Motorola DSP96002 User Manual page 645

; Input angle in d6 in degrees, -180 < d6 < 180
;
fabs.x d6
move
fcmp d7,d6
fsub.x d6,d7
ftfr.x d6,d7
fneg.x d3
;
; First quadrant CORDIC trig computation
; Input angle in d7 in degrees
; Output d1=sine, d0=cosine
;
move
fclr d1
fclr d5
do #tabsize,_cordic
fcmp d5,d7
fneg.x d4
fsub.x d6,d5
fadd.x d6,d5
fmpy.x d1,d4,d2
fmpy d0,d4,d2 fsub.x d2,d0
fadd.x d2,d1
fscale.x #-1,d6
_cordic
fcopys.s
ftfr.s d1,d0
fseedd d1,d4
ftfr.s d4,d1
fneg.s d1
fmpy.s d1,d4,d1
fmpy d0,d4,d0
fmpy.s d1,d2,d1
fmpy d0,d4,d0
fmpy.s d0,d3,d0
end
Argument Reduction
Quadrantizing
CORDIC Algorithm
Division/Error Check
B-126
d6.s,d3.s
#90.0,d7.s
#180.0,d7.s
ffge
fflt
ffge
#tantab,r0
#scale,d0.s
#45.0,d6.s
x:(r0)+,d4.s
fflt
fflt
ffge
d3,d0
d0.s,d1.s
ffinf
ffinf
fsub.s d1,d2
fsub.s d1,d3
DSP96002 USER'S MANUAL
;make positive, save sign
;get pi/2
;see if greater than 90
;reduce to less than 90
;transfer if no change
;flip if other quadrant
;point to tangent table
;y=0, x=scale
;z=0,alp=45
;angle < z? get tangent
;yes, rotate cw
;yes, subtract angle
;no, add angle for ccw
;y*tan
;x*tan, x'=x-y*tan
;y'=y+x*tan
;alp=alp/2
;fix sign of tangent
;exchange d0
;d0/d1
#2.0,d2.s
d2.s,d3.s
d2.s,d4.s
;tangent
Program ICycles
Words
10 10
8 8
16 8N+9
10 10
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d1
MOTOROLA