[destination] ← [destination] shifted by <count>
LSL Dx,Dy
LSR Dx,Dy
LSL #<data>,Dy
LSR #<data>,Dy
LSL <ea>
LSR <ea>Size byte, word, longword
Logically shift the bits of the operand in the specified direction (i.e., left or right). A zero is shifted into the input position and the bit shifted out is copied into both the C- and the X-bit of the CCR. 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 - from 0 to 63. If no count is specified, one shift is made (e.g., LSL <ea> shifts the word at the effective address one position left).
If [D3.W] = 11001100101011102 , the instruction LSL.W #5,D3 produces the result 10010101110000002. After the shift, both the X-and C-bits of the CCR are set to 1 (since the last bit shifted out was a 1).
| X | N | Z | V | C |
|---|---|---|---|---|
| * | * | * | 0 | * |
The X-bit is set to the last bit shifted out of the operand and is equal to the C-bit. However, a zero shift count leaves the X-bit unaffected and the C-bit cleared.
| 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.