Intel 82559 用户手册

120

 

For maximum accuracy of link status, the Auto-Negatiation Complete bit (bit 5), should be polled 
at a continuous interval of at least 300 milliseconds. After the Auto-Negotiation process has 

completed, the sticky bit will be set to 1. When the Auto-Negotiation Complete bit equals 1, the 

Link Status bit is updated for accuracy. Failure to delay the recommended time or using the Link 
Status bit before a valid resolution of the Auto-Negotiation Complete bit can cause inaccurate 

results.

8

Full/Half

R/W

1= Full duplex
0 = Half duplex

0

7

Collision Test Enable

R/W

This bit is valid only when the device in is in 
loopback mode. When it is used for transmitting 
broadcast frames, it increases the collision count 
statistic. After the transmission collision test is 
finished, the PHY should be reset to ensure it 
returns to normal mode operation. (Using this bit 
outside of loopback mode is inappropriate and may 
cause unpredictable behavior.)
1 = enable the collision CDT test during loopback

0

6:0

Reserved

R/W

Written as 0, don't care on read

0

15

T4 capable

RO

1= T4 capable
0 = Not T4 capable

0

14

TX full duplex capable

RO

1= TX full duplex capable
0 = Not TX full duplex capable

1

13

TX half duplex capable

RO

1 = TX half duplex capable
0 = Not TX half duplex capable

1

12

10BASE-T full duplex 
capable

RO

1 = 10BASE-T full duplex capable
0 = Not 10BASE-T full duplex capable 

1

11

10BASE-T half duplex 
capable

RO

1 = 10BASE-T half duplex capable
0 = Not 10BASE-T half duplex capable 

1

10:6

Reserved

RO

These bits are reserved and written as 0.

0

5

Auto-negotiation 
complete

RO

1 = Auto-negotiation complete
0 = Auto-negotiation not complete

Sticky bit

4

Remote fault detect

RO

1 = Remote fault detected
0 = Remote fault not detected

0

3

Auto-negotiation ability

RO

1 = Auto-negotiation enabled
0 = Auto-negotiation disabled

1