RL BC
RL HL     Rotate Left Through Carry     Rabbit 4000 Instruction

Opcode	Instruction	Clocks	Operation
62	RL BC	2	{CF,BC} = {BC,CF}
42	RL HL	2	{CF,HL} = {HL,CF}

Flags				ALTD			IOI/IOE
S	Z	L/V	C	F	R	SP	S	D
·	·	L	·	·	·

Description

Rotates BC or HL to the left with the C flag. Each bit in the register moves to the next highest-order bit position (bit 0 moves to bit 1, etc.) while the C flag moves to bit 0 and bit 15 moves to the C flag.

Figure 1: Bit logic of the RL instruction