docs: def configure(self):
          """
          Configure SPI controller with the SPI mode and operating frequency
          """
  
          # Convert standard SPI sheme to USBISS scheme
          lookup_table = [0, 2, 1, 3]
          mode = lookup_table[self._mode]
  
          # Add signal for SPI switch
          iss_mode = self._usbiss.SPI_MODE + mode
  
          # Configure USB-ISS
          self._usbiss.mode = [iss_mode, self.sck_divisor]