cfft.asm

C50_melp.tar.gz为美军2400bps语音压缩编码算法

* 
* 
*2.4 kbps MELP Proposed Federal Standard speech coder
*
*TMS320C5x assembly code
*
*version 1.0
*
*Copyright (c) 1998, Texas Instruments, Inc.  
*
*Texas Instruments has intellectual property rights on the MELP
*algorithm.  The Texas Instruments contact for licensing issues for
*commercial and non-government use is William Gordon, Director,
*Government Contracts, Texas Instruments Incorporated, Semiconductor
*Group (phone [phone]).
*
*
*************************************************************************
*
* The following code was hand optimized for the Texas Instuments
* TMS320C5x DSP by DSPCon, Inc.  For information, please contact DSPCon
* at:
* 
*                       DSPCon, Inc.
*                       380 Foothill Road
*                       Bridgewater, New Jersey 08807
*                       [phone]
*                       [e-mail]
*                       www.dspcon.com
*
*************************************************************************
	 .file      "cfft.asm"
	 .title     "512 point DIT Radix-2, Complex FFT"
	 .width     120

******************************************************************************
*                                                                            *
*    512 - POINT COMPLEX, RADIX-2 DIF FFT WITH THE TMS320C5x / LOOPED CODE   *
*    ---------------------------------------------------------------------   *
*                                                                            *
* THE PROGRAM IS BASED ON THE BOOK 'DIGITAL SIGNAL PROCESSING APPLICATIONS'  *
* FROM TEXAS INSTRUMENTS P. 69. IT IS OPTIMIZED FOR THE TMS320C5x INCLUDING  *
* BIT REVERSAL ADDRESSING MODE.                                              *
*                                                                            *
*    WRITTEN BY: MANFRED CHRIST  REVISION: 2.00   21. Mar. 94                *
*                                                                            *
*    COPYRIGHT TEXAS INSTRUMENTS INC. 1990/1994                              *
*                                                                            *
******************************************************************************
*                                                                            *
*    USED  REGISTER: INDX,AR0..AR5,ACCU,PREG,TREG0,PMST,BRCR                 *
*                    2 Stacklevel, Block B0                                  *
*                                                                            *
*    PROGRAM MEMORY:  219 WORDS ('FFTLEN') WITHOUT INITIALIZATION            *
*                                                                            *
*    COEFFICIENTS  :   16 BITS  (Q15 Format) SCALING :    1/2^9 = 1/512      *
*                                                                            *
*    CYCLES        : 36016 CYLCES => 1800.8  us 1260.6  us  900.4  us        *
*                         T-CYCLE =>      50 ns      35 ns      25 ns        *
*                                                                            *
*    MEMORY USAGE: FFT PROGRAM    [ 00600H -  006daH ]                       *
*                  INPUT DATA     [ 01000H -  013ffH ]                       *
*                  DATA WORKSPACE [ 00800H -  00bffH ]                       *
*                  TWIDDLES       [ 00100H -  003edH ]                       *
*                                                                            *
*    INPUT DATA AT ADDRESS 1000h-13ffh:                                      *
*    ----------------------------------                                      *
*    THE DATA ARE STORED IN 'input' IN THE SEQUENCE: X(0),X(1),...,X(511)    *
*                                                    Y(0),Y(1),...,Y(511)    *
*                                                                            *
*    OUTPUT DATA AT ADDRESS 0800h-0bffh:                                     *
*    -----------------------------------                                     *
*    THE DATA ARE STORED IN SECIION 'fftdata' IN THE SEQUENCE:               *
*    X(0),Y(0),X(1),Y(1),... ... ,X(511),Y(511)                              *
******************************************************************************
*                                                                            *
*    THIS PROGRAM INCLUDES FOLLOWING FILES:                                  *
*    --------------------------------------                                  *
*    'TWIDDLES.Q15' contains all twiddle factors in Q15 format (sine,cosine) *
*    'C5CXRAD2.ASM' consists of all macros for all FFTs                      *
*    'INIT-FFT.ASM' for initialisation                                       *
******************************************************************************

	 .mmregs

	.def    _fft_data       ; output data buffer
	.def    _cfft


N       .set    512             ; NUMBER OF POINTS FOR FFT


;
;  Aligned data workspace
;

_fft_data  .usect  "fftdata",N*2   ; working data array

DATA    .set    _fft_data       ; data buffer


;
;  Twiddle factor table; referenced in place
;

	 .sect   "twiddles"
TWID     .set    $

	 .label TWIDSTRT
	 .include twidfull.q15   ; table of twiddle factors for the FFT
	 .label TWIDEND

TWIDLEN  .set    TWIDEND-TWIDSTRT


;
;  Initialized  variables; copied onto B2 at execution
;

	 .sect   "ffttab"
TABB     .set    $

	 .label TABSTRT

DATAADD .set    60h             ; START ADDRESS OF DATA
	.word   DATA

;        .def    STAGE1
DATA2   .set    61h             ; DATA+2
sin1    .set    62h             ; start of sine in stage    1
cos1    .set    63h             ; start of cosine in stage  1
	.word   DATA+2,SIN1,COS1

;        .def    STAGE2
DATA4   .set    64h             ; DATA+4
sin2    .set    65h             ; start of sine in stage    2
cos2    .set    66h             ; start of cosine in stage  2
	.word   DATA+4,SIN2,COS2

;        .def    STAGE3
DATA8   .set    67h             ; DATA+8
sin3    .set    68h             ; start of sine in stage    3
cos3    .set    69h             ; start of cosine in stage  3
	.word   DATA+8,SIN3,COS3

;        .def    STAGE4
DATA16  .set    6Ah             ; DATA+16
sin4    .set    6Bh             ; start of sine in stage    4
cos4    .set    6Ch             ; start of cosine in stage  4
	.word   DATA+16,SIN4,COS4

;        .def    STAGE5
DATA32  .set    6Dh             ; DATA+32
sin5    .set    6Eh             ; start of sine in stage    5
cos5    .set    6Fh             ; start of cosine in stage  5
	.word   DATA+32,SIN5,COS5

;        .def    STAGE6
DATA64  .set    70h             ; DATA+64
sin6    .set    71h             ; start of sine in stage    6
cos6    .set    72h             ; start of cosine in stage  6
	.word   DATA+64,SIN6,COS6

;        .def    STAGE7
DATA128 .set    73h             ; DATA+128
sin7    .set    74h             ; start of sine in stage    7
cos7    .set    75h             ; start of cosine in stage  7
	.word   DATA+128,SIN7,COS7

;        .def    STAGE8
DATA256 .set    76h             ; DATA+256
sin8    .set    77h             ; start of sine in stage    8
cos8    .set    78h             ; start of cosine in stage  8
	.word   DATA+256,SIN8,COS8

;        .def    STAGE9
DATA512 .set    79h             ; DATA+512
sin9    .set    7Ah             ; start of sine in stage    9
cos9    .set    7Bh             ; start of cosine in stage  9
	.word   DATA+512,SIN9,COS9

	 .label TABEND
TABLEN   .set   TABEND - TABSTRT

;
; Uninitialized temporary variables
;
saveFP  .set    7Ch
saveSP  .set    7Dh
saveIDX .set    7Eh




do_btfly .macro  num
	 CALLD   butterfly      ; delayed call follows
	 LACL    #:num:-1       ; make it DP-independend
	 SAMM    BRCR           ; execute num times BUTTFLYI
	 .endm

stdmacro .macro  stage,num,loops,add
	 LAR     AR0,#num*2      ; index register = num * 2
	 LAR     AR1,DATAADD     ; ar1 -> DATA
	 LAR     AR2,DATA:add:   ; ar2 -> DATA+16
	 LAR     AR5,#:loops:    ; ar5 is loopcounter -> repeat loop+1 times
loop?:   LAR     AR3,cos:stage:  ; start of cosine in this stage