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Altera_Forum's avatar
Altera_Forum
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8 years ago

SignalTap & Keep Attribute - how to prepare signals for SignalTap during RTL coding?

Hi All, I'm using the keep attribute in order to prevent from the Quartus Synthesizer to optimize (rename/delete/etc) the signals, which have such attribute. So, is it possible to select ...
GZwei's avatar
GZwei
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6 years ago

Unfortunately, this is not entirely true as it seems. Nodes that get removed in synthesis cannot be selected in SignalTap using pre-synthesis. The signals are visible when using the option "Design Entry (all names)", but attaching SignalTap to registers that get optimized away is not possible. Neither the syn_keep attribute and the preserve attributes work. The only way to get SignalTap to attach to these registers is to combine them with a dummy logic function that is never true, and then or it to some other signal that is used. :-(