Because the DME signaling rate for these two fields is reduced by a factor of 8, each coefficient and status transmission contain 128 / 8 = 16 bits, each numbered from 15–0. Table: Coefficient and Update Field Bit Definitions and Table: Status Report Field Bit Definitions define these bits in the order in which they are transmitted starting with bit 15 and ending with bit 0.
Table D-1: Coefficient and Update Field Bit Definitions
Bits
|
Name
|
Description
|
15:14
|
Reserved
|
Transmitted as 0, ignored on reception.
|
13
|
Preset
|
1 = Preset coefficients
0 = Normal operation
|
12
|
Initialize
|
1 = Initialize coefficients
0 = Normal operation
|
11:6
|
Reserved
|
Transmitted as 0, ignored on reception.
|
5:4
|
Coefficient (+1) update
|
5
1
0
1
0
|
4
1=
1=
0=
0=
|
Reserved
Increment
Decrement
Hold
|
3:2
|
Coefficient
|
3
1
0
1
0
|
2
1=
1=
0=
0=
|
Reserved
Increment
Decrement
Hold
|
1:0
|
Coefficient (-1) update
|
1
1
0
1
0
|
0
1=
1=
0=
0=
|
Reserved
Increment
Decrement
Hold
|
Table D-2: Status Report Field Bit Definitions
Bits
|
Name
|
Description
|
15
|
Receiver ready
|
1 = The local receiver has determined that training is complete and is prepared to receive data.
0 = The local receiver is requesting that training continue.
|
14:6
|
Reserved
|
Transmitted as 0, ignored on reception.
|
5:4
|
Coefficient (+1) update
|
5
1
0
1
0
|
4
1=
1=
0=
0=
|
Maximum
Updated
Minimum
Not updated
|
3:2
|
Coefficient (0) update
|
3
1
0
1
0
|
2
1=
1=
0=
0=
|
Maximum
Updated
Minimum
Not updated
|
1:0
|
Coefficient (-1) update
|
1
1
0
1
0
|
0
1=
1=
0=
0=
|
Maximum
Updated
Minimum
Not updated
|
The functions of each bit are defined in IEEE 802.3 Clause 72, “72.6.10.2 Training frame structure”. Their purpose is to communicate the adjustments of the transmit equalizer during the process of link training. The corresponding signal names are defined in Port Descriptions.