lab5.asm

一些在CCS上可以运行的初级DSP汇编程序

**********************************************
* LENGTH-80 LINEAR-PHASE PASSBAND FIR FILTER *  
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        .title  "lab5.asm"

        .mmregs
        .def    start
        .bss    y,1
x_new   .usect  "DATA1",40
x_old   .usect  "DATA2",40
size    .set    40
PA0     .set  0
PA1     .set  1

        .data        
COEF    .word   0ffdch,0001fh,00051h,0ffe9h,0ffe6h
        .word   0ffbah,0ffb4h,0004bh,0fff9h,00069h
        .word   000a2h,0ff6fh,0fffeh,0ff70h,0fef4h
        .word   000cbh,0000bh,000e6h,00187h,0fee5h
        .word   0000bh,0fe7fh,0fdbfh,00192h,0ffb5h
        .word   0026ah,00368h,0fdc2h,000c0h,0fc0ah
        .word   0faa3h,00347h,0fe3dh,00747h,009bbh
        .word   0fa3dh,0052bh,0eb59h,0dc2ah,02d57h

        .text
start:  LD      #y,DP
        SSBX    FRCT
        STM     #x_new,AR2
        STM     #x_old+(size-1),AR3
        STM     #size,BK
        STM     #-1,AR0
        PORTR   PA1,*AR2
FIR     ADD     *AR2+0%,*AR3+0%,A
        RPTZ    B,#(size-1)
        FIRS    *AR2+0%,*AR3+0%,COEF
        STH     B,@y
        PORTW   @y,PA0
        MAR     *+AR2(2)%
        MAR     *AR3+%
        MVDD    *AR2,*AR3+0%
        BD      FIR
        PORTR   PA1,*AR2
        .END