Abstract: A method of upgrading a program, used in a data processing device having a permanent memory, from a version n to a version n+1, wherein, at any time, both the recent version and the previous version of the program are stored in a first and a second location of the memory. Each one of version n and version n+1 of the program is using configuration data of format n and format n+1, respectively, when it is used as a current version. The configuration data of format n are automatically stored into the memory when version n+1 of the program is stored into the second location of memory.

Abstract: A data switch is described with a multi-port data switching element, one or more input/output adapters for receiving user data cells from outside the switch and for transmitting cells switched through the switching element to a network outside the switch, and a control element including a control processor. To reduce the complexity of the data switch, the single control processor is used to control operations of hardware modules on both the the control element on which the processor is located and on the input/output adapters. The control is provided by means of control cells which generally traverse the same data paths as user data cells and generally conform to the format of user data cells, at least within the data switch. Both the control processor and the hardware modules are capable of generating control cells and transmitting them toward a target, either the control processor or hardware modules.