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Motorola DSP96002 User Manual

Page 539

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B-20

DSP96002 USER’S MANUAL

MOTOROLA

;

; t3 = dr + br

; t4 = dr - br

;

; t5 = ai + ci

; t6 = ai - ci

;

; t7 = bi + di

; t8 = bi - di

;

; t9 = t2 + t8

; t10 = t2 - t8

;

; t11 = t6 + t4

; t12 = t6 - t4

;

; ar’ = t1 + t3

; t13 = t1 - t3

;

; ai’ = t5 + t7

; t14 = t5 - t7

;

; br’ = t9*wr1 + t11*wi1

; bi’ = t11*wr1 - t9*wi1

;

; cr’ = t13*wr2 + t14*wi2

; ci’ = t14*wr2 - t13*wi2

;

; dr’ = t10*wr3 + t12*wi3

; di’ = t12*wr3 - t10*wi3

;

; Address pointers are organized as follows:

;

; r0 = ar,ai,br,bi pointer n0 = butterflies per group

; r1 = wr (cos) pointer n1 = rotation factor

; r2 = temp storage pointer n2 = groups per pass

; r3 = group index counter n3 = rotation factor

; r4 = cr,ci,dr,di pointer n4 = butterflies per group

; r5 = wi (sin) pointer n5 = rotation factor