Forum Discussion
Altera_Forum
Honored Contributor
18 years agoQuartus will automatically convert wide/large shift registers into alt_shift_taps megafunctions. (This is the "shoe-horn" method that uses a small memory and an external counter to do the logic.) Functionally it's identical to a shift register.
To be honest, I think the SRL16 looks better and would provide better area. Yet I've converted many design with them(especially DSP designs) and have yet to see one where they had an area advantage. I admittedly have always been surprised by this, but have seen it time and time again. I'm sure such designs exist but don't know about them and doubt if they're common. (What I am sure is common, are there are a lot of X designers that use lots of SRL16s and assume they will have bad area in an Altera part, even if they don't verify this...)