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AR# 6853

2.1i COREGEN, F2.1i FOUNDATION, NGDBUILD: Unexpanded block error -- ... because one or more pins on the block ... were not found

Description

KEYWORDS: coefficient, core, virtex, multiplier, ngdbuild

URGENCY: standard

GENERAL DESCRIPTION:
NGDBUILD produces an unexpanded error similar to the following
during the Translate process when processing a Foundation design containing
a v1.0 CORE Generator Dynamic Constant Coefficient Multiplier or
v1.0 Variable Parallel Multiplier for Virtex:

"File <module_name>.ngo cannot be merged into block U1 (TYPE =
<module_name>) because one or more pins on the block, including pin CE,
were not found in the file. Please make sure that all pins on the instantiated
component match pins in the lower-level design block (irrespective of case)..."

The error message may also refer to the optional pins ACLR, ASET, SCLR
and SSET in the case of the Virtex Variable Parallel Multiplier.

When the error is issued in the context of the Dynamic Constant Coefficient
Multiplier , the problem is that a CE pin is created on the Foundation schematic
symbol even when the user has not requested a clock enable. This
causes a mismatch with the associated EDIF file for the module,
which does not have a reference to a CE pin.

Similarly with the Virtex Variable Multiplier, the optional pins CE, ACLR, ASET,
SSCLR, and SSET appear on the Foundation symbol for the generated
core regardless of whether they are requested or not.

Solution


This problem is fixed in the latest 2.1i Service Pack available at:
http://support.xilinx.com/support/techsup/sw_updates/

If you are unable to access the Service Pack,
the workaround is to use NET2SYM to generate the Foundation symbol
from the EDN file for the module instead of the .XSF file that the CORE
Generator normally generates and uses as input.

See (Xilinx Solution #4631) for details on how to run NET2SYM.

AR# 6853
Date Created 06/23/1999
Last Updated 04/02/2002
Status Archive
Type General Article