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AR# 41197

Soft Error Mitigation Controller - What is the difference between the EBC and the EBD file generated by the BitGen essential bits command?


What is the difference between the EBC and the EBD file generated by the BitGen essential bits command?


When Correction by Replace or Error Classification with any correction method  (repair, enhanced repair, or replace) is used, BitGen uses the "-g essentialbits:yes" option to generate EBC and EBD files.

  • The EBC file is a reference file and contains the memory cell content.
    This is the same content read back by the SEM controller during the SEU readback of the FPGA. 
    It is important to note that this file is not the same as the bitstream used to program the part. 

  • The EBD file shows the bits of the SEU Readback that are marked as essential.

The EBD file is used to mask the EBC file meaning that a 1 in the EBD file corresponds to an essential bit in the EBC file. 

Note: An EBC file bit of 1 or 0 can be essential or critical depending on if there is a corresponding 1 in the EBD file for this bit.

If the user selects to use the "Correction by Repair" mode and also enables error classification, then the EBD file is used to classify a bit error as critical or not. 

If the "Correction by Repair" mode is used but without error classification then the EBD file is not needed.

If the user decides to use the "Correction by Replace" mode, then the EBC file is used by the controller to correct the frames containing errors.

The core comes with a tcl file called "makedata.tcl" . 

Depending on the user options selected during the SEM IP customization process, the tcl file creates the MCS file with the EBC and/or EBD file depending on which is needed.

Please refer to the Implementation section of the Example Design in Section II or III of the SEM Product Guide (PG036) for details on generating these external memory programming files.


Related Articles:
(Xilinx Answer 41199) - Soft Error Mitigation Controller - How many essential bits are in my design?
(Xilinx Answer 39288) - Soft Error Mitigation Controller - Is the MCS file used for error correction by replace the same as the configuration bitstream
(Xilinx Answer 39286) - Soft Error Mitigation Controller - Is there a way to convert the MCS file to BIN format?
(Xilinx Answer 39285) - Soft Error Mitigation Controller - How is the MCS data used for correction programmed to SPI memory?

Revision History,
03/10/2011 - Initial release

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AR# 41197
Date Created 03/11/2011
Last Updated 06/17/2014
Status Active
Type General Article
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  • Virtex-6Q
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  • Soft Error Mitigation