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Flags function, Precautions, 2 instructions – Omron SYSMAC CP CP1E-N@@D@-@ User Manual

Page 178: Nasl, Nsll

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2 Instructions

2-142

CP1E CPU Unit Instructions Reference Manual(W483)

Flags

Function

NASL

NASL(580) shifts D (the shift word) by the specified number of binary bits (specified in C) to the left
(from the rightmost bit to the leftmost bit). Either zeros or the value of the rightmost bit will be placed
into the specified number of bits of the shift word starting from the rightmost bit.

NSLL

NSLL(582) shifts D and D+1 (the shift words) by the specified number of binary bits (specified in C) to
the left (from the rightmost bit to the leftmost bit). Either zeros or the value of the rightmost bit will be
placed into the specified number of bits of the shift word starting from the rightmost bit.

Precautions

For any bits which are shifted outside the specified word, the contents of the last bit is shifted to the

Carry Flag (CY), and all other data is lost.

When the number of bits to shift (specified in C) is “0,” the data will not be shifted. The appropriate

flags will turn ON and OFF, however, according to data in the specified word.

Name

Label

Operation

Error Flag

P_ER

ON when the control word C (the number of bits to shift) is not within range.

OFF in all other cases.

Equals Flag

P_EQ

ON when the shift result is 0.

OFF in all other cases.

Carry Flag

P_CY

ON when 1 is shifted into the Carry Flag (CY).

OFF in all other cases.

Negative Flag

P_N

ON when the leftmost bit is 1 as a result of the shift.

OFF in all other cases.

C

0

8

11

12

15

0

3

4

7

D

a

a

D

CY

Shift n-bits

Contents of “a” or “0” shifted in

N bits

Lost

C

0

8

11

12

15

0

3

4

7

D+1

D

CY

a

a

Shift n-bits

Contents of “a”
or “0” shifted in

N bits

Lost

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