speech_decode_frame.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:     Speech_Decode_Frame() in sp_dec.c			           **
**                                                                         **
** Inputs                                                                  **
**                                                                         **
**	 Speech_Decode_FrameState *st, /* io: post filter states               **    
**   Word16 *serial,               /* i : serial bit stream                **    
**                                                                         **
** Outputs:                                                                **
**                                                                         **
**   Word16 *synth                 /* o : synthesis speech (postfiltered   **
**  										   				output)        **
**                                                                         **
** Return value :       		                                           **
**                                                                         **
** Attribute    :       Cycles:         Pm: 	                           **
**                      Modified Registers:  					           **
**                                                                         **
** Programmer   :       YANG zhiwei                                        **
*****************************************************************************
		.global		 _Speech_Decode_Frame
		
		;.ref		_Speech_Decode_Frame_init	
		.ref		_Bits2prm
		.ref		_Decoder_amr
		.ref		_Post_Filter
		.ref		_Post_Process
						
		.ref		_buffer3
		.ref		_buffer4
		.ref		parm
		.ref		_synth
		.ref		y2_hi
		.ref		A_t
		.ref        _demodushift
		.ref		L_FRAME
		
NO13BIT	.set	1
						
_Speech_Decode_Frame:
        MOVW	 DP,#200H
		;lcr		_Speech_Decode_Frame_init	
		
		;mov		ar0,#181 - 1
		;addb	sp,#4
	
_loop_main:
		;mov		*-sp[2],ar0

		; Serial to parameters   
		
		;movl	xar1, #_buffer3
		movl	xar1, #_buffer4
		movl    xar2, #_demodushift
		mov     acc,  *xar2 
		addl	xar1, acc		     	;xar1 point to serial[]
		
		movl	xar3,#parm				;xar3 point to parm[]	
		lcr		_Bits2prm

		;Synthesis
		lcr		_Decoder_amr
	    movl	xar3,#_synth
	    movl	xar1,#A_t 
        lcr		_Post_Filter
        nop
        lcr		_Post_Process
      	;post HP filter, and 15->16 bits

		;.if	    !NO13BIT
		;Truncate to 13 bits
		;movl	xar2,#synth	
		;mov		al,#0xfff8
	;	rpt		#L_FRAME - 1
	;	||and		*xar2++,al
	;	.endif
		;movz	ar0,*-sp[2]
		;banz	_loop_main,ar0--
		
		;sub		sp,#4
		lretr