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Altera_Forum
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12 years ago

Non-positive replication multiplier inside concat

Hi,recently I am focusing on a MSK IQ demodulating. after synthesize with Q2.9.1 and Pro Synplify.9.6.2,there come the warnings as following: # ** Warning: (vsim-8607) D:/altera/91/quartus/eda/...
Altera_Forum's avatar
Altera_Forum
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12 years ago

Usually a problem of data and coefficient word widths. If they are not well considered, some result bits might be undriven. 'Z' state can only occur, if you are driving an inout port, respectively a signal vector intentionally initialized to 'Z'.

In simulation, you should be always able to locate the "source" of undriven signals.