AM79C978A AMD [Advanced Micro Devices], AM79C978A Datasheet - Page 186

• Manufacturer Part Number: AM79C978A
• Description: Single-Chip 1/10 Mbps PCI Home Networking Controller
• Manufacturer: AMD [Advanced Micro Devices]

TBR19: 10BASE-T PHY Management Extension
Register (Register 19)
Table 59 contains the PHY Management Extension
Register (Register 19) bits.
Reserved Register: 10BASE-T Configuration Regis-
ter (Register 22)
This register is reserved.
Reserved Register: 10BASE-T Carrier Status Reg-
ister (Register 23)
This register is reserved.
186
Reg
Bit(s)
15-4
19
19
19
3
2
1
0
15:6
Bits
4-0
5
Full-Duplex
Link Status
Reserved
AutoNEG
Table 59. TBR19: 10BASE-T PHY Management Extension Register (Register 19)
Speed
Name
Alert
PHY Address
Mgmt Frame
Reserved
Table 60. TBR24: 10BASE-T Summary Status Register (Register 24)
Format
Name
Write as 0; Ignore on Read
1 = Link Status is up
0 = Link Status is down
Operating in Full-Duplex mode
Operating in Half-Duplex mode
1 = AutoNEG status has changed
0 = AutoNEG status unchanged
1 = Operating at 100 Mbps
0 = Operating at 10 Mbps
Write as 0; ignore on read
1 = Last management frame
was invalid (opcode error, etc.)
0 = Last management frame
was valid
PHY Address defaults to 11110
Description
Description
Am79C978A
TBR24: 10BASE-T Summary Status Register (Reg-
ister 24)
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 Aler t, and Speed. See
Table 60.
Read/Write
RO
RO
RO
Default Value
Read/
Write
R/O
R/O
R/O
R/O
11110
0
0
0
H/W or Soft
Soft Reset
Reset
Previous
Retains
Value
0
0
0
0
0
0
0