INSTRUCTION SET

S3C84E5/C84E9/P84E9

 

 

OR — Logical OR

ORdst,src

Operation: dst dst OR src

The source operand is logically ORed with the destination operand and the result is stored in the destination. The contents of the source are unaffected. The OR operation results in a "1" being stored whenever either of the corresponding bits in the two operands is a "1", otherwise, a "0" is stored.

Flags:

C:

Unaffected.

 

Z: Set if the result is "0"; cleared otherwise.

 

S: Set if the result bit 7 is set; cleared otherwise.

 

V: Always cleared to "0".

 

D:

Unaffected.

 

H:

Unaffected.

Format:

 

 

 

 

 

 

 

 

 

 

 

Bytes

Cycles

Opcode

Addr Mode

 

 

 

 

 

 

(Hex)

dst

src

 

 

 

 

 

 

 

 

 

 

opc

dst src

 

2

4

42

r

r

 

 

 

 

 

6

43

r

lr

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

opc

src

dst

3

6

44

R

R

 

 

 

 

 

6

45

R

IR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

opc

dst

src

3

6

46

R

IM

 

 

 

 

 

 

 

 

 

Examples:

Given:

R0 = 15H, R1

= 2AH, R2

= 01H, register 00H = 08H, register 01H = 37H,

 

and register 08H = 8AH

 

 

 

 

 

 

 

OR

R0,R1

R0 = 3FH, R1 = 2AH

 

 

 

OR

R0,@R2

R0 = 37H, R2 = 01H, register 01H = 37H

 

OR

00H,01H

Register 00H

=

3FH, register 01H

=

37H

 

OR

01H,@00H

Register 00H

=

08H, register 01H

=

0BFH

 

OR

00H,#02H

Register 00H

=

0AH

 

 

 

In the first example, if the working register R0 contains the value 15H and the register R1 the value

 

2AH, the statement "OR

R0,R1" logical-ORs the R0 and R1 register contents and stores the result

 

(3FH) in the destination register R0.

 

 

 

 

 

Other examples show the use of the logical OR instruction with various addressing modes and formats.

6-62

Page 189
Image 189
Samsung S3C84E5 user manual Or Logical or, 0BFH, 00H,#02H Register 00H