Apparatus and method for controlling operation of a processor device during startup
AssigneeTexas Instruments Incorporated
InventorMichael Lane Mitchell
Life of this patent
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Abstract
An apparatus for controlling operation of a processor device during startup of the processor device includes: (a) a signal treating circuit receiving a voltage supply signal at a voltage supply locus; the signal treating circuit using the voltage supply signal for generating a first treated signal and a second treated signal; and (b) an output circuit coupled with the signal treating circuit; the output circuit receiving the first treated signal and the second treated signal and generating a control signal at an output locus based upon a relationship between the first treated signal and the second treated signal; the output locus being coupled with the processor device; the control signal effecting the controlling.
Claims18
An apparatus for generating a status signal on an output node according to a voltage applied between a power node and a ground node, the apparatus comprising:
- a comparator circuit with a first input node, a second input node, and a decision node coupled to the output node;
- a voltage divider circuit coupled between the ground node and the power node and having an output node coupled to the second input node of the comparator circuit;
- an RC circuit, comprising a first resistive element and a capacitive element coupled in series;
- the RC circuit coupled between the ground node and the power node;
- and an output node between the first resistive element and the capacitive element coupled to the first input node of the comparator circuit;
- and
- a discharge circuit coupled between the power node and the first input node of the comparator circuit.
An apparatus for a digital processor system for generating a status signal on an output node according to a voltage applied between a ground node and a power node, the apparatus comprising:
- a comparator circuit with a first input node, a second input node, and a decision node coupled to the output node;
- a voltage divider circuit coupled between the ground node and the power node and having an output node coupled to the second input node of the comparator circuit;
- wherein the voltage divider comprises at least two resistors and the voltage divider output node is between the at least two resistors;
- an RC circuit, comprising a first resistive element and a capacitive element coupled in series;
- the RC circuit coupled between the ground node and the power node and having an RC circuit output node between the first resistive element and the capacitive element;
- the RC circuit output node coupled to the first input node of the comparator circuit;
- and
- a discharge circuit coupled between the power node and the first input node of the comparator;
- the discharge circuit comprising a second resistive element and a diode circuit;
- the second resistive element coupled between the power node and a cathode of the diode circuit;
- and an anode of the diode circuit is coupled to the first input node of the comparator.
A method for generating a power-on or reset status signal on an output node according to a supply voltage applied between a ground node and a power node, the method comprising the following steps:
- comparing a reference voltage with a second voltage to generate a decision result provided to the output node;
- generating the power-on or reset signal based on the decision result;
- generating the reference voltage on an output node of a voltage divider which is coupled between the power node and the ground node;
- the voltage divider comprising at least two resistive elements in series and the output node of the voltage divider is located between these at least two elements;
- generating the second voltage on an output node between a first resistive element and a capacitive element in an RC circuit as the capacitive element is charging or discharging responsive to the voltage between the power node and the ground node;
- wherein the RC circuit is coupled between the power node and the ground node;
- and
- discharging the capacitor by an alternative circuit when the supply voltage is resetting, where the alternative circuit is coupled between the power node and the output node of the RC circuit.
Dependencies are inferred from the claim text.