Method of operating a timer

A method of operating a timer in an electronic data processing device is described, in which the contents of at least one timer register (T1, T2, T3, T4) is updated once during an update cycle (Tu) by a predetermined time increment (1000 nsecs), said update cycle including a predetermined number (nu) of operating cycles (tc) of the electronic data processing device. During each updating cycle (Tu), the contents of an adjustment register (ADJ) is shifted and rotated by one bit position and, if the bit value at a particular position of this adjustment register (ADJ) is a wait-bit having a predetermined bit value ("1"), actual updating of the time register or registers (T1, T2, T3, T4) during one update cycle is omitted.