AM79C978A AMD [Advanced Micro Devices], AM79C978A Datasheet - Page 177

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

9-8
7
6-2
1-0
BCR50-BCR55: Reserved Locations
These registers must be 00h.
10BASE-T PHY Management Registers
(TBRs)
The Am79C978A home networking device supports
the MII basic register set and extended register set.
Both sets of registers are accessible through the PHY
Management Interface. As specified in the IEEE stan-
dard, the basic register set consists of the Control
Register (Register 0) and the Status Register (Regis-
ter 1). The extended register set consists of Registers
2 to 31 (decimal).
PHY_SEL_DEFAULT
PHY_SEL_LOOK
RES
PHY_SEL
PHY Select Default. These bits
store the desired default PHY.
These bits have no effect on the
operation of the device and are
provided only as a storage loca-
tion.
PHY Select Lock. Setting this bit
prevents the PHY_SEL bits from
being overwritten by subsequent
soft resets. The user may write
this bit at any time. It is cleared
during Power-On Reset.
Reserved. Must be written as zero.
PHY Select. These bits define the
active PHY as follows:
00
01
10
11
10BASE-T PHY
HomePNA PHY
External PHY
Reserved/Undefined
Am79C978A
Table 47 lists all the 10BASE-T registers implemented
in the device. All the reserved registers should not be
written to, and reading them will return a zero value.
(in Decimal)
Register
Address
20-23
25-31
8-15
2-3
Table 47. Am79C978A 10BASE-T PHY
16
17
18
19
24
0
1
4
5
6
7
Management Register Set
Auto-Negotiation Next
Auto-Negotiation Link
Interrupt Enable and
PHY Control/Status
PHY Management
Auto-Negotiation
Auto-Negotiation
Summary Status
Register Name
Advertisement
Partner Ability
PHY Identifier
PHY Control
PHY Status
Expansion
Extension
Reserved
Reserved
Reserved
Reserved
Status
Page
Extended
Basic/
B
B
E
E
E
E
E
E
E
E
E
E
E
E
E
177