US 12,072,728 B2
Devices, systems, and methods for implementing a real time clock
Wei Wang, Munich (DE); Lingyun Li, Ottobrunn (DE); Mihail Jefremow, Augsburg (DE); Holger Dienst, Feldkirchen (DE); Juergen Schaefer, Oberhaching (DE); and Soenke Ohls, Dreieich (DE)
Assigned to Infineon Technologies AG, Neubiberg (DE)
Filed by Infineon Technologies AG, Neubiberg (DE)
Filed on Oct. 28, 2022, as Appl. No. 17/975,661.
Prior Publication US 2024/0143018 A1, May 2, 2024
Int. Cl. G06F 1/12 (2006.01); G06F 1/08 (2006.01)
CPC G06F 1/08 (2013.01) [G06F 1/12 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A device comprising:
at least one processor, a first pin, a second pin, and an analog-to-digital (ADC) circuit coupled to the first pin;
an oscillator circuit comprising a crystal having a first port and a second port, a first capacitor coupled to the first port of the crystal is coupled to the first pin and a second capacitor coupled to the second port of the crystal;
wherein the at least one processor is configured to generate an excitation signal and provide the excitation signal to the crystal via the first pin or second pin;
wherein after providing the excitation signal,
the ADC circuit is configured to obtain as input a signal from the first port of the crystal via the first pin and convert the signal to a digital output;
the at least one processor is configured to compare the digital output of the ADC circuit to a plurality of thresholds and based on the comparisons is further configured to drive the second port of the crystal to cause the crystal to operate as a pierce oscillator and generate a clock signal from at least of one of the comparisons.