E-Tile Transceiver PHY User Guide

ID 683723
Date 7/08/2024
Public
Document Table of Contents

8.13. Enabling Low Power Mode for Multiple Channels

For a given design instance, there is a set of base addresses that correspond to the relative channel for each.

NRZ addresses go one channel at a time (eight channels in this example).

Channel Number Base Address
0 0x00000
1 0x80000
2 0x100000
3 0x180000
4 0x200000
5 0x280000
6 0x300000
7 0x380000

PAM4 addresses go in multiples of two since they use every other channel (four channels in this example).

Channel Number Base Address
0 0x00000
1 0x100000
2 0x200000
3 0x300000

Because LPM is enabled and disabled on a per channel basis, each channel is addressed individually.

For NRZ Channels

To enable LPM for channel 0 use these register writes targeting base address 0x00000:
  1. Write 0x01 to 0x200 to enable LPM, or write 0x00 to 0x200 to disable LPM.
  2. Write 0x00 to 0x201 as this should be all 0’s.
  3. Write 0x00 to 0x202 to target the calling channel (channel 0 in this case).
  4. Write 0x98 to 0x203 to use the OPCODE for LOW_POWER_MODE.
  5. Read 0x207 until it becomes 0x80. This indicates that the operation completed successfully.
To enable LPM for channel 5 use these register writes targeting base address 0x280000:
  1. Write 0x01 to 0x200 to enable LPM, or write 0x00 to 0x200 to disable LPM.
  2. Write 0x00 to 0x201 as this should be all 0’s.
  3. Write 0x00 to 0x202 to target the calling channel (channel 5 in this case).
  4. Write 0x98 to 0x203 to use the OPCODE for LOW_POWER_MODE.
  5. Read 0x207 until it becomes 0x80. This indicates that the operation completed successfully.

For PAM4 Channels

To enable LPM for channel 0 use these register writes targeting base address 0x00000:
  1. Write 0x01 to 0x200 to enable LPM, or write 0x00 to 0x200 to disable LPM.
  2. Write 0x00 to 0x201 as this should be all 0’s.
  3. Write 0x00 to 0x202 to target the calling channel (channel 0 in this case).
  4. Write 0x98 to 0x203 to use the OPCODE for LOW_POWER_MODE.
  5. Read 0x207 until it becomes 0x80. This indicates that the operation completed successfully.
To enable LPM for channel 3 use these register writes targeting base address 0x300000:
  1. Write 0x01 to 0x200 to enable LPM, or write 0x00 to 0x200 to disable LPM.
  2. Write 0x00 to 0x201 as this should be all 0’s.
  3. Write 0x00 to 0x202 to target the calling channel (channel 3 in this case).
  4. Write 0x98 to 0x203 to use the OPCODE for LOW_POWER_MODE.
  5. Read 0x207 until it becomes 0x80. This indicates that the operation completed successfully.