c54-6.asm

来自「G723.1语音压缩解压在tms320c54系列上的实现代码,本人已在CCS上仿」· 汇编 代码 · 共 49 行

;
;;;;;;;;;;;;;;;;;;Function;;;;;;;;;;;;;;;;;;  
;        


	.mmregs
             .global        _c54_smpy
_c54_smpy:

   	.if    __far_mode
        FRAME 2;
	MVMM SP,AR0;  //参数2地址放入AR0
	FRAME -2
       	.else
        FRAME 1;
	MVMM SP,AR0;  //参数2地址放入AR0
	FRAME -1
        .endif

	LD *AR0,B;  //参数2放入B
	STLM A,T;  //参数1低16位放T
	MPY *AR0,A;  //A = 参数1(T中)*参数2(*AR0指向)
	SFTA A,1,A;  //A = A << 1
	STM #0x8000,BH
	STM #0x0000,BL
	SUB A,0,B;  //B = B - (A<<0),判断A中内容和0x80000000的大小
	BC next,BEQ;  //if B=0 到next
	B result
next:
	STM #0xffff,AL
	STM #0x7fff,AH
	
result:
	.if __far_mode
        FRETD
        NOP
        NOP
	.else
        RETD
        NOP
        NOP
        NOP
	.endif
	.end