# US 8,788,858 B2 · Network device and network connecting method for supporting power saving mechanism through auto-negotiation of HDMI > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,858 B2 - Document ID: US8788858B2 - Status: Granted - Kind: B2 - Application number: 13/305,746 - Filed: 2011-11-29 - Published: 2012-05-31 - Granted: 2014-07-22 - Earliest claimed: 2010-11-29 - Assignees: Realtek Semiconductor Corp. - Applicants: Liang-Wei Huang; Shieh-Hsing Kuo; Ming-Feng Hsu; Yuan-Jih Chu - Inventors: Liang-Wei Huang; Shieh-Hsing Kuo; Ming-Feng Hsu; Yuan-Jih Chu - Web page: https://patentgrep.com/patent/US8788858B2 ## CPC - G09G 5/006: {Details of the interface to the display terminal (specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04)} - H04N 21/4122: {additional display device, e.g. video projector (digital output for controlling a plurality of local displays G06F3/1423)} - H04N 21/43635: {HDMI} - H04N 21/4436: {Power management, e.g. shutting down unused components of the receiver (power management in computer systems G06F1/3203; hibernate or awake process in computer systems G06F9/4418)} - G09G 2330/021: Power management, e.g. power saving - G09G 2370/12: Use of DVI or HDMI protocol in interfaces along the display data pipeline - H04N 21/44231: {Monitoring of peripheral device or external card, e.g. to detect processing problems in a handheld device or the failure of an external recording device (configuring of peripheral devices in general G06F9/4411; reporting information sensed by appliance or service execution status of appliance services in a home automation network H04L12/2823; monitoring the status of connected device in data switched networks H04L43/0817)} - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A network device, for supporting a power saving mechanism through an auto-negotiation of HDMI, includes a transmitting circuit and a receiving circuit. The transmitting circuit is arranged for generating a link pulse signal to a second network device, wherein the network device and the second network device perform the auto-negotiation of a network connection by using the link pulse signal through HDMI in order to support the power saving mechanism. After the receiving circuit of the network device receives another link pulse signal transmitted from the second network device through HDMI, the network device is controlled to be operated under the power saving mechanism. ## Claims ### Claim 1 A network device for supporting a power saving mechanism through an auto-negotiation (NWAY) of High Definition Multimedia Interface (HDMI), the network device comprising: a transmitting circuit, arranged for generating a link pulse signal to a second network device, wherein the network device and the second network device perform the auto-negotiation of a network connection by using the link pulse signal through HDMI in order to support the power saving mechanism; and a receiving circuit, coupled to the transmitting circuit, wherein after the receiving circuit receives a second link pulse signal transmitted from the second network device through HDMI, the network device is controlled to be operated under the power saving mechanism. ### Claim 2 (depends on 1) The network device according to claim 1, wherein the transmitting circuit comprises: a link pulse signal generator, arranged for converting a first logic level of the link pulse signal into a first voltage level, and for converting a second logic level of the link pulse signal into a second voltage level. ### Claim 3 (depends on 2) The network device according to claim 2, wherein the link pulse signal is a square wave signal; the first logic level indicates a first time length, and the second logic level indicates a second time length being different from the first time length. ### Claim 4 (depends on 2) The network device according to claim 2, wherein the link pulse signal generator is a digital-to-analog converter (DAC). ### Claim 5 (depends on 2) The network device according to claim 2, wherein a voltage difference between the first voltage level and the second voltage level is equal to a voltage amplitude supported by the HDMI. ### Claim 6 (depends on 1) The network device according to claim 1, further comprising: an echo cancellation circuit, coupled between the transmitting circuit and the receiving circuit, arranged for performing an echo cancellation in order to eliminate echo caused by the link pulse signal of the transmitting circuit. ### Claim 7 (depends on 1) The network device according to claim 1, wherein the receiving circuit comprises: an analog-to-digital converter (ADC), arranged for converting a first voltage level of a receipt signal received by the receiving circuit into a first logic level, and for converting a second voltage level of the receipt signal received by the receiving circuit into a second logic level; and an energy accumulator, arranged for accumulating energy of the receipt signal and for comparing the accumulated energy with a threshold in order to eliminate echo caused by the link pulse signal of the transmitting circuit. ### Claim 8 (depends on 1) The network device according to claim 1, wherein the receiving circuit comprises: an analog-to-digital converter, arranged for converting a first voltage level of a receipt signal received by the receiving circuit into a first logic level, and for converting a second voltage level of the receipt signal received by the receiving circuit into a second logic level; and a counter, arranged for eliminating echo caused by the link pulse signal of the transmitting circuit with reference to a predetermined time length. ### Claim 9 (depends on 8) The network device according to claim 8, wherein the predetermined time length is a time duration starting from when the link pulse signal is generated by the transmitting circuit to when the echo caused by the link pulse signal is inputted to the receiving circuit. ### Claim 10 (depends on 1) The network device according to claim 1, wherein the power saving mechanism complies with IEEE 802.3az Energy Efficient Ethernet standard (EEE) defined by the Institute of Electrical and Electronic Engineers (IEEE). ### Claim 11 A network connecting method, applied to a network device, for supporting a power saving mechanism through an auto-negotiation (NWAY) of High Definition Multimedia Interface (HDMI), the method comprising: generating a link pulse signal to a second network device, wherein the network device and the second network device perform the auto-negotiation of a network connection by using the link pulse signal through HDMI in order to support the power saving mechanism; and after a second link pulse signal transmitted from the second network device is received through HDMI, controlling the network device to be operated under the power saving mechanism. ### Claim 12 (depends on 11) The network connecting method according to claim 11, wherein the step of generating the link pulse signal to the second network device comprises: converting a first logic level of the link pulse signal into a first voltage level, and converting a second logic level of the link pulse signal into a second voltage level. ### Claim 13 (depends on 12) The network connecting method according to claim 12, wherein the link pulse signal is a square wave signal; the first logic level indicates a first time length, and the second logic level indicates a second time length being different from the first time length. ### Claim 14 (depends on 12) The network connecting method according to claim 12, wherein a voltage difference between the first voltage level and the second voltage level is equal to a voltage amplitude supported by the HDMI. ### Claim 15 (depends on 11) The network connecting method according to claim 11, further comprising: performing an echo cancellation in order to eliminate echo caused by the link pulse signal. ### Claim 16 (depends on 11) The network connecting method according to claim 11, wherein the step of controlling the network device to be operated under the power saving mechanism comprises: converting a first voltage level of a receipt signal into a first logic level, and converting a second voltage level of the receipt signal into a second logic level; and accumulating energy of the receipt signal, and comparing the accumulated energy with a threshold in order to eliminate echo caused by the link pulse signal. ### Claim 17 (depends on 11) The network connecting method according to claim 11, wherein the step of controlling the network device to be operated under the power saving mechanism comprises: converting a first voltage level of a receipt signal into a first logic level, and converting a second voltage level of the receipt signal into a second logic level; and eliminating echo caused by the link pulse signal with reference to a predetermined time length. ### Claim 18 (depends on 17) The network connecting method according to claim 17, wherein the predetermined time length is a time duration of the echo caused by the link pulse signal being inputted to the network device. ### Claim 19 (depends on 17) The network connecting method according to claim 17, wherein the predetermined time length is a time duration starting from when a second link pulse signal transmitted by a second network device to when the receipt signal is received by the network device. ### Claim 20 (depends on 11) The network connecting method according to claim 11, wherein the power saving mechanism complies with IEEE 802.3az Energy Efficient Ethernet standard (EEE) defined by the Institute of Electrical and Electronic Engineers (IEEE).