Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
SMSC LAN8720/LAN8720i 35 Revision 1.0 (05-28-09)
DATASHEET
Figure 4.10 MDIO Timing and Frame Structure - READ Cycle
Figure 4.11 MDIO Timing and Frame Structure - WRITE Cycle
MDC
MDI0
Read Cycle
...
32 1's 0110A4A3A2A1A0R4R3R2R1R0
D1
...
D15 D14 D0
Preamble
Start of
Frame
OP
Code
PHY Address Register Address
Turn
Around
Data
Data From Phy
Data To Phy
MDC
MDIO
...
32 1's 0 1 10 A4A3A2A1A0R4R3R2R1R0
Write Cycle
D15 D14 D1 D0
...
DataPreamble
Start of
Frame
OP
Code
PHY Address Register Address
Turn
Around
Data To Phy