Unsigned Sum of Absolute Differences, and Accumulate unsigned sum of absolute differences.
is an optional condition code.
is the destination register.
is the register holding the first operand.
is the register holding the second operand.
is the register holding the accumulate operand.
USAD8 instruction finds the four differences
between the unsigned values in corresponding bytes of
It adds the absolute values of the four differences, and saves the
USADA8 instruction adds the absolute values
of the four differences to the value in
and saves the result to
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.
These ARM instructions are available in ARMv6 and above.
These 32-bit Thumb instructions are available in ARMv6T2 and above. For the ARMv7-M architecture, they are only available in an ARMv7E-M implementation.
There are no 16-bit Thumb versions of these instructions.
USADA8 r2, r4, r6 ; USADA8 requires four registers USADA16 r0, r4, r0, r1 ; no such instruction