system_func.asm

这是我在ADSP tiger sharc 201上面实现的OFDM(标准是wimax)同步算法哦!具有非常高的指令效率.

// -------- CACHE 2 INVALIDATE ----------------------------------------------- //

//	CCAIR2 = 0x00000000;;
        J0 = 0;;          //modified by Frank
	CCAIR2 = J0;;     //modified by Frank

	CACMD2 = (CACMD_INV | CACMD_NOSTALL | (511 << CACMD_LEN_P));;

.align_code 4;
_check_invalidate_cache_2:
	XR0 = CASTAT2;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_invalidate_cache_2 (NP);;	
_check_invalidate_cache_2.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 4 INVALIDATE ----------------------------------------------- //

//	CCAIR4 = 0x00000000;;
        J0 = 0;;          //modified by Frank
	CCAIR4 = J0;;     //modified by Frank

	CACMD4 = (CACMD_INV | CACMD_NOSTALL | (511 << CACMD_LEN_P));;

.align_code 4;
_check_invalidate_cache_4:
	XR0 = CASTAT4;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_invalidate_cache_4 (NP);;	
_check_invalidate_cache_4.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 6 INVALIDATE ----------------------------------------------- //

//	CCAIR6 = 0x00000000;;
        J0 = 0;;          //modified by Frank
	CCAIR6 = J0;;     //modified by Frank

	CACMD6 = (CACMD_INV | CACMD_NOSTALL | (511 << CACMD_LEN_P));;

.align_code 4;
_check_invalidate_cache_6:
	XR0 = CASTAT6;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_invalidate_cache_6 (NP);;	
_check_invalidate_cache_6.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 8 INVALIDATE ----------------------------------------------- //

//	CCAIR8 = 0x00000000;;
        J0 = 0;;          //modified by Frank
	CCAIR8 = J0;;     //modified by Frank

	CACMD8 = (CACMD_INV | CACMD_NOSTALL | (511 << CACMD_LEN_P));;

.align_code 4;
_check_invalidate_cache_8:
	XR0 = CASTAT8;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_invalidate_cache_8 (NP);;	
_check_invalidate_cache_8.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 10 INVALIDATE ---------------------------------------------- //

//	CCAIR10 = 0x00000000;;
        J0 = 0;;          //modified by Frank
	CCAIR10 = J0;;     //modified by Frank

	CACMD10 = (CACMD_INV | CACMD_NOSTALL | (511 << CACMD_LEN_P));;

.align_code 4;
_check_invalidate_cache_10:
	XR0 = CASTAT10;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_invalidate_cache_10 (NP);;	
_check_invalidate_cache_10.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

.align_code 4;
_invalidate_cache.end:

// ~~~
// ~~~ SET REFRESH
// ~~~

.align_code 4;
_set_refresh:

// -------- CACHE 0 REFRESH -------------------------------------------------- //

	CACMD0 = (CACMD_REFRESH | REFRESH_RATE);;

.align_code 4;
_check_refresh_cache_0:
	XR0 = CASTAT0;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_refresh_cache_0 (NP);;	
_check_refresh_cache_0.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 2 REFRESH -------------------------------------------------- //

	CACMD2 = (CACMD_REFRESH | REFRESH_RATE);;

.align_code 4;
_check_refresh_cache_2:
	XR0 = CASTAT2;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_refresh_cache_2 (NP);;	
_check_refresh_cache_2.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 4 REFRESH -------------------------------------------------- //

	CACMD4 = (CACMD_REFRESH | REFRESH_RATE);;

.align_code 4;
_check_refresh_cache_4:
	XR0 = CASTAT4;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_refresh_cache_4 (NP);;	
_check_refresh_cache_4.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 6 REFRESH -------------------------------------------------- //

	CACMD6 = (CACMD_REFRESH | REFRESH_RATE);;

.align_code 4;
_check_refresh_cache_6:
	XR0 = CASTAT6;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_refresh_cache_6 (NP);;	
_check_refresh_cache_6.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 8 REFRESH -------------------------------------------------- //

	CACMD8 = (CACMD_REFRESH | REFRESH_RATE);;

.align_code 4;
_check_refresh_cache_8:
	XR0 = CASTAT8;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_refresh_cache_8 (NP);;	
_check_refresh_cache_8.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 10 REFRESH ------------------------------------------------- //

	CACMD10 = (CACMD_REFRESH | REFRESH_RATE);;

.align_code 4;
_check_refresh_cache_10:
	XR0 = CASTAT10;;
	XBITEST R0 BY CASTAT_COM_ACTIVE_P;;
	IF NXSEQ, JUMP _check_refresh_cache_10 (NP);;	
_check_refresh_cache_10.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

.align_code 4;
_set_refresh.end:

// ~~~
// ~~~ RE-ENABLE CACHE
// ~~~

.align_code 4;
_cache_reenable:

// -------- CACHE 0 RE-ENABLE ------------------------------------------------ //

	CACMD0 = CACMD_EN;;

.align_code 4;
_check_reenable_cache_0:
	XR0 = CASTAT0;;
	XBITEST R0 BY CASTAT_ENBL_P;;
	IF XSEQ, JUMP _check_reenable_cache_0 (NP);;	
_check_reenable_cache_0.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 2 RE-ENABLE ------------------------------------------------ //

	CACMD2 = CACMD_EN;;

.align_code 4;
_check_reenable_cache_2:
	XR0 = CASTAT2;;
	XBITEST R0 BY CASTAT_ENBL_P;;
	IF XSEQ, JUMP _check_reenable_cache_2 (NP);;	
_check_reenable_cache_2.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 4 RE-ENABLE ------------------------------------------------ //

	CACMD4 = CACMD_EN;;

.align_code 4;
_check_reenable_cache_4:
	XR0 = CASTAT4;;
	XBITEST R0 BY CASTAT_ENBL_P;;
	IF XSEQ, JUMP _check_reenable_cache_4 (NP);;	
_check_reenable_cache_4.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 6 RE-ENABLE ------------------------------------------------ //

	CACMD6 = CACMD_EN;;

.align_code 4;
_check_reenable_cache_6:
	XR0 = CASTAT6;;
	XBITEST R0 BY CASTAT_ENBL_P;;
	IF XSEQ, JUMP _check_reenable_cache_6 (NP);;	
_check_reenable_cache_6.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 8 RE-ENABLE ------------------------------------------------ //

	CACMD8 = CACMD_EN;;

.align_code 4;
_check_reenable_cache_8:
	XR0 = CASTAT8;;
	XBITEST R0 BY CASTAT_ENBL_P;;
	IF XSEQ, JUMP _check_reenable_cache_8 (NP);;	
_check_reenable_cache_8.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

// -------- CACHE 10 RE-ENABLE ----------------------------------------------- //

	CACMD10 = CACMD_EN;;

.align_code 4;
_check_reenable_cache_10:
	XR0 = CASTAT10;;
	XBITEST R0 BY CASTAT_ENBL_P;;
	IF XSEQ, JUMP _check_reenable_cache_10 (NP);;	
_check_reenable_cache_10.end:	

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

.align_code 4;
_cache_reenable.end:

//
// -------- BTB ENABLE ------------------------------------------------------- //

.align_code 4;
_check_btb_enable:
	XR0 = SQSTAT;;
	XR0 = SQSTAT;;
	XBITEST R0 BY SQSTAT_BTBEN_P;;
	IF NXSEQ, JUMP _check_btb_enable.end (NP);;

	nop;;
	nop;;
	nop;;
	nop;;
	nop;;
	nop;;

	BTBEN;;
.align_code 4;
_check_btb_enable.end:			 
	
// ~~~
// ~~~ EPILOGUE RESTORES CJMP, "PRESERVED" REGISTERS, AND FRAME AND STACK POINTER
// ~~~ 

	CJMP = [J26 + 64];;

	YR27:24 = q[K27 + 16];		XR27:24 = q[J27 + 24];;
	YR31:28 = q[K27 + 12];		XR31:28 = q[J27 + 20];;
	K19:16  = q[K27 + 8 ];		J19:16  = q[J27 + 16];;
	K23:20  = q[K27 + 4 ];		J23:20  = q[J27 + 12];;

	cjmp (ABS);	J27:24=q[J26+68];	K27:24=q[K26+68];	nop;;

.align_code 4;

_system_func.end:	
	
// <<    END FUNCTION                                                       << //
// <<                                                                       << //
// <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< //

/*  fft32.asm

	July 2004 PM

	This is assembly routine for the Complex radix-2 C-callable FFT on TigerSHARC 
	family of DSPs only. It elaborates on complex only inputs. The real case has been excluded

	I. Description of Calling.

		1. Inputs:
			j4 -> input (ping-pong buffer 1)
			j5 -> ping-pong buffer 1
      		j6 -> ping-pong buffer 2
			j7 -> output
			
			//j27+0x18 -> N = Number of points

		2. C-Calling Example:
			fft32(&(input), &(ping_pong_buffer1), &(ping_pong_buffer2), &(output), N);

		3. Limitations:
			a. All buffers must be aligned on memory boundary which is a multiple of 4.
			b. N must be between 32 and MAX_FFT_SIZE.
			c. If memory space savings are required and input does not have to be
			   preserved, ping_pong_buffer1 can be the same buffer as input.
			d. If memory space savings are required, output can be the same buffer
			   as ping_pong_buffer2 if the number of FFT stages is even (i.e. 
			   Log2(N) is even) or the same as ping_pong_buffer1 if the number of
			   FFT stages is odd (i.e. Log2(N) is odd).

		4. MAX_FFT_SIZE can be selected via #define. Larger values allow for more choices
		   of N, but its twiddles will occupy more memory.
    5. This C - callable function can process up to 64K blocks of data on TS201 
        (16K blocks on TS101) because C environment itself necessitates memory. 
        Therefore, if more input points are necessary, assembly language development 
        may become a must. On TS201, a block of memory is 128K words long, so 
        maximum N is 64K complex points. TS101 contains only 2 blocks of data memory 
        of 64K words and 4 buffers must be accommodated. 
        Therefore, maximum N is 16K complex words.

	
	II. Description of the FFT algorithm.

		1. The input data is treated as complex interleaved N-point.
		2. Due to re-ordering, no stage can be done in-place.
		3. The bit reversal and the first two stages are combined into
		   a single loop. This loop takes data from input and stores it
		   in the ping-pong buffer1.
		4. Each subsequent stage ping-pongs the data between the two ping-pong
		   buffers. The last stage uses FFT output buffer for its output.
		5. Although the FFT is designed to be called with any point size
		   N <= MAX_FFT_SIZE by subsampling the twiddle factors, for ADSP-TS20x
		   processors, the best cycle optimization is achieved when MAX_FFT_SIZE=N.
		   For ADSP-TS101 all choices of MAX_FFT_SIZE are equally optimal.



	III.For all additional details regarding this algorithm and code, see EE-218
	    application note, available from the ADI web site.		   

*/
//************************************ Includes **********************************