Table of Contents
Advertisement
INSTRUCTION SET
RLC
— Rotate Left Through Carry
RLC
dst
dst (0) ? ← C
Operation:
C ← dst (7)
dst (n + 1) ← dst (n), n = 0–6
The contents of the destination operand with the carry flag are rotated left one bit position. The initial
value of bit 7 replaces the carry flag (C); the initial value of the carry flag replaces bit zero.
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, that is, if the sign of the destination changed during rotation;
cleared otherwise.
D: Unaffected.
H: Unaffected.
Format:
opc
Examples:
Given: Register 00H = 0AAH, register 01H = 02H, and register 02H = 17H, C = "0":
RLC
RLC
In the first example, if general register 00H has the value 0AAH (10101010B), the statement "RLC
00H" rotates 0AAH one bit position to the left. The initial value of bit 7 sets the carry flag and the
initial value of the C flag replaces bit zero of register 00H, leaving the value 55H (01010101B). The
MSB of register 00H resets the carry flag to "1" and sets the overflow flag.
6-72
C
dst
00H
?
Register 00H = 54H, C = "1"
@01H
?
Register 01H = 02H, register 02H = 2EH, C = "0"
7
0
Bytes
2
Cycles
Opcode
(Hex)
4
10
4
11
S3C80A5B
Addr Mode
dst
R
IR
Advertisement
Table of Contents
