16 bit Assembly
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RCR - Roll Right Instruction
The RCR instruction is used to rotate the bits to the right.
This command has 3 part the Instruction, A Register or memory address, and the number of bits to rotate right.
As each bit is rotated it passes in to the Carry flag, where it can be assessed using a conditional jump JC or JNC.
As each bit moves off the highest bit it is inserted in the lowest bit.
| Assembly Sample | Description | 16 bit Machine Code |
|---|---|---|
| RCR AL, 1 | ; Rotate AL right by 1 bit | D0 D8 |
| RCR AL, CL | ; Rotate AL right by value of CL | D2 D8 |
| RCR AL, 0x03 | ; Rotate AL right by 8 bit immediate | C0 D8 03 |
| RCR AX, 1 | ; Rotate AX right by 1 bit | D1 D8 |
| RCR AX, CL | ; Rotate AX right by value of CL | D3 D8 |
| RCR AX, 0x03 | ; Rotate AX right by 8 bit immediate | C1 D8 03 |
| RCR [BX], 1 | ; Rotate memory address right by 1 bit | D0 1F |
| RCR [BX], CL | ; Rotate memory address right by value of CL | D2 1F |
| RCR [BX], 0x03 | ; Rotate memory address right by 8 bit immediate | C0 1F 03 |
| RCR [BX+2], 1 | ; Rotate memory address right by 1 bit | D1 5F 02 |
| RCR [BX+2], CL | ; Rotate memory address right by value of CL | D2 5F 02 |
| RCR [BX+2], 0x03 | ; Rotate memory address right by 8 bit immediate | C0 5F 02 03 |
Last Update 11/02/2023