fir_filter.inc

用DSP仿真实现FIR滤波器

         .text
       
fir_init:
           STM #fir_coff_tbl,AR5
           RPT #127
           MVPD #fir_coff,*AR5+;
           STM #data_buf,AR4
           RPTZ A,#127
           STL A,*AR4+
           STM #data_buf,AR4
           
           
           STM #1,AR0
           RETD
           STM #fir_coff_tbl,AR5
           
           
fir_task:
           STM #res_buf,AR7
           STM #sin_noise,AR6
           STM #255,BRC
           RPTBD fir_flt_loop-1
           STM #128,BK
           LD  *AR6+,A
           
           
           
fir_filter:
            STL A,*AR4+%
            RPTZ A,#127
            MAC *AR5+0%,*AR4+0%,A
            SFTL A,1
            STH   A,*AR7+
fir_flt_loop:
               RET