieve... The original
    post seemed like you're trying to create <something> that connects to
    powerline networking. It also seems like you're focused on testing /
    proof-of-concept for the powerline technology.

    If you connect the PHY to an Ethernet controller, it needs a CPU, and
    the CPU needs driver software, a protocol stack, and an application to
    be useful. All that plus a PCB design is a considerable project, and
    you need at least 2 working units for an end-to-end connection.

    Pardon the bluntness, but you're headed for failure if you try to tackle
    this from scratch in 3 weeks, having not selected a microcontroller or
    Ethernet controller, written the software, or have a ready PCB design.
    To achieve your goal, the best bet is to wire modules together; the more
    turnkey the better.

    The most turnkey option will be a dev board for a microcontroller that
    has integrated Ethernet with MII as it's primary output. It will likely
    come complete with working reference driver code, an IP protocol stack,
    and sample applications; you just need to supply / replace the PHY,
    which you have. There are several, but Freescale's Coldfire comes to
    mind. I'm sure you'll find a suitable dev board here:
    They can be bought someplace like

    The next best option would be to modify the NICholas board, and wire it
    between a micro of your choosing and the PHY you're testing. If you
    pick Atmel's AVR, and if Fred will accommodate with his old PDF docs and
    his published programs, you *might* get this working in 3 weeks, but
    probably not in your spare time.
  15. Ant_Magma

    Ant_Magma Guest

    Perhaps you could explain what you're trying to achieve... The original

    I'm trying to interface with my Belfuse powerline module mentioned in
    my first post. This module uses MII interface that's why i need an
    ethernet module that is able to communicate with the MAC in my
    powerline module.

    The whole project is to use the Bel powerline module to communication
    between 2 PCs. Since the PL module supports MII/GPSI interface and MII
    Host/DTE interface, i need an ethernet PHY to connect the module to the
    both PC's network card, like this:

    PC1 (network card) => Ethernet PHY => PL module => Power line => PL
    module => Ethernet PHY => PC2 (network card)
    The powerline module contains the MAC, thus i only need to have a PHY
    to connect to the network card of a PC through RJ45.

    My instructor assured me that no programming was required.
    I should have had more time than i do now. But that's another story for
    another day.

    I have in my possession now 2 Micrel KS8721B ethernet phy transceiver
    and all of its components. So now i plan to use this to build my
    ethernet module.
    I don't think i would need an MCU right? Since my module should be able
    to act as an MCU? I'm new, please correct me if i'm wrong.
  16. Richard H.

    Richard H. Guest

    Ah. You are making an Ethernet PHY converter - this should not require
    an Ethernet controller. (The PC's NIC is serving this function.)

    From the rough info on the BelFuse site, you were headed down the right
    path making a simple board with the Micrel PHY. What you will end up
    with is PowerlineModule<->MII<->10/100 PHY<->cable<->PC NIC.

    The PCB could be simple if the pins are mirrored on the two MII devices,
    otherwise you'll need 2 layers to "roll" the MII signals.

    Right. You'd be using the MII as the "handoff point" between the
    back-to-back PHY modules. The PC's Ethernet card and CPU will be doing
    the meaningful work.

    This sounds much more viable for your timeline.
  17. Ant_Magma

    Ant_Magma Guest

    You don't know how relieved i am to get an assuarance from someone else
    that it's possible. Thank you Richard =)
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