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help need to implement Sin function using lookup table in Assembly language

Started by xtra...@yahoo.co.uk February 15, 2008
Dear all,

I am new to the group, In the part of my project(using TMS320VC33), I would like to implement Sine function using lookup table in Assembly language.
the C source for sine function using lookup table is as follows:
************************************
signed int Sin(unsigned int phase)
{
const static S16 sin_table[66] {
0,804,1608,2410,3212,4011,4808,5602,
6393,7179,7962,8739,9512,10278,11039,11793,
12539,13279,14010,14732,15446,16151,16846,17530,
18204,18868,19519,20159,20787,21403,22005,22594,
23170,23731,24279,24811,25329,25832,26319,26790,
27245,27683,28105,28510,28898,29268,29621,29956,
30273,30571,30852,31113,31356,31580,31785,31971,
32137,32285,32412,32521,32609,32678,32728,32757,
32767,32757
};

S16 s0;
U16 tmp_phase, tmp_phase_hi;

tmp_phase = phase&0x7fff;

if(tmp_phase&0x4000) tmp_phase = 0x8000 - tmp_phase;

tmp_phase_hi = tmp_phase>>8; // 0...64

s0 = sin_table[tmp_phase_hi];

s0 += ((S16)((((S32)(sin_table[tmp_phase_hi+1] - s0))*(tmp_phase&0xff))>>8));

if(phase&0x8000) s0 = -s0;

return s0;
}
***************************
which is working fine.
I am trying to implement "C" source code(Sin function using lookup table) in to TMS320VC33 Assembly language.
In the part of my implementation I was trying to access a table like below, which was in a file as "sintb360.asm".
*******************************************
;Module definitions for external reference.
.def SINTAB_360
;==========================================================================;-------------------
; Sine look-up table
; No. Entries : 256
; Angle Range : 360 deg
; Number format : Q15 with range -1 < N < +1
;-------------------
.sect ".text"

; SINVAL ; Index Angle Sin(Angle)
SINTAB_360
.word 0 ; 0 0 0.0000
.int 804 ; 1 1.41 0.0245
.int 1608 ; 2 2.81 0.0491
.int 2410 ; 3 4.22 0.0736
.int 3212 ; 4 5.63 0.0980
.word 4011 ; 5 7.03 0.1224
.word 4808 ; 6 8.44 0.1467
.word 5602 ; 7 9.84 0.1710
.word 6393 ; 8 11.25 0.1951
.word 7179 ; 9 12.66 0.2191
.word 7962 ; 10 14.06 0.2430
.word 8739 ; 11 15.47 0.2667
.word 9512 ; 12 16.88 0.2903
.word 10278 ; 13 18.28 0.3137
.word 11039 ; 14 19.69 0.3369
.word 11793 ; 15 21.09 0.3599
.word 12539 ; 16 22.50 0.3827
.word 13279 ; 17 23.91 0.4052
.word 14010 ; 18 25.31 0.4276
.word 14732 ; 19 26.72 0.4496
.word 15446 ; 20 28.13 0.4714
.word 16151 ; 21 29.53 0.4929
.word 16846 ; 22 30.94 0.5141
.word 17530 ; 23 32.34 0.5350
.word 18204 ; 24 33.75 0.5556
.word 18868 ; 25 35.16 0.5758
.word 19519 ; 26 36.56 0.5957
.word 20159 ; 27 37.97 0.6152
.word 20787 ; 28 39.38 0.6344
.word 21403 ; 29 40.78 0.6532
.word 22005 ; 30 42.19 0.6716
.word 22594 ; 31 43.59 0.6895
.word 23170 ; 32 45.00 0.7071
.word 23731 ; 33 46.41 0.7242
.word 24279 ; 34 47.81 0.7410
.word 24811 ; 35 49.22 0.7572
.word 25329 ; 36 50.63 0.7730
.word 25832 ; 37 52.03 0.7883
.word 26319 ; 38 53.44 0.8032
.word 26790 ; 39 54.84 0.8176
.word 27245 ; 40 56.25 0.8315
.word 27683 ; 41 57.66 0.8449
.word 28105 ; 42 59.06 0.8577
.word 28510 ; 43 60.47 0.8701
.word 28898 ; 44 61.88 0.8819
.word 29268 ; 45 63.28 0.8932
.word 29621 ; 46 64.69 0.9040
.word 29956 ; 47 66.09 0.9142
.word 30273 ; 48 67.50 0.9239
.word 30571 ; 49 68.91 0.9330
.word 30852 ; 50 70.31 0.9415
.word 31113 ; 51 71.72 0.9495
.word 31356 ; 52 73.13 0.9569
.word 31580 ; 53 74.53 0.9638
.word 31785 ; 54 75.94 0.9700
.word 31971 ; 55 77.34 0.9757
.word 32137 ; 56 78.75 0.9808
.word 32285 ; 57 80.16 0.9853
.word 32412 ; 58 81.56 0.9892
.word 32521 ; 59 82.97 0.9925
.word 32609 ; 60 84.38 0.9952
.word 32678 ; 61 85.78 0.9973
.word 32728 ; 62 87.19 0.9988
.word 32757 ; 63 88.59 0.9997
.word 32767 ; 64 90.00 1.0000
.word 32757 ; 65 91.41 0.9997
.word 32728 ; 66 92.81 0.9988
.word 32678 ; 67 94.22 0.9973
.word 32609 ; 68 95.63 0.9952
.word 32521 ; 69 97.03 0.9925
.word 32412 ; 70 98.44 0.9892
.word 32285 ; 71 99.84 0.9853
.word 32137 ; 72 101.25 0.9808
.word 31971 ; 73 102.66 0.9757
.word 31785 ; 74 104.06 0.9700
.word 31580 ; 75 105.47 0.9638
.word 31356 ; 76 106.88 0.9569
.word 31113 ; 77 108.28 0.9495
.word 30852 ; 78 109.69 0.9415
.word 30571 ; 79 111.09 0.9330
.word 30273 ; 80 112.50 0.9239
.word 29956 ; 81 113.91 0.9142
.word 29621 ; 82 115.31 0.9040
.word 29268 ; 83 116.72 0.8932
.word 28898 ; 84 118.13 0.8819
.word 28510 ; 85 119.53 0.8701
.word 28105 ; 86 120.94 0.8577
.word 27683 ; 87 122.34 0.8449
.word 27245 ; 88 123.75 0.8315
.word 26790 ; 89 125.16 0.8176
.word 26319 ; 90 126.56 0.8032
.word 25832 ; 91 127.97 0.7883
.word 25329 ; 92 129.38 0.7730
.word 24811 ; 93 130.78 0.7572
.word 24279 ; 94 132.19 0.7410
.word 23731 ; 95 133.59 0.7242
.word 23170 ; 96 135.00 0.7071
.word 22594 ; 97 136.41 0.6895
.word 22005 ; 98 137.81 0.6716
.word 21403 ; 99 139.22 0.6532
.word 20787 ; 100 140.63 0.6344
.word 20159 ; 101 142.03 0.6152
.word 19519 ; 102 143.44 0.5957
.word 18868 ; 103 144.84 0.5758
.word 18204 ; 104 146.25 0.5556
.word 17530 ; 105 147.66 0.5350
.word 16846 ; 106 149.06 0.5141
.word 16151 ; 107 150.47 0.4929
.word 15446 ; 108 151.88 0.4714
.word 14732 ; 109 153.28 0.4496
.word 14010 ; 110 154.69 0.4276
.word 13279 ; 111 156.09 0.4052
.word 12539 ; 112 157.50 0.3827
.word 11793 ; 113 158.91 0.3599
.word 11039 ; 114 160.31 0.3369
.word 10278 ; 115 161.72 0.3137
.word 9512 ; 116 163.13 0.2903
.word 8739 ; 117 164.53 0.2667
.word 7962 ; 118 165.94 0.2430
.word 7179 ; 119 167.34 0.2191
.word 6393 ; 120 168.75 0.1951
.word 5602 ; 121 170.16 0.1710
.word 4808 ; 122 171.56 0.1467
.word 4011 ; 123 172.97 0.1224
.word 3212 ; 124 174.38 0.0980
.word 2410 ; 125 175.78 0.0736
.word 1608 ; 126 177.19 0.0491
.word 804 ; 127 178.59 0.0245
.word 0 ; 128 180.00 0.0000
.word 64731 ; 129 181.41 -0.0245
.word 63927 ; 130 182.81 -0.0491
.word 63125 ; 131 184.22 -0.0736
.word 62323 ; 132 185.63 -0.0980
.word 61524 ; 133 187.03 -0.1224
.word 60727 ; 134 188.44 -0.1467
.word 59933 ; 135 189.84 -0.1710
.word 59142 ; 136 191.25 -0.1951
.word 58356 ; 137 192.66 -0.2191
.word 57573 ; 138 194.06 -0.2430
.word 56796 ; 139 195.47 -0.2667
.word 56023 ; 140 196.88 -0.2903
.word 55257 ; 141 198.28 -0.3137
.word 54496 ; 142 199.69 -0.3369
.word 53742 ; 143 201.09 -0.3599
.word 52996 ; 144 202.50 -0.3827
.word 52256 ; 145 203.91 -0.4052
.word 51525 ; 146 205.31 -0.4276
.word 50803 ; 147 206.72 -0.4496
.word 50089 ; 148 208.13 -0.4714
.word 49384 ; 149 209.53 -0.4929
.word 48689 ; 150 210.94 -0.5141
.word 48005 ; 151 212.34 -0.5350
.word 47331 ; 152 213.75 -0.5556
.word 46667 ; 153 215.16 -0.5758
.word 46016 ; 154 216.56 -0.5957
.word 45376 ; 155 217.97 -0.6152
.word 44748 ; 156 219.38 -0.6344
.word 44132 ; 157 220.78 -0.6532
.word 43530 ; 158 222.19 -0.6716
.word 42941 ; 159 223.59 -0.6895
.word 42365 ; 160 225.00 -0.7071
.word 41804 ; 161 226.41 -0.7242
.word 41256 ; 162 227.81 -0.7410
.word 40724 ; 163 229.22 -0.7572
.word 40206 ; 164 230.63 -0.7730
.word 39703 ; 165 232.03 -0.7883
.word 39216 ; 166 233.44 -0.8032
.word 38745 ; 167 234.84 -0.8176
.word 38290 ; 168 236.25 -0.8315
.word 37852 ; 169 237.66 -0.8449
.word 37430 ; 170 239.06 -0.8577
.word 37025 ; 171 240.47 -0.8701
.word 36637 ; 172 241.88 -0.8819
.word 36267 ; 173 243.28 -0.8932
.word 35914 ; 174 244.69 -0.9040
.word 35579 ; 175 246.09 -0.9142
.word 35262 ; 176 247.50 -0.9239
.word 34964 ; 177 248.91 -0.9330
.word 34683 ; 178 250.31 -0.9415
.word 34422 ; 179 251.72 -0.9495
.word 34179 ; 180 253.13 -0.9569
.word 33955 ; 181 254.53 -0.9638
.word 33750 ; 182 255.94 -0.9700
.word 33564 ; 183 257.34 -0.9757
.word 33398 ; 184 258.75 -0.9808
.word 33250 ; 185 260.16 -0.9853
.word 33123 ; 186 261.56 -0.9892
.word 33014 ; 187 262.97 -0.9925
.word 32926 ; 188 264.38 -0.9952
.word 32857 ; 189 265.78 -0.9973
.word 32807 ; 190 267.19 -0.9988
.word 32778 ; 191 268.59 -0.9997
.word 32768 ; 192 270.00 -1.0000
.word 32778 ; 193 271.41 -0.9997
.word 32807 ; 194 272.81 -0.9988
.word 32857 ; 195 274.22 -0.9973
.word 32926 ; 196 275.63 -0.9952
.word 33014 ; 197 277.03 -0.9925
.word 33123 ; 198 278.44 -0.9892
.word 33250 ; 199 279.84 -0.9853
.word 33398 ; 200 281.25 -0.9808
.word 33564 ; 201 282.66 -0.9757
.word 33750 ; 202 284.06 -0.9700
.word 33955 ; 203 285.47 -0.9638
.word 34179 ; 204 286.88 -0.9569
.word 34422 ; 205 288.28 -0.9495
.word 34683 ; 206 289.69 -0.9415
.word 34964 ; 207 291.09 -0.9330
.word 35262 ; 208 292.50 -0.9239
.word 35579 ; 209 293.91 -0.9142
.word 35914 ; 210 295.31 -0.9040
.word 36267 ; 211 296.72 -0.8932
.word 36637 ; 212 298.13 -0.8819
.word 37025 ; 213 299.53 -0.8701
.word 37430 ; 214 300.94 -0.8577
.word 37852 ; 215 302.34 -0.8449
.word 38290 ; 216 303.75 -0.8315
.word 38745 ; 217 305.16 -0.8176
.word 39216 ; 218 306.56 -0.8032
.word 39703 ; 219 307.97 -0.7883
.word 40206 ; 220 309.38 -0.7730
.word 40724 ; 221 310.78 -0.7572
.word 41256 ; 222 312.19 -0.7410
.word 41804 ; 223 313.59 -0.7242
.word 42365 ; 224 315.00 -0.7071
.word 42941 ; 225 316.41 -0.6895
.word 43530 ; 226 317.81 -0.6716
.word 44132 ; 227 319.22 -0.6532
.word 44748 ; 228 320.63 -0.6344
.word 45376 ; 229 322.03 -0.6152
.word 46016 ; 230 323.44 -0.5957
.word 46667 ; 231 324.84 -0.5758
.word 47331 ; 232 326.25 -0.5556
.word 48005 ; 233 327.66 -0.5350
.word 48689 ; 234 329.06 -0.5141
.word 49384 ; 235 330.47 -0.4929
.word 50089 ; 236 331.88 -0.4714
.word 50803 ; 237 333.28 -0.4496
.word 51525 ; 238 334.69 -0.4276
.word 52256 ; 239 336.09 -0.4052
.word 52996 ; 240 337.50 -0.3827
.word 53742 ; 241 338.91 -0.3599
.word 54496 ; 242 340.31 -0.3369
.word 55257 ; 243 341.72 -0.3137
.word 56023 ; 244 343.13 -0.2903
.word 56796 ; 245 344.53 -0.2667
.word 57573 ; 246 345.94 -0.2430
.word 58356 ; 247 347.34 -0.2191
.word 59142 ; 248 348.75 -0.1951
.word 59933 ; 249 350.16 -0.1710
.word 60727 ; 250 351.56 -0.1467
.word 61524 ; 251 352.97 -0.1224
.word 62323 ; 252 354.38 -0.0980
.word 63125 ; 253 355.78 -0.0736
.word 63927 ; 254 357.19 -0.0491
.word 64731 ; 255 358.59 -0.0245
.word 65535 ; 256 360.00 0.0000

************************

my part of implementation is as follows,
;***********************************************************************;
;* *;
;* File Name : qsinlt.asm *;
;***********************************************************************;
.def _qsinlt
.global SINTAB_360
_qsinlt

PUSH AR3
LDIU SP,AR3
ADDI 3h,SP

LDIU 7fffh,R0
AND *-AR3(2),R0
STI R0,*+AR3(2)

LDIU 4000h,R0
TSTB *+AR3(2),R0
BZ L3

LDIU *+AR3(2),R0
SUBRI 8000h,R0
STI R0,*+AR3(2)

L3 LDIU *-AR3(2),R0
LSH -8,R0
STI R0,*+AR3(3)

LDI @SINTAB_360,AR0 <--------
LDIU *+AR3(3),IR0
LDIU *+AR0(IR0),R0
STI R0,*+AR3

LDIU *-AR3,R1
LDIU *AR3,AR3
SUBI 5h,SP
BU R1

But, the problem is I am not able to access the address of memory location of Table, SINTAB_360 ( as shown in arrow)in AR0 register.When i try to read the Index IR0, let us IR0P, element, AR0(IR0) is not displaying correct value while debugging.

Is any one body can provide better solution, and solving this problem for implementing this sin function using lookup table in Assembly language.

your help will greatly appreciated.

waiting for your messages and help,

regards,
Pydiraju
Check Out Industry's First Single-Chip, Multi-Format, Real-Time HD Video Transcoding Solution for Commercial & Consumer End Equipment: www.ti.com/dm6467
Dear Pydiraju,

> LDI @SINTAB_360,AR0 <--------

Try:

LDI SINTAB_360, AR0

The @ acts like * in C; that is, it dereferences a pointer.
Bill
Check Out Industry's First Single-Chip, Multi-Format, Real-Time HD Video Transcoding Solution for Commercial & Consumer End Equipment: www.ti.com/dm6467