AM79C971VCW Advanced Micro Devices, AM79C971VCW Datasheet - Page 149

• Manufacturer Part Number: AM79C971VCW
• Description: PCnet-FAST Single-Chip Full-Duplex 10/100 Mbps Ethernet Controller for PCI Local Bus
• Manufacturer: Advanced Micro Devices

Note that several registers have no default value.
BCR0, BCR1, BCR3, BCR8, BCR10-17, and BCR21
are reserved and have undefined values. BCR2 and
BCR34 are not observable without first being pro-
grammed through the EEPROM read operation or a
user register write operation.
BCR0, BCR1, BCR16, BCR17, and BCR21 are regis-
ters that are used by other devices in the PCnet family.
BCR0: Master Mode Read Active
Bit
31-16 RES
10-15
RAP
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
0
1
2
3
4
5
6
7
8
9
Name
Mnemonic
EBADDRU
EBADDRL
IOBASEU
SRAMSIZ
Reserved
Reserved
Reserved
IOBASEL
MIIADDR
PCISVID
SRAMIC
MSWRA
INTCON
MIIMDR
MSRDA
SRAMB
MIICAS
EECAS
PCILAT
PCISID
PCIVID
STVAL
BSBC
LED0
LED1
LED2
LED3
SWS
FDC
EBD
MC
Reserved locations. Written as
zeros and read as undefined.
Description
Default
FFFFh
00C0h
FF06h
0005h
0005h
0002h
0084h
0088h
0090h
0000h
9001h
0002h
0000h
0000h
0000h
0000h
0000h
0000h
0000h
0000h
1022h
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Table 30. BCR Registers
P R E L I M I N A R Y
Expansion Bus Address Lower
Expansion Bus Address Upper
EEPROM Control and Status
Miscellaneous Configuration
Am79C971
PCI Subsystem Vendor ID
Expansion Bus Data Port
SRAM Interface Control
MII Control and Status
MII Management Data
Burst and Bus Control
Software Timer Value
Full-Duplex Control
PCI Subsystem ID
SRAM Boundary
Software Style
PCI Vendor ID
LED0 Status
LED1 Status
LED2 Status
LED3 Status
PCI Latency
MII Address
SRAM Size
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Writing to these registers have no effect on the opera-
tion of the Am79C971 controller.
Writes to those registers marked as “Reserved” will
have no effect. Reads from these locations will produce
undefined values.
15-0
Name
MSRDA
Reserved
H_RESET, the value in this regis-
ter will be 0005h. The setting of
this register has no effect on any
Am79C971 controller function. It
is only included for software com-
patibility with other PCnet family
devices.
Read always. MSRDA is read
only. Write operations have no ef-
fect.
User
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
Programmability
locations.
EEPROM
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
After
149