16 bit Assembly
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SHR - Shift Right Instruction
The SHR instruction is used to perform a logical shift right, resulting in a division.
This command has 3 part the Instruction, A Register or memory address, and the number of bits to shift right.
As each bit is shifted, it passes in to the Carry flag, where it can be assessed using a conditional jump JC or JNC.
As each bit moves right the highest bit becomes zero.
| Assembly Sample | Description | 16 bit Machine Code |
|---|---|---|
| SHR AL, 1 | ; Shift AL right by 1 bit | D0 E8 |
| SHR AL, CL | ; Shift AL right by value of CL | D2 E8 |
| SHR AL, 0x03 | ; Shift AL right by 8 bit immediate | C0 E8 03 |
| SHR AX, 1 | ; Shift AL right by 1 bit | D1 E8 |
| SHR AX, CL | ; Shift AL right by value of CL | D3 E8 |
| SHR AX, 0x03 | ; Shift AL right by 8 bit immediate | C1 E8 03 |
| SHR [BX], 1 | ; Shift memory address right by 1 bit | D0 2F |
| SHR [BX], CL | ; Shift memory address right by value of CL | D2 2F |
| SHR [BX], 0x03 | ; Shift memory address right by 8 bit immediate | C1 2F 03 |
| SHR [BX+2], 1 | ; Shift memory address right by 1 bit | D1 6F 02 |
| SHR [BX+2], CL | ; Shift memory address right by value of CL | D3 6F 02 |
| SHR [BX+2], 0x03 | ; Shift memory address right by 8 bit immediate | C1 6F 02 03 |
Last Update 11/02/2023