A stepper motor is driven according to step driving modes including a full-step driving mode, a half-step driving mode and micro-stepping modes. The stepper motor may also be driven in an acceleration phase. A method of controlling the stepper motor includes controlling the current step driving mode of the motor by a processing unit. During the acceleration phase of the stepper motor and the stepper motor being in driven in a current step driving mode other than the full-step driving mode, the processing unit tests, after each speed increase, if a remaining computing power of the processing unit is sufficient for control of the stepper motor to remain in the current step driving mode, and if not the processing unit, in presence of a first switching condition, switches control of the stepper motor to the driving mode having the closest coarser step.

The mechanical timepiece movement includes at least one barrel, a set of gear wheels driven at one end by the barrel, and an escapement mechanism of a local oscillator with a resonator in the form of a sprung balance and a feedback system for the timepiece movement. The escapement mechanism is driven at another end of the set of gear wheels. The feedback system includes at least one precise reference oscillator combined with a frequency comparator to compare the frequency of the two oscillators and a mechanism for regulating the local oscillator resonator to slow down or accelerate the resonator based on the result of a comparison in the frequency comparator.

A stepper motor is driven according to step driving modes including a full-step driving mode, a half-step driving mode and micro-stepping modes. The stepper motor may also be driven in an acceleration phase. A method of controlling the stepper motor includes controlling the current step driving mode of the motor by a processing unit. During the acceleration phase of the stepper motor and the stepper motor being in driven in a current step driving mode other than the full-step driving mode, the processing unit tests, after each speed increase, if a remaining computing power of the processing unit is sufficient for control of the stepper motor to remain in the current step driving mode, and if not the processing unit, in presence of a first switching condition, switches control of the stepper motor to the driving mode having the closest coarser step.

The mechanical timepiece movement includes at least one barrel, a set of gear wheels driven at one end by the barrel, and an escapement mechanism of a local oscillator with a resonator in the form of a sprung balance and a feedback system for the timepiece movement. The escapement mechanism is driven at another end of the set of gear wheels. The feedback system includes at least one precise reference oscillator combined with a frequency comparator to compare the frequency of the two oscillators and a mechanism for regulating the local oscillator resonator to slow down or accelerate the resonator based on the result of a comparison in the frequency comparator.