Interrupt/Wake-Up of an Electronic Device in a Low Power Sleep Mode When Detecting a Sensor or Frequency Source Activated Frequency Change
First Claim
Patent Images
1. An electronic device having a low power sleep mode, comprising:
- circuits capable of being placed in a sleep mode;
input-output (I/O) capable of being placed in the sleep mode, the I/O coupled to the circuits;
sleep/wake-up logic for controlling when the circuits and the I/O are in the sleep mode or in an operational mode;
a frequency differentiator having an output coupled to the circuits, the output presenting output values representative of frequencies at an input of the frequency differentiator;
an external frequency source connection adapted for coupling to an external frequency source and coupled to the input of the frequency differentiator;
whereinthe frequency differentiator output is at a first output value when the external frequency source is at a first frequency, andthe frequency differentiator output is at a second output value when the external frequency source is at a second frequency; and
a watchdog timer coupled to the sleep/wake-up logic, wherein the watchdog timer periodically causes the sleep/wake-up logic to wake up the circuits and the I/O from the sleep mode to the operational mode for a certain time so that the circuits can sample the output values from the frequency differentiator, wherein when a present output value sample is different then a prior output value sample, then the circuits and the I/O will remain in the operational mode.
8 Assignments
0 Petitions
Accused Products
Abstract
Activation of an external sensor coupled to an electronic device will change the frequency of a low power oscillator in the electronic device that runs during a low power sleep mode of the electronic device. When a change in frequency of the low power oscillator is detected, the electronic device will wake-up from the low power sleep mode. In addition, when a change in frequency from an external frequency source is detected, the electronic device will wake-up from the low power sleep mode.
-
Citations
36 Claims
-
1. An electronic device having a low power sleep mode, comprising:
-
circuits capable of being placed in a sleep mode; input-output (I/O) capable of being placed in the sleep mode, the I/O coupled to the circuits; sleep/wake-up logic for controlling when the circuits and the I/O are in the sleep mode or in an operational mode; a frequency differentiator having an output coupled to the circuits, the output presenting output values representative of frequencies at an input of the frequency differentiator; an external frequency source connection adapted for coupling to an external frequency source and coupled to the input of the frequency differentiator; wherein the frequency differentiator output is at a first output value when the external frequency source is at a first frequency, and the frequency differentiator output is at a second output value when the external frequency source is at a second frequency; and a watchdog timer coupled to the sleep/wake-up logic, wherein the watchdog timer periodically causes the sleep/wake-up logic to wake up the circuits and the I/O from the sleep mode to the operational mode for a certain time so that the circuits can sample the output values from the frequency differentiator, wherein when a present output value sample is different then a prior output value sample, then the circuits and the I/O will remain in the operational mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
-
34. A method for waking up circuits of an electronic device when in a low power sleep mode, the method comprising the steps of:
-
providing circuits and input-output (I/O) capable of being placed in a low power sleep mode; providing sleep/wake-up logic for controlling when the circuits and I/O are in the low power sleep mode or in an operational mode; providing a frequency differentiator having a first or second output value depending upon whether an external frequency source is at a first or second frequency, respectively; providing a watchdog timer for periodically causing the sleep/wake-up logic to wake up the circuits and the I/O from the sleep mode to the operational mode for a certain time so that the circuits can sample the output values from the frequency differentiator, wherein when a present output value sample is different then a prior output value sample, then the circuits and the I/O will remain in the operational mode. - View Dependent Claims (35, 36)
-
Specification