def readS16(self, register, little_endian=True):
result = self.readU16(register, little_endian)<EOL>if result > <NUM_LIT>:<EOL><INDENT>result -= <NUM_LIT><EOL><DEDENT>return result<EOL>
Read a signed 16-bit value from the specified register, with the
        specified endianness (default little endian, or least significant byte
        first).