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| <html> |
| <head> |
| <meta charset="UTF-8"> |
| <link href="style.css" type="text/css" rel="stylesheet"> |
| <title>CLD—Clear Direction Flag </title></head> |
| <body> |
| <h1>CLD—Clear Direction Flag</h1> |
| <table> |
| <tr> |
| <th>Opcode</th> |
| <th>Instruction</th> |
| <th>Op/En</th> |
| <th>64-bit Mode</th> |
| <th>Compat/Leg Mode</th> |
| <th>Description</th></tr> |
| <tr> |
| <td>FC</td> |
| <td>CLD</td> |
| <td>NP</td> |
| <td>Valid</td> |
| <td>Valid</td> |
| <td>Clear DF flag.</td></tr></table> |
| <h3>Instruction Operand Encoding</h3> |
| <table> |
| <tr> |
| <td>Op/En</td> |
| <td>Operand 1</td> |
| <td>Operand 2</td> |
| <td>Operand 3</td> |
| <td>Operand 4</td></tr> |
| <tr> |
| <td>NP</td> |
| <td>NA</td> |
| <td>NA</td> |
| <td>NA</td> |
| <td>NA</td></tr></table> |
| <h2>Description</h2> |
| <p>Clears the DF flag in the EFLAGS register. When the DF flag is set to 0, string operations increment the index regis-ters (ESI and/or EDI). Operation is the same in all modes.</p> |
| <h2>Operation</h2> |
| <pre>DF ← 0;</pre> |
| <h2>Flags Affected</h2> |
| <p>The DF flag is set to 0. The CF, OF, ZF, SF, AF, and PF flags are unaffected.</p> |
| <h2>Exceptions (All Operating Modes)</h2> |
| <p>#UD</p> |
| <p>If the LOCK prefix is used.</p></body></html> |