Intel 210200-002 manual ROL Rotate Left ROL, ROL destination, count

ROL ROTATE LEFT ROL

Operation:	Flags Affected:
(temp) - COUNT	CF,OF
do while (temp)"* 0
(CF) - high-order bit of (EA)
(EA) - (EA) * 2 + (CF)
(temp) - (temp)-1
if COUNT = 1 then
if high-order bit of (EA)"* (CF)
then (OF)-1
else (OF) - 0
else (OF) undefined
Description:
ROL destination, count

ROL (Rotate Left) rotates the destination byte or word left by the number of bits specified in the count operand.

Encoding:

11101 OOvw ImodOOOr/ml

if v = 0 then COUNT = 1 else COUNT = (CL)

ROL Operands	Clocks*	Transfers	Bytes	ROL Coding Example
register, .1	2	-	2	ROL BX,1
register, CL	8+4/bit	-	2	ROL DI, CL
memory, 1	15(23)+EA	2	2-4	ROL FLAG_BYTE [DI], 1
memory, CL	20(28) + EA +41 bit	2	2-4	ROL ALPHA, CL

*b(w): where b denotes the number" of clock cycles for byte operands and w denotes the number of clock cycles for word operands.

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