AM79C901AJCT AMD [Advanced Micro Devices], AM79C901AJCT Datasheet - Page 65

• Manufacturer Part Number: AM79C901AJCT
• Description: HomePHY Single-Chip 1/10 Mbps Home Networking PHY
• Manufacturer: AMD [Advanced Micro Devices]

TBR19: 10BASE-T PHY Management Extension Register (Register 19)
Table 2 contains the PHY Management Extension Reg-
ister (Register 19) bits.
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
Bits
15:4
Bits
15:6
3
2
1
0
4:0
5
Auto-Negotiation
Full-Duplex
Link Status
Reserved
Mgmt Frame Format
Table 2. TBR19: 10BASE-T PHY Management Extension Register (Register 19)
Name
Speed
Alert
PHY Address
Reserved
Name
Table 3. TBR24: 10BASE-T Summary Status Register (Register 24)
Write as 0; Ignore on Read
1 = Link Status is up
0 = Link Status is down
1 = Operating in Full-Duplex mode
0 = Operating in Half-Duplex mode
1 = Auto-Negotiation status has changed
0 = Auto-Negotiation 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 000X1
X = Value on pin PHY_ADD (i.e., 00001 or
00011)
P R E L I M I N A R Y
Description
Am79C901A
Description
register access can convey. The Summary Status regis-
ter indicates the following: Link Status, Full-Duplex Sta-
tus, Auto-Negotiation Alert, and Speed. See Table 3.
Read/Write
Read/Write
R
R
R
R
R
R
R
R
Default Value
Default Value
01/03
(hex)
(hex)
0
0
0
0
0
0
0
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