Quartus does not support the module IO were defined as real or user defining ?

[Altera_Forum]

for example: 

ENTITY interpolation_filter IS  PORT( clk : IN std_logic;   clk_enable : IN std_logic;   reset : IN std_logic;   filter_in : IN real; -- double  filter_out : OUT real -- double  );  END interpolation_filter;  Compiling eror: Error (10414): VHDL Unsupported Feature error at interpolation_filter.vhd(39): cannot synthesize non-constant real objects or values Error (10414): VHDL Unsupported Feature error at interpolation_filter.vhd(40): cannot synthesize non-constant real objects or values

[Altera_Forum]

The error log is self exaplanatory. 

Real variables are not synthesized.

[Altera_Forum]

thanks for reply! it seems user defining type also will report error. please see the picture. this filter program was produced by the Matlab, so I can not make sure if the VHDL or Quartus does not support 'real' type in the module IO definition? br njjjl