AR# 10123: 3.1i XST - ERROR: (VHP_0837) - Index size for dimension 1 of <port_name> is not ##.
AR# 10123
3.1i XST - ERROR: (VHP_0837) - Index size for dimension 1 of <port_name> is not ##.
描述
Keywords: Foundation, ISE, XST, VHDL, generic, VHP_0837, index, size, dimension, exit, code, 0001, VHDL_0053, 0006, constant, value
Urgency: Standard
General Description: If a generic is given a default value within a component declaration:
component foo ( generic ( width : integer := 24 ); port ( a : in std_logic_vector( width downto 0 ); b : out std_logic ); end component;
this error will result:
ERROR: (VHP_0837). C:\my_code.vhd (Line ##). Index size for dimension 1 of 'a' is not 24.
Furthermore, if the default value for the generic is provided in the component declaration and NOT in the architecture description, the following error occurs:
ERROR: (VHDL_0053). C:\my_code.vhd (Line ##). Constant must have a value : 'width'
解决方案
As of Foundation ISE release 3.2.03i, XST VHDL does not support the assignment of default values for generics inside component declarations. If a default value is to be specified, it must appear in the architecture description for that component. It is acceptable to forego default values, as long as a generic map is provided in the component instantiation.
NOTE: This problem is fixed in the 4.1i software release.