Current mode bus interface system, method of performing a mode transition and mode control signal generator for the same

Abstract

A current mode bus interface system includes a host interface device configured to transmit a reference current and a clock current, and to transmit a data current during a first transfer mode, and to receive a reverse direction data current and compare the reverse direction data current with the reference current to generate a reverse direction data voltage during a second transfer mode; and a client interface device configured to receive the reference current and the clock current and compare the reference current with the clock current to generate a clock voltage, to receive the data current and compare the data current with the reference current to generate a data voltage during the first transfer mode, and to transmit the reverse direction data current through a conducting wire over which the data current is received during the second transfer mode.

1 . A method of performing a mode transition in a current mode bus interface system, the method comprising:
 cutting off transmitted currents from a host when the host enters into a suspend mode in response to a sleep request from the host;   causing a client to enter into a suspend mode when the client senses the cut-off of the transmitted currents; and   causing the host or the client to perform a transition from the suspend mode to a normal operation mode in response to a wake-up request from the host or the client.   
   
   
       2 . The method of  claim 1 , wherein the transmitted currents comprise a reference current, a clock current and a data current, and
 wherein the client enters into the suspend mode when the client senses the cut-off of the reference current.   
   
   
       3 . The method of  claim 2 , wherein causing the host and the client to perform the transition comprises:
 transmitting the reference current from the host in response to the wake-up request of the host, and   wherein the client performs the transition from the suspend mode to the normal operation mode when the client senses the reference current transmitted from the host.   
   
   
       4 . The method of  claim 3 , wherein the host transmits the clock current and the data current after the client performs the transition from the suspend mode to the normal operation mode. 
   
   
       5 . The method of  claim 2 , wherein causing the host and the client to perform the transition comprises:
 transmitting a reverse direction data current having a predetermined level from the client in response to the wake-up request from the client; and   transmitting the reference current to the client after the host senses the reverse direction data current received from the client, and   wherein the client performs the transition from the suspend mode to the normal operation mode when the client senses the reference current transmitted from the host.   
   
   
       6 . The method of  claim 5 , wherein the host transmits the clock current and the data current after the client performs the transition from the suspend mode to the normal operation mode. 
   
   
       7 . The method of  claim 2 , wherein causing the host and the client to perform the transition comprises:
 transmitting the reference current to the client from the host in response to the wake-up request from the host;   transmitting the reverse direction data current to the host from the client via a conducting wire over which the data current is received, in response to the wake-up request of the client; and   causing the client to perform a transition from the suspend mode to a forward direction transfer mode after the client stops the transmission of the reverse direction data current when the client senses the reference current transmitted from the host.   
   
   
       8 . The method of  claim 7 , wherein the host transmits the clock current and the data current after the client stops the transmission of the reverse direction data current to the host and performs the transition from the suspend mode to the forward direction transfer mode.