Mail franking machine including an interface application specific integrated circuit

摘要

A mail franking machine which prints stamps and totals stamp values comprises a motor and drums carrying digits in relief for printing a stamp. A microprocessor controls the motor and totals the values of stamps printed. Position encoders connected to respective drums translate into binary words the values of the digits printed on the stamp and the states of manually operable switches. Interfaces essentially formed by an application specific integrated circuit include circuits for receiving and executing an instruction to start or stop the motor or a single instruction to scan and transmit the values translated by all the encoders and the states of all the switches.