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IP175C/IP175C LF/IP175CH/IP175CH LF
Data Sheet
2.15
Serial management interface
175C supports two serial management interfaces (SMI). User can access IP175C/IP175CH’s MII
registers through MDC0 and MDIO0. Its format is shown in the following table. To access MII register in
IP175C/IP175CH, MDC should be at least one more cycle than MDIO. That is, a complete command
consists of 32 bits MDIO data and at least 33 MDC clocks. When the SMI is idle, MDIO is in high
impedance.
When IP175C/IP175CH interfaces to an external PHY, it uses MDC1 and MDIO1 to read the status of the
external PHY.
Frame
format
<Idle><start><op code><PHY address><Registers address><turnaround><data><idle>
Read
Operation
<Idle><01><10><A4A3A2A1A0><R4R3R2R1R0><Z0><b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1b0><Idle>
Write
Operation
<Idle><01><01><A4A3A2A1A0><R4R3R2R1R0><10><b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1b0><Idle>
0
0
0
0
0
0
0
0
1
1
0
0
1
1
0
0
0
1
0
0
0
0
0
1
0
0
0
0
1
0
1
0
1..1
idle
start
op
code
PHY address =
01h
Reg address =
00h
TA
Register data
b
1
5
b
1
4
b
1
3
b
1
2
b
1
1
b
1
0
b
9
b
8
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0
idle
A
4
A
3
A
2
A
1
A
0
R
4
R
3
R
2
R
1
R
0
write
z
z
0
0
0
0
0
0
0
0
1
0
0
0
1
1
0
0
0
Z
0
0
0
0
0
1
0
0
0
0
0
1
1
0
idle
start
op
code
PHY address =
01h
Reg address =
00h
TA
Register data
b
1
5
b
1
4
b
1
3
b
1
2
b
1
1
b
1
0
b
9
b
8
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0
idle
A
4
A
3
A
2
A
1
A
0
R
4
R
3
R
2
R
1
R
0
read
z
zz
MDC
MDIO
MDC
MDIO
1..1
1..1
1..1
Mar 09, 2007
54/111
Copyright © 2004, IC Plus Corp.
IP175C/IP175CH-DS-R14
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