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S3C8248/C8245/P8245/C8247/C8249/P8249
RL
— Rotate Left
RL
dst
C ← dst (7)
Operation:
dst (0) ← dst (7)
dst (n + 1) ← dst (n), n = 0–6
The contents of the destination operand are rotated left one bit position. The initial value of bit 7
is moved to the bit zero (LSB) position and also replaces the carry flag.
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; cleared otherwise.
D: Unaffected.
H: Unaffected.
Format:
opc
Examples:
Given: Register 00H = 0AAH, register 01H = 02H and register 02H = 17H:
RL
RL
In the first example, if general register 00H contains the value 0AAH (10101010B), the statement
"RL 00H" rotates the 0AAH value left one bit position, leaving the new value 55H (01010101B)
and setting the carry and overflow flags.
C
dst
→
00H
Register 00H = 55H, C = "1"
→
@01H
Register 01H = 02H, register 02H = 2EH, C = "0"
7
0
Bytes
2
INSTRUCTION SET
Cycles
Opcode
(Hex)
4
90
4
91
Addr Mode
dst
R
IR
6-71
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