[destination] ← [destination] rotated by <count>
ROL Dx,Dy
ROR Dx,Dy
ROL #<data>,Dy
ROR #<data>,Dy
ROL <ea>
ROR <ea>Size byte, word, longword
Rotate the bits of the operand in the direction indicated. The extend bit, X, is not included in the operation. A rotate operation is circular in the sense that the bit shifted out at one end is shifted into the other end. That is, no bit is lost or destroyed by a rotate operation. The bit shifted out is also copied into the C-bit of the CCR, but not into the X-bit. The shift count may be specified in one of three ways: the count may be a literal, the contents of a data register, or the value 1. An immediate count permits a shift of 1 to 8 places. If the count is in a register, the value is modulo 64, allowing a range of 0 to 63. If no count is specified, the word at the effective address is rotated by one place (e.g., ROL <ea>).
| X | N | Z | V | C |
|---|---|---|---|---|
| - | * | * | 0 | * |
The X-bit is not affected and the C-bit is set to the last bit rotated out of the operand (C is set to zero if the shift count is 0).
| Dn | An | (An) | (An)+ | ‑(An) | (d,An) | (d,An,Xi) | ABS.W | ABS.L | (d,PC) | (d,PC,Xn) | imm |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
From MOTOROLA M68000 FAMILY Programmer's reference manual. Copyright 1992 by Motorola Inc./NXP. Adapted with permission.