EP2299337B1 - Radiosynchronous signal receiver for adjusting a time base, and method for controlling the receiver - Google Patents

Description

The invention relates to a radio-synchronous signal receiver for adjusting a time base, in particular for a timepiece, such as a watch. The receiver comprises a radio-synchronous signal receiving antenna, at least one low-noise amplifier for amplifying and filtering the signals picked up by the antenna, a frequency converting unit for frequency conversion of the filtered and amplified picked-up signals and a unity of processing receiving data signals from the conversion unit for setting the time base.

The invention also relates to a method for activating the radio-synchronous signal receiver for setting a time base of a timepiece.

In order to perform an automatic adjustment operation of a time base, in particular a timepiece, such as a watch, a multifrequency receiver of the VLF type is generally clocked on the basis of a watch quartz. It is the same for adjusting the resonant frequency of the receiver antenna, which must be capable of capturing radio-synchronous signals. The antenna may be composed of a ferrite core around which is wound a wire to be able to capture such radio-synchronous signals.

A standard radio-synchronous signal receiver, which is incorporated in a watch, is usually a direct receiver for receiving signals, which may have a frequency of around 77 kHz. Advantages are the simplicity and low consumption of such a receiver. However, the frequency of the radio-synchronous signals to be picked up may be different from the aforementioned frequency. Therefore, at each frequency of the radio-synchronous signals which it is desired to receive, the receiver must comprise an individual filter in the form of a specific quartz, which is outside the main integrated circuit of the receiver. This is a disadvantage of such a standard receiver.

The patent application US 2009/0185615 discloses a radio-synchronous signal receiver, which includes a time code for the correction of a timebase of a watch. This receiver comprises a reception unit for sensing said radio-synchronous signals, which are frequency-converted in a mixer by oscillating signals provided by an oscillator circuit. The intermediate signals supplied by the mixer are filtered by at least one band-pass filter. The filtered and amplified intermediate signals are provided to a time code detection circuit for providing time data to a central processing unit, which decodes the time of the time data to correct the time base. A reception channel selection of radio-synchronous signals is performed in the receiver to configure the oscillator circuit. The configured oscillator circuit provides oscillating signals whose frequency depends on the frequency of the selected channel of the radio-synchronous signals to be sensed. However, the frequency of the oscillating signals is not automatically adapted according to the frequency of the signals picked up so that the frequency of the intermediate signals is in the frequency band of the band-pass filter.

The patent application US 2006/023572 described as the previous document a receiver of radio-synchronous signals for the correction of a time base of a watch. At the input of the receiver, a frequency selection circuit is controlled by a processing unit to adapt to the frequency of the received radio-synchronous signals, whose frequency may be at 40 kHz, 50 kHz or 60 kHz. The signals received are frequency converted in a mixer by oscillating signals provided by a crystal oscillator. With a frequency of the crystal oscillator set at 50 kHz, it is possible to pick up radio waves at 40 kHz or 60 kHz by having at the output of the mixer intermediate signals at the frequency of the order of 10 kHz. A bandpass filter at the output of the mixer can be centered on 10 kHz to filter the intermediate signals. The filtered and amplified signals are then supplied to a detection circuit connected to a demodulator for the correction of the time base. In the case where the frequency of the radio-synchronous signals is of the same value as the frequency of the oscillating signals, the processing unit momentarily disconnects the oscillator circuit. On the other hand, no adaptation of the frequency of the oscillating signals is provided to automatically adjust the frequency of the intermediate signals in the frequency band of the band-pass filter as a function of the frequency of the radio-synchronous signals picked up.

The patent US 6,704,554 describes an FM modulated receiver, which may be used for receiving RDS type signals. This receiver includes an antenna for receiving signals in the FM transmission band between 88 and 108 MHz. The frequency of the data signals in the received signals is of the order of 57 kHz (subcarrier) for RDS data or 38 kHz for audio data. These data signals do not make it possible to correct the time of a time base. A mixer is also provided for frequency conversion of the shaped signals by an input RF stage by means of oscillating signals provided by a local oscillator. Intermediate frequency signals of the order of 70 kHz are provided at the output of the mixer and are filtered in a bandpass filter and amplified before being supplied to a demodulator. An automatic frequency controller is also provided to adapt the frequency of the oscillating signals of the local oscillator to ensure a constant frequency of the intermediate signals at the output of the mixer. However this receiver of complex realization does not make it possible to correct the time of a base of time of a watch. In addition, this receiver is not intended to perform an automatic adjustment of the frequency of the intermediate signals in the frequency band of the band-pass filter as a function of the frequency of captured radio-synchronous signals.

The antenna frequency of this standard receiver should also be tuned to the receive frequency. This is done by external capacitors, which are normally selected in the manufacturing steps as a function of the frequency of the radio-synchronous signals that can be picked up. The tuning of the reception frequency by these external capacitors is also performed when the receiver is switched on with a tolerance compensation and these can be switched according to the application in which the receiver is used. All these steps of adaptation with external components are long and expensive, which constitutes another disadvantage of such a standard receiver.

As another receiver of the state of the art, mention may be made of the patent application EP 1 666 995 A2 , which describes a watch provided with a radio-synchronous signal receiver for setting the time of the watch. To do this, the receiver notably comprises an antenna, means for adapting the reception frequency in connection with the antenna, means for receiving signals picked up by the antenna, processing means connected to a memory, and receiving a time code signal from the receiving means for setting the time.

The means for adapting the resonance frequency for receiving radio-synchronous signals mainly consist of a network of diodes with variable capacitance. These variable capacitance diodes may be selectively placed in parallel with the coil antenna by a control signal provided by the processing means. The control signal is a function of a capacitive value stored in the memory to enable selection of the number of capacitive diodes to be placed in parallel with the antenna according to the frequency of the radio-synchronous signals to be sensed. Only a certain number of capacitive values are stored to adapt the reception frequency to the level of the antenna. This is a disadvantage because the resonance frequency at the antenna is not precisely determined to receive radio frequency signals at a predetermined frequency under better conditions.

Patent applications EP 1630960 and EP 1 698 950 also disclose a switchable capacitor network capable of being placed in parallel with the radio-synchronous signal receiving antenna to adapt the resonance frequency of the antenna. This resonance frequency of the antenna is therefore adapted on the basis of the known frequency of the captured radio-synchronous signals. The radio-synchronous signals thus captured provide temporal data for correcting a time base of a watch. However, the adaptation of the resonant frequency is not automatically performed after a measurement of the frequency of the captured radio-synchronous signals in order to perform a good demodulation of the temporal data.

The receiving means includes a variable gain amplifier for amplifying the radio-synchronous signals, a filter for filtering the amplified signals, and a detection circuit receiving the filtered signals to provide a time code signal to the processing means. The filter comprises a plurality of crystals that can be individually selected according to the frequency of the captured radio-synchronous signals. The detection circuit also controls the gain of the amplifier. A disadvantage of the receiving means is that it is necessary to provide several quartz for the filter in order to operate a good filter according to the frequency of the captured radio-synchronous signals, which makes the receiver expensive.

We can also mention the patent application WO 2006/054576 , which describes a VHF radio signal receiver. This receiver is arranged in a very flexible way for mounting different reception antennas. To do this, two switches controlled by a control logic are provided which are designed to connect one or the other of the reception antennas. A switched capacitor network is also placed in parallel with either of the antennas to be used to match the resonance frequency of the selected antenna. A The disadvantage of this receiver is that it uses several antennas for the reception of radio-synchronous signals. Another disadvantage is that an adaptation of the resonant frequency of the selected antenna is controlled on the basis of a stored capacitive value, which does not make it possible to precisely adapt this resonance frequency automatically as a function of the frequency of the signals picked up. .

In the patent document DE 35 40 380 a superheterodyne receiver circuit is described. A switch is provided as input to switch two ferrite core antennas. The input stage also comprises, following the antenna, an amplifier, a 77.5 kHz quartz filter, a mixer for mixing the signals picked up by the antenna with the signals, which are at a frequency of order of 77.283 kHz, provided by a quartz oscillator. A band-pass filter is provided at the output of the mixer followed by a shaping unit to provide a time-correction signal to a microcontroller connected to a clock quartz (32.768 kHz). A disadvantage of this receiver circuit is that it also comprises several antennas selectable input. In addition, nothing is provided to adapt the receiver circuit according to the frequency of the radio-synchronous signals to be picked up.

The object of the invention is therefore to provide a radiosynchronous signal receiver of simple design and capable of being adapted automatically to receive the radio-synchronous signals at different frequencies with a single local oscillator stage while overcoming the aforementioned drawbacks of the state of the art.

For this purpose, the invention relates to a radio-synchronous signal receiver, which comprises the features mentioned in independent claim 1.

Particular embodiments of the receiver are defined in dependent claims 2 to 10.

To this end, the invention also relates to a method of actuating the radio-synchronous signal receiver, which comprises the characteristics of the independent claim 11.

Particular steps of the process are defined in dependent claims 12 to 14.

• la figure 1 représente de manière simplifiée une forme d'exécution d'une partie du récepteur de signaux radiosynchrones pour l'adaptation de la fréquence du signal fourni par l'étage oscillateur à quartz selon l'invention, et
• la figure 2 représente de manière simplifiée une forme d'exécution d'une partie du récepteur de signaux radiosynchrones pour l'adaptation de la fréquence de résonance au niveau de l'antenne du récepteur selon l'invention.

The purposes, advantages and characteristics of the radio-synchronous signal receiver and the receiver activation method will appear better in the following description on the basis of at least one non-limiting embodiment illustrated by the drawings in which:

• the figure 1 is a simplified embodiment of a part of the radio-synchronous signal receiver for adapting the signal frequency provided by the crystal oscillator stage according to the invention, and
• the figure 2 is a simplified embodiment of a part of the radio-synchronous signal receiver for the adaptation of the resonant frequency at the antenna of the receiver according to the invention.

In the following description, all the components of the radio-synchronous signal receiver for adjusting a time base, in particular a timepiece, which are well known to a person skilled in this technical field, are only described in detail. in a simplified way. The said radio-synchronous signal receiver may preferably be a superheterodyne receiver capable of receiving radio-synchronous signals at different frequencies to adjust the time base. The setting of said time base can be mainly provided to precisely adjust the time of a watch in any place and taking into account the time zones without limiting the scope only to such a timepiece.

The figure 1 is a simplified representation of the various components of the multifrequency superheterodyne receiver 1 capture radio-synchronous signals. The receiver 1 comprises an antenna 2 for receiving radio-synchronous signals S _R , at least one low-noise amplifier LNA 3 for amplifying and filtering the signals picked up by the antenna, a frequency conversion unit 7 for converting the signals picked up to frequency. filtered and amplified low noise amplifier, and a processing unit 8 receiving data signals data_out of the conversion unit. These data signals, which may be a few bits / sec or also 1 bit / sec, allow adjustment of the time base via the processing unit, in particular to adjust the time of a watch in which receiver is placed.

The frequency conversion unit 7 comprises a local oscillator stage 10 for providing frequency-determined oscillating signals Sm, at least one mixing block 4 for mixing the filtered and amplified captured signals with the oscillating signals supplied by the local oscillator stage so as to producing IF intermediate signals, a bandpass filter 5 for filtering the intermediate signals and a demodulator 6 for demodulating time data of the filtered intermediate signals to provide the data signals to the processing unit. The frequency of the intermediate signals supplied by the mixer unit 4 is equal to the difference between the frequency of the oscillating signals and a carrier frequency of the captured radio-synchronous signals.

Since the frequency of the radio-synchronous signals may be different depending on the transmission system used for example from one geographic location to another location, the local oscillator stage 10 is provided to be automatically configured by a control signal Cm provided by the unit. treatment. The frequency of the oscillating signals Sm of the local oscillator stage is adapted on the basis of the frequency of the radio-synchronous signals picked up in such a way that the frequency of the IF intermediate signals at the output of the mixer unit 4 is in the frequency band of the pass filter. -bandaged.

The frequency of the radio-synchronous signals S _R picked up by the antenna 2 of the receiver 1 can be, for example, between 66 and 80 kHz, preferably at 77 kHz. The oscillating signals can be adapted to a frequency of the order of 67 kHz or 87 kHz to produce IF intermediate signals at a frequency of the order of 10 kHz, which in this case is the center frequency of the bandpass filter with a bandwidth that can be of the order of 2 kHz or less. However, the bandpass filter 5, which is preferably a narrowband active filter, can be centered at a frequency of a few kHz lower for example at 10 kHz above. In this case, the frequency of the oscillating signals must of course be adapted so that, after mixing in the mixer unit 4, the intermediate signals are at a frequency close to the central frequency of the bandpass filter in order to perform a good demodulation of the data. time.

The demodulator 6 may also include a signal strength indicator of the intermediate signals of the RSSI type. This indicator is capable of providing, in particular, an indication of the amplitude level of the signals filtered by the bandpass filter at the processing unit 8. Depending on this indication, the processing unit, which comprises configuration software, can adapt in several successive steps the frequency of the oscillating signals Sm supplied by the local oscillator stage 10 by means of the control signal Cm. This adaptation of the frequency of the oscillating signals by frequency step is carried out until the amplitude of the intermediate signals detected by the indicator is at a level sufficient to be able to demodulate the time data by the demodulator 6.

The local oscillator stage 10, which is adapted by the control signal Cm of the processing unit 8, may comprise a reference oscillator 11 provided with a single clock quartz 12. This reference oscillator 11 traditionally provides signal signals. REF reference at a frequency of the order of 32.768 kHz. Preferably, the local oscillator stage is a frequency synthesizer. This frequency synthesizer thus comprises the clock quartz reference oscillator 11 for supplying the reference signal ref to a phase and frequency detector 13 in a phase-locked loop. This frequency synthesizer further comprises a voltage controlled oscillator VCO 15, which receives signals filtered by a low-pass filter 14 from the phase and frequency detector, to provide the oscillating signals Sm, and a multi-mode divider 16 for divide the frequency of the oscillating signals and provide divided signals to the phase and frequency detector.

The multi-mode divider 16 of the phase lock loop of the frequency synthesizer is controlled by the control signal Cm of the processing unit to divide the frequency of the oscillating signals Sm by a factor modified in time. Thus, the frequency of the oscillating signals of the voltage-controlled oscillator 15 is adapted in time until the frequency of the intermediate signals IF is in the frequency band of the band-pass filter 5. To do this, it may be provided in the processing unit, a sigma-delta type modulator well known to provide a control signal Cm having a succession of modes equal to 0 or 1 to define a modified division factor of the multi-mode divider. The processing unit 8 may also comprise a processor for processing the data and commands, an analog-digital converter, and at least one memory for storing certain calibration frequencies in digital form and the configuration software.

Once the frequency of the oscillating signals Sm has been adapted or calibrated as a function of the frequency of the captured radio-synchronous signals S _R , it may be envisaged also to adapt the resonant frequency at the antenna in accordance with the frequency of the signals. radio-synchronous signals to be picked up. To do this and as shown in the figure 2 , the receiver 1 comprises a switchable capacitor network 21 placed in parallel with the antenna 2 to adapt the resonance frequency at the antenna as a function of the frequency of the captured radio-synchronous signals.

The antenna 2 is usually defined by a paralleling of an inductance L, a capacitor C and a resistor R. The switchable capacitor network 21, placed in parallel with the antenna, is conventionally composed of several capacitors C ₁ , C ₂ to C _n , the capacitive value of each capacitor of the network can be weighted by power of 2. A switch, such as a MOS transistor, is arranged in series with each corresponding capacitor C ₁ , C ₂ to C _n . To select one or another capacitor to be placed in parallel with the antenna, the switches are controlled by an n-bit configuration word Cc, which is provided by a logic circuit 20. In the case of switches in the form of MOS transistors, the configuration word Cc is applied respectively to the gates of these transistors MOS, which is well known. This logic circuit is also controlled by a frequency selection word Sel supplied by the processing unit 8 once the frequency of the oscillating signals has been adapted in the conversion unit 7.

To adapt the resonance frequency, it is advantageously planned to make an oscillator of the LC type with the antenna 2. To do this, the receiver 1 comprises an excitation system 22, which is connected to a terminal of the antenna 2 and the switchable capacitor network 21. The excitation system is controlled by a start-up signal Co supplied by the logic circuit 20. Preferably, this excitation system behaves like a negative resistor -R to make an oscillator LC type with antenna 2.

Once the excitation system 22 is turned on, the oscillation frequency f _m of the oscillator LC is measured by the logic circuit following the amplifier LNA 3. The logic circuit is clocked by a signal ref reference of a reference oscillator 11 quartz 12, which is none other than the crystal oscillator of the conversion unit 7. To operate the measurement of the oscillation frequency for a given period, the circuit logic counts a number of pulses of the LC oscillator, as well as a number of pulses of the reference oscillator. The ratio between the number of pulses of the LC oscillator and the number of pulses of the reference oscillator allows the logic circuit to determine the oscillation frequency of the LC oscillator. A comparison can be made in the logic circuit with the frequency selection word Sel provided by the processing unit so as to establish a configuration word Cc which takes into account the resonance frequency relative to the frequency of the radio-synchronous signals to be picked up. . This well-established configuration word is transmitted to the capacitor network switchable 21 to place a set of selected capacitors in parallel with the antenna.

Once the capacitors have been selected in the switchable capacitor array 21 to determine the resonance frequency at the antenna, the excitation system can be disconnected to allow reception of radio-synchronous signals.

It should be noted that all the components of the receiver except the antenna 2, the low noise amplifier 3, the clock quartz 12, can be integrated in a single integrated circuit. This integrated circuit can be realized in a CMOS technology at 0.18 microns for example.

From the description that has just been given, several variants of the radio-synchronous signal receiver may be designed by those skilled in the art without departing from the scope of the invention defined by the claims. The local oscillator stage may be an oscillator of the RC type or the like. It may also be provided to adapt the bandwidth of the bandpass filter or its center frequency.

Claims (14)

1. Radio-synchronous signal (S_R) receiver (1) for adjusting a time base, particularly of a timepiece, said receiver including an antenna (2) for receiving radio-synchronous signals, at least one low noise amplifier (3) configured for amplifying and filtering the signals picked up by the antenna, a frequency conversion unit (7) configured for converting the frequency of the filtered and amplified incoming signals from the low noise amplifier, and a processing unit (8) receiving data signals (data_out) from the conversion unit for adjusting the time base, said conversion unit including:

   - a local oscillator stage (10) configured for supplying oscillating signals (Sm) at a determined frequency;

   - at least one mixer unit (4) configured for mixing the filtered and amplified incoming signals with the oscillating signals supplied by the local oscillator stage, so as to generate intermediate signals (IF) whose frequency is equal to the difference between the oscillating signal frequency and a carrier frequency of the incoming signals;

   - a band-pass filter (5) configured for filtering the intermediate signals (IF) and

   - a demodulator (6) receiving the filtered intermediate signals and supplying the data signals at output,

   said local oscillator stage being automatically configured by a control signal (Cm) from the processing unit so that the frequency of the oscillating signals (Sm) from the local oscillator stage is adapted in accordance with the frequency of the incoming radio-synchronous signals such that the intermediate signal (IF) frequency is within the band-pass filter frequency band,
   characterized in that the demodulator (6) includes a strength indicator for the intermediate signals (IF), which is able to provide an indication of the amplitude of the signals filtered by the band-pass filter to the processing unit (8), and in that the processing unit includes configuration software for adapting the frequency of the oscillating signals (Sm) supplied by the local oscillator stage (10), via the control signal (Cm), until the intermediate signal amplitude detected by the indicator is at a sufficient level to allow the demodulator (6) to demodulate the time data.
2. Receiver (1) according to claim 1, characterized in that the local oscillator stage (10) includes a reference oscillator (11) with a single timepiece quartz (12).
3. Receiver (1) according to claim 1, characterized in that the local oscillator stage (10) is a frequency synthesiser, which includes an oscillator (11) with a timepiece quartz (12) for supplying a reference signal (ref) to a phase and frequency detector (13) in a phase lock loop, a voltage controlled oscillator (15) receiving signals filtered by a lowpass filter (14) originating from the phase and frequency detector, so as to supply the oscillating signals (Sm), and a multi-mode divider (16) for dividing the oscillating signal frequency and supplying divided signals to the phase and frequency detector.
4. Receiver (1) according to claim 3, characterized in that the multi-mode divider (16) of the frequency synthesiser phase lock loop is controlled by the control signal (Cm) from the processing unit, so as to divide the frequency of the oscillating signals (Sm) by a time changed factor to adapt the frequency of the oscillating signals from the voltage controlled oscillator (15).
5. Receiver (1) according to claim 1, characterized in that the band-pass filter (5) is a narrow band active band-pass filter centred on a frequency of a few kHz.
6. Receiver (1) according to claim 5, characterized in that the band-pass of the active band-pass filter (5) is centred on a frequency close to 10 kHz with a bandwidth of around 2 kHz or less.
7. Receiver (1) according to claim 1, characterized in that it includes an array of switchable capacitors (21) placed in parallel to the antenna (2) for adapting the antenna resonant frequency in accordance with the incoming radio-synchronous signal frequency, selection of the capacitors from the array to be placed in parallel to the antenna being controlled by a configuration word (Cc) supplied by a logic circuit (20), and in that the logic circuit is controlled by a frequency selection word (Sel) supplied by the processing unit to adapt the antenna resonant frequency.
8. Receiver (1) according to claim 7, characterized in that it includes an excitation system (22), connected to a terminal of the antenna and to the switchable capacitor array (21), the excitation system being controlled by a power-on signal (Co) from the logic circuit (20) to form an LC oscillator with the antenna (2), the oscillation frequency (f_m) of the LC oscillator being measured by the logic circuit, and in that the logic circuit (20) supplies a configuration word (Cc) to the switchable capacitor array (21) taking account of the frequency selection word (Sel) and the measured oscillation frequency, so as to adapt the antenna resonant frequency by placing a selected set of capacitors in parallel to the antenna.
9. Receiver (1) according to claim 8, characterized in that the logic circuit (20) is switched on by the processing unit (8), in that the logic circuit is clocked by a reference oscillator (11) with a timepiece quartz (12), in that the logic circuit is arranged for measuring, over a certain period of time, a number of the LC oscillator pulses and a number of the reference oscillator pulses to determine the oscillation frequency of the LC oscillator.
10. Receiver (1) according to claim 9, characterized in that the reference oscillator (11) with a timepiece quartz forms part of the local oscillator stage of the frequency conversion unit (7).
11. Method of activating a radio-synchronous signal receiver (1) according to any of the preceding claims, for adjusting the time base in particular of a timepiece, the method including the initial step of converting the radio-synchronous signals (S_R) picked up by the antenna into intermediate signals (IF) by mixing, in a mixer unit (4), the filtered and amplified incoming signals with oscillating signals (Sm) supplied by the local oscillator stage (10), the method comprising the steps consisting in:

    - automatically adapting the frequency of the oscillating signals (Sm) from the local oscillator stage (10) via a control signal (Cm) from the processing unit until the frequency of the intermediate signals (IF) is within the frequency band of the band-pass filter (5) of the conversion unit (7), and

    - demodulating the time data from the intermediate signals in the demodulator (6) so as to supply data signals (data_out) to the processing unit for adjusting the time base,

    characterized in that during the step of adapting the oscillating signal frequency, the demodulator (6) supplies an indication of the amplitude of the filtered intermediate signals (IF) to the processing unit (8) to enable said processing unit, which includes configuration software, to adapt the oscillating signal (Sm) frequency successively via the control signal (Cm), until the amplitude of the intermediate signals detected by the demodulator indicator is at a sufficient level for the demodulator (6) to demodulate the time data.
12. Method according to claim 11, characterized in that once the oscillating signal (Sm) frequency has been adapted in accordance with the frequency of the radio-synchronous signals picked up by the antenna to obtain intermediate signals with sufficient amplitude, the resonant frequency of the antenna (2) is adapted to the incoming radio-synchronous signal frequency by placing a selected set of capacitors of a switchable capacitor array (21) in parallel to the antenna, said array being controlled by a configuration word (Cc) from a logic circuit dependent upon a frequency selection word (Sel) supplied by the processing unit.
13. Method according to claim 12, characterized in that the logic circuit supplies a power-on signal (Co) to an excitation system (22), which is connected to a terminal of the antenna and the switchable capacitor array to form an LC oscillator with the antenna (2), the oscillation frequency (f_m) of the LC oscillator being measured by the logic circuit to supply a configuration word (Cc) to the switchable capacitor array (21) taking account of the frequency selection word (Sel) to adapt the resonant frequency automatically by placing the selected set of capacitors in parallel to the antenna.
14. Method according to claim 13, characterized in that while the resonant frequency is being adapted at the level of the antenna, the oscillation frequency is measured in the logic circuit by counting a number of the LC oscillator pulses and a number of pulses of a reference oscillator (11), which clocks the logic circuit, over a certain period of time, and the ratio between the number of the LC oscillator pulses and the number of the reference oscillator pulses determining the oscillation frequency of the LC oscillator to define the configuration word (Cc), taking account of the frequency selection word (Sel).

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