mpy_32.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

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** Description:     mpy_32()      in oper_32b.c                            **
** Inputs :                                                                **
**          *xar7-- word16 hi1       : hi part of first number             **
**          *xar6-- word16 lo1       : low part of first number            **
**          *xar2-- word16 hi2       : hi part of second number            **
**          *xar3-- word16 lo2       : low part of second number           **
** Outputs:                                                                **
**								                                           **
** Return value :    			                                           **
**                      ACC :  word 32                                     **
** Attribute    :       Cycles:65          Pm: 9                           **
**                                                                         **
**               Modified Registers: ACC,P,T,AR4                           **                      
**                                                                         **
** Programmer   :       ZHOU Bei       (ok! MAR 12th,2003)                 **
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	    .global	 _mpy_32
_mpy_32:
		ZAPA
        MAC	    P,*XAR2,*XAR7  		;P=hi1*hi2
	    MAC	    P,*XAR3,*XAR7    	;ACC=P,P=hi1*lo2
	    MOVH    AR4,P               ;Get upper 16bit without sign
	    ADD     ACC,AR4<<#1      	;Add to ACC	 
	    MOV	    T,*XAR2		
	    MPY	    P,T,*XAR6           ;P=lo1*hi2
	    MOVH    AR4,P   			;Get upper 16bit without sign
	    ADD     ACC,AR4<<#1	        ;Add to ACC	  
	    LRETR