Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [mii]

17 questions
7
votes
1 answer

Can an RMII phy be connected directly to another RMII phy

I have some Microchip (SMSC) LAN9303 Ethernet switches in my system. The LAN9303 is a 3-port switch which has 2 connections for twisted pair cables and one MII connection. The switch chips are some distance apart and each is connected to an FPGA…
Will
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4
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2 answers

Embedded Ethernet Solution w/ PoE+; SPI or MII?

I am currently undertaking my first hardware design attempt of an embedded Ethernet project w/ PoE+. I have experience working with embedded systems with Ethernet (mostly ARM M3/M4 processors with RMII interface to an external Ethernet PHY…
zme
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4
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1 answer

Ethernet Transmission with one MAC and Multiple PHYs

I have been recently learning about ethernet subsystem. I see that the MDIO interface is shared across multiple (upto 32) PHYs from a single MAC and each PHY's state can be accessed using the 5-bit PHY address. But can I route the MII/RMII signals…
gmancity
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3
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2 answers

Media Independent Interface signals

For the MII interface signals, I read on Wikipedia - MII on the Tx and Rx signals. But I am confused about why there are two clocks (for Tx and Rx)? Are the directions mentioned for transmitter signals and receiver signals mentioned in the wikipedia…
user220456
1
vote
1 answer

How should I connect two MII devices back to back?

I have researched a bit on this topic. Each time I found different opinions and examples. Earlier, I've made a successful connection between a RMII featured micro-chip and an ethernet PHY, again RMII featured LAN8720A. Now I want to connect an…
Sener
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0 answers

MII/GMII switch for 10/100 Mbps vs 1Gbps

The lack of search results I've got so far suggests that I have a fundamental misconception here, but: for a PHY with a MII/GMII interface such as the KSZ9031MNX, how does the MAC decide whether to use MII or GMII signaling? Should I wait for the…
Simon Richter
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1 answer

Ethernet Phy Rx developed in a FPGA to send data to an ethernet Mac

I'm trying to send data from a FPGA to the Ethernet Mac port of a SoC which has the stmmac Synopsys IP. I'm using the MII protocol at 25MHz for 100Mb/s (4-bit per clock cycle). I'm sending the following fake ethernet frame: FF FF FF FF FF FF …
gregoiregentil
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1
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1 answer

MDIO bus pull-ups

What is the proper way to connect multiple ethernet devices via MDIO bus? I know that MDIO (similarly to I2C) is open drain, so I think that I need (just as in I2C) two 1-4, 7 kOhm pull-ups both for MDIO and MDC pins (Do I actually need a pull-up…
Andy
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1
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2 answers

Lan9500 to Switch (KSZ8795) MII wiring

I'm an experienced analog/power designer that's been asked by a coworker to scrub a digital design. He's pretty junior, but a good friend, so I am helping. (So now we're BOTH in trouble. ;-P We are connecting a LAN9500 and a KSZ8795CLXIC and…
EforDogsFan
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0 answers

Ethernet MAC TO MAC Communication between S32K148_SAMA5D27 Schematic Review

I am doing RMII MAC TO MAC Communication between S32K and SAMA5D27.Please find the attached schematic file. Could you please review it. May I know the level shifters directions are correct or not. My Pin mappings are given below. From the pin…
Hari
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0
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1 answer

MII inpedance matching for LAN9313i

I am designing an ethernet switch using the LAN9313i and the ADIN1100. For my understanding MII traces should be routed to match 50 Ω. However, Microchip recommends 68 Ω in their routing checklist and their reference schematic. I can't find any…
Paul Mustermann
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0
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0 answers

Using an Ethernet Phy and XFMR instead of RS422

We've been using a quad RS485 setup for some time. No problems. Now we'd like to increase the speed over what we can get away with on RS485 with the micro we're using. Essentially, we've been implementing an SPI port using four RS485 parts. I've…
GaryLa
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0
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1 answer

How to connect two Ethernet switch ICs together using MII Interface

I have been searching on how to connect two Ethernet switch ICs together. I have designed a custom PCB. Beside some other features, it accommodates an Ethernet Switch IC. This works OK. The bandwidth I use is not more than 100 Mbps. It is time now…
Sener
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0
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1 answer

Using SMI to check speed of ethernet phy

I am trying to use the ethernet PHY which comes with my Digilent Nexus 4 DDR, a Microchip LAN8720A (datasheet). I wrote a controller which lets me read and write values to the smi registers using the mdio and mdc signals. Now I need to be able to…
chasep255
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0
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1 answer

Ethernet MII Timings MAC<->PHY

I am a student working on my graduation project, which will need an Ethernet interface. For such job I choose a microcontroller with built in MAC (STM32F777BIT) and for the PHY, the LAN 8740. I have seen many schematics and reference deisgns, which…
Pedro Santos
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