SMSC flexpwr lan8720 User Manual
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
0
1
1
0
A4
A3
A2
A1
A0
R4
R3
R2
R1
R0
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
1
0
A4
A3
A2
A1
A0
R4
R3
R2
R1
R0
Write Cycle
D15
D14
D1
D0
...
Data
Preamble
Start of
Frame
OP
Code
PHY Address
Register Address
Turn
Around
Data To Phy