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<h4 class="subsection">9.38.3 Instruction syntax</h4>
<p><a name="index-instruction-syntax_002c-s390-1889"></a><a name="index-s390-instruction-syntax-1890"></a>
The assembler syntax closely follows the syntax outlined in
Enterprise Systems Architecture/390 Principles of Operation (SA22-7201)
and the z/Architecture Principles of Operation (SA22-7832).
<p>Each instruction has two major parts, the instruction mnemonic
and the instruction operands. The instruction format varies.
<ul class="menu">
<li><a accesskey="1" href="s390-Register.html#s390-Register">s390 Register</a>: Register Naming
<li><a accesskey="2" href="s390-Mnemonics.html#s390-Mnemonics">s390 Mnemonics</a>: Instruction Mnemonics
<li><a accesskey="3" href="s390-Operands.html#s390-Operands">s390 Operands</a>: Instruction Operands
<li><a accesskey="4" href="s390-Formats.html#s390-Formats">s390 Formats</a>: Instruction Formats
<li><a accesskey="5" href="s390-Aliases.html#s390-Aliases">s390 Aliases</a>: Instruction Aliases
<li><a accesskey="6" href="s390-Operand-Modifier.html#s390-Operand-Modifier">s390 Operand Modifier</a>: Instruction Operand Modifier
<li><a accesskey="7" href="s390-Instruction-Marker.html#s390-Instruction-Marker">s390 Instruction Marker</a>: Instruction Marker
<li><a accesskey="8" href="s390-Literal-Pool-Entries.html#s390-Literal-Pool-Entries">s390 Literal Pool Entries</a>: Literal Pool Entries
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