UM012811-0904
eZ8 CPU Instruction Set Description
eZ8 CPU
User Manual
157
RL
Rotate Left
RL dst
Operation
Description
The destination operand contents rotate left by one bit position. The initial value of Bit 7 is
moved to the Bit 0 position and also into the Carry (C) flag.
Flags
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address modes R or IR specify a Working Register. If
the destination address is prefixed by
EH
(1110B), a Working Register is inferred. For
example, if Working Register R12 (
CH
) is the desired destination operand, use
ECH
as the
destination operand in the opcode. To access Registers with addresses
E0H
to
EFH
, either
set the Working Group Pointer, RP[7:4], to
EH
or use indirect addressing.
C
Set if the bit rotated from the most-significant bit position was 1 (that is, Bit 7 was 1).
Z
Set if the result is zero; reset otherwise.
S
Set if Bit 7 of the result is set; reset otherwise.
V
Set if an arithmetic overflow occurs; reset otherwise.
D
Unaffected.
H
Unaffected.
Mnemonic
Destination
Opcode (Hex)
Operand 1
Operand 2
Operand 3
RL
R1
90
R1
—
—
RL
@R1
91
R1
—
—
D7 D6 D5 D4 D3 D2 D1 D0
dst
C