Intel® Cyclone® 10 GX Transceiver PHY User Guide

ID 683054
Date 4/14/2023
Public
Document Table of Contents

6.12.1. Changing VOD, Pre-emphasis Using Direct Reconfiguration Flow

  1. Perform the necessary steps from steps 1 to 7 in Steps to Perform Dynamic Reconfiguration.
  2. Read from the PMA analog feature address of the channel you want to change. For example, to change pre-emphasis 1st post-tap, read and store the value of address 0x105.
  3. Select a valid value for the feature according to the Cyclone® 10 GX register map. For example, a valid setting for pre-emphasis 1st post-tap has a bit encoding of 5'b00001.
  4. Perform a read-modify-write to the address of the PMA analog feature using the valid value. For example, to change the pre-emphasis 1st post-tap, write 5'b00001 to address 0x105.
  5. Perform the necessary steps from steps 9 to 12 in Steps to Perform Dynamic Reconfiguration.
Table 198.  Register Map for PMA Analog Feature
PMA Analog Feature Address Bit Values
Pre-emphasis 1st post-tap 0x105 [4:0]

5'b00000 - 5'b11001

Pre-emphasis 1st post-tap polarity 0x105 [6]

1'b0 = positive

1'b1 = negative

Pre-emphasis 2nd post-tap 0x106 [3:0]

4'b0000 - 4'b1100

Pre-emphasis 2nd post-tap polarity 0x106 [5]

1'b0 = positive

1'b1 = negative

Pre-emphasis 1st pre-tap 0x107 [4:0]

5'b00000 - 5'b10000

Pre-emphasis 1st pre-tap polarity 0x107 [5]

1'b0 = positive

1'b1 = negative

Pre-emphasis 2nd pre-tap 0x108 [2:0]

3'b000 - 3'b111

Pre-emphasis 2nd pre-tap polarity 0x108 [4]

1'b0 = positive

1'b1 = negative

Differential output voltage (VOD) 0x109 [4:0]

5'b00000 - 5'b11111

The PMA analog settings are governed by a set of rules. Not all combinations of VOD and pre-emphasis are valid. The following table lists the maximum pre-emphasis settings for the corresponding VOD settings.

Table 199.  Valid Maximum (Absolute) Pre-Emphasis Settings
VOD Maximum (Absolute) Pre-Emphasis Settings
1st Post-Tap 1st Pre-Tap 2nd Post-Tap 2nd Pre-Tap
31 25 16 12 7
30 25 16 11 6
29 25 16 10 5
28 25 16 9 4
27 25 16 8 3
26 25 16 7 2
25 25 16 6 1
24 25 16 5 0
23 24 16 4 0
22 23 16 3 0
21 22 16 2 0
20 21 16 1 0
19 20 16 0 0
18 19 15 0 0
17 18 14 0 0
16 17 13 0 0
15 16 12 0 0
14 15 11 0 0
13 14 10 0 0
12 13 9 0 0