System and method for switch timing synchronization
AssigneeApplied Micro Circuits Corporation
InventorsDavid Thomas Dougherty, Philip Michael Clovis
Life of this patent
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Abstract
A system and method have been provided for synchronizing the timing of line cards and switch cards in a broadband switch. Synchronization is accomplished using an auxiliary data link between the line and switch cards. One of the switch cards is selected as the master switch card. The master switch card receives timing information from the line cards, and in turn, sends timing correction signals to each of the line cards. Each line card acquires synchronization using its respective timing correction. A master line card is selected from among the line cards, and the slave switch cards adopt the timing of the master line card, becoming synchronized to the master switch card.
Claims20
A method for synchronizing timing in a broadband switch that includes a plurality of line cards for transceiving information packets and a plurality of switch cards for controlling distribution of the information packets between the line cards, the method comprising:
- from the plurality of switch cards, designating a master switch card having a master switch timing reference and slave switch cards;
- from the plurality of line cards, designating a master line card and slave line cards;
- synchronizing the plurality of line cards;
- and
- synchronizing the plurality of switch cards in response to communications with the line cards;
- wherein synchronizing the plurality of line cards includes synchronizing line cards to the master switch timing reference in response to communications with the master switch card;
- and
- wherein synchronizing the plurality of switch cards in response to communications with the line cards includes:
- synchronizing the slave switch cards to the master switch timing reference in response to communications with the master line card;
- and
- establishing communications exclusively between the switch cards and the line cards.
A system for synchronizing switch timing, the system comprising:
- a plurality of line cards, each line card having an information port to transmit and receive information packets and a control port to accept commands for controlling the distribution of the information packets, each line card maintaining synchronization in response to timing signals communicated through the control port;
- and
- a plurality of switch cards, each switch card having a control port connected to the plurality of line cards to send information packet control commands, each switch card maintaining synchronization in response to timing signal communications with the line cards through the control port;
- the plurality of switch cards including a master switch card having a master switch timing reference and slave switch cards;
- and
- the line cards maintaining synchronization in response to timing signal communications with the master switch card;
- wherein the plurality of line cards include a master line card and slave line cards;
- wherein the slave switch cards maintain synchronization in response to timing signal communications with the master line card;
- and
- wherein the switch card control ports are connected exclusively to line card control ports.
Dependencies are inferred from the claim text.