📄 example 3-7.asm
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; Stage 5 - using BUTTFLYI Macro
;==============================================================================
STAGE5:
MAR *, AR2 ;-->AR2
LAR AR0, #4 ;Used to Inc Twiddle pointers
LAR AR1, #(B0_SADR) ;-->P (0-->15)
LAR AR2, #(B0_SADR+32) ;-->Q (16-->31)
LAR AR5, #B2_SADR ;Gen purp reg @ 60h
;---------------------------------------------------------------------------
STG5_BLK1 LAR AR3, #(TWID_TBL+N/4) ;COS(angle)
LAR AR4, #(TWID_TBL) ;COS(angle+pi/4)
LAR AR7, #(N/8-1) ;Loop counter (16 times)
STAGE51_LP:
BFLY 7
BANZ STAGE51_LP,*-,AR2
;---------------------------------------------------------------------------
STG5_BLK2:
LAR AR1, #(B0_SADR+64) ;-->P (32-->47)
LAR AR2, #(B0_SADR+96) ;-->Q (48-->63)
LAR AR3, #(TWID_TBL+N/4) ;COS(angle)
LAR AR4, #(TWID_TBL) ;COS(angle+pi/4)
LAR AR7, #(N/8-1) ;Loop counter (16 times)
STAGE52_LP:
BFLY 7
BANZ STAGE52_LP,*-,AR2
;---------------------------------------------------------------------------
STG5_BLK3:
LAR AR1, #(B0_SADR+128) ;-->P (64-->79)
LAR AR2, #(B0_SADR+160) ;-->Q (80-->95)
LAR AR3, #(TWID_TBL+N/4) ;COS(angle)
LAR AR4, #(TWID_TBL) ;COS(angle+pi/4)
LAR AR7, #(N/8-1) ;Loop counter (16 times)
STAGE53_LP:
BFLY 7
BANZ STAGE53_LP,*-,AR2
;---------------------------------------------------------------------------
STG5_BLK4:
LAR AR1, #(B0_SADR+192) ;-->P (96-->111)
LAR AR2, #(B0_SADR+224) ;-->Q (112-->127)
LAR AR3, #(TWID_TBL+N/4) ;COS(angle)
LAR AR4, #(TWID_TBL) ;COS(angle+pi/4)
LAR AR7, #(N/8-1) ;Loop counter (16 times)
STAGE54_LP:
BFLY 7
BANZ STAGE54_LP,*-,AR2
;==============================================================================
; Stage 6 - Using BFLY Macro
;==============================================================================
STAGE6:
MAR *, AR2 ;-->AR2
LAR AR0, #2 ;used to Inc Twiddle pointers
LAR AR1, #(B0_SADR) ;-->P (0-->31)
LAR AR2, #(B0_SADR+64) ;-->Q (32-->63)
LAR AR5, #B2_SADR ;Gen purp reg @ 60h
;---------------------------------------------------------------------------
STG6_BLK1 LAR AR3, #(TWID_TBL+N/4) ;COS(angle)
LAR AR4, #(TWID_TBL) ;COS(angle+pi/4)
LAR AR7, #(N/4-1) ;Loop counter (32 times)
STAGE61_LP:
BFLY 7
BANZ STAGE61_LP,*-,AR2
;---------------------------------------------------------------------------
STG6_BLK2:
LAR AR1, #(B0_SADR+128) ;-->P (64-->95)
LAR AR2, #(B0_SADR+192) ;-->Q (96-->127)
LAR AR3, #(TWID_TBL+N/4) ;COS(angle)
LAR AR4, #(TWID_TBL) ;COS(angle+pi/4)
LAR AR7, #(N/4-1) ;Loop counter (32 times)
STAGE62_LP:
BFLY 7
BANZ STAGE62_LP,*-,AR2
;==============================================================================
; Stage 7 - Using BFLY Macro
;==============================================================================
STAGE7:
MAR *, AR2 ;-->AR2
LAR AR0, #1 ;Used to Inc Twiddle pointers
LAR AR1, #(B0_SADR) ;-->P (0-->63)
LAR AR2, #(B0_SADR+128) ;-->Q (64-->128)
LAR AR5, #B2_SADR ;Gen purp reg @ 60h
LAR AR3, #(TWID_TBL+N/4)
LAR AR4, #(TWID_TBL)
LAR AR7, #(N/2-1) ;Loop counter (64 times)
STG_7_LP BFLY 7
BANZ STG_7_LP,*-,AR2
;==============================================================================
; Convert Real/Img into Magnitude ( Mag = sqr(Xr[n]) + sqr(Xi[n]) )
;==============================================================================
LAR AR1, #B0_SADR
LAR AR2, #B1_SADR
LARKAR3, #127 ;loop 128 times
LAR AR4, #(B1_SADR+128)
MAR *, AR1
MAG_LP ZAC
MPYK0
SQRA *+ ;Xr[n]**2
SQRA *+,AR2 ;Xi[n]**2
APAC
SACH *+,0,AR4
SACH *+,0,AR3 ;XOUT(I) = X(I)**2 + Y(I)**2
BANZ MAG_LP,*-,AR1
;==============================================================================
; Normalize Values of the FFT
;==============================================================================
.bssMAX,1
.bssQUOTIENT,1
.text
NOP
LAR AR1,#(B1_SADR+128)
LAR AR2,#127
LDP #0
SPLK #0,MAX ;Initialize the variable MAX
SPLK #0,QUOTIENT ;Initizlize the variable QUOTIENT
;The following section finds the maximum value among the FFT magnitudes
MAR *,AR1 ;ARP = AR1
FIND_MAX LACC*+,0,AR2 ;ACC = Value pointed by AR1; AR1 = AR1+1
SUB MAX ;Subtract MAX
BCND RESUME,LEQ ;If the result is less than zero, then
;the value is not larger than MAX, else
ADD MAX
SACL MAX ;Store the new MAX value
RESUME BANZ FIND_MAX,*-,AR1 ;Go through all the magnitudes to find the
;maximum value, then normalize the values
;The following section makes everything a ratio according to the maximum value
LAR AR1,#(B0_SADR+256) ;AR1 = B1_SADR
LAR AR2,#127 ;AR2 = 128-1; Number of Magnitudes to Normalize
LAR AR3,#(B1_SADR+128) ;AR3 = B1_SADR + 128
LAR AR4,#MAX ;AR4 = Address for MAX value
LAR AR5,#QUOTIENT ;AR5 = Address for Q15 quotient
LAR AR6,#15 ;AR6 = 16 - 1; Number of times to subtract
MAR *,AR5 ;ARP = AR5
DIVIDING
LACC* ;ACC = QUOTIENT
SACL*,1,AR3 ;QUOTIENT = QUOTIENT * 2; 1st shift doesn't matter
;because QUOTIENT = 0
LACC *,0,AR4 ;ACC = Value pointed by AR3
SUB * ;Subtract MAX
BCND ADD_ONE,GEQ ;If ACC is still positive, then increment
;the ones place of the quotient, and shift
;the remainder in the ACC, else
;shift the remainder in the ACC
;Check the following section to reduce unnecessary instructions
ADD *,AR3
SAC L*,1,AR6 ;Store the remainder * 2 to location
;pointed by AR3
BANZ DIVIDING,*-,AR5 ;AR6 = AR6 - 1; Repeat the dividing
B NEXT_VALUE ;After repeating 16 times, fetch another
;value
ADD_ONEMAR *,AR3 ;ARP = AR3
SACL*,1,AR5 ;Store the Remainder shifted by 1 back
;into the buffer
LACC* ;ACC = Quotient
ADD #1 ;Increment the quotient
SACL*,0,AR6 ;Store the new value of quotient; ARP = AR6
BANZ DIVIDING,*-,AR5 ;AR6 = AR6 - 1; Repeat the dividing
B NEXT_VALUE
NEXT_VALUE
LAR AR6,#15 ;Reset AR6 to 15
MAR *,AR3 ;ARP = AR3
SACL*+,0,AR5 ;Store the quotient into the buffer
SPLK#0,*,AR2 ;Clear the variable QUOTIENT
BANZ DIVIDING,*-,AR5 ;Repeat the dividing routine for all 128 values
;The following section corrects the value obtained when the maximum value is
;divided by itself. Changes 8000h to max Q15 value of 7FFFh
LAR AR1,#(B1_SADR+128)
LAR AR2,#127
MAR *,AR1 ;ARP = AR1
CHANGING
LACC* ;ACC = Value pointed by AR1
SUB #8000h ;Subtract 8000h
BCND CONTINUE,NEQ ;If equal to 8000h, then
LACC #0FFFFh ;ACC = FFFFh, else
CONTINUE
ADD #8000h
SACL*+,0,AR2 ;Check the next value
BANZ CHANGING,*-,AR1 ;Go through the entire buffer
;The following section multiplies the Q15 numbers by the maximum value (FFFh)
;of the DAC on the EVM
LAR AR1,#(B1_SADR+128)
LAR AR2,#127
MAR *,AR1 ;ARP = AR1
NORMALIZE
LT * ;TREG = Value pointed by AR1
MPY #0FFFh ;Multiply by FFFh
PAC ;ACC = PREG
SACH*+,1,AR2 ;Store the high word, elimnate extra sign bit
BANZ NORMALIZE,*-,AR1 ;Normalize all of the magnitudes
;==============================================================================
; Output the values on the DAC of the EVM
;==============================================================================
LAR AR1, #B1_SADR ;AR1 = Beginning of Un-normalized magnitudes
LAR AR2, #63 ;AR2 = 64 - 1; Display first 64 magnitudes
MAR *,AR1 ;ARP = AR1
LDP #0
SPLK #2,uSEC ;Variable uSEC = 2
;The following section outputs the un-normalized values
;OUTPUTSETCXF ;Set XF high
; LACC*+,AR2 ;ACC = value pointed by AR1
; SACLDAC0VAL ;DAC0VAL = ACC
; OUT DAC0VAL,DAC0 ;Write value to channel 0 of DAC
; OUT DAC0VAL,DACUPDATE ;Output the value
; CALLDELAY ;Wait
; MAR *,AR2 ;ARP = AR2
; BANZOUTPUT,*-,AR1 ;Output the remaining values
; CLRCXF ;Clear XF once all values have been output
LAR AR1, #(B1_SADR+128) ;AR1 = Beginning of normalized magnitudes
LAR AR2, #63 ;AR2 = 64 -1; Display first 64 magnitudes
MAR *,AR1 ;ARP = AR1
;The following section outputs the normalized values
OUTPUT2
SET CXF ;Set XF high
LACC*+,AR2 ;ACC = value pointed by AR1
SACL DAC0VAL ;DAC0VAL = ACC
OUT DAC0VAL,DAC0 ;Write value to channel 0 of DAC
OUT DAC0VAL,DACUPDATE ;Output the value
CALL DELAY ;Wait
MAR *,AR2 ;ARP = AR2
BANZ OUTPUT2,*-,AR1 ;Output the remaining values
SPLK #0,DAC0VAL ;DAC0VAL = 0
OUT DAC0VAL,DAC0 ;Clear channel 0 of DAC
OUT DAC0VAL,DACUPDATE ;Output 0V
CLRCXF ;Clear XF
REPEAT ;Go back and wait for next 128 samples
DEND B DEND
;=====================================================================
; Routine Name: DELAY
;
; Description:Produces a multiple of 1.6uS delays using the RPT
; instruction. The Delay produced is based on the
; value loaded in uSEC (i.e. Delay = uSEC x 1.6mS).
; Indirect addressing is used to count the number
; of times the delay loop is repeated.
;
; Calling Convention:
;
; Variables on Entry on Exit
; --------------------------------------------------------------------
; DP XX 0x0000
; ARP XX AR7
; ACC XX XX
; uSEC value in 1.6 uS un-touched
; --------------------------------------------------------------------
;=====================================================================
DELAY:
LDP #0h ;DP-->0000h-007Fh
LACC#32
SACL RPT_NUM ;RPT_NUM = 32
LAR AR7,uSEC ;Set AR0 to generate a
MAR *,AR7 ;(AR0*0.1)mSEC delay loop
DELAY_LOOP:
LDP #0h ;DP-->0000h-007Fh
RPT RPT_NUM ;32 cycles = 1.6uS
NOP ;1 cycle
BANZ DELAY_LOOP ;Repeat DELAY_LOOP
RET ;Return from DELAY SR
;==============================================================================
; I S R - PHANTOM
;
; Description:Dummy ISR, used to trap spurious interrupts.
;
; Modifies:
;
; Last Update:16-06-95
;==============================================================================
PHANTOM B PHANTOM
;==============================================================================
; TWIDDLES FOR N=128 FFT (96 entries)
;==============================================================================
PS_TWID_STRT:
.word 00000h ; 0.000
.word 00648h ; 2.812
.word 00c8ch ; 5.625
.word 012c8h ; 8.438
.word 018f9h ; 11.250
.word 01f1ah ; 14.062
.word 02528h ; 16.875
.word 02b1fh ; 19.688
.word 030fch ; 22.500
.word 036bah ; 25.312
.word 03c57h ; 28.125
.word 041ceh ; 30.938
.word 0471dh ; 33.750
.word 04c40h ; 36.562
.word 05134h ; 39.375
.word 055f6h ; 42.188
.word 05a82h ; 45.000
.word 05ed7h ; 47.812
.word 062f2h ; 50.625
.word 066d0h ; 53.438
.word 06a6eh ; 56.250
.word 06dcah ; 59.062
.word 070e3h ; 61.875
.word 073b6h ; 64.688
.word 07642h ; 67.500
.word 07885h ; 70.312
.word 07a7dh ; 73.125
.word 07c2ah ; 75.938
.word 07d8ah ; 78.750
.word 07e9dh ; 81.562
.word 07f62h ; 84.375
.word 07fd9h ; 87.188
.word 07fffh ; 90.000
.word 07fd9h ; 92.812
.word 07f62h ; 95.625
.word 07e9dh ; 98.438
.word 07d8ah ; 101.250
.word 07c2ah ; 104.062
.word 07a7dh ; 106.875
.word 07885h ; 109.688
.word 07642h ; 112.500
.word 073b6h ; 115.312
.word 070e3h ; 118.125
.word 06dcah ; 120.938
.word 06a6eh ; 123.750
.word 066d0h ; 126.562
.word 062f2h ; 129.375
.word 05ed7h ; 132.188
.word 05a82h ; 135.000
.word 055f6h ; 137.812
.word 05134h ; 140.625
.word 04c40h ; 143.438
.word 0471dh ; 146.250
.word 041ceh ; 149.062
.word 03c57h ; 151.875
.word 036bah ; 154.688
.word 030fch ; 157.500
.word 02b1fh ; 160.312
.word 02528h ; 163.125
.word 01f1ah ; 165.938
.word 018f9h ; 168.750
.word 012c8h ; 171.562
.word 00c8ch ; 174.375
.word 00648h ; 177.188
.word 00000h ; 180.000
.word 0f9b8h ; 182.812
.word 0f374h ; 185.625
.word 0ed38h ; 188.438
.word 0e707h ; 191.250
.word 0e0e6h ; 194.062
.word 0dad8h ; 196.875
.word 0d4e1h ; 199.688
.word 0cf04h ; 202.500
.word 0c946h ; 205.312
.word 0c3a9h ; 208.125
.word 0be32h ; 210.938
.word 0b8e3h ; 213.750
.word 0b3c0h ; 216.562
.word 0aecch ; 219.375
.word 0aa0ah ; 222.188
.word 0a57eh ; 225.000
.word 0a129h ; 227.812
.word 09d0eh ; 230.625
.word 09930h ; 233.438
.word 09592h ; 236.250
.word 09236h ; 239.062
.word 08f1dh ; 241.875
.word 08c4ah ; 244.688
.word 089beh ; 247.500
.word 0877bh ; 250.312
.word 08583h ; 253.125
.word 083d6h ; 255.938
.word 08276h ; 258.750
.word 08163h ; 261.562
.word 0809eh ; 264.375
PS_TWID_END:
.word 08027h ; 267.188 ⌨️ 快捷键说明
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