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Questions tagged [mac]

Media access control or MAC should not be confused with Apple MAC, this is part of the Data-Link Layer which is one of the seven layers of the OSI-ISO. It is most commonly used access technologies such as Wifi, WiMAX and Zigbee. It mainly deals with the handling and granting channel access and also coordinating with physical layer.

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Ethernet MAC Controller IC design process

I'm from an embedded software background, and I am trying to learn more about chip design. To this end I want to understand what goes into designing and implementing a digital IC like an ethernet ...
NeedToKnow's user avatar
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Do we need differential routing TX and RX in Ethernet RMII MAC to MAC Connection

I am implementing an Ethernet mac to mac connection between SAMA5D27C-D1G-CU and FS32K148UJT0VLQT micro-controller. In MAC to MAC communication PHY TX is connected to RX of MAC and vice versa as shown ...
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How to define PHY mode and MAC mode between back to back switches

I'm planning to use this Switch IC connected to another another switch ic which is the same part number. When connecting these devices in back to back mode with RGMII interface between then, I need to ...
Freshman's user avatar
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Silver Coating on the front glass inside a crt

I recently disassembled a defective Macintosh SE. When taking apart the CRT (safely) to preserve the front glass panel to screw back in, i noticed a silver coating on the inside of said front glass ...
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Connection between MCUs with PHY peripherals

I plan to use a MAC TO MAC communication. RMII is decided to be used. One processor is SAMA5D27 and the other is S32K148. The signal connections seems to be OK. But would this configuration work? Also ...
Freshman's user avatar
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1 answer
343 views

MAC to MAC connection TX to RX [duplicate]

I'm connecting two MACs back to back. One is the IMX6 processor. The other device is this Microchip LAN9370 "5-Port AVB/TSN Gigabit Ethernet Switch with Integrated 100BASE-T1 PHYs". In that ...
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16 votes
2 answers
3k views

Why are Ethernet MAC and PHY separate?

I’ve been looking for a MCU/MPU with built-in Ethernet connectivity, and I’ve noticed that most only contain a built-in Ethernet MAC interface and require an external PHY. Why is this the case, as in ...
cdubs's user avatar
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How to build multiport Ethernet switch? [closed]

I have been researching how to build managed/multiport Ethernet switch. There are things that I do not understand and would like to know more. Some Ethernet switches have built in MACs and if I use ...
OnurTR's user avatar
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Additional processor needed for WiFi-MCU module?

I'm reading up on the design of WiFi-to-Ethernet converters, and came across the Ubiquiti U6-LR Teardown. I noticed that both this device and its competitors have not just a WiFi-enabled MCU and PHY, ...
cdubs's user avatar
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-4 votes
1 answer
264 views

Does an ASIC have an instruction set? [closed]

Does an Application Specific Integrated Circuit have an instruction set like a CPU? If yes, then that would contradict the statement "ASIC is faster than CPU" because having an instruction ...
Noob_Guy's user avatar
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Ethernet PHY MAC Controller - DHCP Request not responding

I am working with this Ethernet PHY. This is the - MAC Controller IC. I'm using the RMII interface. When Renesas send the DHCP request, I have the feeling (not 100% sure, I will try to find it out) ...
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2 votes
1 answer
549 views

Ethernet PHY MAC Address - DHCP Request not responding

I am working with this Ethernet PHY and little bit confused on the topic of MAC address. This is the - MAC Controller IC. I'm using RMII interface. One thing I want to understand is that what should I ...
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Mechanism/purpose of the NAV and its relation to the exposed node problem in 802.11

802.11 uses csma/ca as the mac protocol. Every station senses the medium, if something is being sent, then they will set their NAV to the duration ID from the packet being sent weather RTS, CTS, DATA, ...
user062's user avatar
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721 views

Ethernet Switch IC

I'd like to understand a little more on the Ethernet switches. Consider this Ethernet Switch which is a 3 port switch. Like, it has 2 copper ports and one digital (MAC side interface) port. It is ...
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Connect 100Mbit GMAC to a 1Gbit GMAC VSC8211

I would like to connect a 100Mbit GMAC on the SAMe70 with a 1000BASE-SX Switch. What will happen if I connect VSC8211 to this device and then attach a 1000BASE-SX Switch? Will the Autoneg on the ...
Aard's user avatar
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Ethernet switch IC ports in MAC and PHY mode

I come from analog/RF background and have limited knowledge in digital interfaces. According to TI's articles about Ethernet PHY found here and here, single MAC to single PHY connection seems very ...
sp2821's user avatar
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Connect a GMAC to another GMAC

I am looking into the KSZ9893 3-port switch. It has two(2) ports 10/100/1000 PHY. And one(1) GMAC with RGMII/RMII/MII interface. When I check the schematic of the SAMA5D3 Evaluation board they connect ...
Aard's user avatar
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CSMA/CA - What happens if a faulty WiFi station does not silence itself when an RTS/CTS is received?

In a WiFi network, assume a WiFi station does not silence itself for an RTS/CTS reception from other stations and it keeps on transmitting. I have few questions related to this scenario, 1.Will that ...
Franc's user avatar
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2 answers
792 views

How to create an ATX -5 volt rail for vintage Macintosh

I am trying to build a simple adapter for a mini ATX power supply for a vintage mac, I need a 5 volt rail that has it’s own separate ground (+5 volts to -5 volts) how would I go about doing this?
Harold Slovinski's user avatar
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What is the purpose of EEPROM in the PCIe accelerator card?

As i am exploring the many PCIe accelerator card features and design aspects, in few design I could find the Block called as 'MAC ID PROM'. And in the design they have provided the EEPROM circuit. In ...
BalkisMM's user avatar
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1 answer
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What is the operating voltage of Media access controllers? [closed]

Do MAC and PHY operate on same voltage levels?
Govind Srivastav's user avatar
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855 views

10GBASE-R 64B/66B Encoding/Decoding Unusual Control Block Formats

I need to design a 64B/66B decoder on receiver side of the GTY transceiver. Currently, I get 2 bit header and corresponding 64 bit descrambled payload at positive edge of every other clock cycle. So ...
utopian's user avatar
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2 votes
2 answers
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MAC Address as Serial Number in Embedded Systems

Is it ok to use a MAC Address as a serial number in an SoC with BLE? Are there any security threats to this perhaps? Or drawbacks?
Luke Galea's user avatar
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1 answer
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The SERDES/transceiver design inside the Ethernet MAC controller

I'm a little confused about the "SERDES" interface between MAC and PHY chip, and I drew some figures to illustrate the connections which confuse me as shown below. The MAC controllers in 3 figures are ...
Nobody's user avatar
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A few questions about the application of ethernet controller and PHY chip and SFP module

I have a question about the connection/application between the ethernet controller and PHY/SFP modules. Actually, there're so many scenarios for building up a NIC card, which makes me confused. For ...
Nobody's user avatar
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1 answer
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which interface to use TBI, GMII or MII? (FPGA)

I am working with the SoC FPGA Smartfusion2 M2S010-MKR-KIT. It is intended to exchange some data between the SoC and the PC. For that reason, I aim to use Ethernet. As far as I understood, in order ...
Lavender's user avatar
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7 votes
1 answer
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Design ethernet switch for multiple devices on PCB?

I'm working on a PCB design with a Raspberry Pi CM module and a microcontroller with ethernet capacity. The goal is to connect the devices to the internet. I'm currently using a normal ethernet switch,...
pascal0312's user avatar
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3 answers
1k views

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 ...
imd70's user avatar
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3 votes
1 answer
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Is there a need to use public OUI numeration for "private" Ethernet ports?

So I'm working on a product which will have two Ethernet ports: One for "public" network, which will be used by the customer, and one internal, within the machine chassis, which needs to be opened, ...
AndrejaKo's user avatar
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2 votes
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Development of proprietary WiFi protocol

I would like to do some customizations to IEEE 802.11 MAC layer protocol and implement it on hardware. I searched rigorously but I could not find any chipset with 802.11 PHY (RF + baseband chipset) ...
Ashutosh's user avatar
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4 votes
1 answer
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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 ...
gmancity's user avatar
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2 answers
188 views

usage of at24c02 eeprom with ethernet module

ı design a altium circuit schematic which consists of lan8720 tranciever rj45 and also at24c02 eeprom .However ı dont know exactly what MAC means and what it does. Why do we use eeprom with ethernet?...
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1 answer
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Ethernet Switch used for CCA to CCA comm without FPGA/Proc for MAC

I'd like to connect Ethernet between devices through magnetics without the FPGA or processor involved. For example, I have several off board (PWB) Ethernet signals coming onto my board and then onto ...
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1 answer
3k views

Purpose of QSGMII

I do not understand the purpose of QSGMII. QSGMII is supposed to combine 4 SGMII signals from 4 MACs into 1 QSGMII signal at 5 GHz. However, there is no Ethernet standard that works at 4 (or 5) GHz. ...
pierre123's user avatar
1 vote
1 answer
960 views

SGMII, MDIO and link training

I am reading this document : https://www.nxp.com/webapp/Download?colCode=AN3869 I got this link from NXP support, but I did not get a precise answer to my questiosn and I would like to be sure : The ...
pierre123's user avatar
1 vote
1 answer
3k views

Does SGMII use MDIO?

I was reading the SGMII specification and the documentation of a Gigabit MII to SGMII converter (see MAX24287). I do not see a MDIO to control the registers of the PHY (Basic Mode Status Register, ...
pierre123's user avatar
2 votes
3 answers
3k views

Ethernet PHY/MAC/SWITCH IC available?

I'm wanting to use an ethernet switch/Phy LAN9303 to output 2, maybe 3 ethernet signals. I know that I need a 25MHz clock, supporting resistors and caps as well as the magnetics, but I want to know if ...
user avatar
2 votes
1 answer
2k views

GMII/RGMII TX_ER signal: guaranteed functionality?

I have a question seeking to clarify EXACTLY what happens during a GMII exchange between MAC and PHY. Specifically, regarding the TX_ER signal. IEEE 802.3 Section 3: TX_ER is driven by the ...
asmvolatile's user avatar
1 vote
2 answers
156 views

Scheduling: Is is a Physical layer functionality or a Data(MAC) layer functionality or is it both?

Fellas, When we use the term SCHEDULING in wired/wireless communication, does it relate to a physical layer functionality or a Data (MAC) layer functionality or to both?
nashynash's user avatar
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1 answer
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MAC PHY defenitions

from Wikipedia: The media-independent interface (MII) was originally defined as a standard interface used to connect a Fast Ethernet (i.e., 100 Mbit/s) media access control (MAC) block to a ...
Meir's user avatar
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1 answer
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Ethernet PHY Layer Compatibility

I have two different embedded devices with ethernet connection. One is based on Texas Intruments DM648 DSP chip and the internals of the other are unknown to me. When I connect each one of them ...
Artium's user avatar
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2 votes
1 answer
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LTSpice netlist: plotting Vth vs length

I'm using LTspice on Mac, and trying to only use netlists, no GUI. I'm trying to follow berkeley ee240. They use a model that I don't think is available online so I'm just using default mosfet models. ...
Gswffye's user avatar
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5 votes
3 answers
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How to Get IP address from MAC Address using ESP8266 wifi Module

I am trying to use my esp8266 to discover several WiFi devices (sensor) in my home. I only know these devices MAC address, and I need to send TCP packets to their IP address. Using RPi, I can do that ...
bonchenko's user avatar
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8 votes
3 answers
43k views

What is the exact difference between SGMII and 1000Base-X?

I was wondering what the exact difference between SGMII and 1000Base-X is, because both seem very similar. Is the "big" difference only the physical medium they are supposed to be transmitted on? Both ...
andrsmllr's user avatar
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2 votes
1 answer
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Why RTS/CTS do not solve completely the hidden terminal problem and exposed terminal problem?

I was doing some reading online and textbooks about the RTS/CTS protocol for wireless transmission. Although, the textbook that I read said that the hidden terminal (and exposed terminal) is solved by ...
Kristof Tak's user avatar
3 votes
1 answer
436 views

What are retimers?

I am working with a low latency 10G MAC IP core for a Stratix V FPGA. One of the parameters is "High performance mode". The documentation states When enabled, high performance mode enables all ...
Randomblue's user avatar
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1 vote
2 answers
3k views

Viewing netlist on native ltspice for mac

I have a mac os x 10.9.3 and I run the native ltspice on it. I cannot seem to access the netlist (the text file version of the schematic) on it. Looking at the website: http://www....
erik mckee's user avatar
1 vote
2 answers
448 views

WiFi and collisions

since all WiFi operates in the same frequency which is 2.4 GHZ , if we set a certain number of access points in the same Region , for example , the maximum distance between them is 15 meters , could ...
hbak's user avatar
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7 votes
2 answers
10k views

Media Independent Interface (MII) vs Media Dependent Interface (MDI)

Is my understanding about Ethernet - MII & MDI correct? MII - Media Independent Interface is about the connectivity between MAC and PHY. In other words, it is about TXD and RXD signals from MAC ...
V V Rao's user avatar
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2 votes
1 answer
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W5100: get MAC address from devices in network? [closed]

I'm using a single Arduino Ethernet Shield with an Wiznet W5100 chip to scan a network for all devices. (Find the project source code on Github). All devices are in the same Ethernet segment. They ...
powtac's user avatar
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