DM8203
2-port switch with MII / RMII Interface
9.3.3 Serial Management Interface
The serial control interface uses a simple
two-wired serial interface to obtain and control the
status of the physical layer through the MII interface.
The serial control interface consists of MDC
(Management Data Clock), and MDI/O (Management
Data Input/Output) signals.
The MDIO pin is bi-directional and may be shared
by up to 32 devices.
9.3.4 Management Interface - Read Frame Structure
MDC
MDIO Read
//
//
0
1
1
0
A4
A3
A0
R4
R3
R0
32 "1"s
0
D15
D14
D1
D0
Z
Idle Preamble
SFD
Op Code
PHY Address
Register Address
Turn Around
Data
Idle
Read
Write
9.3.5 Management Interface - Write Frame Structure
MDC
MDIO Write
32 "1"s
0
1
0
1
A4
A3
A0
R4
R3
R0
1
0
D15
D14
Data
D1
D0
Idle Preamble
SFD
Op Code
PHY Address
Register Address
Write
Turn Around
Idle
Preliminarydatasheet
DM8203-15-DS-P05
October 23, 2008
49
DAVICOM [ DAVICOM SEMICONDUCTOR, INC. ]
