Integer Instructions
MOTOROLA M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL 4-161
ROL,ROR Rotate (Without Extend) ROL,ROR
(M68000 Family)
Condition Codes:
X — Not affected.
N — Set if the most significant bit of the result is set; cleared otherwise.
Z — Set if the result is zero; cleared otherwise.
V — Always cleared.
C — Set according to the last bit rotated out of the operand; cleared when the rotate
count is zero.
Instruction Format:
REGISTER ROTATE
Instruction Fields:
Count/Register field:
If i/r = 0, this field contains the rotate count. The values 1 – 7 represent counts of 1
– 7, and zero specifies a count of eight.
If i/r = 1, this field specifies a data register that contains the rotate count (modulo 64).
dr field—Specifies the direction of the rotate.
0 — Rotate right
1 — Rotate left
Size field—Specifies the size of the operation.
00 — Byte operation
01 — Word operation
10 — Long operation
i/r field—Specifies the rotate count location.
If i/r = 0, immediate rotate count.
If i/r = 1, register rotate count.
Register field—Specifies a data register to be rotated.
XNZVC
—∗∗0∗
1514131211109876543210
1110
COUNT/
REGISTER
dr SIZE i/r 1 1 REGISTER
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