def read_i2c_block_data(self, address, register, length):
        """
        I2C block transactions do not limit the number of bytes transferred
        but the SMBus layer places a limit of 32 bytes.

        I2C Block Read:  i2c_smbus_read_i2c_block_data()
        ================================================

        This command reads a block of bytes from a device, from a
        designated register that is specified through the Comm byte.

        S Addr Wr [A] Comm [A]
                   S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P

        Functionality flag: I2C_FUNC_SMBUS_READ_I2C_BLOCK
        """
        return self.smbus.read_i2c_block_data(address, register, length)