SXTB Signed extend byte This instruction extracts an 8-bit value from a register, sign-extends it to the size of the register, and writes the result to the destination register. If PSTATE.DIT is 1: The execution time of this instruction is independent of: The values of the data supplied in any of its registers. The values of the NZCV flags. The response of this instruction to asynchronous exceptions does not vary based on: The values of the data supplied in any of its registers. The values of the NZCV flags. SBFM 0 0 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 SXTB <Wd>, <Wn> SBFM <Wd>, <Wn>, #0, #7 Unconditionally 1 1 SXTB <Xd>, <Wn> SBFM <Xd>, <Xn>, #0, #7 Unconditionally <Wd> Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field. <Wn> Is the 32-bit name of the general-purpose source register, encoded in the "Rn" field. <Xd> Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.