User Guide

Parameter Values Description
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.
1.5. ALTERA_CORDIC IP Core Signals
Table 6. Common Signals
Name Type Description
clk Input Clock.
en Input Enable. Only available when you turn on Generate an enable port.
areset Input Reset.
Table 7. Sin Cos Function Signals
Name Type Configurati
on
Range Description
a
Input Signed
input
[−π,+π] Specifies the number of fractional bits (F
IN
). The total width of this
input is F
IN
+3.Two extra bits are for the range (representing π) and
one bit for the sign. Provide the input in two’s complement form.
Unsigned
input
[0,+π/2] Specifies the number of fractional bits (F
IN
). The total width of this
input is w
IN
=F
IN
+1. The one extra bit accounts for the range
(required to represent π/2).
s, c
Output Signed
input
[−1,1]
Computes sin(a) and cos(a) on a user-specified output fraction
width(F). The output has width w
OUT
= F
OUT
+2 and is signed.
Unsigned
input
[0,1]
Computes sin(a) and cos(a) on a user-specified output fraction
width(F
OUT
). The output has the width w
OUT
= F
OUT
+1 and is
unsigned.
Table 8. Atan2 Function Signals
Name Type Configurati
on
Range Details
x, y
Input Signed
input
Given by
w, F
Specifies the total width (w) and number fractional bits (F) of the
input. Provide the inputs in two’s complement form.
Unsigned
input
Specifies the total width (w) and number fractional bits (F) of the
input.
a
Ouput Signed
input
[−π,+π]
Computes atan2(y,x) on a user-specified output fraction width (F).
The output has the width w
OUT
= F
OUT
+2 and is signed.
Unsigned
input
[0,+π/2]
Computes atan2(y,x) on output fraction width (F
OUT
). The output
format has the width w
OUT
= F
OUT
+2 and is signed. However, the
output value is unsigned.
1. ALTERA_CORDIC IP Core User Guide
683808 | 2017.05.08
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ALTERA_CORDIC IP Core User Guide
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