
30
Am79C875
Auto-Negotiation Expansion Register (Register 6)
Table 14.
Reg
Bit
Name
Description
Read/
Write
Default
6
15:5
Reserved
Ignore when read.
RO
0
6
4
Parallel Detection
Fault
1 = Fault detected by parallel detection logic, this fault is due
to more than one technology detecting concurrent link up
condition. This bit can only be cleared by reading this register
via management interface.
0 = No fault detected by parallel detection logic.
RO/LH
0
6
3
Link Partner Next
Page Able
1 = Link partner support next page function.
0 = Link partner does not support next page function.
RO
0
6
2
Next Page Able
Next page is supported, i.e., this bit is permanently ties to 1.
RO
1
6
1
Page Received
It is set when a new link code word has been received into the
Auto-Negotiation Link Partner Ability Register. This bit is
cleared upon a read of this register.
RO/LH
0
6
0
Link Partner Auto-
Negotiation Able
1 = Link partner is Auto-Negotiation able.
0 = Link partner is not Auto-Negotiation able
RO
0
Auto-Negotiation Expansion Register (Register 6)
Auto-Negotiation Next Page Advertisement Register (Register 7)
Table 15.
Reg
Bit
Name
Description
Read/
Write
Default
7
15
NP
Next page indication:
1 = Another Next Page desired.
0 = No other Next Page Transfer desired
RW
0
7
14
Reserved
Ignore when read.
RO
0
7
13
MP
Message page:
1 = Message page
0 = Un-formatted page.
RW
1
7
12
ACK2
Acknowledge 2
1 = Will comply with message.
0 = Cannot comply with message.
RW
0
7
11
TOG_TX
Toggle:
1 = Previous value of transmitted link code word equals to 0
0 = Previous value of transmitted link code word equals to 1
RW
0
7
10:0
CODE
Message/Un-formatted Code Field.
RW
001
Auto-Negotiation Next page Advertisement Register (Register 7)
Reserved Registers (Registers 8-15, 22-23, 25-31)
The NetPHY 4LP device contains reserved registers
at addresses 8-15, 22-23, 25-31. These registers
should be ignored when read and should not be written
at any time.