TBR19: 10BASE-T PHY Management Extension
Register (Register 19)
Table 76 contains the PHY Management Extension
Register (Register 19) bits.
Table 76. TBR19: 10BASE-T PHY Management Extension Register (Register 19)
Bits
Name
Description
Read/Write
Default Value
Soft Reset
15:6
Reserved
Write as 0; ignore on read
1 = last management frame was
RO
0
0
5
Mgmt Frame Format invalid (opcode error, etc.) 0 = last
management frame was valid
RO
RO
0
0
Retains
Previous Value
4-0
PHY Address
PHY Address defaults to 11110
11110
Reserved Register: 10BASE-T Configuration
Register (Register 22)
TBR24: 10BASE-T Summary Status Register
(Register 24)
This register is reserved.
The Summary Status register is a global register con-
taining status information. This register is Read/Only
and represents the most important data which a single
register access can convey. The Summary Status reg-
ister indicates the following: Link Status, Full-Duplex
Status, Auto-Negotiation Alert, and Speed. See Table
77.
Reserved Register: 10BASE-T Carrier Status
Register (Register 23)
This register is reserved.
Table 77. TBR24: 10BASE-T Summary Status Register (Register 24)
Read/
H/W or Soft
Reset
Bit(s)
Name
Description
Write
15-4
Reserved
Write as 0; Ignore on Read
0
0
1 = Link Status is up
3
2
1
0
Link Status
Full-Duplex
R/O
0
0 = Link Status is down
Operating in Full-Duplex mode
Operating in Half-Duplex mode
R/O
R/O
R/O
0
0
0
AutoNEG
Alert
1 = AutoNEG status has changed
0 = AutoNEG status unchanged
1 = Operating at 100 Mbps
0 = Operating at 10 Mbps
Speed
Am79C978
197
AMD [ AMD ]
