<<<
[#insns-cm_sb,reftext="cm.sb: Store byte, 16-bit encoding"]
=== cm.sb

Synopsis::
Store byte, 16-bit encoding

Mnemonic::
cm.sb _rs2'_, _uimm_(_rs1'_)

Encoding (RV32, RV64)::
[wavedrom, , svg]
....
{reg:[
    { bits:  2, name: 0x0, attr: ['C0'] },
    { bits:  3, name: 'rs2\'' },
    { bits:  2, name: 'uimm[2:1]' },
    { bits:  3, name: 'rs1\'' },
    { bits:  2, name: 'uimm[0|3]' },
    { bits:  1, name: 0x0 },
    { bits:  3, name: 0x5, attr: ['FUNCT3'] },
],config:{bits:16}}
....

[NOTE]
  If _uimm < 4_ the encoding is designated for custom use, as the functionality overlaps with <<insns-c_sb>>.

include::cm_lbsb_imm_offset.adoc[]

Description::
This instruction stores the least significant byte of _rs2'_ to the memory address formed by adding _rs1'_ to the zero extended immediate _uimm_. 

[NOTE]
  _rs1'_ and _rs2'_ are from the standard 8-register set x8-x15.

Prerequisites::
None

32-bit equivalent::
<<insns-sb>>

Operation::
[source,sail]
--
//This is not SAIL, it's pseudo-code. The SAIL hasn't been written yet.

mem[X(rs1c)+EXTZ(uimm)][7..0] = X(rs2c)
--

include::Zcmb_footer.adoc[]
