Sign extend Byte, to extend an 8-bit value to a 32-bit value.
is an optional condition code.
is the destination register.
is the register holding the value to extend.
is one of:
is rotated right 8 bits.
is rotated right 16 bits.
is rotated right 24 bits.
is omitted, no rotation is performed.
This instruction does the following:
Rotates the value from
right by 0, 8, 16 or 24 bits.
Extracts bits[7:0] from the value obtained.
Sign extends to 32 bits.
You cannot use PC for any register.
You can use SP in ARM instructions but this is deprecated in ARMv6T2 and above. You cannot use SP in Thumb instructions.
This instruction does not change the flags.
The following form of this instruction is available in Thumb code, and is a 16-bit instruction:
must both be Lo registers.
This ARM instruction is available in ARMv6 and above.
This 32-bit Thumb instruction is available in ARMv6T2 and above. For the ARMv7-M architecture, it is only available in an ARMv7E-M implementation.
This 16-bit Thumb instruction is available in ARMv6 and above.