rifft.lst

54系列dsp算法程序

TMS320C54x COFF Assembler       Beta Version 1.16     Mon Sep 23 13:59:22 1996
Copyright (c) 1996        Texas Instruments Incorporated 

rifft.asm                                                            PAGE    1

       1            *********************************************************************************
       2            *       (C) COPYRIGHT TEXAS INSTRUMENTS, INC. 1996                              *
       3            *********************************************************************************
       4            *********************************************************************************
       5            *                                                                               *
       6            * FILE NAME:  rIFFT.asm                                                         *
       7            *                                                                               *
       8            * AUTHORS:    Simon Lau and Nathan Baltz                                        *
       9            *                                                                               *
      10            * DESCRIPTION:                                                                  *
      11            *  - TMS320C54x 2N-point Real IFFT                                              *
      12            *    Radix 2, in-place DIT algorithm                                            *
      13            *  - For various input sizes (16 - 1024), simply modify N and LOGN.             *
      14            *  - Input data is assumed to be in Q0.15 format, stored in natural order,      *
      15            *    all real, in a data file named "Indata1"                                   *
      16            *  - Bit-reversal of input data is done automatically before performing the IFFT*
      17            *  - Computation is done in place, so the outputs come in natural order,        *
      18            *    interleaved real/complex.                                                  *
      19            *  - Twiddle factors are stored in normal order in two separate tables,         *
      20            *    one for sine values and the other for cosine.                              *
      21            *  - Total size of twiddle tables is 1024 bytes for IFFT size up to 1024 points.*
      22            *    Same twiddle tables are used for IFFT size from 16 to 1024.                *
      23            *  - For additional information about the implementation of this code refer to  *
      24            *    the readme.txt file.                                                       *
      25            *                                                                               *
      26            * DATE:       Summer 1996                                                       *
      27            *                                                                               *
      28            *********************************************************************************
      29            
      30                    .mmregs
      31                    .global reset,begin,stage,group,btflyend
      32            
      33      0008  N       .set 8                          ; number of complex points 
      34      0003  LOGN    .set 3                          ; number of stages (=logN/log2)
      35            
      36            ; Copy input data and twiddle tables from files
      37            
      38 000000               .data
      39 000000       DATA    .space 2*N*16                   ; start addr. of complex output data
      40            INPUT   .copy indata1                   ; start addr. of complex input data   
 A     1            *********************************************************************************
 A     2            *       (C) COPYRIGHT TEXAS INSTRUMENTS, INC. 1996                              *
 A     3            *********************************************************************************
 A     4 000010 0000          .word       0
 A     5 000011 187E          .word       6270
 A     6 000012 2D41          .word       11585
 A     7 000013 3B21          .word       15137
 A     8 000014 4000          .word       16384
 A     9 000015 3B21          .word       15137
 A    10 000016 2D41          .word       11585
 A    11 000017 187E          .word       6270
 A    12 000018 0000          .word       0
 A    13 000019 E782          .word      -6270
 A    14 00001a D2BF          .word      -11585
 A    15 00001b C4DF          .word      -15137
TMS320C54x COFF Assembler       Beta Version 1.16     Mon Sep 23 13:59:22 1996
Copyright (c) 1996        Texas Instruments Incorporated 

rifft.asm                                                            PAGE    2

 A    16 00001c C000          .word      -16384
 A    17 00001d C4DF          .word      -15137
 A    18 00001e D2BF          .word      -11585
 A    19 00001f E782          .word      -6270
 A    20                
      41            
      42 000000               .sect "twiddle1"
      43            TWI1    .copy twiddle1                  ; sine table
 B     1            *********************************************************************************
 B     2            *       (C) COPYRIGHT TEXAS INSTRUMENTS, INC. 1996                              *
 B     3            *********************************************************************************
 B     4            ; sine table for FFT
 B     5 000000 0000       .word     0h
 B     6 000001 00C9       .word 000c9h     ;    0.352