example 2-20.asm

《基于TI DSP的通用算法实现》程序代码

	.bss SINEVAL,1 		;Value from look up table

NORMAL 	.set 500

	.text

	LDP 	#0 ;DP = 0
	SPLK 	#0000h,TABLE 		;Initialize Pointer to Top
	SPLK 	#STABLE,TOPTABLE 	;Initialize TOPTABLE to
					; address of sine table
	SPLK 	#4,FREQSTEP 		;Set the step size to 4
	SPLK 	#0000h,MODREG 		;Initialize the 16 bit
					; counter register
	CLRC 	INTM 			;Enable interrupts
END 	B 	END 			;End of Program

;-------------------------------------------------------------------
; Generate PWM Sine Wave ISR
;-------------------------------------------------------------------

	SINE 	LDP #0 		; DP = 0
	LACC 	MODREG 		; ACC = 16 bit Counter Register
	ADD 	FREQSTEP 	; ACC = Counter + Step
	SACL 	MODREG 		; Counter assigned new value
	LACC 	MODREG,8 	; ACC = Counter shifted to left
				; by 8
	SACH 	TABLE 		; TABLE = upper byte of
				; counter = pointer
	LACC 	TABLE 		; ACC = TABLE = Pointer
	ADD 	TOPTABLE 	; Offset Addr from top of table
	TBLR 	SINEVAL 	; Read sine value and store to
				; SINEVAL

;Normalization of the Sine value to prevent the compare value from
; being negative

	LT 	SINEVAL 	; TREG = SINEVAL (Q15)
	MPY 	#NORMAL 	; PREG = TREG * NORMAL (Q30)
				; NORMAL = T/2
	PAC 			; ACC = PREG (Q30)
	SACH 	COMPARET1,1	; COMPARET1 = PREG (Q15)
	LACC 	COMPARET1 	; ACC = COMPARET1
	ADD 	#NORMAL 	; ACC = COMPARET1 + NORMAL
	LDP 	#232 		; DP = 232
	SACL 	T1CMPR 		; T1CMPR = ACC = Normalize Sine
				; Value
				;Clear the interrupt flags of the Event Manager Module
	LACC 	EVIFRA 		; ACC = EVIFRA
	SACL 	EVIFRA 		; EVIFRA = ACC; resets the

; interrupt flag

	CLRC 	INTM 		; Enable core interrupts
	RET 			; Return to end of program

;-------------------------------------------------------------------
; Sine look-up table
; No. Entries : 256
; Angle Range : 360 deg
; Number format : Q15 with range -1 < N < +1
;-------------------------------------------------------------------

;SINVAL 		; Index Angle Sin(Angle)

STABLE 	.word 0 	; 0 0 0.0000
	.word 804 	; 1 1.41 0.0245
	.word 1608 	; 2 2.81 0.0491
	.word 2410 ; 3 4.22 0.0736
	.word 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

;===================================================================
; I S R - PHANTOM
;
; Description: Dummy ISR, used to trap spurious interrupts.
;
; Modifies: Nothing
;
; Last Update: 16 June 95
;===================================================================

	PHANTOM KICK_DOG 		;Resets WD counter
	B 	PHANTOM