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US 2011/0258476 A1Published application
Apparatus for detecting presence or absence of oscillation of clock signal
AssigneeRenesas Electronics Corporation
InventorKimiharu ETO
Life of this patent
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Abstract
A semiconductor apparatus includes an arithmetic circuit that executes a program based on an operating clock signal input through a clock transfer node, an internal oscillator that generates an internal clock signal to be used internally, a watch dog timer that counts the internal clock signal, detect that a count value reaches a predetermined value of an execution time of the program in the arithmetic circuit and output a notification signal, and a clock monitor circuit that detects presence or absence of the operating clock signal in response to the notification signal.
Claims11
A microprocessor comprising:
- a first oscillator that generates a first clock signal;
- a second oscillator that generates a second clock signal different from the first clock signal;
- a memory that stores a program;
- a Central Processing Unit (CPU) that is responsive to the first clock single to execute the program;
- and
- a clock monitor that is responsive to the second clock signal to monitor an oscillation configuration of the first clock signal,
- wherein the clock monitor detects presence or absence of an oscillation of the first clock signal during a first periods set based on the second clock signal, and does not detect presence or absence of the oscillation of the first clock signal during a second period other than the first period.
4 more elements
Dependencies are inferred from the claim text.