Coefficient and Status - 3.1 English

UltraScale+ Devices Integrated 100G Ethernet Subsystem Product Guide (PG203)

Document ID
PG203
Release Date
2023-11-01
Version
3.1 English

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.