Disclosed examples include non-volatile counter systems to generate and store a counter value according to a sensor pulse signal, and power circuits to generate first and second supply voltage signals to power first and second power domain circuits using power from the sensor pulse signal, including a switch connected between first and second power domain supply nodes, a boost circuit, and a control circuit to selectively cause the switch to disconnect the first and second power domain circuits from one another after the first supply voltage signal rises above a threshold voltage in a given pulse of the sensor pulse signal, and to cause the boost circuit to boost the second supply voltage signal after the regulator output is disconnected from the second power domain supply node in the given pulse.

A monotonic counter memory system including a counter circuit and a memory circuit is provided. The counter circuit is configured to increase a count by one in response to a clock signal and output a count value of n bits, where n is a positive integer. The memory circuit includes a plurality of memory cells. The memory circuit is configured to store the count value. The stored count value changes one bit at each input count of the clock signal, and a bit switching time of the stored count value are smaller than 2.sup.n1 times.

The present application relates to a system hosting a monotonic counter and a method of operating the system. The system comprises a non-volatile memory (110) for holding a save counter value and a volatile memory (120) for maintaining a current counter value. The system (100) is configured during a startup phase to retrieve the saved counter value of the monotonic counter from the non-volatile memory (110); to detect whether a previous shutdown of the system (100) was an uncontrolled shutdown; and to adjust the retrieved counter value in accordance with a step size (130) provided at the system (100) in case an previous uncontrolled shutdown is detected.

A method for implementing a non-volatile counter using non-volatile memory is disclosed. In an embodiment, the method involves distributing operations for storing a low word of a counter in non-volatile memory across memory cells in a memory array in the non-volatile memory, and storing additional bits of the counter in the non-volatile memory in memory cells outside of the memory array, wherein the location in the memory array at which the low word is stored is determined for each count based on the upper bits of the counter.

Disclosed examples include non-volatile counter systems to generate and store a counter value according to a sensor pulse signal, and power circuits to generate first and second supply voltage signals to power first and second power domain circuits using power from the sensor pulse signal, including a switch connected between first and second power domain supply nodes, a boost circuit, and a control circuit to selectively cause the switch to disconnect the first and second power domain circuits from one another after the first supply voltage signal rises above a threshold voltage in a given pulse of the sensor pulse signal, and to cause the boost circuit to boost the second supply voltage signal after the regulator output is disconnected from the second power domain supply node in the given pulse.

A method for implementing a non-volatile counter using non-volatile memory is disclosed. In an embodiment, the method involves distributing operations for storing a low word of a counter in non-volatile memory across memory cells in a memory array in the non-volatile memory, and storing additional bits of the counter in the non-volatile memory in memory cells outside of the memory array, wherein the location in the memory array at which the low word is stored is determined for each count based on the upper bits of the counter.

The present application relates to a system hosting a monotonic counter and a method of operating the system. The system comprises a non-volatile memory (110) for holding a save counter value and a volatile memory (120) for maintaining a current counter value. The system (100) is configured during a startup phase to retrieve the saved counter value of the monotonic counter from the non-volatile memory (110); to detect whether a previous shutdown of the system (100) was an uncontrolled shutdown; and to adjust the retrieved counter value in accordance with a step size (130) provided at the system (100) in case an previous uncontrolled shutdown is detected.

Upon a first transition from a first state to a second state, a first bit in a memory unit comprising a plurality of bits is programmed. Upon a first transition from the second state to the first state, a second bit in the memory unit is programmed, the second bit being before the first bit in the sequence of the plurality of bits. Upon a second transition from the first state to the second state, a third bit in the memory unit is programmed, the third bit being subsequent to the first bit by at least two bits in the sequence of the plurality of bits. Upon a second transition from the second state to the first state, a fourth bit in the memory unit is programmed, the fourth bit being before the third bit in the sequence of the plurality of bits.

A method of storing a counter in at least two non-volatile memory pages, including: a step of initializing a page with an initial value and then, on each update of the counter value, a step of storing an update value and an opcode associated with this value, selected from a set of opcodes, the current value of the counter being given by application of the successive update operations to the initial value of the page.

A circuit for sensing local operating properties of an integrated circuit is disclosed. The circuit may include one or more sensor circuits configured to sense the local operating properties of the integrated circuit. The sensor circuits may receive a supply voltage with a magnitude in a limited range from a digital power supply that is different from the digital power supply that provides power to functional circuits in the integrated circuit. Level shifters may be coupled to the sensor circuits to shift output signals from the sensor circuits to levels that correspond to the digital power supply that provides power to functional circuits in the integrated circuit. Counters and a shift register may be coupled to the level shifters to receive the shifted output signals, the values of which may be used to determine the local operating properties of the integrated circuit as sensed by the sensor circuits.