AM79C978 Advanced Micro Devices, AM79C978 Datasheet - Page 197

• Manufacturer Part Number: AM79C978
• Description: Single-Chip 1/10 Mbps PCI Home Networking Controller
• Manufacturer: Advanced Micro Devices

TBR19: 10BASE-T PHY Management Extension
Register (Register 19)
Table 76 contains the PHY Management Extension
Register (Register 19) bits.
Reserved Register: 10BASE-T Configuration
Register (Register 22)
This register is reserved.
Reserved Register: 10BASE-T Carrier Status
Register (Register 23)
This register is reserved.
Bit(s)
15-4
Bits
15:6
4-0
3
2
1
0
5
Mgmt Frame Format
Full-Duplex
Link Status
PHY Address
Reserved
AutoNEG
Table 76. TBR19: 10BASE-T PHY Management Extension Register (Register 19)
Speed
Reserved
Name
Alert
Name
Table 77. TBR24: 10BASE-T Summary Status Register (Register 24)
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
Am79C978
TBR24: 10BASE-T Summary Status Register
(Register 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 Alert, and Speed. See Table
77.
Read/Write
RO
RO
RO
Default Value
Read/
Write
11110
R/O
R/O
R/O
R/O
0
0
0
Previous Value
H/W or Soft
Soft Reset
Reset
Retains
0
0
0
0
0
0
0
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