Samsung S3C9228/P9228, 8-Bit CMOS Microcontroller user manual RLC Rotate Left Through Carry

SAM88RI INSTRUCTION SET S3C9228/P9228

RLC — Rotate Left Through Carry

RLCdst

Operation: dst (0) ¨ C

C ¨ dst (7)

dst (n + 1) ¨ dst (n), n = 0–6

The contents of the destination operand with the carry flag are rotated left one bit position. The initial value of bit 7 replaces the carry flag (C); the initial value of the carry flag replaces bit zero.

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
	D:	rotation; cleared otherwise.
		Unaffected.
	H:	Unaffected.

Format:
Bytes Cycles Opcode	Addr Mode
(Hex)	dst

opc

dst

2 4 10 R

4 11IR

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

RLC	00H	→	Register 00H	= 54H, C = "1"
RLC	@01H	→	Register 01H	= 02H, register 02H = 2EH, C = "0"

In the first example, if general register 00H has the value 0AAH (10101010B), the statement "RLC 00H" rotates 0AAH one bit position to the left. The initial value of bit 7 sets the carry flag and the initial value of the C flag replaces bit zero of register 00H, leaving the value 55H (01010101B). The MSB of register 00H resets the carry flag to "1" and sets the overflow flag.

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