公开(公告)号：US11817870B2

公开(公告)日：2023-11-14

申请号：US17265980

申请日：2019-08-19

Applicant: RENESAS ELECTRONICS CORPORATION

Inventor： Volker Langer ,  Thomas Kattwinkel

IPC: H03L7/181 ,  H03K3/353

CPC classification number: H03L7/181 ,  H03K3/353

Abstract: Oscillator circuitry is disclosed. The oscillator circuitry comprises a free-running oscillator for generating pulses at a frequency, and a frequency adjustment circuit for adaptively adjusting the frequency of the free-running oscillator. The frequency adjustment circuit comprises a counter configured to count a number of pulses generated by the free-running oscillator and logic configured to compare the number of pulses with an expected number of pulses (corresponding to a target frequency) to determine a difference value and to adjust the frequency of the free-running oscillator in dependence on the difference value. The frequency adjustment circuit is configured, in response to receiving a synchronisation pulse, to trigger an update of the number of pulses to be compared.