Microcontroller with auto-alarm device

• US 6,357,012 B1
• Filed: 04/26/1999
• Issued: 03/12/2002
• Est. Priority Date: 03/19/1996
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Aab, Volker
• Primary Examiner(s): Lefkowitz, Sumati
• Application Number:
  US09/142,979
• Time in Patent Office: 1,051 Days
• Field of Search: 713/300-340, 714/14
• US Class Current: 713/322
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A microcontroller with a self-prompting (self-wake-up) device, particularly for use in electrical adjusting drives, having a control device for specifying an active and an inactive operating state to economize on supply power, contains an oscillator for emitting a prompting signal or a clock frequency. This oscillator is a low-frequency, power-saving oscillator. Provided in the microcontroller is a circuit, preferably a disconnectible phase-locking loop, which, from the low frequency of the oscillator, generates a substantially higher clock frequency for microcontroller core. The low-frequency oscillator is also integrated as an original component into the microcontroller. An undervoltage detection, whose output signal is able to be supplied directly to the microcontroller core, indicates undervoltage conditions immediately. Using a time-switch logic which monitors a non-operative time of the microcontroller core, the core is activated again via a prompting circuit. In the case of certain functions, it is also possible to work in a power-saving manner solely with the low frequency. Thus, a necessary buffer capacitance can be smaller.

Claims

1. A microcontroller for an electrical adjusting drive, comprising:

a microcontroller core setting an active operating state and an inactive operating state of the microcontroller to conserve a supply power;

a prompting circuit generating a prompting signal to the microcontroller core for switching the microcontroller from the inactive operating state to the active operating state after a predetermined time period or in response to an occurrence of a predetermined event;

a low-frequency oscillator providing a basic clocking function and generating an oscillator signal which has a first clock frequency, the low-frequency oscillator being an original component of the microcontroller;

a further circuit generating, as a function of the oscillator signal, a circuit signal for the microcontroller core, the circuit signal having a second clock frequency which is higher than the first clock frequency;

an undervoltage detection circuit generating an output signal which is provided directly to the microcontroller core,

wherein, if the undervoltage detection circuit determines that a voltage is below a predetermined level;

the microcontroller core evaluates position signals of position sensors and disconnects the position sensors,

a first arrangement determines the predetermined time period,

a second arrangement changes a system clock pulse from the circuit signal having the second clock frequency to the oscillator signal having the first clock frequency, and

the microcontroller is switched into the inactive operating state.

2. The microcontroller according to claim 1, wherein, after an activation phase and before the prompting circuit generates a next prompting signal, the microcontroller core disconnects the microcontroller using an automatic shutdown procedure.

3. The microcontroller according to claim 1,

wherein the undervoltage detection circuit detects at least one of a sudden voltage drop and a gradual voltage drop, and

wherein the microcontroller core switches the microcontroller from the active operating state to the inactive operating state based on one of the sudden voltage drop and the gradual voltage drop.

4. The microcontroller according to claim 1, wherein the further circuit includes a disconnectable phase-locking loop arrangement.

5. The microcontroller according to claim 1,

wherein the first arrangement includes a time-switch logic arrangement, and

wherein, after the predetermined time period, the time-switch logic arrangement acts on the prompting circuit to generate the prompting signal to the microcontroller core for switching the microcontroller from the inactive operating state to the active operating state.

6. The microcontroller according to claim 5, wherein the prompting signal activates the further circuit, the further circuit generating the circuit signal as a function of the oscillator signal, the microcontroller core switching the microcontroller from the inactive operating state to the active operating state using the second clock frequency.

7. The microcontroller according to claim 1,

wherein the second arrangement includes a multiplexer, the multiplexer providing the oscillator signal to the microcontroller core to set a frequency of the microcontroller core equal to the first clock frequency.

8. The microcontroller according to claim 5,

wherein the time-switch logic arrangement determines the predetermined time period, and

wherein the time-switch logic arrangement includes a time-comparison register for storing the predetermined time period.

9. The microcontroller according to claim 1,

wherein the low-frequency oscillator generates the oscillator signal having the first clock frequency equal to 100 kHz, and

wherein the microcontroller core receives the circuit signal having the second clock frequency equal to 10 MHZ.

10. The microcontroller according to claim 1, wherein the undervoltage detection circuit is connected directly to an electrical-system voltage of the electrical adjusting drive for detecting undervoltage conditions without a time delay and for providing the undervoltage conditions to the microcontroller core, the electrical adjusting drive being provided in a motor vehicle.