Error: Internal Sub-system: MEM, File: /quartus/ccl/mem/mem_segment.cpp, Line: 735

Due to a problem in the Quartus® II software version 11.1 SP2 and earlier, this error may be generated during synthesis if your HDL code include bit string literals in VHDL-2008 format.

For example, the following code may generate the above error:

constant CSR   : std_logic_vector(4 downto 0) := 5d"0";

To work around this problem, avoid using VHDL-2008 bit string literals. For example, replace the above code with:

constant CSR   : std_logic_vector(4 downto 0) := “00000”;

This problem is fixed beginning with the Quartus II software version 12.0.