Method And Apparatus For A Two-Wire Serial Command Bus Interface

Abstract

A method for bi-directional transmission of data between a source and a sink over a two-wire interface includes re-mapping a data signal and a clock signal from a first local bus on the source into a different protocol signal. Transmitting the different protocol signal from the source to the sink over the two-wire interface. Re-mapping the different protocol signal back into the data signal and the clock signal for use on a second local bus on the sink. Re-mapping the data signal and the clock signal from the second local bus into the different protocol signal; and transmitting the different protocol signal from the sink to the source over the two-wire interface.

1 . A system for transmission of a signal between a source and sink over a single-wire interface comprising:
 a first translator responsive to and operative to develop a first local bus signal and responsive to and operative to develop a different protocol signal;   a first buffer responsive to and operative to develop the first local bus signal and responsive to and operative to develop a buffered signal;   a logic responsive to the first local bus signal and operative to control a first switch coupled to the single-wire interface wherein the switch connects to the first translator, to the first buffer, or to a isolation setting;   a second translator responsive to and operative to develop the different protocol signal and responsive to and operative to develop a second local bus signal when the first switch is connected to the first translator and a second switch coupled to the single-wire interface is connected to the second translator; and   a second buffer responsive to and operative to develop the buffered signal and responsive to and operative to develop the second local bus signal when the first switch is connected to the first buffer and the second switch coupled to the single-wire interface is connected to the second buffer.   
   
   
       2 . A system as in  claim 1 , wherein the signal is one of a data signal and a clock signal. 
   
   
       3 . A system for transmission of at least one information signal over a wire interface, the system comprising:
 a transmitter including:
 (a) a first translator responsive to and operative to develop a first local bus signal and responsive to and operative to develop a different protocol signal; 
 (b) a first buffer responsive to and operative to develop the first local bus signal and responsive to and operative to develop a buffered information signal; and 
 (c) a logic responsive to the first local bus signal and operative to control a first switch coupled to the wire interface wherein the first switch connects to the first translator, to the first buffer, or to an isolation setting; and 
   a receiver including:
 (d) a second translator responsive to and operative to develop the different protocol signal and responsive to and operative to develop a second local bus signal when the first switch is connected to the first translator and a second switch coupled to the wire interface is connected to the second translator; 
 (e) a second buffer responsive to and operative to develop the buffered data signal and the buffered clock signal and responsive to and operative to develop the second local bus signal when the first switch is connected to the first buffer and the second switch coupled to the wire interface is connected to the second buffer; and 
   a control that controls connectivity of at least one of the first translator, first buffer, second translator, and second buffer during operation.   
   
   
       4 . A system as in  claim 3 , wherein the at least one information signal is selected from the set of information signals consisting of: a serial data signal, a serial clock signal, and both a serial clock signal and a serial data signal. 
   
   
       5 . A system as in  claim 4 , wherein when the selected information signal is both a serial clock signal and a serial data signal, then:
 (i) the transmitter first translator includes a first translator clock portion and a first translator data portion for translating the transmitter clock signal and transmitter data signal respectively;   (ii) the transmitter first buffer includes a first buffer clock portion and a first buffer data portion for buffering the transmitter clock signal and the transmitter data signal respectively;   (iii) the receiver second translator includes a second translator clock portion and a second translator data portion for translating the receiver clock signal and receiver data signal respectively; and   (iv) the receiver second buffer includes a second buffer clock portion and a second buffer data portion for buffering the receiver clock signal and the receiver data signal respectively.   
   
   
       6 . A system as in  claim 3 , wherein the system further includes a second switch within the receiver, and the control controls the state of the first and second switches in a default position where the wire interface is connected to at least one of the first and second buffers or to at least one of the first and second translators. 
   
   
       7 . A system as in  claim 3 , wherein the information signal comprises a data signal and the buffered information signal comprises a buffered data signal. 
   
   
       8 . A system as in  claim 3 , wherein the information signal comprises a clock signal and the buffered information signal comprises a buffered clock signal. 
   
   
       9 . A system as in  claim 3 , wherein the information signal comprises a data signal and a clock signal and the buffered information signal comprises a buffered data signal and a buffered clock signal. 
   
   
       10 . A system as in  claim 3 , wherein the wire interface comprises a single wire interface for communicating one or a serial clock information signal and a serial data information signal. 
   
   
       11 . A system as in  claim 3 , wherein the wire interface is a single-wire interface for communicating one or a serial clock information signal and a serial data information signal. 
   
   
       12 . A system as in  claim 3 , wherein the wire interface is a two-wire interface for communicating both a serial clock information signal and a serial data information signal. 
   
   
       13 . A system for communicating at least one information signal over a wired interface, the system comprising:
 a transmitter; and   a receiver;   at least one of the transmitter and receiver including:
 (a) a first translator responsive operative to develop at least one of (i) a different protocol signal from a local bus signal, and (ii) a local bus signal from a different protocol signal; 
 (b) a first buffer operative to develop at least one of (i) a buffered signal from a local bus signal, and (ii) a local bus signal from a buffered signal; and 
 (c) a first switch for enabling or disabling a coupling between the wire interface and one of the first buffer and the first translator, the switch having a default state in which the coupling is enabled to couple the wire interface to the first buffer and an optional controlled state in which the coupling to the first buffer is disabled and enabled to the first translator. 
   
   
   
       14 . A system as in  claim 13 , further comprising a logic unit responsive to the first local bus signal and operative to control the first switch to alter the switch state from the default state coupling the wire interface to the first buffer and the optional controlled state coupling the wire interface to the first translator. 
   
   
       15 . A system as in  claim 13 , wherein the logic unit is coupled with the transmitter, the first switch is a switch in the transmitter, and the switch controls a coupling of the first translator or the first buffer within the transmitter to the wire interface. 
   
   
       16 . A system as in  claim 13 , wherein only one of the transmitter and receiver includes the first translator, the first buffer, and the first switch. 
   
   
       17 . A system as in  claim 13 , wherein only the transmitter includes the first translator, the first buffer, and the first switch. 
   
   
       18 . A system as in  claim 13 , wherein only the receiver includes the first translator, the first buffer, and the first switch. 
   
   
       19 . A system as in  claim 13 , wherein the first buffer includes a first buffer circuit. 
   
   
       20 . A system as in  claim 19 , wherein the first buffer further includes a second buffer circuit. 
   
   
       21 . A system as in  claim 19 , wherein the first buffer circuit is adapted for buffering a serial data signal. 
   
   
       22 . A system as in  claim 20 , wherein the second buffer circuit is adapted for buffering a serial clock signal. 
   
   
       23 . A system as in  claim 13 , wherein one of the transmitter and the receiver include the first buffer and the first translator and the first switch and the other of the transmitter and the receiver do not include the first buffer and the first translator and the first switch. 
   
   
       24 . A system as in  claim 13 , wherein the buffered signal includes a buffered data signal and a buffered clock signal. 
   
   
       25 . A system as in  claim 13 , wherein the local bus signal includes a local bus data signal and a local bus clock signal. 
   
   
       26 . A system as in  claim 13 , wherein the local bus data signal comprises a serial data signal (SDA). 
   
   
       27 . A system as in  claim 13 , wherein the local bus clock signal comprises a serial clock signal (SCL). 
   
   
       28 . A system for buffering information between a transmitter and a receiver over a wire interface, the system comprising:
 a transmitter including:
 a first buffer responsive to a first local bus signal and operative to develop a buffered information signal; and 
 a logic unit responsive to the first local bus signal and operative to control a first switch coupled to the wire interface, wherein the first switch connects to the first buffer or an isolation setting; and 
   the receiver coupled to the wire interface and responsive to the buffered information signal when the switch is connected to the first buffer.   
   
   
       29 . A system as in  claim 28 , wherein the safe setting comprises a firewall setting wherein access to the wire interface is selectively closed. 
   
   
       30 . A system as in  claim 28 , wherein the first switch may alternately connect to a translator. 
   
   
       31 . A system for buffering information between a transmitter and a receiver over a wire interface, the system comprising:
 a receiver including:
 a first buffer responsive to a first local bus signal and operative to develop a buffered information signal; and 
 a logic unit responsive to the first local bus signal and operative to control a first switch coupled to the wire interface, wherein the first switch connects to the first buffer or an isolation setting; and 
   the transmitter coupled to the wire interface and responsive to the buffered information signal when the switch is connected to the first buffer.   
   
   
       32 . A system as in  claim 31 , wherein the safe setting comprises a firewall setting wherein access to the wire interface is selectively closed. 
   
   
       33 . A system as in  claim 31 , wherein the first switch may alternately connect to a translator. 
   
   
       34 . A method for communicating at least one information signal over a wired interface between a transmitter and a receiver, the method comprising:
 a transmitter; and   a receiver;   at least one of the transmitter and receiver including:
 (a) developing a first translation, within at least one of the transmitter and the receiver, including at least one of (i) a different protocol signal from a local bus signal, and (ii) a local bus signal from a different protocol signal; 
 (b) generating at least one of (i) a buffered signal from a local bus signal, and (ii) a local bus signal from a buffered signal; and 
 (c) switching to couple either the first translation or one of the at least one of (i) a buffered signal from the local bus signal, and (ii) the local bus signal from the buffered signal to the wired interface. 
   
   
   
       35 . A method of transmitting two frequency signals over a two-wire interface comprising:
 mixing a first frequency signal on a first bus and a second frequency signal on a second bus by using a first switch to alternately connect the first bus and the second bus to the two-wire interface;   transmitting the first frequency signal and the second frequency signal over the two-wire interface; and   separating the first frequency signal from the second frequency signal by using a second switch to alternately connect a third bus for carrying the first frequency signal and a fourth bus for carrying the second frequency signal to the two-wire interface.   
   
   
       36 . A system for transmitting two frequency signals over a two-wire interface comprising:
 a first switch for alternately connecting a first bus carrying a first frequency signal and a second bus carrying a second frequency signal to the two-wire interface;   the two-wire interface for transmitting the first frequency signal and the second frequency signal; and   a second switch for separating the first frequency signal from the second frequency signal by alternately connecting a third bus for carrying the first frequency signal and a fourth bus for carrying the second frequency signal to the two-wire interface.   
   
   
       37 . A method of transmitting two voltage signals over a two-wire interface comprising:
 mixing a first voltage signal on a first bus and a second voltage signal on a second bus by using a first switch to alternately connect the first bus and the second bus to the two-wire interface;   transmitting the first voltage signal and the second voltage signal over the two-wire interface; and   separating the first voltage signal from the second voltage signal by using a second switch to alternately connect a third bus for carrying the first voltage signal and a fourth bus for carrying the second voltage signal to the two-wire interface.   
   
   
       38 . A system for transmitting two voltage signals over a two-wire interface comprising:
 a first switch for alternately connecting a first bus carrying a first voltage signal and a second bus carrying a second voltage signal to the two-wire interface;   the two-wire interface for transmitting the first voltage signal and the second voltage signal; and   a second switch for separating the first voltage signal from the second voltage signal by alternately connecting a third bus for carrying the first voltage signal and a fourth bus for carrying the second voltage signal to the two-wire interface.