SXTB
Sign extend Byte, to extend an 8-bit value to a 32-bit value.
Syntax
SXTB
{
}
{cond
}, Rd
{,Rm
} rotation
where:
cond
is an optional condition code.
Rd
is the destination register.
Rm
is the register holding the value to extend.
rotation
is one of:
ROR #8
Value from
is rotated right 8 bits.Rm
ROR #16
Value from
is rotated right 16 bits.Rm
ROR #24
Value from
is rotated right 24 bits.Rm
If
is omitted, no rotation is performed.rotation
Operation
This instruction does the following:
Rotates the value from
right by 0, 8, 16 or 24 bits.Rm
Extracts bits[7:0] from the value obtained.
Sign extends to 32 bits.
Register restrictions
You cannot use PC for any operand.
You can use SP in A32 instructions but this is deprecated. You cannot use SP in T32 instructions.
Condition flags
This instruction does not change the flags.
16-bit instructions
The following form of this instruction is available in T32 code, and is a 16-bit instruction:
SXTB
Rd
,Rm
andRd
must both be Lo registers.Rm
Availability
The 32-bit instruction is available in A32 and T32.
The 16-bit instruction is available in T32.