main.asm

此程序为TMS320c5410下用汇编语言实现产生一个正弦波

 .title "fir filter..."
 .mmregs
 .ref _c_int00
wave_ptr .set 062h
new_ad .set 063h
out_wave_ptr .set 064h

t_ar4 .set 065h
t_ar5 .set 066h
t_ar6 .set 067h
t_ar7 .set 068h

wave_buf .set 0900h
out_wave_buf .set 01000h
N  .set 38
fir_coef_buf .set 100h
new_data_buf .set 200h

 .text
_c_int00:
 ssbx intm
 ssbx sxm  ;extend sign
 ssbx frct ;fraction multiply
 stm #10h,26h
 stm #0ffh,sp
 ld #0,dp
 stm #0ffffh,ifr    ;clear all int

;**********************************
;Initialize RAM.Variable...
;*********************************
 stm #wave_buf,ar6
 stm #1,ar0
 rpt #24
 mvpd wave_data,*ar6+0  ;move data to wave_buf
 stm #wave_buf,wave_ptr ;save wave buffer_ptr
 stm #out_wave_buf,out_wave_ptr   ;save out wave buffer'ptr,
                                 ;because use circular address
								 ; so when save out_wave date,must++

 stm #fir_coef_buf,ar6
 rpt #N-1
 mvpd fir_coef,*ar6+  ;move fir coef to fir_coef_buf in data mem
 
 stm #fir_coef_buf,t_ar2
 stm #wave_buf,t_ar3
 stm #out_wave_buf,t_ar4
 stm #new_data_buff,t_ar5

;***************************************
;The following codes is used to FIR,new AD DATA in new_ad(0x64)
;FIR buffer coef->0x100(ar2), FIR window buffer->0x900(ar3)
;*********************************************
 ld #100,b
 mvdm #t_ar5,ar5
fir:
 pshm st1
 pshm st0
 pshm bk
 pshm ar7
 pshm ah
 pshm al
 pshm ar0
 pshm ar1
 pshm ar2
 pshm ar3
 pshm ar4

 mvdm #t_ar2,ar2
 mvdm #t_ar3,ar3
 mvdm #t_ar4,ar4

 ld new_ad,-2,a
 stl a,*ar5+


 stm #1,ar0
 stm #N,bk
 stl a, *ar3+%
 rptz a,#N-1  ;0->a ,then repeat 34 times
             ; done FIR filter,result in ah
 mac *ar2+0%,*ar3+0%,a
 mvmd ar3,#t_ar3
 mvmd ar4,#t_ar2

 stm #1,ar0
 stm #100h,bk
 sth a, *ar4+%
 mvmd ar4,#t_ar4  ; give the output data to output data buffer

con_fir:
 popm ar4
 popm ar3
 popm ar2
 popm ar1
 popm ar0
 popm al
 popm ah
 popm ar7
 popm bk
 popm st0
 popm st1
 
 sub #1,b
 bc fir,bneq
 ld #100,b
 nop
 b fir
;***************************************
;The following data is used by make wave when using,must
;copy to wave_buffer->0x1000
;********************************************
wave_data:
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 03ffch
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h
 .word 0c000h

;*********************************************************
;filter type  lowpass
;filter length 38
;sampling 25.00000000
;upper band edge 1.20000005
;lower band edge 2.79999995
;**********************************************************

fir_coef:
 .word 34
 .word 235
 .word 500
 .word 735
 .word 808
 .word 587
 .word 0
 .word -914
 .word -1972
 .word -2854
 .word -3163
 .word -2518
 .word -662
 .word 2432
 .word 6516
 .word 11078
 .word 15431
 .word 18849
 .word 20728
 .word 20728
 .word 18849
 .word 15431
 .word 11078
 .word 6516
 .word 2432
 .word -662
 .word -2518
 .word -3163
 .word -2854
 .word -1972
 .word -914
 .word 0
 .word 587
 .word 808
 .word 735
 .word 500
 .word 235
 .word 34
  
 .end