resave.asm

2407DSP开发应用程序实例（有14个常用模块程序）

		.def	_resave
;128 points DIT Radix-2 complex FFT
;N		.set	128					;number of points
;64 points DIT Radix-2 complex FFT
;N		.set	64                  ;number of points
;32 points DIT Radix-2 complex FFT  
N		.set	32                  ;number of points

        .global	_resave
        .global	_input
        .global	_indatr
        .global	_indati
_resave:
;-------------------------------------------------------------------
;C compatible 
;-------------------------------------------------------------------
		POPD	*+
		SAR		AR0,*+
		SAR		AR1,*
		LAR		AR0,*+,AR3
;------------------------------------------------------------------
;store N sample datas into _input in B0 with bit-reverse addressing
;------------------------------------------------------------------
		LAR		AR2,#_input
		LAR		AR3,#_indatr
		LAR		AR0,#N
		LAR		AR4,#(N-1) 
RESAV1	LACC	*+,0,AR2
		SACL	*BR0+,AR4
		BANZ	RESAV1,*-,AR3
;		LAR		AR3,#_indati
;		LAR		AR4,#(N-1)
;RESAV2	LACC	*+,AR2
;		SACL	*BR0+,AR4
;		BANZ	RESAV2,*-,AR3
;-------------------------------------------------------------------
;C compatible 
;-------------------------------------------------------------------
		MAR		*,AR1
		SBRK	#2
		LAR		AR0,*-
		PSHD	*
		RET