The 8088 instruction set VII - rotate instructions
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This document discusses four rotate instructions in assembly language programming: ROL and ROR rotate bits left and right by a specified number of positions without affecting the carry flag, while RCL and RCR rotate bits left and right along with the carry flag. All four instructions affect the carry and overflow flags.
The 8088 instruction set VII - rotate instructions
- 1. Assembly Language Programming Chapter 10 The 8088 Instruction Set VII Rotate Instructions
- 2. ROL Meaning Format Operation Flags Affected Rotate Left ROL D, count Rotate the destination to the left by the number of bit positions equal to Count. Each bit rotated out from the leftmost bit goes back into the rightmost bit position. CF, OF
- 3. ROR Meaning Format Operation Flags Affected Rotate Right ROR D, count Rotate the destination to the right by the number of bit positions equal to Count. Each bit rotated out from the rightmost bit goes back into the leftmost bit position. CF, OF
- 4. RCL Meaning Format Operation Flags Affected Rotate Left through carry RCL D, count Rotate the destination to the left by the number of bit positions equal to Count. Carry flag is part of the rotate. Each bit rotated out from the leftmost bit goes back into the rightmost bit position. CF, OF
- 5. RCR Meaning Format Operation Flags Affected Rotate Right through carry RCR D, count Rotate the destination to the right by the number of bit positions equal to Count. Carry flag is part of the rotate. Each bit rotated out from the rightmost bit goes back into the leftmost bit position. CF, OF
- 6. RCR Meaning Format Operation Flags Affected Rotate Right through carry RCR D, count Rotate the destination to the right by the number of bit positions equal to Count. Carry flag is part of the rotate. Each bit rotated out from the rightmost bit goes back into the leftmost bit position. CF, OF