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AR# 23643

8.2i Virtex-5 MAP - DRC error due to MAP absorbing registers in DSP48E and creating conflict between AREG and ACASCREG


At times, MAP introduces DRC errors in DSP48Es when absorbing registers. The following is an example of the error: 


"ERROR:PhysDesignRules:1525 - Unsupported programming for DSP48E. The DSP48E 

block Maddsub__mult0000/Maddsub__mult0000 has attributes AREG and ACASCREG 

set to incompatible values. The attributes must have have the value to be 

compatible or AREG set 2 is compatible with ACASCREG set 1." 


To work around this issue, set the environment variable "XIL_MAP_NO_DSP48E_AUTOREG" to "1". 


For general information about setting ISE environment variables, see (Xilinx Answer 11630).


This problem has been fixed in the latest 8.2i Service Pack available at: 

The first service pack containing the fix is 8.2i Service Pack 1.

AR# 23643
Date Created 09/04/2007
Last Updated 05/20/2014
Status Archive
Type General Article