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
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
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
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.
Applies To
IP
- Endpoint Block Plus Wrapper for PCI Express