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AR# 37704 MIG v3.5 Spartan-6 MCB - Calibration does not complete (calib_done=0) when C_SIMULATION=FALSE

An issue was found with the MIG v3.5 Spartan-6 FPGA MCB design when the C_SIMULATION parameter is set to FALSE. This parameter is used to skip portions of the initialization process to speed up simulation run time. By default, the MIG design sets this parameter to TRUE in the generated testbench (sim_tb_top) and to FALSE in the top-level rtl module (to ensure the initialization process is not abbreviated in hardware).

This issue found in v3.5 causes calibration to not complete (cal_done remains 0) when the C_SIMULATION parameter is set to FALSE in the simulation testbench (default setting is C_SIMULATION=TRUE) for both VHDL and Verilog design. This will additionally affect successful hardware implementation for all VHDL designs. Hardware failures can be seen as calibration failures, data errors, or a random combination of these. Because of this, the update is required for all VHDL designs but is only required for Verilog designs when users wish to run simulation with C_SIMULATION set to FALSE.

To work around this issue, rtl updates to the mcb_soft_calibration.v/.vhd files are required. These files are located in both the 'user_design/rtl' and 'example_design/rtl' directories. The following ftp location contains the updated mcb_soft_calibration.v/.vhd files that should be used over those generated by MIG v3.5:
http://www.xilinx.com/txpatches/pub/applications/misc/ar37704.zip

This issue only exists in MIG v3.5 and is resolved in MIG v3.6 which is released with theISE 12.3 software.

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
36211 MIG v3.5 - Release Notes and Known Issues for ISE Design Suite 12.2 N/A N/A
AR# 37704
Date Created 08/31/2010
Last Updated 05/20/2012
Status Active
Type Known Issues
Devices
  • Spartan-6 LX
  • Spartan-6 LXT
IP
  • MIG
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