A buffer circuit, a frequency dividing circuit, and a communications device are disclosed. The buffer circuit includes a buffer, a first control circuit, and a second control circuit. The buffer is coupled to a frequency divider, and the buffer is configured to receive a first signal output by the frequency divider, and output a fourth signal by using an output terminal of the buffer circuit when driven by the first signal, where the first signal is obtained by the frequency divider by performing frequency division on a group of differential signals, and the differential signals include a second signal and a third signal. The first control circuit is configured to perform delay control on a rising edge of the fourth signal based on the second signal. The second control circuit is configured to perform delay control on a falling edge of the fourth signal based on the third signal.

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.

A duty cycle correction circuit (DCCC) for a multi-modulus frequency divider, the DCCC comprising: a corrector chain comprising a plurality of flip-flops each configured to receive one of the internal signals; and at least one delay selection logic element, each configured to receive an output signal from different ones of the flip-flops and the output of each delay selection logic element is based on the received output signal and the division factor; the DCCC is configured such that: a first state change in its output signal is defined by a transition to a first logic state of one of the internal signals; and a second state change in its output signal is based on a transition to a second logic state of one of the internal signals after a delay period, wherein the duty cycle of the output signal is based on the delay period.

A duty cycle correction circuit (DCCC) for a multi-modulus frequency divider, the DCCC comprising: a corrector chain comprising a plurality of flip-flops each configured to receive one of the internal signals; and at least one delay selection logic element, each configured to receive an output signal from different ones of the flip-flops and the output of each delay selection logic element is based on the received output signal and the division factor; the DCCC is configured such that: a first state change in its output signal is defined by a transition to a first logic state of one of the internal signals; and a second state change in its output signal is based on a transition to a second logic state of one of the internal signals after a delay period, wherein the duty cycle of the output signal is based on the delay period.

A dual-edge aware clock divider configured to generate an output clock based on the input clock and a ratio of an integer M over an integer N is disclosed herein. The frequency of the output clock is based on a frequency of the input clock multiplied by the ratio (M/N), wherein M may be set to a range up to N. The output clock includes M pulses within a sequence time window having a length of N periods of the input clock. The output clock includes one or more rising edges that are substantially time aligned with one or more rising edges and one or more falling edges of the input clock, respectively. The dual-edge aware clock divider is configured to generate the output clock based on inverted and non-inverted portions of the input clock. A hybrid clock divider including the dual-edge and single-edge aware techniques is provided.

A dual-edge aware clock divider configured to generate an output clock based on the input clock and a ratio of an integer M over an integer N is disclosed herein. The frequency of the output clock is based on a frequency of the input clock multiplied by the ratio (M/N), wherein M may be set to a range up to N. The output clock includes M pulses within a sequence time window having a length of N periods of the input clock. The output clock includes one or more rising edges that are substantially time aligned with one or more rising edges and one or more falling edges of the input clock, respectively. The dual-edge aware clock divider is configured to generate the output clock based on inverted and non-inverted portions of the input clock. A hybrid clock divider including the dual-edge and single-edge aware techniques is provided.

An event counter circuit can be configured to monitor operation of a system where a moving average register circuit can be configured to store a moving average value updated in each cycle of operation of the system by adding a number of system events occurring during a current cycle of the system operation to either 1) a current moving average value stored in the moving average register circuit or 2) a keep value generated by partitioning the current moving average value into the keep value and a transfer value representing system events not included in a determination of the moving average value for subsequent cycles of operation of the system.

An event counter circuit can be configured to monitor operation of a system where a moving average register circuit can be configured to store a moving average value updated in each cycle of operation of the system by adding a number of system events occurring during a current cycle of the system operation to either 1) a current moving average value stored in the moving average register circuit or 2) a keep value generated by partitioning the current moving average value into the keep value and a transfer value representing system events not included in a determination of the moving average value for subsequent cycles of operation of the system.

A fail bit number counting circuit includes a data transfer circuit configured by a series circuit in which switch elements turned on for calculation result data indicating a pass bit from each page buffer portion and turned off for calculation result data indicating a fail bit are connected in series; a control circuit inputs a counting enable signal to one input terminal of the data transfer circuit, and sequentially transfers the counting enable signal till the next switch element being turned off via the series circuit corresponding to a clock with a prescribed cycle; and the fail bit number counting circuit includes a clock counter by which the number of clocks till the counting enable signal reaches the other output terminal of the data transfer circuit after the counting enable signal is input to one input terminal of the data transfer circuit is counted as a fail bit number.

A fail bit number counting circuit includes a data transfer circuit configured by a series circuit in which switch elements turned on for calculation result data indicating a pass bit from each page buffer portion and turned off for calculation result data indicating a fail bit are connected in series; a control circuit inputs a counting enable signal to one input terminal of the data transfer circuit, and sequentially transfers the counting enable signal till the next switch element being turned off via the series circuit corresponding to a clock with a prescribed cycle; and the fail bit number counting circuit includes a clock counter by which the number of clocks till the counting enable signal reaches the other output terminal of the data transfer circuit after the counting enable signal is input to one input terminal of the data transfer circuit is counted as a fail bit number.