1.4. CORDIC IP Parameters
Parameter  Values  Description 

Input data widths  
Fraction F  1 to 64  Number of fraction bits. 
Width w  Derived  Width of fixedpoint data. 
Sign  signed or unsigned  The sign of the fixedpoint data. 
Output data widths  
Fraction  1 to 64, where F _{OUT} ≤ F _{IN}  Number of fraction bits. 
Width  Derived  Width of fixedpoint data. 
Sign  Derived  The sign of the fixedpoint data. 
Generate enable port  On or off  Turn on for enable signal. 
Parameter  Values  Description 

Input data widths  
Fraction  1 to 64  Number of fraction bits. 
Width  3 to 64  Width of fixedpoint data. 
Sign  signed or unsigned  The sign of the fixedpoint data. 
Output data widths  
Fraction  Number of fraction bits.  
Width  Derived  Width of fixedpoint data. 
Sign  Derived  The sign of the fixedpoint data. 
Generate enable port  On or off  Turn on for enable signal. 
LUT Size Optimization  On or off  Turn on to move some of the typical CORDIC operations into look up tables to reduce implementation cost. 
Manually Specify LUT Size  On or off  Turn on to input the LUT size. Larger values (911) enable mapping some computations to memory blocks Only when LUT Size Optimization is on. 
Parameter  Values  Description 

Input data widths  
Fraction  1 to 64  Number of fraction bits. 
Width 

Width of fixedpoint data. 
Sign  signed or unsigned  The sign of the fixedpoint data 
Output data widths  
Fraction  1 to 64  Number of fraction bits. 
Width  Derived  Width of fixedpoint data. 
Sgn  Derived  The sign of the fixedpoint data 
Generate enable port  On or off  Turn on for enable signal. 
Scale factor compensation  On or off  For vector translate, a CORDIC specific constant that converges to 1.6467602... scales the magnitude of the vector (x^{2}+y^{2})^{0.5} so that the value for the magnitude, M, is M = K(x^{2}+y^{2})^{0.5}. The format of the output depends on the input format. The largest output value occurs when both the inputs are equal to the maximum representable input value, j. In this context: M = K(j ^{2}+j ^{2})^{0.5} = K(2j ^{2})^{0.5} = K2^{0.5}(j ^{2})^{0.5} = K 2^{0.5} j = 2.32j Therefore, two extra bits left of the MSB of j are required to ensure M is representable. If scale factor compensation is selected, M becomes: M = j^{0.5} ~ 1.41 j One extra bit is sufficient for representing the range of M. Scale factor compensation affects the total width of the output. 
Parameter  Values  Description 

Input data widths  
X,Y inputs  
Fraction  1 to 64  Number of fraction bits. 
Width  Derived  Width of fixedpoint data. 
Sign  signed  The sign of the fixedpoint data. 
Angle input  
Fraction  Derived   
Width  Derived   
Sign  Derived   
Output data widths  
Fraction  1 to 64  Number of fraction bits. 
Width  Derived  Width of fixedpoint data. 
Sign  Derived  The sign of the fixedpoint data 
Generate enable port  On or off  Turn on for enable signal. 
Scale factor compensation  On or off  Turn on to compensate the CORDICspecific constant on the magnitude output. For both signed and unsigned inputs, turning on decreases by 1 the weight of the magnitude for x0 and y0. The outputs belong to the interval [2^{0.5}, +2^{0.5}]K. Under default settings, the output interval will therefore be [2^{0.5}K , +2^{0.5}K] (with K~1.6467602...), or ~[2.32, +2.32]. Representing the values in this interval requires 3 bits left of the binary point, one of which is for the sign. When you turn on Scale factor compensation, the output interval becomes [2^{0.5}, +2^{0.5}] or ~[1.41, 1.41], which requires two bits left of the binary point, one of which is for the sign. Scale factor compensation affects the total width of the output. 