Method and apparatus for power glitch detection in integrated circuits

An apparatus comprising:

• a multiplexer coupled to receive a plurality of reference voltages including a first reference voltage;
• a comparator coupled to receive one of the plurality of reference voltages from an output of the multiplexer on a first comparator input and a supply voltage on a second comparator input;
• a flip-flop having a clock input coupled to receive a logic signal from the comparator;
• and
• a register coupled to receive and configured to store a logic output from the flip-flop, wherein:
• the comparator is configured to change a state of the logic signal output by the comparator responsive to determining that the value of the supply voltage is less than the first reference voltage;
• the flip-flop is configured to change a value of the logic output to a first logic value from a second logic value responsive to the comparator changing the state of the logic signal;
• and
• the multiplexer is configured to select each remaining one of the plurality of reference voltages to cause the comparator to compare the supply voltage to each remaining one of the plurality of reference voltages and determine if the supply voltage falls below any one of the plurality of reference voltages, wherein the comparator and flip-flop are configured to cause any instances of the supply voltage being less than the reference voltage to be recorded in the register.

A method comprising:

• providing a logic signal from an output of a first comparator to a clock input of a first flip-flop;
• storing, in a register, a logic value output by the first flip-flop;
• comparing a first value of a reference voltage to a value of a supply voltage, wherein said comparing is performed by the first comparator;
• changing a state of the logic signal output by the comparator responsive to determining that the value of the supply voltage is less than the first value of the reference voltage;
• changing the logic value output by the flip-flop to a first logic value from a second logic value responsive to the comparator changing the state of the logic signal;
• resetting the first flip-flop to output the second logic value;
• changing the reference voltage to a second value;
• and
• repeating said comparing subsequent to changing the reference voltage to the second value.

An integrated circuit comprising:

• a plurality of detection circuits each configured to detect voltage transients on a supply voltage node in which a supply voltage temporarily falls below a reference voltage, wherein each of the detection circuits includes:
• a multiplexer having a plurality of inputs each coupled to receive a corresponding one of a plurality of reference voltages;
• a comparator configured to compare a value of a supply voltage to one of the plurality of reference voltages received from the multiplexer and configured to change a state of an output signal responsive to determining that the supply voltage is less than the one of the plurality of reference voltages;
• and
• a flip-flop having a clock input coupled to receive the output signal from the comparator and a data input coupled to a fixed voltage, wherein the flip-flop is configured to change a logic value output therefrom to a first state from a second state responsive to the comparator changing the state of the its output signal;
• and
• a register coupled to receive and store a logic value from each the flip-flop of each of the plurality of detection circuits,
• wherein the multiplexer is configured to select each remaining one of the plurality of reference voltages to cause the comparator to compare the supply voltage to each remaining one of the plurality of reference voltages, wherein the comparator and the flip-flop are configured to cause any instance of the supply voltage being less than a given one of the plurality of reference voltages to be recorded in the register.

A method comprising:

• determining, in one or more of a plurality of detection circuits in an integrated circuit, an occurrence of a transient on a supply voltage node causing a value of a supply voltage to temporarily fall below a value of a reference voltage, wherein determining the occurrence of the transient comprises comparing, using a comparator, the value of the supply voltage to the first value of the reference voltage and providing, from an output of the comparator, an indication to a clock input of a flip-flop responsive to the comparator determining that the value of the supply voltage has fallen below the value of the reference voltage;
• writing, to a register, an indication of detecting the transient on the supply voltage node from each of the plurality of detection circuits that detects the transient;
• identifying which of the one or more of the plurality of detection circuits detected the transient on the supply voltage node;
• determining one or more locations within the integrated circuit where the transient occurred on the supply voltage node;
• wherein the method further comprises determining, in one or more of the plurality of detection circuits in an integrated circuit, an occurrence of a transient on a supply voltage node for two or more values of the reference voltage.