Z8
®
CPU
User Manual
UM001604-0108 Instruction Description
219
Rotate Left
Syntax
RL dst
Instruction Format
Operation
C ← dst(7)
dst(0) ← dst(7)
dst(1) ← dst(0)
dst(2) ← dst(1)
dst(3) ← dst(2)
dst(4) ← dst(3)
dst(5) ← dst(4)
dst(6) ← dst(5)
dst(7) ← dst(6)
The contents of the destination operand are rotated left by one bit position. The initial
value of bit 7 is moved to the bit 0 position and also into the Carry Flag, as shown below.
Address modes R or IR can be used to specify a 4-bit Working Register. In this format, the
destination Working Register operand is specified by adding
1110b (Eh) to the high nibble
Cycles
OPC
(Hex)
Address Mode
dst
OPC dst
690 R
691 IR
Flag Description
C Set if the bit rotated from the most significant bit position was 1 (
i.e., bit 7 was 1).
Z Set if the result is zero; cleared otherwise.
S Set if the result in bit 7 is set; cleared otherwise.
V Set if arithmetic overflow occurred (if the sign of the destination
operand changed during rotation); cleared otherwise.
D Unaffected.
H Unaffected.
C D7D6D5D4D3D2D1D0
Note:
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