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AR# 497

LCA files tied by Makebits tie do not always pass DRC, possible Fatal Error 301's


PROGRAM: Makebits

VERSION: 5.1 and earlier

PLATFORM(s): all


SHORT DESCRIPTION: LCA files tied by Makebits tie do not always pass DRC

ERROR MESSAGE: **FATAL 301: Input P31.T unused in IOB `LED/LED2_P'
(P31), but 1 input pip is on


PROBLEM: LCA files created by using makebits tie and saved via
the interactive makebits "norestore" option (or the command
line makebits -n option) will not necessarily pass cleanly
through DRC.

CAUSE: Tie currently does not guarantee that the resulting .lca file
(output from tie-save) is drc-error free, as it
does not go into programmable blocks and "use" the pins
it ties. None of the errors will affect the proper
operation of the part.

Note that the same fatal error coming from an untied design
*would* need to be addressed.

SOLUTION: Errors of this type in a tied design referring to unused
inputs with input pips that are "on" (which are not
also in the untied version of the design) can be
safely ignored.

AR# 497
Date Created 08/31/2007
Last Updated 03/31/1997
Status Archive