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  3. AR# 7211: Where can I find quality and reliability information for Xilinx parts?
  4. AR# 72110: UltraScale+ GTM - Does GTM support Manual Eyescan like GTY and GTH do?

AR# 72110

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UltraScale+ GTM - Does GTM support Manual Eyescan like GTY and GTH do?

描述

Is manual eye scan supported on UltraScale+ GTM?

解决方案

(UG581) mentions a Sampled Eye Diagram for margin analysis.

In the 2019.1.3 version and later, the scan data can be read out from GTM. 

They do not represent a single eye BER picture as is the case for GTY or GTH, but a sequence of sampled data.

The following information will be added to (PG315) for 2019.2:

Sampled Eye Scan functionality:

  • In the 2019.1.3 release new ports have been added which could be used to get the Sampled Eye Scan data as described below:
PortDirectionClock DomainDescription
es_fifo_request [7:0]INASYNCEnables sampled Eye Scan for selected channel {D3Ch1, D3Ch0, D2Ch1, D2Ch0, D1Ch1, D1Ch0, D0Ch1, D0Ch0}
(Note1: If multiple bits are simultaneously asserted, only the channel of the LSB will be serviced)
(Note2: De-assert es_fifo_request when the es_fifo_full flag asserts)
es_fifo_rclkINES_FIFO_RCLKFIFO Read Clk, Recommended to use the same as freerun_clk in the GTM Wizard example design
es_fifo_axis_0_treadyINES_FIFO_RCLKAXI4-Stream Interface: Indicates that the slave can accept a transfer in the current cycle
es_fifo_axis_0_tvalidOUTES_FIFO_RCLKAXI4-Stream Interface: Indicates that the master is driving a valid transfer.
A transfer takes place when both tvalid and tready are asserted
(Note: tvalid also serves as the Empty flag for the FIFO)
es_fifo_axis_0_tdata [15:0]OUTES_FIFO_RCLKAXI4-Stream Interface: Read Dataout from the FIFO
es_fifo_fullOUTDRP_CLKStatus flag that indicates sampled Eye Scan for selected channel has completed and FIFO is filled
 
  • The Sampled Eye Scan function will populate a FIFO with equalized ADC samples and loop coefficients used for SNR calculation
  • Each sample of "es_fifo_full" above from "es_fifo_request" would contain 1750 data samples with the following data structure:
FIFO locationDATA Content
1DUAL/Channel ID
2Coefficient (H0_P3X)
3Coefficient (H0_P2X)
4Coefficient (H0_P1X)
5Coefficient (H0_0)
6Coefficient (H0_M1X)
7Coefficient (H0_M2X)
8Coefficient (H0_M3X)
9YK_DATA2[7:0],YKDATA1[7:0]
10YK_DATA4[7:0],YKDATA3[7:0]
..
..
883YK_DATA1750[7:0],YKDATA1749[7:0]
 
  • Sampled Eye Scan function is shared between 4 DUALs and only one channel can be serviced at a time
  • Instructions on usage of GTM Sampled Eye Scan feature:
    • After GT RXRESET completes, user can assert "es_fifo_request" at any time to initiate Sampled Eye Scan for a specific DUAL.
      "es_fifo_request" should stay asserted while monitoring the "es_fifo_full" flag.
    • Once the "es_fifo_full" flag asserts, the user is required to de-assert the "es_fifo_request" input.
    • The user can begin reading the data through the added es_fifo_* AXI4S interface
    • Upon completely draining the es_fifo the "es_fifo_axis_0_tvalid" will go low, preventing further reads.
    • YK_DATAx are signed values (2s complement), they are not continuous samples, it is just a data set of equalized sampled data and can be plotted directly
    • H0_* - these are not necessary to plot the data
  • The user can acquire additional Sampled Eye data by repeating the above steps on each of the target required transceivers

AR# 72110
日期 09/24/2019
状态 Active
Type 综合文章
器件
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