dotp4a_init.asm

DSP原理及其C编程开发技术的源码 真的很好呀

;Dotp4a_init.asm ASM program to init variables. Calls dotp4afunc.asm

	      .def		 init       ;starting address
	      .ref		 dotp4afunc ;called ASM function
	      .text			      ;section for code
x_addr      .short	 1,2,3,4    ;numbers in x array
y_addr      .short 	 0,2,4,6    ;numbers in y array
result_addr .short 	 0	      ;initialize sum of products
					
init        MVK	result_addr,A4    ;A4 = lower 16-bit addr -->A4 
	      MVKH	result_addr,A4    ;A4 = higher 16-bit addr-->A4
	      MVK	0,A3 		      ;A3 = 0
	      STH	A3,*A4	      ;init result to 0
	      MVK	x_addr,A4         ;A4 = 16 MSBs address of x 
	      MVK	y_addr,B4	      ;B4 = 16 LSBs address of y 
            MVKH	y_addr,B4	      ;B4 = 16 MSBs address of y 
	      MVK	4,A6		      ;A6 = size of array
	      B	dotp4afunc	      ;branch to function dotp4afunc 
	      MVK	ret_addr,b3	      ;B3 = return addr from dotp4a
	      MVKH	ret_addr,b3	      ;B3 = return addr from dotp4a
	      NOP	3                 ;3 more delay slots(branch)

ret_addr    MVK	result_addr,A0    ;A0 = 16 LSBs result_addr
	      MVKH	result_addr,A0    ;A0 = 16 MSBs result_addr
            STW	A4,*A0	      ;store result 
wait	      B	wait		      ;wait here
	      NOP	5		      ;delay slots for branch