converter.asm

GSM移动通信系统中上变器的DSP实现程序

 	.title "Converter.asm"
    .include   "Init_54x.asm"
*SIN25K
SINSTP    .set    0H
SIN25P    .set    1H
SINNB0    .set    2H
SINNB1    .set    3H
SININT    .set   4H
SINTLP    .set    5H
SINOUT    .set    6H
COS25P    .set    7H
COSOUT    .set    8H
*MAIN
TEMPM     .set    9H
INPHASE   .set   0AH
QUAD      .set   0BH
MUOUT     .set   19H
MIXDIN    .set  1BH

K_IF80     .set  25/80*128  ;步进相位步长

MAIN IDLE  #1               ;等待下一个中频采样数据输入
     CALL  SIN25K           ;产生25kHZ的中频正弦余弦信号子程序
     STM  #MIXDIN+K_AD,AR3  ;数字正交混频
     STM  #COSOUT+K_AD,AR4
     MPY  *AR4,*AR3,A
     STH   A,INPHASE           ;同相分量
     STM  #SINOUT+K_AD,AR4
     MPY  *AR4,*AR3,A
     STH  A,QUAD              ;正交分量
     B MAIN
SIN25K:    ST   #K_IF80,SINSTP   ;设置中频步长
SIN2GO     LD   SIN25P,A       ;SIN25P存着数字压控振荡器上一时刻的相位
           ADD  SINSTP,A
           AND  #07FH,A
           STL  A,SIN25P       ;迭代出这一次相位的地址

           ADD  #SINTAB,A       ;读出这次正弦值
           READA  SINOUT
      LD SIN25P,A               ;迭代出这次的余弦值的地址
      ADD  #32,A
      AND  #7FH,A
      READA COSOUT

SINRET    RET 

**
SINTAB
 .word 07FFFH,07FD8H,07F61H,07E9CH,07D89H,07C29H,07A7CH,07884H
 .word O764BH,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,08277H,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,00648H,00C8CH,012C8H,018F9H,01F1AH,02528H,02B1FH
 .word 030FBH,036BAH,03C56H,041CEH,0471CH,04C3FH,05133H,055F5H
 .word 05A82H,05ED7H,062F1H,066CFH,06ADDH,06DC9H,070E2H,073B5H
 .word 0764BH,07884H,07A7CH,07C29H,07D89H,07E9CH,07F61H,07FD8H
 .word 07FFFH
.END