method and apparatus for allocation of the identity to a unit of a cultural of unit function and for the selection of the unit

摘要

A stored program controlled system has its control unit (1) connected to a plurality of function units (2) via an information bus (6) for transferring control information and via an addressing means (7) which converts an address number assigned to one of the function units into an access signal which is sent to said function unit. Incorrect information reception in the function units is avoided and system handling facilitated by means of giving identity to the function units every time the system is started. The control unit includes a number pair generator (5) for generating an identification number parallel with the address number, which number pair is assigned to the same function unit. The identification number is transferred via the information bus (6) and is registered during system starting in a registering means (11, 12) included in said function unit. The function unit includes a converter (15-18) for converting the access signal during system operation to a selection signal only if the identification number obtained from the number pair generator (5) agrees with the identification number stored in the registering means (11, 12). The selection signal activates the function unit for reception of control information.