Intel 8253 - Rotate Left

4/17/98 6-149 Addressing Modes and Data Types
RL Rotate Left
Syntax: RL Rd, #data4
Operation:
Description: The variable specified by the destination operand is rotated left by the number of bits
specified in the immediate data operand. The data size may be 8 or 16 bits. The number of bit
positions shifted may be from 0 to 15.
Size: Byte, Word
Flags Updated: N, Z
Bytes: 2
Clocks: 4 + 1 for each 2 bits of shift
Encoding:
MSB LSB
(Rd)
count <- #data4
Do While (count not equal to 0)
(dest
0
) <- (dest
msb
)
(dest
n
) <- (dest
n-1
)
(count) <- count -1
End While
1 1 0 1 SZ 0 1 1 d d d d #data4