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<title>Using as: M32C-Modifiers</title>
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<a name="M32C_002dModifiers"></a>
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<div class="header">
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<p>
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Next: <a href="M32C_002dChars.html#M32C_002dChars" accesskey="n" rel="next">M32C-Chars</a>, Up: <a href="M32C_002dSyntax.html#M32C_002dSyntax" accesskey="u" rel="up">M32C-Syntax</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
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<a name="Symbolic-Operand-Modifiers"></a>
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<h4 class="subsubsection">9.20.2.1 Symbolic Operand Modifiers</h4>
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<a name="index-M32C-modifiers"></a>
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<a name="index-modifiers_002c-M32C"></a>
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<p>The assembler supports several modifiers when using symbol addresses
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in M32C instruction operands. The general syntax is the following:
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</p>
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<div class="smallexample">
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<pre class="smallexample">%modifier(symbol)
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</pre></div>
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<dl compact="compact">
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<dd><a name="index-symbol-modifiers-2"></a>
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</dd>
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<dt><code>%dsp8</code></dt>
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<dt><code>%dsp16</code></dt>
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<dd>
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<p>These modifiers override the assembler’s assumptions about how big a
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symbol’s address is. Normally, when it sees an operand like
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‘<samp>sym[a0]</samp>’ it assumes ‘<samp>sym</samp>’ may require the widest
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displacement field (16 bits for ‘<samp>-m16c</samp>’, 24 bits for
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‘<samp>-m32c</samp>’). These modifiers tell it to assume the address will fit
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in an 8 or 16 bit (respectively) unsigned displacement. Note that, of
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course, if it doesn’t actually fit you will get linker errors. Example:
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</p>
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<div class="smallexample">
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<pre class="smallexample">mov.w %dsp8(sym)[a0],r1
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mov.b #0,%dsp8(sym)[a0]
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</pre></div>
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</dd>
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<dt><code>%hi8</code></dt>
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<dd>
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<p>This modifier allows you to load bits 16 through 23 of a 24 bit
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address into an 8 bit register. This is useful with, for example, the
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M16C ‘<samp>smovf</samp>’ instruction, which expects a 20 bit address in
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‘<samp>r1h</samp>’ and ‘<samp>a0</samp>’. Example:
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</p>
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<div class="smallexample">
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<pre class="smallexample">mov.b #%hi8(sym),r1h
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mov.w #%lo16(sym),a0
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smovf.b
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</pre></div>
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</dd>
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<dt><code>%lo16</code></dt>
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<dd>
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<p>Likewise, this modifier allows you to load bits 0 through 15 of a 24
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bit address into a 16 bit register.
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</p>
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</dd>
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<dt><code>%hi16</code></dt>
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<dd>
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<p>This modifier allows you to load bits 16 through 31 of a 32 bit
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address into a 16 bit register. While the M32C family only has 24
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bits of address space, it does support addresses in pairs of 16 bit
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registers (like ‘<samp>a1a0</samp>’ for the ‘<samp>lde</samp>’ instruction). This
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modifier is for loading the upper half in such cases. Example:
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</p>
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<div class="smallexample">
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<pre class="smallexample">mov.w #%hi16(sym),a1
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mov.w #%lo16(sym),a0
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…
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lde.w [a1a0],r1
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</pre></div>
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</dd>
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</dl>
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Next: <a href="M32C_002dChars.html#M32C_002dChars" accesskey="n" rel="next">M32C-Chars</a>, Up: <a href="M32C_002dSyntax.html#M32C_002dSyntax" accesskey="u" rel="up">M32C-Syntax</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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