beautypg.com

Motorola DSP96002 User Manual

Page 594

background image

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

--- ---

Totals: 11 11