×

Method and apparatus for a two-wire serial command bus interface

  • US 7,441,065 B2
  • Filed: 03/01/2007
  • Issued: 10/21/2008
  • Est. Priority Date: 06/13/2002
  • Status: Expired due to Term
First Claim
Patent Images

1. A system for bi-directional transmission of data between a source and sink over a Display Data Channel (DDC) compatible two-wire interface, the system comprising:

  • a first translator responsive to and operative to develop a first local I2C bus signal for signal current flow in a first direction and responsive to and operative to develop a different protocol signal over the DDC-compatible two-wire interface for signal current flow in a second direction;

    the first translator including an I2C port for converting serial data signal and serial clock signal into internal signal blocks, a translation logic for translating the internal signal blocks to the different protocol signal, and a physical interface for interfacing the translated different protocol signal onto the DDC-compatible two-wire interface;

    a first buffer responsive to and operative to develop the first local I2C bus signal for signal current flow in the first direction and responsive to and operative to develop a buffered signal including a buffered data signal and a buffered clock signal for signal current flow in the second direction;

    the first buffer including a first data buffer circuit for assisting the current flow of the serial data signal to extend the distance over which the serial data signal may be communicated, and a first clock buffer circuit for assisting the current flow of the serial clock signal to extend the distance over which the serial clock signal may be communicated;

    the buffered data signal being communicated over a first wire of the DDC-compatible two-wire interface and the buffered clock signal being communicated over a second wire of the DDC-compatible two-wire interface;

    a logic responsive to the first local I2C bus signal and operative to control a first switch coupled to the DDC-compatible two-wire interface wherein the first switch connects the DDC-compatible two-wire interface to one of the first translator, the first buffer, and an isolation firewall in which electrical access to the source via the DDC two-wire interface is cut off;

    a second translator responsive to and operative to develop the different protocol signal for signal current flow in the first direction and responsive to and operative to develop a second local I2C bus signal for signal current flow in the second direction when the first switch is connected to the first translator and a second switch coupled to the DDC-compatible two-wire interface is connected to the second translator; and

    a second buffer responsive to and operative to develop the buffered signal including the buffered data signal and the buffered clock signal for signal current flow in the second direction; and

    responsive to and operative to develop the second local I2C bus signal for signal current flow in the first direction when the first switch is connected to the first buffer and the second switch coupled to the DDC-compatible two-wire interface is connected to the second buffer.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×