Motorola DSP96002 - Manual (Page 589)

B-70 DSP96002 USER’S MANUAL MOTOROLA
Bezier Cubic Evaluation Program ICycles
Words
move #Ptable+2,r0
move #2,n0
move #TK,r4
move x:(r0)-,d4.s 1 1
move x:(r4)+,d0.s y:,d5.s 1 1
fmpy d4,d0,d1 fsub.s d5,d0 x:(r0)-,d4.s d0.s,d5.s 1 1
fmpy.s d4,d0,d2 y:(r4)-,d4.s 1 1
fmpy d4,d5,d1 fsub.s d1,d2 1 1
fmpy.s d1,d2,d2 1 1
fmpy.s d0,d0,d1 x:(r0)+n0,d4.s 1 1
fmpy.s d1,d4,d1 d5.s,d4.s 1 1
fmpy d4,d4,d1 fsub.s d1,d2 1 1
fmpy.s d0,d2,d2 1 1
fmpy.s d1,d4,d1 x:(r0)+n0,d5.s 1 1
fmpy.s d1,d5,d1 1 1
fadd.s d1,d2 1 1
--- ---
Totals: 13 13
The result x(t) is in d2. The setup of the pointers is not included because this is application dependent and
does not have to be performed for each evaluation of x(t). The first two moves may also be application
dependent and be merged with other data ALU operations for a savings of two more cycles and program
steps.
Reference: "Fundamentals of Interactive Computer Graphics",
James D. Foley Andries Van Dam
Addison-Wesley 1982
B.1.38 Byte/16 Bit Packing/Unpacking From/To 32 Bits
B.1.38.1 Pack Four Bytes Into a 32 Bit Word
The following packs four 8 bit bytes into a single 32 bit word. The bytes to be packed are right justified in
four separate registers:
d0 = xxxA d2 = xxxC
d1 = xxxB d3 = xxxD