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AR# 738

XBLOX 5.x: internal error 20224, representation_error


Keywords: XBLOX, error, representation

Urgency: Standard

General Description:

XBLOX may issue the following error on designs with very wide data paths.

*** XBLOX: ERROR 20224:
Please contact Xilinx Technical Support. Please provide the
following details to the support personnel. This information
will be needed by the software developers.
1. representation_error(is(_529,+(*(268435455,16),15)),2,
'integer overflow')

This can be caused by having binary counters with a COUNT_TO value of
greater than 31 bits. XBLOX represents this COUNT_TO value as a signed
32-bit integer; therefore, the maximum COUNT_TO value is 2^31-1.


As a workaround, cascade two half-sized COUNTERs. Although this provides a
valid solution, please note that this does reduces the performance somewhat
(especially in XC4000 designs), due to the break in the carry chain.
AR# 738
Date Created 12/13/1995
Last Updated 05/24/1999
Status Archive
Type General Article