Motorola DSP96002 - Manual (Page 594)

MOTOROLA DSP96002 USER’S MANUAL B-75
B.1.41 64x64 Bit Unsigned Multiply
This performs a double precision unsigned integer multiply. The 64 bit integer is formed by the concatena-
tion of two 32 bit registers.
Let X = A:B and Y = C:D, then X*Y can be written as:
A B
* C D
------------------
+ B * D
+ A * D
+ B * C
+ A * C
------------------
= W X Y Z
64x64 Bit Unsigned Multiply
Program ICycles
d3:d7:d6:d4 = d0:d1 * d2:d3 Words
mpyu d0,d2,d7 1 1
mpyu d0,d3,d5 1 1
mpyu d1,d3,d4 d7.h,d3.l 1 1
mpyu d1,d2,d6 d4.h,d0.l 1 1
move d6.h,d2.l 1 1
add d0,d5 d5.h,d1.l 1 1
addc d1,d2 1 1
inc d3 ifcs 1 1
add d5,d6 1 1
addc d2,d7 1 1
inc d3 ifcs 1 1
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Totals: 11 11