E-Tile Hard IP User Guide: E-Tile Hard IP for Ethernet and E-Tile CPRI PHY Intel® FPGA IPs

ID 683468
Date 7/23/2024
Public
Document Table of Contents

2.12.2.24. Status for TX PLDs

Offset: 0x351

Status for TX PLDs Fields

Bit Name Description Access Reset
24 err_tx_avst_fifo_overflow TX AVST FIFO Overflow
  • Indicates that the FIFO was written while full
  • Overflow would never happen—if it does, this indicates a problem with the way i_valid is being driven
  • Once asserted this bit holds value until the i_clear_internal_error port is asserted to clear it
  • This bit doesn't need to be polled—o_internal_err is asserted if this signal goes high.
RO 0x0
23 err_tx_avst_fifo_empty TX AVST FIFO ran empty unexpectedly
  • Asserts when the TX FIFO runs empty (regardless of read enable)
  • Does not apply when in MAC Mode
  • Empty should never happen—if it does, this indicates a problem with the way i_valid is being driven
RO 0x1
22 err_tx_avst_fifo_underflow TX AVST FIFO Underflow
  • Indicates that the FIFO was read when empty after steady state reading was established
  • Underflow should never happen—if it does, this indicates a problem with the way i_valid is being driven
  • Once asserted this bit holds value until the i_clear_internal_error port is asserted to clear it, or the TX datapath is reset
  • This bit doesn't need to be polled—o_internal_err is asserted if this signal goes high.
RO 0x0
21:16 tx_dsk_active_chans Active Channels.

[n]=1: Corresponding channel is part of the deskew set and has received a deskew marker since reset

  • This is a sticky bit that clears on reset and dsk_clear
  • Use this set of status bits to confirm that channels are receiving deskew markers
  • Remember that single lane channels only uses this when PTP is active, and in that case, uses bits 0 and 4 only
Note: This status is for TX EMIB deskew, and has nothing to do with RX skew from the serial line.
RO 0x0
13:8 tx_dsk_monitor_err Skew Monitor Error Detected

[n]=1: An out-of-alignment EMIB deskew marker was detected on EMIB channel n after deskew

  • In single lane mode, channels 0 and 4 are used when PTP is active, where channel 4 is the PTP channel
  • Valid only when tx_dsk_eval_done = 1
  • .
Note: This status is for TX EMIB deskew, and has nothing to do with RX skew from the serial line.
RO 0x0
3:1 tx_dsk_status EMIB Deskew Status

0: 0 cycles of delay added to remove TX EMIB skew

1: 1 cycle of delay added to remove TX EMIB skew

2: 2 cycles of delay added to remove TX EMIB skew

3: 3 cycles of delay added to remove TX EMIB skew

4: 4 cycles of delay added to remove TX EMIB skew

5: 5 cycles of delay added to remove TX EMIB skew

6: Reserved

7: Deskew Error—too much EMIB skew was detected

  • Valid only when tx_dsk_eval_done = 1
  • When an error is detected, deskew_clear can be used to restart the deskew state machine
Note: This status is for TX EMIB deskew, and has nothing to do with RX skew from the serial line.
RO 0x0
0 tx_dsk_eval_done Deskew evaluation is complete

1: The TX PLD has finished attempting to deskew the EMIB channels connected to EHIP

0: TX PLD is still waiting for enough TX deskew markers to evaluate deskew
Note: Evaluation complete does not mean that deskew was successful; it just means that the deskew state machine has come to a conclusion.
  • This signal is always required for hip_ready for multilane channels unless EMIB channels are deliberately excluded from deskew
  • For single lane channels, this signal is only needed when using PTP
Note: This deskew is has nothing to do with RX PCS deskew or the serial input.
RO 0x0