Ethernet mac

[Stijn Goris]

hi all,

A beginners question: can someone explain me what an Ethernet MAC does (like
the one from Realtek) and what is the advatage of an MII interface?

kind regards
Stijn

 

[Daniel Kelly \(AKA Jack\)]

Hi,

MAC stands for "media access control". As I understand it, the MAC address
is a unique label that gets assigned to the Ethernet adapter. Try these
sites:

http://en.wikipedia.org/wiki/MAC_address
http://en.wikipedia.org/wiki/Media_Access_Control

Hope that helps,
Jack

 

[Jeroen]

The MAC is the hardware that converts the ethernet frames into a format
usable by the CPU, e.g. it deserializes the data, calculates the FCS, checks
it, waits for the right MAC address to pass by etc.etc.

MII is an standard to save pins in switch/router products.

http://www.national.com/appinfo/lan/rmii.pdf

Hope this helps,

Jeroen

 

[Amnon]

MII and its predecessors standards (RMII, SMII, GMII) are used to convert
the differential serial analog signal, coming by the Ethernet cable, into a
parallel digital bus to allow passing the Ethernet data/ control information
from the PHY chip to/ from the card (MAC chip/ CPU).
MII - for 10/ 100Mhz: 4 data lines, x 2.5/25Mhz each
RMII - for 10/ 100Mhz: 2 data lines, x 5/50Mhz each
SMII - for 10/ 100Mhz: 1 data line, x 10/100Mhz

GMII - for Giga Ethernet, 125Mhz bus

Amnon Pomerants