78Q2120C Teridian Semiconductor Corp. (TDK Semiconductor), 78Q2120C Datasheet - Page 10

• Manufacturer Part Number: 78Q2120C
• Description: 10/100 Ethernet PHYS
• Manufacturer: Teridian Semiconductor Corp. (TDK Semiconductor)

REGISTER DESCRIPTION
The 78Q2120C implements 11 16-bit registers, which are accessible via the MDIO and MDC pins. The supported
registers are shown below in the following table. Attempts to read unsupported registers will be ignored and the
MDIO pin will not be enabled as an output, as per the IEEE 802.3 specification. All of the registers except those,
which are unique to the 78Q2120C, will respond to the broadcast PHYAD value of ‘00000’. The registers specific
to the 78Q2120C occupy address space MR16-22.
Legend:
© 2003 TDK Semiconductor Corporation, Proprietary and Confidential
Type
SC
0/1
Address
R
8-14
15
16
17
18
19
0
1
2
3
4
5
6
7
Description
Readable by management.
Writeable by management. Self
Clearing.
Default value upon power up or
reset
Symbol
MR8-14
MR15
MR16
MR17
MR18
MR19
MR0
MR1
MR2
MR3
MR4
MR5
MR6
MR7
Name
Control
Status
PHY Identifier 1
PHY Identifier 2
Auto-Negotiation Advertisement
Auto-Negotiation Link Partner Ability
Auto-Negotiation Expansion
Not Implemented
Reserved
Not Implemented
Vendor Specific
Interrupt Control/Status Register
Diagnostic Register/Test Register
Transceiver Control
Type
(0/1)
RC
W
- 10 -
Description
Writeable by management.
Readable by management.
Cleared upon a read operation.
Default value dependent on pin
settings. The value in bracket
indicates typical case.
10/100BASE-TX Transceiver
Default (Hex)
(01E1)
(3100)
(7809)
(0140)
4XXX
70C5
000E
0000
0000
0000
0000
0000
0000
0000
78Q2120C
Rev_1.1