After a state structure has been created, it can be used as many times as required to simulate the FFT core. A simulation is run using the second function,
xilinx_ip_xfft_v9_1_bitacc_simulate
. Call this function with the pointer to the existing state structure and structures that hold the inputs and outputs of the C model. The input structure members are shown in
Table: Members of the Inputs Structure
.
Table 5-3:
Members of the Inputs Structure
|
Member
|
Type
|
Description
|
|
nfft
|
int
|
Transform length
|
|
xn_re
|
double*
|
Pointer to array of doubles: real part of input data
|
|
xn_re_size
|
int
|
Number of elements in xn_re array
|
|
xn_im
|
double*
|
Pointer to array of doubles: imaginary part of input data
|
|
xn_im_size
|
int
|
Number of elements in xn_im array
|
|
scaling_sch
|
int*
|
Pointer to array of ints containing scaling schedule
|
|
scaling_sch_size
|
int
|
Number of elements in scaling_sch array
|
|
direction
|
int
|
Transform direction: 1=forward FFT, 0=inverse FFT (IFFT)
|
The notes under the following headings apply to the inputs structure.
•
General
•
FFTs with Fixed-Point Interface
•
FFTs with Floating-Point Interface