<<<
[#insns-cm_lb,reftext="Load signed byte, 16-bit encoding"]
=== cm.lb

Synopsis::
Load signed byte, 16-bit encoding

Mnemonic::
cm.lb _rd'_, _uimm_(_rs1'_)

Encoding (RV32, RV64)::
[wavedrom, , svg]
....
{reg:[
    { bits:  2, name: 0x0, attr: ['C0'] },
    { bits:  3, name: 'rd\'' },
    { bits:  2, name: 'uimm[2:1]' },
    { bits:  3, name: 'rs1\'' },
    { bits:  2, name: 'uimm[0|3]' },
    { bits:  1, name: 0x0 },
    { bits:  3, name: 0x1, attr: ['FUNCT3'] },
],config:{bits:16}}
....

include::cm_lbsb_imm_offset.adoc[]

Description::
This instruction loads a byte from the memory address formed by adding _rs1'_ to the zero extended immediate _uimm_. The resulting byte is sign extended to XLEN bits and is written to _rd'_. 

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

Prerequisites::
None

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

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

X(rdc) = EXTS(mem[X(rs1c)+EXTZ(uimm)][7..0]);
--

include::Zcmb_footer.adoc[]
