Ethernet Controllers
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
18-23
18.7.1
Operating Modes
Each Ethernet controller can a number of Ethernet modes, as described in the following
subsections.
18.7.1.1 MII Mode
MII is the media-independent interface defined by the IEEE 802.3 standard for 10/100 Mbps
operation. The actual transfer speed is determined by the
TX_CLK
and
RX_CLK
signals, which are
driven by the transceiver. The transceiver either auto-negotiates the speed, or software controls it
via the transceiver serial management interface (
MDC
/
MDIO
). This mode is only supported by
Ethernet controller 1.
18.7.1.2 RMII Mode
The RMII interface (low pin count Reduced Media Independent Interface as specified by the
RMII Consortium standard), is a reduced MII interface. The purpose of this interface is to
provide a low cost alternative to the MII, with an 8-pin interface instead of 16 (
MDC
and
MDIO
pins not included).
18.7.1.3 SMII Mode
SMII is a serial MII interface. The SMII can operate as a MAC-to-PHY or a MAC-to-MAC
connection:
A MAC-to-PHY conveys complete MII information between a 10/100 PHY and MAC
using two signals per port, and generates the output SYNC signal to allow a MAC-to-PHY
connection. The SMII reference clock generates both transmit and receive clocks for the
MII interface clocks.
For a MAC-to-MAC connection, the SMII interface uses a SYNC input signal to support
data synchronization and disables the typical output SYNC signal generation. The SMII
reference clock generates both transmit and receive clocks for the MII Mode interface.
18.7.1.4 RGMII Mode
The RGMII is intended to be an alternative to the IEEE 802.3u MII, the IEEE 802.3z GMII, and
TBI standards. The principle objective is to reduce the number of pins required to interconnect
the MAC and the PHY from a maximum of 28 pins (TBI) to 12 pins in a cost effective and
technology independent manner. In order to accomplish this objective, the data paths and all
associated control signals are reduced and control signals are multiplexed together and both
edges of the clock are used. For Gigabit operation, the clocks operate at 125 MHz.
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...