AR# 10671

4.1i XST - "ERROR: Xst:777 - file_name.vhd (Line xx). Unexpected value. Unable to derive it to an integer."

Description

Keywords: 'range, others, attribute, pre, defined

Urgency: Standard

General Description:
While XST supports most uses of the 'range attribute, the following construct is not supported:

sig <= (sig'range => '0');

When I utilize this construct, the following error is reported:

"ERROR: Xst:777 - file_name.vhd (Line xx). Unexpected value. Unable to derive it to an integer."

Solution

To avoid this error, replace the above construct with the following:

sig <= (others => '0');

NOTE: The above construct is supported in the 5.1i version of XST.
AR# 10671
Date 08/06/2003
Status Archive
Type General Article