Motorola DSP96002 - Manual (Page 591)

B-72 DSP96002 USER’S MANUAL MOTOROLA
B.1.39 Nth Order Polynomial Evaluation for Two Points
;An Nth order polynomial c1X
N
+ c2X
N-1
+ ...cNX + cN+1 can be factored
;and represented as ((c1X + c2)X + c3)X + ...) + cN+1. This routine
;evaluates the polynomial at both X = s and X = t.
;
;Memory Map : X Y
;
; r1 -> s t
; .
; .
; r0 -> c1
; c2
; c3
; .
; .
; cN+1
; Setup N equ order of polynomial
move #coef,r0
move #2_pts,r1
move x:(r1)+,d5.s y:,d4.s ; s, t
move x:(r0)+,d1.s ; c1
move d1.s,d0.s
; Inner loop for evaluating 2 consecutive points
do #N,_loop
fmpy.x d1,d5,d1 x:(r0)+,d2.s ; c(n)*s, c(n+1)
fmpy d0,d4,d0 fadd.x d2,d1 ; c(n)*t, c(n)*s+c(n+1)
fadd.x d2,d0 ; c(n)*t+c(n+1) _loop
B.1.40 Graphics BITBLT (Bit Block Transfer)
The bit block transfer (BITBLT) is an operation that transfers a bit field from one area of memory to another.
Four parameters describe the BITBLT operation:
SOURCE - The source address of the block to be transferred. Data transferred from the source starts at
the lsb of the first data word.
COUNT - The number of words to transfer from the source field. This must be greater than zero.
DEST - Destination starting address.
OFFSET - The starting bit number of the destination word that the transfer is to start. The offset is in the
range of 0-31.
Note that the source data starts at the lsb of the first word whereas the destination starts at an arbitrary
offset from the lsb.