Glitch detector and test glitch generator
First Claim
1. An integrated circuit (IC) tamper detection apparatus comprising:
- a glitch detection circuit configured to receive a predetermined reference voltage signal (VREF) and a monitored supply voltage signal (MVSUPPLY), which is a function of a main supply voltage signal (VMAIN) configured to supply operating power to a target circuit, the glitch detection circuit comprising;
a first voltage divider configured to generate a plurality of voltage signals, each of the voltage signals representing a fraction of the MVSUPPLY voltage,a first selection circuit configured to select one of the plurality of voltage signals in response to a glitch depth selection signal;
a comparator operably coupled to receive and compare the selected one of the plurality of voltage signals and the VREF to generate a depth detection signal (DEPTH_DET) in response to the MVSUPPLY transitioning from a nominal supply voltage range for the target circuit to a range between a minimum operating voltage and a power-on-reset voltage threshold for the target circuit; and
,a glitch duration filter configured to receive the DEPTH_DET and a glitch width selection signal, the glitch duration filter configured to generate a glitch detection signal (DEPTH+WIDTH_DET) in response to the duration of the depth detection signal (DEPTH_DET) exceeding a selected glitch width responsive to the glitch width selection signal.
1 Assignment
0 Petitions
Accused Products
Abstract
Apparatus and associated methods relate to a glitch detection circuit monitoring a duration that a selected fractional supply voltage is below a predetermined voltage threshold. The selected fractional supply voltage may be at the predetermined threshold when the supply voltage is between a valid circuit-supply voltage and a power-on circuit-reset (POR). A glitch detect signal may be generated, for example, when the monitored duration is greater than a predetermined duration threshold. A test glitch generator may generate a test glitch, for example, having selectable voltage and duration, which may be selectably applied to the glitch detection circuit to verify operation. Various exemplary glitch detection circuits may advantageously determine externally produced tampering attempts by detecting circuit-supply voltages and durations that meet specific selectable supply voltage and duration criteria, improving security of sensitive field programmable gate array (FPGA) data by taking protective action in response to the detection.
12 Citations
20 Claims
-
1. An integrated circuit (IC) tamper detection apparatus comprising:
-
a glitch detection circuit configured to receive a predetermined reference voltage signal (VREF) and a monitored supply voltage signal (MVSUPPLY), which is a function of a main supply voltage signal (VMAIN) configured to supply operating power to a target circuit, the glitch detection circuit comprising; a first voltage divider configured to generate a plurality of voltage signals, each of the voltage signals representing a fraction of the MVSUPPLY voltage, a first selection circuit configured to select one of the plurality of voltage signals in response to a glitch depth selection signal; a comparator operably coupled to receive and compare the selected one of the plurality of voltage signals and the VREF to generate a depth detection signal (DEPTH_DET) in response to the MVSUPPLY transitioning from a nominal supply voltage range for the target circuit to a range between a minimum operating voltage and a power-on-reset voltage threshold for the target circuit; and
,a glitch duration filter configured to receive the DEPTH_DET and a glitch width selection signal, the glitch duration filter configured to generate a glitch detection signal (DEPTH+WIDTH_DET) in response to the duration of the depth detection signal (DEPTH_DET) exceeding a selected glitch width responsive to the glitch width selection signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method of operating an integrated circuit (IC), the method comprising:
-
receiving, with a glitch detection circuit, a predetermined reference voltage signal (VREF) and a monitored supply voltage signal (MVSUPPLY), which is a function of a main supply voltage signal (VMAIN) configured to supply operating power to a target circuit, the glitch detection circuit operable to perform operations comprising; generating, with a first voltage divider, a plurality of voltage signals, each of the voltage signals representing a fraction of the MVSUPPLY voltage, selecting, with a first selection circuit, one of the plurality of voltage signals in response to a glitch depth selection signal; receive and compare, with a comparator, the selected one of the plurality of voltage signals and the VREF to generate a depth detection signal (DEPTH_DET) in response to the MVSUPPLY transitioning from a nominal supply voltage range for the target circuit to a range between a minimum operating voltage and a power-on-reset voltage threshold for the target circuit; and
,receiving, with a glitch duration filter, the DEPTH_DET and a glitch width selection signal, the glitch duration filter configured to generate a glitch detection signal (DEPTH+WIDTH_DET) in response to the duration of the depth detection signal (DEPTH_DET) exceeding a selected glitch width responsive to the glitch width selection signal. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
-
Specification