ifft.lst

54系列dsp算法程序

TMS320C54x COFF Assembler       Beta Version 1.16     Mon Sep 23 13:58:16 1996
Copyright (c) 1996        Texas Instruments Incorporated 

ifft.asm                                                             PAGE    1

       1            *********************************************************************************
       2            *       (C) COPYRIGHT TEXAS INSTRUMENTS, INC. 1996                              *
       3            *********************************************************************************
       4            *                                                                               *
       5            * FILE NAME:  IFFT.asm                                                          *
       6            *                                                                               *
       7            * AUTHORS:    Simon Lau and Nathan Baltz                                        *
       8            *                                                                               *
       9            * DESCRIPTION:                                                                  *
      10            *  - TMS320C54x N-point Complex IFFT                                            *
      11            *    Radix 2, in-place DIT algorithm                                            *
      12            *  - For various input sizes (16 - 512), simply modify N and LOGN.              *
      13            *  - Input data is assumed to be in Q0.15 format, stored in natural order,      *
      14            *    interleaved real/complex, in a data file named "Indata1"                   *
      15            *  - Bit-reversal of input data is done automatically before performing the IFFT*
      16            *  - Computation is done in place, so the outputs come in natural order,        *
      17            *    interleaved real/complex.                                                  *
      18            *  - Twiddle factors are stored in normal order in two separate tables,         *
      19            *    one for sine values and the other for cosine.                              *
      20            *  - Total size of twiddle tables is 1024 bytes for IFFT size up to 1024 points.*
      21            *    Same twiddle tables are used for IFFT size from 16 to 512.                 *
      22            *  - For additional information about the implementation of this code refer to  *
      23            *    the readme.txt file.                                                       *
      24            *                                                                               *
      25            * DATE:       Summer 1996                                                       *
      26            *                                                                               *
      27            *********************************************************************************
      28            
      29                    .mmregs
      30                    .global reset,begin,stage,group,btflyend
      31            
      32      0010  N       .set 16                         ; number of complex points 
      33      0004  LOGN    .set 4                          ; number of stages (=logN/log2)
      34            
      35            ; Copy input data and twiddle tables from files
      36            
      37 000000               .data
      38 000000       DATA    .space 2*N*16                   ; start addr. of complex output data
      39            INPUT   .copy indata1                   ; start addr. of complex input data   
 A     1 000020 0000          .word       0
 A     2 000021 0000          .word       0
 A     3 000022 187E          .word       6270
 A     4 000023 0000          .word       0
 A     5 000024 2D41          .word       11585
 A     6 000025 0000          .word       0
 A     7 000026 3B21          .word       15137
 A     8 000027 0000          .word       0
 A     9 000028 4000          .word       16384
 A    10 000029 0000          .word       0
 A    11 00002a 3B21          .word       15137
 A    12 00002b 0000          .word       0
 A    13 00002c 2D41          .word       11585
 A    14 00002d 0000          .word       0
 A    15 00002e 187E          .word       6270
 A    16 00002f 0000          .word       0
TMS320C54x COFF Assembler       Beta Version 1.16     Mon Sep 23 13:58:16 1996
Copyright (c) 1996        Texas Instruments Incorporated 

ifft.asm                                                             PAGE    2

 A    17 000030 0000          .word       0
 A    18 000031 0000          .word       0
 A    19 000032 E782          .word      -6270
 A    20 000033 0000          .word       0
 A    21 000034 D2BF          .word      -11585
 A    22 000035 0000          .word       0
 A    23 000036 C4DF          .word      -15137
 A    24 000037 0000          .word       0
 A    25 000038 C000          .word      -16384
 A    26 000039 0000          .word       0
 A    27 00003a C4DF          .word      -15137
 A    28 00003b 0000          .word       0
 A    29 00003c D2BF          .word      -11585
 A    30 00003d 0000          .word       0
 A    31 00003e E782          .word      -6270
 A    32 00003f 0000          .word       0
 A    33                
      40            
      41 000000               .sect "twiddle1"
      42            TWI1    .copy twiddle1                  ; sine table
 B     1            ; sine table for FFT
 B     2 000000 0000       .word     0h
 B     3 000001 00C9       .word 000c9h     ;    0.352