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AR# 10783

3.1i XST - ERROR: (VHDL_0056). file_name.vhd (Line #). Unexpected value. Unable to derive it to an integer.

Description

Keywords: generic, integer, constant, array

Urgency: Standard

General Description:
XST will incorrectly process an array of constants when an index of the array is a generic.

For example:

generic (loc_x ... : INTEGER := 0;);
...
regoutA: FDBUS GENERIC MAP (... loc_x => pos_ram_mul_x(loc_x), ...);

will generate the error:

ERROR: (VHDL_0056). file_name.vhd (Line 90). Unexpected value. Unable to derive it to an integer.

NOTE: This problem is fixed in the 4.1i software release.

Solution

The work-around is to add "+0":

regoutA: FDBUS GENERIC MAP (... loc_x => pos_ram_mul_x(loc_x) + 0, ...);
AR# 10783
Date Created 01/12/2001
Last Updated 08/19/2002
Status Archive
Type General Article