From: owner-vhdl-200x@eda.org [mailto:owner-vhdl-200x@eda.org] On Behalf Of David Bishop A “NaN” is a very specific value for a floating point number. An exponent of all “1” (which means infinity) and a fraction which starts with a “1”. Since all of the bits in an integer are valid, I don’t know how you would do an invalid number. You can’t just pick one because somebody will need to use it. I agree – if you want an ‘undriven value’, then it has to be separate. The simulator could track it in whatever softwarey way suits, say via an internal variable with a bit for each resolved integer object which needs to be tracked. In synthesis, a resolved integer could an extra bit to signifiy its “drivenness”. Or either level of tool could allocate a value outside of the valid range for the integer in question (to use internally as a flag), which could be accessed through the language via some suitable abstraction. At this stage, I would propose that Daniel could write up a requirement on the Twiki for what he would like to happen (without implementation details at this stage?) and we can add it to the future discussions... Cheers, Martin -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.Received on Tue Oct 14 05:09:30 2014
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