Signed Saturate and Unsigned Saturate to any bit position, with optional shift before saturating.
SSAT
saturates a signed value to a signed range.
USAT
saturates a signed value to an unsigned
range.
{
op
cond
}Rd
, #sat
,Rm
{,shift
}
where:
op
is either
SSAT
orUSAT
.cond
is an optional condition code.
Rd
is the destination register.
sat
specifies the bit position to saturate to, in the range 1 to 32 for
SSAT
, and 0 to 31 forUSAT
.Rm
is the register containing the operand.
shift
is an optional shift. It must be one of the following:
ASR #
n
where
is in the range 1-32 (ARM) or 1-31 (Thumb)n
LSL #
n
where
is in the range 0-31.n
The SSAT
instruction applies the specified shift,
then saturates to the signed range -2sat-1 ≤ x
≤ 2sat-1 -1.
The USAT
instruction applies the specified shift,
then saturates to the unsigned range 0 ≤ x
≤
2sat - 1.
You cannot use PC for any register.
You can use SP in ARM instructions but these are deprecated in ARMv6T2 and above. You cannot use SP in Thumb instructions.
If saturation occurs, these instructions set the Q flag. To
read the state of the Q flag, use an MRS
instruction.
These ARM instructions are available in ARMv6 and above.
These 32-bit Thumb instructions are available in ARMv6T2 and above.
There are no 16-bit Thumb versions of these instructions.