Semiconductor device, electronic device and sensing method
AssigneeRenesas Electronics Corporation
InventorHiroshi UEKI
Life of this patent
Estimating the term…
Abstract
In order to reduce power consumption, a semiconductor device includes an RTC for generating a piece of time information and a first activation signal SW3, a comparator for determining whether the value of an analog input signal exists within a predetermined range, an AD conversion circuit for converting the analog input signal to a digital signal in response to a common activation signal, and a CPU for processing the digital signal in response to the common activation signal. When the analog input signal does not exist within the predetermined rang, the comparator generates the common activation signal. Then, the CPU stores the piece of digital information corresponding to the digital signal as well as the piece of time information from the RTC into a storage circuit.
Claims12
A semiconductor device comprising:
- a timer circuit for generating a piece of time information and a first activation signal which is flowing periodically;
- a determination circuit for determining whether the value of an analog input signal exists within a predetermined range, in response to the first activation signal;
- a first conversion circuit for converting the analog input signal to a digital signal, in response to a second activation signal;
- and
- a processing circuit for processing the digital signal converted by the first conversion circuit, in response to a third activation signal,
- wherein, when the analog input signal does not exist within the predetermine range, the determination circuit generates the second activation signal and the third activation signal,
- wherein the processing circuit stores a piece of digital information corresponding to the digital signal, as well as the piece of time information from the timer circuit, into a storage circuit.
A sensing method having a processing circuit and a timer circuit to sense an analog input signal at a predetermined time interval by the timer circuit,
- wherein the periods of the predetermined time interval include:
- a first period for determining whether the value of the analog input signal exists within a predetermined range;
- and
- a second period when the processing circuit is turned to the non-operating state,
- wherein when it is determined that the value of the analog input signal does not exist within the predetermined range in the first period, a third period is inserted into the period with the second period being shortened, in order that the processing circuit operates to hold the piece of digital information corresponding to the analog input signal into the storage circuit.
Dependencies are inferred from the claim text.