enc_lag3.asm

基于TMS320F2812的AMR+RS编解码+OFDM调制解调源程序。是stand alone运行版本

*****************************************************************************
** Description:     eng_lag3() in  eng_lag3.c                              **
**                                                                         **
** Inputs                                                                  **
**               
**   ar0---word16  T0                                                     **
**   ar1---Word16  T0_frac                                                **
**   ar2---Word16  T0_prev                                                **
**   ar3---word16  T0_min                                                 **
**   ar4---word16  T0_max                                                 **
**   ar5---word16  delta_flag                                             **
**                                                                         **
** Outputs:  none                                                         **
**                                                                         **
**                                                                         **
** Return value :       ar7                                               **
**                                                                         **
** Attribute    :       Cycles: 84      Pm: 95                           **
**                      Modified Registers:  all                           **
**                                                                         **
** Programmer   :       xie wei                                      **
*****************************************************************************

  .global _enc_lag3
_enc_lag3: 
    
	mov ah,@ar5
 	cmp ah,#0
	sb  _line_51,NEQ
 	mov ah,ar0
 	mov al,ar0
    add ah,#112
    mov @ar7,ah
  	cmp al,#85                        
	sb  _line_117,GT
    mov ah,al
    add al,al
	add al,ah
	sub al,#58
	add al,@ar1
    mov @ar7,al
    b   _line_117, UNC                                                   
_line_51:     
    mov al,@ar2 
    mov @ar6,al             
	sub al,@ar3
	cmp al,#5 
	sb  _line_72,LEQ   
	add al,#5
    mov @ar6,al
_line_72: mov ah,@ar4
    mov al,@ar6 
	sub ah,@al      
	cmp ah,#4
	sb  _line_80,LEQ
	mov al,@ar4
	sub al,#4
    mov @ar6,al 
_line_80: mov ah,@ar0
	mov al,ah
	add ah,ah
	add ah,al
	add ah,@ar1
	mov @ar3,ah
	mov al,@ar6         
	sub al,#2
	mov ah,al
	add al,al
	add al,ah
    mov @ar5,al
    mov ah,@ar3
	cmp al,@ah  
	sb  _line_101,LT
	mov al,@ar6
	mov ah,@ar0
	sub ah,@al
	add ah,#5
    mov @ar7,ah
	b   _line_117,UNC
_line_101: mov al,@ar6
    mov ah,@ar0
	sub ah,@al
	add ah,#11
    mov @ar7,ah
   	add al,#1
	mov ah,al
	add al,al
	add al,ah
   	mov ah,@ar3
	cmp al,@ah
	sb  _line_117,LEQ
	sub ah,@ar5 
	add ah,#3
	mov @ar7,ah
_line_117: 
    LRETR