Samsung 8-Bit CMOS Microcontroller, S3C9228/P9228 user manual RL Rotate Left, Operation ¨ dst

S3C9228/P9228 SAM88RCRI INSTRUCTION SET

RL — Rotate Left

RL	dst
Operation:	C ¨ dst (7)

dst (0) ¨ dst (7)

dst (n + 1) ¨ dst (n), n = 0–6

The contents of the destination operand are rotated left one bit position. The initial value of bit 7 is moved to the bit zero (LSB) position and also replaces the carry flag.

7	0
C

Flags: C: Set if the bit rotated from the most significant bit position (bit 7) was "1".

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

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

V:Set if arithmetic overflow occurred, that is, if the sign of the destination changed during

rotation; cleared otherwise.

D:Unaffected.

H:Unaffected.

Format:

Bytes Cycles Opcode	Addr Mode
(Hex)	dst

opc

dst

2 4 90 R

4 91IR

Examples: Given: Register 00H = 0AAH, register 01H = 02H and register 02H = 17H:

RL	00H	→	Register 00H	= 55H, C = "1"
RL	@01H	→	Register 01H	= 02H, register 02H = 2EH, C = "0"

In the first example, if general register 00H contains the value 0AAH (10101010B), the statement "RL 00H" rotates the 0AAH value left one bit position, leaving the new value 55H (01010101B) and setting the carry and overflow flags.

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