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Remarks: negative value and its absolute value – Delta Electronics Extension Digital I/O Module DOP-EXIO14RAE User Manual

Page 127

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Appendix D Use of Application Instructions|DOP-EXIO Series

D-46

Revision March, 2008, Doc. Name: 2007PDD23000014

X0

CMP

D0

D2

M0

M0

SUB

D0

D2

D4

M2

SUB

D2

D0

D4

M1

Remarks:
Negative value and its absolute value

a)

The sign of a value is indicated by the highest (most left) bit in the register. 0 indicates that the
value is a positive one and 1 indicates that the value is a negative one.

b)

NEG instruction is able to convert a negative value into its absolute value.

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

(D0=2)

(D0=1)

(D0=0)

1 1 1

1

1

1

1

1

1

1

1

1

1 1

1

1

(D0=-1)

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

(D0)+1=1

1 1 1

1

1

1

1

1

1

1

1

1

1 1

1

0

(D0=-2)

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

(D0)+1=2

1 1 1

1

1

0

1

1

1

1

1

1

1 1

1

1

(D0=-3)

0

0

0

1

0

0

0

0

0

0

0

0

0

1

0

0

(D0)+1=3

1 1 1

1

1

0

1

1

1

1

1

1

1 1

1

0

(D0=-4)

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

(D0)+1=4

1 1 1

1

1

1

1

1

1

0

1

1

1 1

1

1

(D0=-5)

0

0

1

1

0

0

0

0

0

0

0

0

0

0

0

0

(D0)+1=5

1 0 0

0

0

1

0

0

0

0

0

0

0 0

0

1

(D0=-32,765)

1

1

1

1

1

1

1

1

0

1

1

1

1

0

1

1

(D0)+1=32,765

1 0 0

0

0

1

0

0

0

0

0

0

0 0

0

0

(D0=-32,766)

1

1

1

0

1

1

1

1

0

1

1

1

1

1

1

1

(D0)+1=32,766

1 0 0

0

0

0

0

0

0

0

0

0

0 0

0

1

(D0=-32,767)

1

1

1

1

1

1

1

1

0

1

1

1

1

1

1

1

(D0)+1=32,767

1 0 0

0

0

0

0

0

0

0

0

0

0 0

0

0

(D0=-32,768)

(D0)+1=-32,768

1 0 0

0

0

0

0

0

0

0

0

0

0 0

0

0

Max. absolute value is 32,767