Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [rmii]

24 questions
12
votes
2 answers

Ethernet RMII on two layer PCB

INTRODUCTION: I'm aiming to design an Ethernet connected system as a hobby ( ie. plenty of time but not wishing to spend much ). My design constraints would ideally be sticking to a 2 layer 100mm x 100mm PCB with 0.3mm min holes and 0.15mm min…
Juan Manuel López Manzano
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7
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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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6
votes
2 answers

RGMII and RMII backwards compatibility

According to Wikipedia: GMII [...] is backwards compatible with the media-independent interface (MII) But is RGMII backwards compatible with RMII? I'm asking this because I'm making a schematic of an iMX6 System on Module. I have the RGMII pins,…
PierreOlivier
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4
votes
1 answer

Is safe to route a rmii (txd0 txd1) track under resistors?

I'm creating a PCB to connect an ESP32 to a PHY (lan8720) and I want do route a trace under some resistors. Is there any problem (crosstalk) doing this? The trace is txd0 (txd- on picture) under the resistor txd1.
rodrigtti
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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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2
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1 answer

Ethernet communication on the same board : do I need a transformer?

I need to communicate between a microcontroller that has an integrated MAC (Datasheet) and a microprocessor that has an integrated MAC and PHY (Datasheet). The pins of the MAC on the processor are already used by design, so I use an Ethernet…
uz3il
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2
votes
1 answer

Ethernet RMII using ribbon cable

I am trying to interface the Ethenet using RMII at 100 Mbps speed. The main board is a RH850 F1 evaluation board. Ethernet RMII transciever is a DP83848 chip on a waveshare External Transciever Board The two boards are connected using an unshielded…
Rishikesh Raje
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2
votes
1 answer

How do I interpret the setup/hold time on this RMII interface?

I'm coding the FPGA (MAC) side of an RMII interface between an Altera FPGA and LAN8720 device. Page 72 of the datsheet (pdf) shows the relevant timing diagram for this interface. The input setup/hold values (tsu and tihold on the TX interface) are…
stanri
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1
vote
2 answers

RMII interface name length matching?

I'm drawing the layout for an RMII interface, but I have two doubts: 1 - Do RMII interface traces need length matching? 2 - Do the traces of the RMII interface have to be impedance controlled? I ask because searching on the internet you find…
Federico Massimi
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1
vote
1 answer

Crystal Oscillator for STM32F407 with LAN8720

I'm planning to build a custom board with STM32F407 chip for a system where I also need Ethernet connectivity. I'm planning to connect this board to a LAN8720 with breakout board from Smart Electronics to have Ethernet connectivity (two independent…
Leandro Loureiro
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1
vote
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
vote
3 answers

Connecting KSZ8863RLL to a MAC using RMII

(Edited to ask further question about the MDIO/MDC pins.) I'm adding a Lantronix xPico 250 to an embedded deivce to provide WiFi access. The device has an ARM based SOM which includes a PHY and there is also an external RJ45. The three are connected…
imd70
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1
vote
2 answers

How to convert RMII signals to LVPECL signals

As far as I understand the RMII output signal of an ethernet PHY is a TTL signal (at least according to wikipedia). I need to convert these into LVPECL signals. So on the one side I have something like TX0 and TX1 from the RMII and on the other…
user90660
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0
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1 answer

Connecting two ethernet PHY's (KSZ8051RNLU) in RMII back toback configuration

I would like to to connect the KSZ8051RNLU in a loopback configuration with itself, I have read that this is possible with other PHY's. Does the KSZ8051RNLU have this capability? Will it auto-configure itself if it can do this? Has anyone does this…
Voltage Spike
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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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