fm1.asm

信号调制中的AM调制方法在DSP5402上面的实验

           .title "fm1.asm"
           .mmregs
		   .def start 
		   .bss sin25p,1 
		   .bss sinstp,1
		   .bss sin25p1,1
		   .bss sinstp1,1
		   .bss x0,1
		   .bss x1,1
           .bss c0,1
           .bss s0,1
           .bss c1,1
           .bss s1,1
y0         .usect "DATA",500
y1         .usect "DATA",500
y          .usect "DATA1",500
		   
           .data
sintab:    .word 00000H,00648H,00C8CH,012C8H,018F9H,01F1AH,02528H,02B1FH
		   .word 030FBH,036BAH,03C56H,041CEH,0471CH,04C3FH,05133H,055F5H
		   .word 05A82H,05ED7H,062F1H,066CFH,06A6DH,06DC9H,070E2H,073B5H
		   .word 07641H,07884H,07A7CH,07C29H,07D89H,07E9CH,07F61H,07FD8H
           .word 07FFFH,07FD8H,07F61H,07E9CH,07D89H,07C29H,07A7CH,07884H
           .word 07641H,073B5H,070E2H,06DC9H,06A6DH,066CFH,062F1H,05ED7H
		   .word 05A82h,055F5H,05133H,04C3FH,0471CH,041CEH,03C56H,036BAH
		   .word 030FBH,02B1FH,02528H,01F1AH,018F9H,012C8H,00C8CH,00648H
		   .word 00000H,0F9B8H,0F374H,0ED38H,0E707H,0E0E6H,0DAD8H,0D4E1H
		   .word 0CF05H,0C946H,0C3AAH,0BE32H,0B8E4H,0B3C1H,0AECDH,0AA0BH
		   .word 0A57EH,0A129H,09D0FH,09931H,09593H,09237H,08F1EH,08C4BH
		   .word 089bfh,0877ch,08584h,083D7H,08227H,08164H,0809FH,08028H
		   .word 08001H,08028H,0809FH,08164H,08277H,083D7H,08584H,0877CH
		   .word 089BFH,08C4BH,08F1EH,09237H,09593H,09931H,09D0FH,0A129H
		   .word 0A57EH,0AA0BH,0AECDH,0B3C1H,0B8E4H,0BE32H,0C3AAH,0C946H
		   .word 0CF05H,0D4E1H,0DAD8H,0E0E6H,0E707H,0ED38H,0F374H,0F9B8H
		   .word 00000H      
           .text
start:     SSBX FRCT 
           LD #sin25p,DP              
           ST #0,sin25p
		   ST #20*128/80,sinstp
		   ST #0,sin25p1
		   ST #1*128/80,sinstp1
           STM #y,AR1
		   STM #y0,AR3
		   STM #y1,AR4
		   ;STM #c1,AR5
		   ;STM #s1,AR6
		   STM #y0,AR7
           STM #500,AR2  
loop:      LD sin25p,A      ;产生载波
           ADD sinstp,A 
           AND #07Fh,A
		   STL A,sin25p
		   ADD #sintab,A    
		   READA s0           ;sinx
		   LD sin25p,A
		   ADD #32,A
		   AND #7FH,A
		   ADD #sintab,A
		   READA c0          ;cosx

		   LD sin25p1,A      ;产生调制信号
           ADD sinstp1,A 
           AND #07Fh,A
		   STL A,sin25p1
		   ADD #sintab,A    
		   READA s1            ;sinx
		   LD sin25p1,A
		   ADD #32,A
		   AND #7FH,A
		   ADD #sintab,A
		   READA c1           ;cosx
         
           LD s0,T
		   MPY s1,A
		   STH A,*AR3
		   LD c0,T
		   MPY c1,A
		   STH A,*AR4
		   SUB *AR3+,*AR4+,A
           ;SUB *AR7+,16,A
		   STH A,*AR1+
		   BANZ loop, *AR2-
here:      B  here
           .END