c4_1_3.asm

dsp入门与实践一书的源代码

			   .mmregs
                 .def    cos_generate,end_of_cose
                 .def    d_cos_delay1,d_cos_delay2,d_theta,d_cosx
d_cos_delay1      .usect  "cos_vars",1
d_cos_delay2      .usect  "cos_vars",1
d_theta           .usect   "cos_vars",1
d_cosx           .usect   "cos_vars",1  

k_cos_delay_1     .set     06602h         			
k_cos_delay_2     .set     064d8h         			
k_cos_theta       .set     07f83h          			
k_2              .set     2h            			
k_256            .set     256           			

COSDATA        .usect   "cos_data",256				

                	.text
                 SSBX    	FRCT				
                 ST       	COSDATA,AR5			
                 NOP
                 STM     	#600H,SP			
 			   LD      	#d_cos_delay1,DP	
            	   NOP 
                                    				
                 STM        #d_cos_delay1,AR3		
                 STM        #d_theta,AR4
                 RPTZ       A, #3h
                 STL        A,*AR3+              
                                    			
                 STM       #1,AR0
                 STM       #d_cosx,AR2
                 STM       #k_2,BK 
                 STM       #k_256-1,BRC 
                 NOP 
                 STM       #d_cos_delay1,AR3
                 ST         #k_cos_delay_1,*AR3+
                 ST         #k_cos_delay_2,*AR3
                 STM       #d_cos_delay1,AR3     
                 ST         #k_cos_theta,d_cosx  
cos_generate:
                 RPTB     end_of_cose-1			
                 MPY      *AR2,*AR3+0%,A 
                 SUB      *AR3,15,A 
                 SFTA      A,1,A
                 STH       A,*AR3             
                 MVDD    *AR3,*AR5+			
                 ; MVDD    *AR3,XSR0			
			   NOP
end_of_cose:      B         cos_generate         														; 可以在此加入指令用于改变输出信号
cosend:          .end