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US 2010/0293366 A1Published application
Frequency and symbol locking using signal generated clock frequency and symbol identification
AssigneesSTMicroelectronics S.r.l., ST Microelectronics SA
InventorOsamu Kobayashi
Life of this patent
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Abstract
Methods and systems are described for displaying video data after a hot plug event during a start-up dead period. In particular, approaches for receiving data, determining whether link training can be performed and, if not, self-configuring a receiver to display the information in a proper format even during the dead period.
Claims25
An integrated circuit package configured to operate in a network device, the package comprising;
- a data interface enabling interconnection with a data link and receipt of an 8B/10B encoded audio-video signal from a first network device connected with the interface through the data link, wherein the link is configured to receive the 8B/10B encoded audio-video signal at a data rate comprising one of a finite number of known bit rates;
- local reference clock circuitry having a stable local reference clock frequency;
- clock generation circuitry operable during a device start-up period prior to the engagement of an operating system, said clock generation circuitry enabling the use of signal edges that form part of the received 8B/10B encoded audio-video signal together with an analysis of the finite number of known bit rates to extract a signal based clock frequency from the 8B/10B encoded audio-video signal wherein the signal based clock is associated with one of said finite number of known bit rates;
- frequency locking circuitry that enables frequency locking the signal based clock frequency with said local reference clock frequency in the absence of link training information;
- and
- decoding circuitry configured to decode the 8B/10B encoded audio-video signal.
3 more elements
A method of communicating audio-video signal between devices in a multimedia network, the method comprising:
- a) connecting a network device in a hot plug event;
- b) receiving an audio-video signal at said network device at a bit rate comprising one of a finite number of known link bit rates associated with a data link;
- c) the network device receiving, in response to the hot plug event, one of (i) link training information associated with said audio-video signal or (ii) said audio-video signal without said link training information;
- d) selectively performing device configuration to enable decoding of the audio-video signal, such that,
- i) when the network device receives said audio-video signal and said link training information, configuring is based on the link training information, thereby enabling the network device to decode said audio-video signal, and
- ii) when said network device receives said audio-video signal, without said link training information, the network device performs device self-configuration using the audio-video signal to determine a signal based clock frequency for the audio-video signal and to determine a symbol rate for the audio-video signal using information contained within said audio-video signal thereby enabling the network device to decode said audio-video;
- and
- e) decoding said audio-video signal based on said device configuration or said device self-configuration.
5 more elements
A computer implementable method, embodied on a tangible computer readable media, for communicating audio-video signal between network devices in a multimedia network, the method comprising computer readable instructions for:
- receiving an audio-video signal at a network device after a hot plug event, the audio-video signal comprising 8B/10B encoded data received at a link rate comprising one of a finite number of known bit rates;
- receiving, by the network device, one of (i) link training information associated with said audio-video signal or (ii) said audio-video signal without said link training information;
- selectively performing device configuration, by the network device, such that,
- i) when the network device receives said audio-video signal and said link training information, the network device performs device configuration based on the link training information, thereby enabling the network device to decode said audio-video, and
- ii) when said network device receives said audio-video signal, without said link training information, the network device performs device self-configuration using the audio-video signal to determine a signal based clock frequency for the audio-video signal and to determine a symbol rate for the audio-video signal using information contained within said audio-video signal thereby enabling the network device to decode said audio-video;
- and
- decoding said audio-video signal based on said device configuration or said device self-configuration;
- displaying the decoded audio-video signal.
5 more elements
A network device communication system configured to operate in an audio-video network comprising;
- a receiver suitable for interconnection with a data link and receiving audio-video signal, the audio-video signal received at a data rate comprising one of a finite number of known bit rates;
- a local reference clock having a stable clock frequency;
- a signal clock generator that enables the self-generation of a signal based clock signal from the based on a received audio-video signal, the clock generator enabling,
- searching the encoded audio-video signal for signal edges that define state transitions in the received encoded audio-video signal, and
- comparing edge spacing patterns with clock frequencies associated with the finite number of known bit rates to extract a signal based clock frequency from the audio-video signal;
- a frequency lock synchronizer for frequency locking the signal based clock frequency with said local reference clock frequency to generate a frequency locked audio-video signal;
- a screener that interrogates the audio video signal to identify signal boundaries in the audio-video signal;
- a symbol lock synchronizer for symbol locking symbols identified for the audio-video with said local reference clock frequency to generate a symbol locked audio-video signal;
- hot plug messaging circuitry configured to transmit hot plug detect messages to a network device connected with the system when the system is hot plugged with the network device;
- a decoder configured to decode the frequency and symbol locked audio-video signal;
- and
- a display for displaying the audio-video signal.
9 more elements
Dependencies are inferred from the claim text.