exp4c55_6.asm

用dsp解压mp3程序的算法

***************************************************************************
* exp4c55_6.asm - An assembly program for C55x CCS simulator
*                 y = sum(0.99) for a total of 256 times in Section 4.6.6
*     
***************************************************************************
* Section allocation
*
	.def	 yl,yh,yg
yl	.usect   "vars",1  ; reserve 1 location for AH
yh	.usect   "vars",1  ; reserve 1 location for AL
yg	.usect   "vars",1  ; reserve 1 location for guard bits

	.text		   ; create code section
	.def	 start	   ; label of the beginning of code

start
	
	BCLR	C54CM	   ; set C55x native mode
	BSET 	SXMD
	BCLR 	SATD
	
add	
	MOV 	#0x7FFF<<#16,AC0	
	RPT 	#254 
	ADD  	#0X7FFF<<#16,AC0

* Write the result to memory location y

write
	MOV	HI(AC0),*(#yh)	; y <- AC0
	MOV	AC0,*(#yl)
	MOV	HI(AC0<<#-16),*(#yg)

end
	NOP
	B	end		; stop here