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| <h5 class="subsubsection">9.14.2.2 Register Names</h5> |
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| <p><a name="index-H8_002f300-registers-1049"></a><a name="index-register-names_002c-H8_002f300-1050"></a>You can use predefined symbols of the form ‘<samp><span class="samp">r</span><var>n</var><span class="samp">h</span></samp>’ and |
| ‘<samp><span class="samp">r</span><var>n</var><span class="samp">l</span></samp>’ to refer to the H8/300 registers as sixteen 8-bit |
| general-purpose registers. <var>n</var> is a digit from ‘<samp><span class="samp">0</span></samp>’ to |
| ‘<samp><span class="samp">7</span></samp>’); for instance, both ‘<samp><span class="samp">r0h</span></samp>’ and ‘<samp><span class="samp">r7l</span></samp>’ are valid |
| register names. |
| |
| <p>You can also use the eight predefined symbols ‘<samp><span class="samp">r</span><var>n</var></samp>’ to refer |
| to the H8/300 registers as 16-bit registers (you must use this form for |
| addressing). |
| |
| <p>On the H8/300H, you can also use the eight predefined symbols |
| ‘<samp><span class="samp">er</span><var>n</var></samp>’ (‘<samp><span class="samp">er0</span></samp>’ <small class="dots">...</small> ‘<samp><span class="samp">er7</span></samp>’) to refer to the 32-bit |
| general purpose registers. |
| |
| <p>The two control registers are called <code>pc</code> (program counter; a |
| 16-bit register, except on the H8/300H where it is 24 bits) and |
| <code>ccr</code> (condition code register; an 8-bit register). <code>r7</code> is |
| used as the stack pointer, and can also be called <code>sp</code>. |
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