Intel Arria 10 User Manual

Phase 0
Phase 0 includes the following steps:
1. The upstream component enters Phase 0 of equalization during
Recovery.Rcvrconfig by sending EQ TS2 training sets with starting presets for the
downstream component. EQ TS2 training sets may be sent at 2.5 GT/s or 5 GT/s.
2. The downstream component enters Phase 0 of equalization after exiting
Recovery.Speed at 8 GT/s. It receives the starting presets from the training
sequences and applies them to its transmitter. At this time, the upstream
component has entered Phase 1 and is operating at 8 GT/s.
3. To move to Phase 1, the receiver must have a BER < 10
-4
. The receiver should be
able to decode enough consecutive training sequences.
4. In order to move to Equalization Phase 1, the downstream component must detect
training sets with Equalization Control (EC) bits set to 2’b01.
Phase 1
During Phase 1 of the equalization process, the link partners exchange Full Swing (FS)
and Low Frequency (LF) information. These values represent the upper and lower
bounds for the TX coefficients. The receiver uses this information to calculate and
request the next set of transmitter coefficients.
1. The upstream component moves to EQ Phase 2 when training sets with EC bits set
to 1’b0 are captured on all lanes. It also sends EC=2’b10, starting pre-cursor,
main cursor, and post-cursor coefficients.
2. The downstream component moves to EQ Phase 2 after detecting these new
training sets.
Use the pipe_g3_txdeemph[17:0] port to select the transmitter de-emphasis. The
18 bits specify the following coefficients:
• [5:0]: C
-1
• [11:6]: C
0
• [17:12]: C
+1
Refer to Preset Mappings to TX De-emphasis for the mapping between presets and TX
de-emphasis.
Phase 2 (Optional)
During Phase 2, the Endpoint tunes the TX coefficients of the Root Port. The TS1 Use
Preset bit determines whether the Endpoint uses presets for coarse resolution or
coefficients for fine resolution.
If you are using the PHY IP Core for PCI Express (PIPE) as the Root Port, the Endpoint
can tune the Root Port TX coefficients.
The tuning sequence typically includes the following steps:
1. The Endpoint receives the starting presets from the Phase 2 training sets sent by
the Root Port.
2. The circuitry in the Endpoint receiver determines the BER. It calculates the next
set of transmitter coefficients using FS and LF. It also embeds this information in
the Training Sets for the Link Partner to apply to its transmitter.
2. Implementing Protocols in Arria 10 Transceivers
UG-01143 | 2018.06.15
Intel
®
Arria
®
10 Transceiver PHY User Guide
275

Intel Arria 10 Specifications

General

Brand	Intel
Model	Arria 10
Category	Transceiver
Language	English