In described examples, a counter system includes a counter, a parity detector, a toggle flop, and a comparator. The counter iterates a count through a set of binary states in response to a clock signal, so that a binary value of a single bit of the count changes at each iteration. The parity detector detects the parity of the count. The toggle flop output is coupled to the toggle flop input. The toggle flop outputs a binary flop value. The binary flop value toggles between zero and one in response to the toggle flop input and the clock signal. The comparator compares the parity of the count and the toggle flop output, and outputs a first comparator value if the parity of the count and the toggle flop output are the same, and a second comparator value if the parity of the count and the toggle flop output are different.

Disclosed herein is an apparatus that includes a first shift register circuit including a plurality of first latch circuits coupled in series, and a second shift register circuit including a plurality of second latch circuits coupled in series. The first and second shift register circuits are cyclically coupled. Each of the first latch circuits is configured to perform the latch operation in synchronization with a rise edge of a first clock signal. Each of the second latch circuits is configured to perform the latch operation in synchronization with a fall edge of a first clock signal when a first selection signal is in a first state. One or more first latch circuits and one or more second latch circuits are configured to be bypassed when a second selection signal indicates a predetermined value.

A bi-directional Gray code counter includes a first set of logic circuitry configured to receive an input having a first sequence of bits representing a first value. The first set of logic circuitry is further configured to convert the first sequence of bits to a second sequence of bits representing the first value. The bi-directional Gray code counter further includes a second set of logic circuitry and third second set of logic circuitry. The second set of logic circuitry is configured to compare the second sequence of bits to a bit index pattern. The third set of logic circuitry is configured to transition one bit in the first sequence of bits from a first state to a second state to form a third sequence of bits representing a second value. The one bit is transitioned in response to the second sequence of bits being compared to the bit index pattern.

Embodiments of the present invention relate to an architecture that uses hierarchical statistically multiplexed counters to extend counter life by orders of magnitude. Each level includes statistically multiplexed counters. The statistically multiplexed counters includes P base counters and S subcounters, wherein the S subcounters are dynamically concatenated with the P base counters. When a row overflow in a level occurs, counters in a next level above are used to extend counter life. The hierarchical statistically multiplexed counters can be used with an overflow FIFO to further extend counter life.

Apparatuses and methods for clock leveling in semiconductor memory are disclosed. In an example apparatus, a latency control circuit is configured to provide in first and second modes an active first control signal having a timing based on latency information and a system clock. A clock leveling control circuit is configured to provide in the first mode an active second control signal responsive to an active first control signal at a clock transition of a first clock and further configured to provide in the second mode clock leveling feedback responsive to the active first control signal at a transition of a second clock. A read clock circuit is configured to provide the multiphase clocks responsive to the active second control signal. A serializer circuit configured to serialize the data based on the multiphase clocks from the read clock circuit to provide the data in series.

A lightning strike counter and a lightning strike counting method are disclosed. The lightning strike counter includes a lightning strike input circuit, a bipolar waveform generating circuit, and a counting circuit. The lightning strike input circuit receives a lightning strike signal from a first lightning strike input end and a second lightning strike input end. The bipolar waveform generating circuit outputs a bipolar waveform signal from a bipolar waveform output end to the counting circuit in response to the lightning strike input circuit receiving the lightning strike signal. The counting circuit outputs a counting output signal from a counting output end in response to receiving the bipolar waveform signal from a counting input end.

Disclosed herein is an apparatus that includes a first shift register circuit including a plurality of first latch circuits coupled in series, and a second shift register circuit including a plurality of second latch circuits coupled in series. The first and second shift register circuits are cyclically coupled. Each of the first latch circuits is configured to perform the latch operation in synchronization with a rise edge of a first clock signal. Each of the second latch circuits is configured to perform the latch operation in synchronization with a fall edge of a first clock signal when a first selection signal is in a first state. One or more first latch circuits and one or more second latch circuits are configured to be bypassed when a second selection signal indicates a predetermined value.

A frequency divider circuit includes: a first latch circuit that including: a pair of input transistors each having a gate thereof configured to connect to a signal line to which a first voltage is supplied; and a pair of output nodes, and configured to receive a single-phase clock signal; and a second latch circuit of SR-type, the second latch circuit having a set input thereof and a reset input thereof configured to connect to the pair of output nodes of the first latch circuit, and configured to output differential clock signals of which frequency is half a frequency of the single-phase clock signal. The first latch circuit is configured to perform amplification and reset operations alternately repeatedly in response to the single-phase clock signal.

A frequency divider circuit includes: a first latch circuit that including: a pair of input transistors each having a gate thereof configured to connect to a signal line to which a first voltage is supplied; and a pair of output nodes, and configured to receive a single-phase clock signal; and a second latch circuit of SR-type, the second latch circuit having a set input thereof and a reset input thereof configured to connect to the pair of output nodes of the first latch circuit, and configured to output differential clock signals of which frequency is half a frequency of the single-phase clock signal. The first latch circuit is configured to perform amplification and reset operations alternately repeatedly in response to the single-phase clock signal.

Disclosed are systems and methods for providing programming of multi-level memory cells using an optimized multiphase mapping with a balanced Gray code. A method includes programming, in a first phase, a first portion of data into memory cells in a first-level cell mode. The method may also include reading, from the memory cells, the programmed first portion of the data. The method may also include programming, in a second phase, a second portion of the data into the memory cells in a second-level cell mode, wherein programming the second phase is based on applying, to the read first portion of the data, a mapping from the first-level cell mode to the second-level cell mode. The mapping may be selected based on minimizing an average voltage change of the memory cells from the first to second phase while maintaining a balanced Gray code.