
330
Registers
Chapter 4
AMD-8111 HyperTransport I/O Hub Data Sheet
24674
Rev. 3.00
April 2003
AMD Preliminary Information
LAN Ethernet Controller Control 2
ENC070
Default:
Bits
31:10 Reserved.
9:8
FMDC. Fast Management Data Clock
. When FMDC is set to 2h the MII Management Data Clock
runs at 10 MHz max. The Management Data Clock is then no longer IEEE 802.3u-compliant, so
setting this bit should be used with care. The accompanying external PHY must also be able to accept
management frames at the new clock rate. When FMDC is set to 1h, the MII Management Data Clock
runs at 5 MHz max. The Management Data Clock is then no longer be IEEE 802.3u-compliant, so
setting this bit should be used with care. The accompanying external PHY must also be able to accept
management frames at the new clock rate. When FMDC is cleared to 0h, the MII Management Data
Clock runs at 2.5 MHz max and is compliant to IEEE 802.3u standards.
7
XPHYRST. External PHY Reset
. When XPHYRST is set, the controller after an H_RESET issues an
MII management frame that resets the external PHY. This bit is needed when there is no way to
ensure the state of the external PHY. This bit must be reprogrammed after every H_RESET.
XPHYRST is only valid when the internal Network Port Manager is scanning for a network port.
6
XPHYANE. External PHY Auto-Negotiation Enable
. This bit forces the external PHY into enabling
Auto-Negotiation. When this bit is cleared to 0, the controller sends an MII management frame
disabling Auto-Negotiation. XPHYANE is only valid when the internal Network Port Manager is
scanning for a network port.
5
XPHYFD. External PHY Full Duplex
. When set, this bit forces the external PHY into full duplex when
Auto-Negotiation is not enabled.XPHYFD is only valid when the internal Network Port Manager is
scanning for a network port.
4:3
XPHYSP. External PHY Speed
. When auto-negotiation is disabled, the controller sends a
management frame to the external PHY to set the data rate based on the contents of this
fi
eld.
0000_0004h
Description
Attribute:
Read-write; write mode 1.
This register contains several miscellaneous control bits. Each byte of this register controls a single
function. It is not necessary to do a read-modify-write operation to change a function's settings if only
2:0
APDW. MII Auto-Poll Dwell Time
. APDW determines the dwell time (or idle time) between MII
Management Frames accesses when Auto-Poll is turned on.
XPHYSP
00
01
1X
Data Rate
10 Mb/s
100 Mb/s
Reserved
APDW
MDC Periods
Between Frames
1
128
256
512
1024
2048
Reserved
Polling Period
(Start frame to start frame)
27.2
μ
s @ 2.5 MHz
77.6
μ
s @ 2.5 MHz
128.8
μ
s @ 2.5 MHz
231.2
μ
s @ 2.5 MHz
436.0
μ
s @ 2.5 MHz
845.6
μ
s @ 2.5 MHz
Reserved
000
001
010
011
100
101
110-111