Coefficient and Status - 2.7 English

1G/10G/25G Switching Ethernet Subsystem Product Guide (PG292)

Document ID
PG292
Release Date
2022-05-11
Version
2.7 English

Because the DME signaling rate for these two fields is reduced by a factor of eight, each coefficient and status transmission contains 128/8=16 bits, each numbered from 15:0. The following tables define these bits in the order in which they are transmitted starting with bit 15 and ending with bit 0.

Table 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
  • 1 1 = reserved
  • 0 1 = increment
  • 1 0 = decrease
  • 0 0 = hold
3:2 Coefficient (0) update
  • 1 1 = reserved
  • 0 1 = increment
  • 1 0 = decrease
  • 0 0 = hold
1:0 Coefficient (-1) update
  • 1 1 = reserved
  • 0 1 = increment
  • 1 0 = decrease
  • 0 0 = hold
Table 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
  • 1 1 = maximum
  • 0 1 = updated
  • 1 0 = minimum
  • 0 0 = not_updated
3:2 Coefficient (0) update
  • 1 1 = maximum
  • 0 1 = updated
  • 1 0 = minimum
  • 0 0 = not_updated
1:0 Coefficient (-1) update
  • 1 1 = maximum
  • 0 1 = updated
  • 1 0 = minimum
  • 0 0 = not_updated

The functions of each bit are defined in IEEE Std. 802.3, Clause 72. Their purpose is to communicate the adjustments of the transmit equalizer during the process of link training. The corresponding signal names are defined in Auto-Negotiation Ports.