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<a name="H8_002f300-Opcodes"></a>Previous: <a rel="previous" accesskey="p" href="H8_002f300-Directives.html#H8_002f300-Directives">H8/300 Directives</a>,
Up: <a rel="up" accesskey="u" href="H8_002f300_002dDependent.html#H8_002f300_002dDependent">H8/300-Dependent</a>
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<h4 class="subsection">9.10.5 Opcodes</h4>
<p><a name="index-H8_002f300-opcode-summary-794"></a><a name="index-opcode-summary_002c-H8_002f300-795"></a><a name="index-mnemonics_002c-H8_002f300-796"></a><a name="index-instruction-summary_002c-H8_002f300-797"></a>For detailed information on the H8/300 machine instruction set, see
<cite>H8/300 Series Programming Manual</cite>. For information specific to
the H8/300H, see <cite>H8/300H Series Programming Manual</cite> (Renesas).
<p><code>as</code> implements all the standard H8/300 opcodes. No additional
pseudo-instructions are needed on this family.
<p><a name="index-size-suffixes_002c-H8_002f300-798"></a><a name="index-H8_002f300-size-suffixes-799"></a>Four H8/300 instructions (<code>add</code>, <code>cmp</code>, <code>mov</code>,
<code>sub</code>) are defined with variants using the suffixes <span class="samp">.b</span>,
<span class="samp">.w</span>, and <span class="samp">.l</span> to specify the size of a memory operand.
<code>as</code> supports these suffixes, but does not require them;
since one of the operands is always a register, <code>as</code> can
deduce the correct size.
<p>For example, since <code>r0</code> refers to a 16-bit register,
<pre class="example"> mov r0,@foo
<br>is equivalent to<br>
mov.w r0,@foo
</pre>
<p>If you use the size suffixes, <code>as</code> issues a warning when
the suffix and the register size do not match.
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