An elastic gear First-In-First-Out (FIFO) buffer architecture is disclosed. The proposed elastic gear FIFO buffer uses a frequency monitor unit to control clock frequency compensation. By using an independent frequency monitor unit, the data latency and FIFO buffer size are best optimized. An elastic gear FIFO could be utilized in applications where clock compensation and asynchronous data width conversion are desired or required.

An electronic digital system includes a digital core and a Serializer Deserializer module. A FIFO device of the core reads and writes on a set of buses coupled to said Serializer Deserializer module. The Serializer Deserializer module transmits data read from the FIFO architecture device on a set of buses as a corresponding serial signals transmitted by transmitters. The serial signals and corresponding transmitters are logically grouped. The transmitters include PLL circuits generating PLL clocks, using as reference a cluster transmitter reference clock common, to a respective cluster of transmitters controlling a frequency of serialization operation and low frequency clocks obtained by the PLL clocks according to one or more groups corresponding to group of buses.

Interface devices and systems that include interface devices are disclosed. In some implementations, a device includes a transceiver configured to transmit and receive data, a lane margining controller in communication with the transceiver and configured to control the transceiver to transmit, through a margin command, to an external device, a request for requesting a state of an elastic buffer of the external device, and control the transceiver to receive the state of the elastic buffer of from the external device, and a port setting controller adjust a clock frequency range of a spread spectrum clocking scheme based on the state of the elastic buffer.

A signal generation device includes m transceivers, a usage amount determination unit that executes a usage amount determination process that determines the usage amount of the FIFO of each transceiver, and a phase adjustment unit that adjusts the phase of the read clock signal for the FIFO. The signal generation device performs the second usage amount determination process on the condition that the count that the usage amount of the FIFO of each transceiver is determined to be less than the usage amount threshold by the first usage amount determination process consecutively reaches the first determination count, and terminates the adjustment of the phase of the read clock signal on the condition that the count that the usage amount of the FIFO of each transceiver is determined by the second usage amount determination process to be greater than the usage amount threshold consecutively reaches the second determination count.

Interface devices and systems that include interface devices are disclosed. In some implementations, a device includes a transceiver configured to transmit and receive data, a lane margining controller in communication with the transceiver and configured to control the transceiver to transmit, through a margin command, to an external device, a request for requesting a state of an elastic buffer of the external device, and control the transceiver to receive the state of the elastic buffer of from the external device, and a port setting controller adjust a clock frequency range of a spread spectrum clocking scheme based on the state of the elastic buffer.

A re-timer device includes transceiver circuitry. The transceiver circuitry includes clock generation circuitry and first receiver circuitry. The clock generation circuitry generates a first clock signal. The first receiver circuitry receives the first clock signal and a first input signal. The first receiver circuitry generates a first frequency offset value based on the first input signal and the first clock signal. The first input signal has a first frequency and the first clock signal has a second frequency different than the first frequency. The first receiver circuitry outputs the first frequency offset value.

An apparatus includes circuitry configured to receive a fill level from N first-in, first-out (FIFOs), N is an integer that is greater than or equal to 1, determine a module clock speed based on the fill level, and program a phase lock loop (PLL) based on the determined module clock speed where the PLL provides a module clock at the module clock speed to a packet processing circuit configured to receive packets from the N FIFOs. A packet processing module includes N FIFOs. N is an integer that is greater than or equal to 1; a programming state machine configured to receive a fill level from the N FIFOs and to program a PLL based thereon; and a packet processing circuit configured to receive packets from the N FIFOs, wherein the packet processing circuit receives a module clock from the PLL with a speed determined by the programming state machine.

A method of operating an interface device including a first elastic buffer is provided. The method of operating the interface device includes performing a link equalization operation, checking a transmission mode of the interface device, and determining a transmission parameter of the interface device based on a status of the first elastic buffer or a status of a second elastic buffer included in another interface device communicating with the interface device when the transmission mode is a transmission parameter adjustment mode.