Rotate left – Zilog Z86193 User Manual
Page 226
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
6
90
R
6
91
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
D7 D6 D5 D4 D3 D2 D1 D0
Note: