Data type conversion in dsp builder

Well advanced blockset does generate floating point hardware, but its does the arithmetic by thinking about the exponent and mantissa bits explicitly. As Tricky says, the 'real' type in VHDL is for simulation; It's not supported in Quartus, and it's not how we generate hardware. The Advanced block-set has data type conversion blocks; to reinterpret floating point signals built and using in DSP Builder Advanced designs as a bit pattern of mantissa, exponent, sign etc.. at the boundaries for example when passing a 32bit IEEE single precision number to DSP Builder. I suggest you use these convert blocks, rather than trying to do the convert yourself. Also Altera doesn't synthesize / as divide - I don't think that's legal syntax.