Marvell Asia Pte., Ltd.

Marvell Israel (misl) Ltd.

Moran Noiman

Eliya Babitsky

Adi Katz

Yaakov Yehezkel

Ofer Halili

Tal Robinson

Michael Weiner

Yaniv Azulay

Yakov Tovar

Yogev Damary

A circuit and corresponding method perform timestamp filtering. The circuit includes recursive filter logic that implements a recursive least-squares (RLS) filter. The circuit (i) generates a filtered timestamp from a received timestamp by filtering the received timestamp via the recursive filter logic. The recursive filter logic applies the RLS filter to a portion of the received timestamp. A number of bits of the portion is less relative to a total number of bits of the received timestamp. The circuit outputs the filtered timestamp generated. Applying the RLS filter to the portion enables the circuit to be more efficient (e.g., smaller adders, fewer flipflops, etc.), thereby reducing area and power consumption of the circuit.

Circuit and method for timestamp filtering with RLS filter

A circuit and corresponding method generate a filtered timestamp. The circuit comprises recursive filter logic. The circuit generates the filtered timestamp from a received timestamp by filtering the received timestamp via the recursive filter logic. The recursive filter logic reduces jitter in the filtered timestamp relative to jitter of the received timestamp. The jitter represents a deviation of the received timestamp from a target (ideal) timestamp. The circuit outputs the filtered timestamp generated. The filtered timestamp is a more accurate representation of the target timestamp, relative to the received timestamp, due to the jitter reduced.

Circuit and method for timestamp jitter reduction

A method of reducing jitter in transmission of a timestamp across a clock domain boundary includes storing N timestamps, generated in N successive clock cycles of an origin clock domain, in N parallel buffers in the origin clock domain under control of a modulo-N counter, transmitting outputs of the N parallel buffers across the clock domain boundary into a destination clock domain along with the modulo-N counter, processing the modulo-N counter in the destination clock domain to derive a selection signal that selects a stable timestamp from among the outputs of the N parallel buffers, and outputting the selected stable timestamp. The modulo-N counter may be Gray-coded modulo-N counter to reduce jitter in the modulo-N counter across the clock domain boundary.

Method and apparatus for passing clock signals between time domains

A circuit and corresponding method perform timestamp filtering. The circuit comprises input format-conversion logic that converts a received timestamp from an original timestamp format to an intermediate timestamp format. The circuit further comprises recursive filter logic coupled to the input format-conversion logic. The recursive filter logic generates a filtered timestamp in the intermediate timestamp format by filtering the received timestamp in the intermediate timestamp format. The circuit further comprises output format-conversion logic coupled to the recursive filter logic. The output format-conversion logic converts the filtered timestamp from the intermediate timestamp format to the original timestamp format and outputs the filtered timestamp in the original timestamp format. Converting the received timestamp into a different format avoids use of complex logic to handle rollover of input values, thereby reducing area and power consumption of the circuit.

Circuit and method for timestamp filtering with input/output format conversion

A hardware queue for an integrated circuit device includes an internal queue memory and at least one external queue memory. The internal queue memory and the external queue memory are operated as a continuous hardware queue memory by monitoring occupancy of the internal queue memory and, based on that occupancy, controlling an internal tail pointer indicating a next write point for inserting new data into the internal queue memory, an internal head pointer indicating a next read point for extracting data from the internal queue memory based on order of insertion, at least one external tail pointer indicating a next write point for inserting new data into the external queue memory, at least one external head pointer indicating a next read point for extracting data from the external queue memory based on order of insertion, and wrap pointers indicating transitions between the internal queue memory and the external queue memory.

Extendable hardware queue structure and method of operation thereof

A FIFO memory device has a first number of data storage units and a second number of internal FIFO memories. Each internal FIFO memory has a third number of internal data storage units. The first number is a product of the second and third numbers. A fourth number of data inputs receives input data units in order. Input multiplexer circuitry connects each one of the data inputs to any one of the internal FIFO memories, for storage of input data units, in order, in a first layer of the FIFO memory device including corresponding storage locations in respective ones of the internal FIFO memories. The first layer may be physical, or may be logical and maintained by pointers. Output multiplexer circuitry coupled to the internal FIFO memories connects each of the internal FIFO memories to any one of the data outputs to read out the stored data units in order.

Scalable-entry FIFO memory device

Embodiments herein use a single buffer that comprises a plurality of serially connected data cells to serially store data attributes and the respective data source identifiers from incoming data requests such that each stored data source identifier is used to match with a response message that corresponds to a respective data request. When a response message is received at the data interface, the data interface searches among the previously stored data attributes at the single buffer and selectively outputs a previously stored data attribute that corresponds to a data request to match with the response message. The data interface then uses information from the previously stored data attribute to route the response message to the data source that originates the data request.

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Kiryat Ono, Israel

Moran Noiman