Answers Database

XBLOX 5.x: Error message regarding CAST (20051, 20141, 20142, 20184, 20177, 20199, 20336)


Record #314

Product Family:  Software

Product Line:  FPGA Core

Problem Title:
XBLOX 5.x: Error message regarding CAST (20051, 20141, 20142, 20184,
20177, 20199, 20336)



Problem Description:
XBLOX gives an error that which states that a CAST symbol must be used.
(The message may be tagged with one of several different error numbers.)

XBLOX 5.x has improve error checking over previous versions.  One of the
design-rule errors it now checks for is conflicting data types: busses with
different data-type specifications coming from different places.  These
design-rule errors often slipped by versions of XBLOX previous to 5.0.


Solution 1:

The CAST symbol is a symbol that translates a bus of one data type to a bus
of another data type.  The bus width is maintained; however, the index
range may be different: e.g., 7:0 may be translated to 9:2.  CAST may be
placed in the schematic between any two XBLOX busses of different data
types, and does not use any LCA resources.  The CAST symbol is included in
XBLOX libraries for XACT 5.0 and later.  See the XBLOX User Guide (either
the 1994 or 1995 editions) on p. 4-24 for more information on the CAST
symbol.

For designs which use the obsolete library, the CAST symbol is not included
in the XBLOX library.  For the Viewlogic interface, it is included in the
shm4000 library, which should be in your search path when processing
existing XC4000 designs with XACT 5.x.	OrCAD users will find this symbol
on the BBS under cast_orc.zip.	The Mentor symbol is automatically placed
in the old libraries $LCA/blox directory on installation.



End of Record #314