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Altera_Forum
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15 years ago

Fixed-point multiplication with "altmult_complex" megafunction

Hi, I am using the altmult_complex (complex multiplier) with inputs dataa (both real and imaginary) having 16 fractional bits, and inputs datab (both real and imaginary) having 2 decimal bits a...
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Altera_Forum
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15 years ago

The product of two 0.16 signed numbers is normally 1.31 in fixed point, I would expect the same shift to take place with altmult_complex, as long as no saturation logic is applied to the result. You may want to keep 17 bits and perform the saturation logic - a result with the MSB set has to be replaced by the most negative value, otherwise, the MSB can be cut.