Physical interface for bidirectional transmission of data for controlling and maintaining fully automatic coffee machine, has initial program loader changing or updating software during supply of device-specific encrypted program codes

摘要

The interface (3) has a microcontroller unit (MCU) with a device-specific software and a nonvolatile memory i.e. electrically EPROM (EEPROM). A MCUs-special memory cell controls characteristics of the MCU. The memory cell is set appropriately to avoid reading of the software. An initial program loader changes or updates the software during supply of device-specific encrypted program codes. The device-specific encrypted software generates a device serial number from a model-specific parent key and stores the device serial number in the MCU and/or the EEPROM. An independent claim is also included for a method for bidirectional transmission of data for controlling and maintaining fully automatic coffee machine.