bit_reverse.lst

基于c166的 FFT算法源程序

C166 COMPILER V6.04, BIT_REVERSE                                                           09/04/2007 16:24:44 PAGE 1   


C166 COMPILER V6.04, COMPILATION OF MODULE BIT_REVERSE
OBJECT MODULE PLACED IN Bit_reverse.OBJ
COMPILER INVOKED BY: C:\Keil\C166\BIN\C166.EXE Bit_reverse.c MODV2 BROWSE MODV2 DEBUG

 stmt lvl     source

    1         /****************************************************************************** 
    2         ;  Module:              Bit_reverse
    3         ;  Filename:    Bit_reverse.c
    4         ;  Project:             DSP library for XC166 microcontroller
    5         ;------------------------------------------------------------------------------
    6         ;  Compiler:    Keil
    7         ;
    8         ;  Version:             V1.2
    9         ;
   10         ;  Description: Reversing the binary bit of the input indices during the 
   11         ;                               FFT operation. This routine is especially written for FFT.
   12         ;             
   13         ;  Date:                May 2003
   14         ;
   15         ;  Copyright:   Infineon Technologies AG
   16         ;*****************************************************************************/
   17         
   18         /******************************************************************************
   19         ; DataS Bit_reverse(DataS* X, DataS N);
   20         ;
   21         ; INPUTS:       
   22         ;               X               the input index vector
   23         ;               N               the size of the vector 
   24         ;
   25         ; RETURN:
   26         ;
   27         ; ALGORITHM:    befor bit reverse:  b7.b6.b5.b4.b3.b2.b1.b0
   28         ;                               after bit reverse:  b0.b1.b2.b3.b4.b5.b6.b7 
   29         ;                          
   30         ; REGISTER USAGE:
   31         ;       1.      From .c file to .asm file:
   32         ;                       defined by compiler
   33         ;
   34         ;       2.      From .asm file to .c file:
   35         ;                       (R4) = exponent of N
   36         ;
   37         ; Assumption:   1.      N must be in the form 2^M, where M in an integer.
   38         ;                               2.      2 <= N <= 2048
   39         ;
   40         ;*****************************************************************************/
   41         
   42         #include "DspLib_Keil.h"
   43                                 
   44         DataS Bit_reverse(DataS* X, DataS N)
   45         {
   46  1         __asm
   47  1        {
   48  1      
   49  1              MOV             R1,N            ;(R1)=N
   50  1      //determinate the exponent of N
   51  1              MOV             R2,#0ffffh      ; clesr register R2=-1
   52  1      next:
   53  1              ADD             R2,#01h         ;(R2)=(R2)+1
   54  1              SHR             R1,#1h          ;(R1)=N/2
   55  1              JMPR    cc_NZ, next     ;if (R1)>0, jump
C166 COMPILER V6.04, BIT_REVERSE                                                           09/04/2007 16:24:44 PAGE 2   

   56  1      
   57  1      //output the exponent of N to R4
   58  1              MOV             R4,R2           ;(R4)=(R2)=exponent of N
   59  1                
   60  1      //bit reverse
   61  1      //if N=2, one bit
   62  1              CMP             R2,#1           
   63  1              JMPR    cc_NE,Neq2      ;if (R2) not equal to 1, jump
   64  1      
   65  1              RET
   66  1      
   67  1      //if N=4, 2 bits
   68  1      Neq2:
   69  1              CMP             R2,#2           
   70  1              JMPR    cc_NE,Neq3      ;if (R2) not equal to 2, jump
   71  1      loop2:
   72  1              MOV             R3,[X]          ;(R3)=x[i]
   73  1              MOV             R2,R3           ;(R2)=(R3)
   74  1              BMOV    R2.1,R3.0       ;bit reverse
   75  1              BMOV    R2.0,R3.1
   76  1              MOV             [X],R2          ;x[i]=(R2)
   77  1              MOV             R2,[X+]         ;just increase the address of X
   78  1              SUB             N,#1            ;(N)=(N)-1
   79  1              JMPR    cc_NZ,loop2     ;if (N)>0, jump
   80  1      
   81  1              RET
   82  1      
   83  1      //if N=8, 3 bits
   84  1      Neq3:
   85  1              CMP             R2,#3           
   86  1              JMPR    cc_NE,Neq4      ;if (R2) not equal to 3, jump
   87  1      loop3:
   88  1              MOV             R3,[X]          ;(R3)=x[i]
   89  1              MOV             R2,R3           ;(R2)=(R3)
   90  1              BMOV    R2.2,R3.0       ;bit reverse
   91  1              BMOV    R2.0,R3.2       ;bit reverse
   92  1              MOV             [X],R2          ;x[i]=(R2)
   93  1              MOV             R2,[X+]         ;increase the address
   94  1              SUB             N,#1            ;(N)=(N)-1
   95  1              JMPR    cc_NZ,loop3     ;if (N)>0, jump
   96  1      
   97  1              RET
   98  1      
   99  1      //if N=16, 4 bits
  100  1      Neq4:
  101  1              CMP             R2,#4           
  102  1              JMPR    cc_NE,Neq5      ;if (R2) not equal to 4, jump
  103  1      loop4:
  104  1              MOV             R3,[X]          ;(R3)=x[i]
  105  1              MOV             R2,R3           ;(R2)=(R3)
  106  1              BMOV    R2.3,R3.0       ;bit reverse
  107  1              BMOV    R2.2,R3.1       ;bit reverse
  108  1              BMOV    R2.1,R3.2       ;bit reverse
  109  1              BMOV    R2.0,R3.3       ;bit reverse
  110  1              MOV             [X],R2          ;x[i]=(R2)
  111  1              MOV             R2,[X+]         ;increase the address
  112  1              SUB             N,#1            ;(X)=(X)-1
  113  1              JMPR    cc_NZ,loop4     ;if (N)>0, jump
  114  1      
  115  1              RET
  116  1      
  117  1      //if N=32, 5 bits
C166 COMPILER V6.04, BIT_REVERSE                                                           09/04/2007 16:24:44 PAGE 3   

  118  1      Neq5:
  119  1              CMP             R2,#5           
  120  1              JMPR    cc_NE,Neq6      ;if (R2) not equal to 5, jump
  121  1      loop5:
  122  1              MOV             R3,[X]          ;(R3)=x[i]
  123  1              MOV             R2,R3           ;(R2)=(R3)
  124  1              BMOV    R2.4,R3.0       ;bit reverse
  125  1              BMOV    R2.3,R3.1       ;bit reverse
  126  1              BMOV    R2.1,R3.3       ;bit reverse
  127  1              BMOV    R2.0,R3.4       ;bit reverse
  128  1              MOV             [X],R2          ;x[i]=(R2)
  129  1              MOV             R2,[X+]         ;increase the address
  130  1              SUB             N,#1            ;(N)=(N)-1
  131  1              JMPR    cc_NZ,loop5     ;if (N)>0, jump
  132  1      
  133  1              RET
  134  1      
  135  1      //if N=64, 6 bits
  136  1      Neq6:
  137  1              CMP             R2,#6           
  138  1              JMPR    cc_NE,Neq7      ;if (R2) not equal to 6, jump
  139  1      loop6:
  140  1              MOV             R3,[X]          ;(R3)=x[i]
  141  1              MOV             R2,R3           ;(R2)=(R3)
  142  1              BMOV    R2.5,R3.0       ;bit reverse
  143  1              BMOV    R2.4,R3.1       ;bit reverse