Omron C200HG Manual Do Utilizador

The following example shows a four-digit subtraction with CY used to place ei-
ther #0000 or #0001 into R+1 to ensure that any carry is preserved.

CLC(41)

00001

SBB(51)

001

LR20

HR 21

MOV(21)

#0000

HR 22

MOV(21)

#0001

HR 22

TR 1

25504

25504

= R

= R+1

= R+1

00000

LD

00001

00001

OUT

TR

1

00002

CLC(41)

00003

SBB(51)

001

LR

20

HR

21

00004

AND NOT

25504

00005

MOV(21)

#

0000

HR

22

00006

LD

TR

1

00007

AND

25504

00008

MOV(21)

#

0001

HR

22

00009

NEG(––)

HR

21

HR

21

NEG(––)

HR21

HR 21

In the case below, the content of LR 20 (#7A03) and CY are subtracted from
IR 001 (#F8C5). The result is stored in HR 21 and the content of HR 22 (#0000)
indicates that the result is positive.

If the result had been negative, CY would have been set, #0001 would have
been placed in HR 22, and the result would have been converted to its 2’s com-
pliment.

Mi: IR 001

F

8

C

5

Su: LR 20

7

A

0

3

0

0

0

0

CY = 0
(from CLC(41))

R: HR 21

7

E

C

2

R+1: HR 22

0

0

0

0

Note The status of the UF and OF flags can be ignored since they are relevant only in

the subtraction of signed binary data.