Fujitsu CM71-00101-5E User Manual

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CHAPTER 3  REGISTER DESCRIPTIONS

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The multiplication/division register (MD) is a register used to contain the result of multiplication

operations, as well as the dividend and result of division operations. The products of multiplication are

stored in the "MD" in 64-bit format. In division operations, the dividend must first be placed in the lower

32 bits of the "MD" beforehand. Then as the division process is executed, the remainder is placed in the

higher 32 bits of the "MD", and the quotient in the lower 32 bits.

Figure 3.3-15 shows an example of the use of the "MD" in multiplication, and Figure 3.3-16 shows an

example of division.  

Before execution of instruction MUL R00,R01

12345678

H

76543210

H

R00

R01

????????????????

H

MD

After execution of instruction MUL R00,R01

12345678

H

76543210

H

R00

R01

086A1C970B88D780

H

MD

Before execution of stepwise division

12345678

H

Using R00

R00

????????76543210

H

MD

After execution of stepwise division 

12345678

H

R00

091A264000000006

H

MD