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AR# 31460

Endpoint Block Plus Wrapper v1.10 and v1.10.1 for PCI Express - The default TXPREEMPHASIS value is incorrect for FXT devices on page 7 of the CORE Generator Customization GUI

Description


Known Issue v1.10, v1.9, v1.8, v1.7.1, v1.6.1, v1.5.2 
 
The default TXPREEMPHASIS value is incorrect for FXT devices on page 7 of the CORE Generator Customization GUI.

Solution


For FXT Block Plus core solutions, the Pre-Emphasis needs to be set to 50%, and TXBUFDIFFCTRL and TXDIFFCTRL should be set to 1000 mv. 
 
Due to this problem in the GUI, the values set in the GUI are not the same as the values that are obtained in the code after generation. To obtain the above settings for the GTX MGTs, set the TXDIFFCTRL to 800, TXPREEMPHASIS to 39, and check TX_DIFF_BOOST even though GTX does not have that feature as shown in the figure below. 
 
When the core generates, these settings are correctly translated to 50% for Pre-emphasis, and 1000 mv for TXBUFFDIFFCTRL and TXDIFFCTRL.  
 
NOTE: For PCI Express, set TXBUFFDIFFCTRL and TXDIFFCTRL to be the same for GTX. 
 
Recommended FXT Default Settings
Recommended FXT Default Settings
 
 
For GTX, other settings for the TXBUFFDIFFCTRL/TXDIFFCTRL can be found using this table. For instance, if you want a swing of 600 mv, set a value of 1100 mv in the Wizard. 
 
TXBUFFDIFFCTRL Wizard Translation
TXBUFFDIFFCTRL Wizard Translation
 
 
Also, for GTX, other settings for the TXPREEMPHASIS can be found using this table. For instance, if you want a value of 25%, set a value of 10.5% in the Wizard. 
 
TXPREEMPHASIS Wizard Translation
TXPREEMPHASIS Wizard Translation
 
 
This problem does not affect GTP-based solutions, and the settings chosen in the GUI are used in the generated core. This problem is fixed in 11.2 or v1.11 of the Block Plus Core. 
 
 
Revision History 
06/24/2009 - Updated to reflect fixed in v1.11 
04/13/2009- Updated for ISE 11.1 and core version v1.10 
03/26/2009 - Clarified information and added tables. 
09/10/2008 - Updated to reflect v1.9. 
08/15/2008 - Initial Release.
AR# 31460
Date Created 09/10/2008
Last Updated 08/26/2013
Status Active
Type General Article
IP
  • Endpoint Block Plus Wrapper for PCI Express