AM79C971VCW Advanced Micro Devices, AM79C971VCW Datasheet - Page 179

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

1
0
MIIILP
FCON
bit will allow the Am79C971 con-
troller to work seamlessly with the
Micro Linear 6692 PHY. See the
section on Working with Micro
Linear 6692 for details.
Media Independent Interface In-
ternal Loopback. When set, this
bit will cause the internal portion
of the MII data port to loopback
on itself. The interface is mapped
in
TXD[3:0] nibble data path is
looped back onto the RXD[3:0]
nibble data path. TX_CLK is
looped back as RX_CLK. TX_EN
is looped back as RX_DV. CRS is
correctly OR’d with TX_EN and
RX_DV and always encompass-
es the transmit frame. TX_ER is
looped back as RX_ER. Howev-
er, TX_ER will not get asserted
by the Am79C971 controller to
signal an error. The TX_ER func-
tion is reserved for future use.
Fast Configuration Mode. When
set this bit will force the internal
Management Port State Machine
into a Fast Configuration Mode.
During this mode, the Manage-
ment Port State Machine will not
attempt to start Auto-Negotiation
on the internal as well as the ex-
ternal PHY. Instead, it will rely on
link beats for link pass state. This
will accelerate the automatic port
selection on the Am79C971 con-
troller.
Read/Write accessible always.
MII L is set to 0 by H_RESET
and is unaffected by S_RESET
and the STOP bit.
valid when the internal Network
Port Manager is scanning for a
network port.
Read/Write accessible always.
MIIILP is set to 0 by H_RESET
and is unaffected by S_RESET
and the STOP bit.
Read/Write accessible always.
FCON is set to 0 by H_RESET
and is unaffected by S_RESET
and the STOP bit. FCON is only
the
following
MII L is only
P R E L I M I N A R Y
way.
The
Am79C971
BCR33: MII Address Register
Bit
31-16 RES
15-10 RES
9-5
4-0
PHYAD
REGAD
Name
valid when the internal Network
Port Manager is scanning for a
network port. See Table 40.
Reserved locations. Written as
zeros and read as undefined.
Reserved locations. Written as
zeros and read as undefined.
MII Management Frame PHY Ad-
dress. PHYAD contains the 5-bit
PHY Address field that is used in
the management frame that gets
clocked out via the MII manage-
ment port pins (MDC and MDIO)
whenever a read or write transac-
tion occurs to BCR34. The inter-
nal
addressed as 11111b. The MII
management frame will not ap-
pear on the MII when reading or
writing to the internal PHY. This is
done for MII compatibility sake.
The Network Port Manager cop-
ies
Am79C971 controller reads the
EEPROM and uses it to commu-
nicate with the external PHY. The
PHY address must be pro-
grammed into the EEPROM prior
to starting the Am79C971 con-
troller.
Read/Write accessible always.
PHYAD
H_RESET and is unaffected by
S_RESET and the STOP bit.
MII Management Frame Register
Address. REGAD contains the 5-
bit Register Address field that is
used in the management frame
that gets clocked out via the MII
management port pins (MDC and
MDIO) whenever a read or write
transaction occurs to BCR34.
Read/Write accessible always.
REGAD
H_RESET and is unaffected by
S_RESET and the STOP bit.
Description
PHY
the
is
is
PHYAD
device
undefined
undefined
is
after
always
after
after
179
the