Abstract:
A communication card with three operational states, including a controller, a battery, a flash storage unit, a wireless modem, and a connector for connecting the communication card to a shell host and to an electronic device host, wherein the communication card (i) operates in a standalone mode when the connector is not connected to a device, (ii) functions as a master when the connector is connected to the shell host, and (iii) functions as a slave when the connector is connected to the electronic device host. A method and a computer-readable storage medium are also described and claimed.

Description:
PRIORITY REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims benefit of U.S. Provisional Application No. 60/933,793, entitled COMMUNICATION CARD WITH THREE OPERATIONAL STATES, filed on Jun. 8, 2007 by inventors Itay Sherman, Itay Cohen and Yaron Segalov. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to communication cards that may be connected to electronic devices and to shells, and that may also operate in a standalone mode. 
       BACKGROUND OF THE INVENTION 
       [0003]    Prior art communication cards include cards with connectors that enable them to interface with different types of electronic devices that serve as hosts. These cards generally include a radio modem, a CPU with ancillary memories, a power source and possibly data storage. 
       SUMMARY OF THE DESCRIPTION 
       [0004]    The present invention provides a novel communication card (i) that may operate in a standalone mode, (ii) that may be connected to a shell that is not an independent device and that cannot operate without the communication card being connected thereto, and (iii) that may be connected to an electronic device that serves as the card&#39;s host. In state (ii) the communication card functions as a master, and in state (iii) the communication card functions as a slave. 
         [0005]    There is thus provided in accordance with an embodiment of the present invention a communication card with three operational states, including a controller, a battery, a flash storage unit, a wireless modem, and a connector for connecting the communication card to a shell host and to an electronic device host, wherein the communication card (i) operates in a standalone mode when the connector is not connected to a device, (ii) functions as a master when the connector is connected to the shell host, and (iii) functions as a slave when the connector is connected to the electronic device host. 
         [0006]    There is additionally provided in accordance with an embodiment of the present invention a method for determining the operational state of a communication card, including providing a communication card that has three operational states, namely, (i) the communication card in a standalone mode (State I), (ii) the communication card connected to a shell (State II), and (iii) the communication card connected to a host (State III), monitoring a first signal on the communication card, and if the first signal has a voltage level lower than a first designated threshold, then concluding that the communication card is in State I, otherwise, concluding that the communication card is connected to a device, and monitoring a second signal on the communication card, and if the second signal has a voltage level lower than a second designated threshold, then concluding that the communication card is in State II, otherwise, concluding that the communication card is in State III. 
         [0007]    There is moreover provided in accordance with an embodiment of the present invention a computer readable storage medium storing program code for causing a computing device to determine the state of a communication card that has three operational states, namely, (i) the communication card in a standalone mode (State I), (ii) the communication card connected to a shell (State II), and (iii) the communication card connected to a host (State III), by monitoring a first signal on the communication card, and if the first signal has a voltage level lower than a designated threshold, then concluding that the communication card is in State I, otherwise, concluding that the communication card is connected to a device, and monitoring a second signal on the communication card, and if the second signal has a voltage level lower than the designated threshold, then concluding that the communication card is in State II, otherwise, concluding that the communication card is in State III. 
         [0008]    There is further provided in accordance with an embodiment of the present invention a communication card with three operational states, including a card connector for connecting a communication card to a shell and to an electronic device, including a connector for incoming and outgoing audio signals, a connector for a power supply, a universal serial bus (USB) connector, and a communication bus, wherein (i) no signals are routed to the communication bus when the card operates in a standalone mode (State I), (ii) secure digital (SD) card signals are routed to the communication bus when the card is connected to a shell (State II), with the card functioning as master, and (iii) SD card signals are routed to the communication bus when the card is connected to an electronic device (State III), with the card functioning as a slave, and circuitry for automatically detecting whether the card is operating in State I, State II or State III. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0009]    The present invention will be more fully understood and appreciated from the following detailed description, taken in conjunction with the drawings in which: 
           [0010]      FIG. 1  is a simplified block diagram of a communication card with three operational states, in accordance with a first embodiment of the present invention; and 
           [0011]      FIG. 2  is a simplified flowchart of a method for a communication card to detect the type of device it is connected to, in accordance with an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0012]    The present invention relates to a communication card that is operable in three states; namely, (I) a standalone state, (II) a state connected to a simple host, and (III) a state connected to a complex host. In State II the simple host is a shell. The communication card operates as a master and the shell operates as a slave. Conversely, in State III the complex host is a consumer electronics (CE) device. The communication card operates as a slave and the CE device operates as a master. 
         [0013]    In State I as a standalone, the card has its own user interface and provides communication data and voice over radio technology, in addition to other services including inter alia MP3 playing. 
         [0014]    In State II connected to a simple host, the shell is not an independent device and cannot operate without the communication card being connected thereto. The shell may include only a display, a keyboard and a simple non-volatile EEPROM storage chip. Optionally, the shell may further include speakers, a microphone and a secondary power source. The communication card supplies power to the shell&#39;s keyboard, display speakers and microphone, and to the card&#39;s own internal circuitry. The communication card uses the shell&#39;s secondary power source to charge the card&#39;s internal power source. 
         [0015]    During initialization, after the communication card is attached to the shell, or at boot time, static configuration parameters are read from the EEPROM of the shell to the communication card. Thereafter, the communication card provides the shell with display information, in the form of screen shots such as bitmap images. 
         [0016]    In State III connected to a complex host, the CE device is an independent device that operates independently of the communication card, such as an MP3/MPP player or a digital camera. Commands and information are shared, and sent over an SD control bus during operation. The CE device includes its own CPU, user interface and power source. The user interface for both the device functionality and the communication card functionality operates through the CE device. The interface to the CE device is via the communication card connector, where pins on the connector have specifically assigned functionalities and use specific protocols. 
         [0017]    It will thus be appreciated by those skilled in the art that the interface to the shell is via the same communication card connector as is the interface to the CE device, but the pins on the connector generally have different functionalities and use different protocols with the shell than those used with the CE device. 
         [0018]    The three operational states of the communication card are summarized in TABLE I hereinbelow. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                 TABLE I 
               
               
                   
               
               
                 Three Operation States of a Communication Card 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 State I 
                 Standalone 
                 Card uses its own interface 
               
               
                 State II 
                 Connected to a 
                 Card is master; Shell is slave 
               
               
                   
                 simple host 
                 Shell cannot operate without card 
               
               
                   
                   
                 Card provides shell with screen shots, in the 
               
               
                   
                   
                 form of bitmap images, for display information 
               
               
                   
                   
                 Communication is through SD bus 
               
               
                 State III 
                 Connected to a 
                 Card is slave; CE device is master 
               
               
                   
                 complex host 
                 CE device operates independently of card 
               
               
                   
                   
                 Card provides shell with screen shots, in the 
               
               
                   
                   
                 form of bitmap images, for display information 
               
               
                   
                   
                 Communication is through SD bus 
               
               
                   
               
             
          
         
       
     
         [0019]    Reference is now made to  FIG. 1 , which is a simplified block diagram of a communication card with three operational states, in accordance with a first embodiment of the present invention. As shown in  FIG. 1 , a communication card  100  includes a connector  105 , a controller  110 , a flash storage unit  115 , a battery subsystem  120 , a USB connector  125  and a modem &amp; applications processor  130 . Modem  130  includes a radio frequency (RF) interface  135  and an audio player  140 . Wireless modem is coupled with an input device  145 , which is a small keyboard, and an output device  150 , which is a small display. 
         [0020]    Also shown in  FIG. 1  is a host device  160  with a host connector  165  that may be connected to the communication card connector  105 . In accordance with an embodiment of the present invention, device  160  may be a shell and may be a CE device. 
         [0021]    It will be appreciated by those skilled in the art that communication card  100  supports the three operational states in TABLE I. Components  105 - 150  enable communication card  100  to function as a standalone device. When host  160  is connected to communication card  100 , communication card  100  may operate as a master or as a slave, and the SD communication between connectors  105  and  165  flows accordingly. Specifically, in State II communication card  100  is the master and host  160  is the slave, and in State III communication card  100  is the slave and host  160  is the master. 
         [0022]    In accordance with an embodiment of the present invention communication card  100  automatically detects its operational environment by monitoring the voltage on designated pins on the connector. I.e., communication card  100  distinguishes between States I-III based on voltage. CE devices and shells generally drive the voltage on these pins differently, which enables communication card  100  to discriminate whether or not it is connected to device  160 , and to detect the type of device  160  it is connected to. 
         [0023]    In this regard, reference is made to  FIG. 2 , which is a simplified flowchart of a method for communication card  100  to detect the type of host  160  it is connected to, in accordance with an embodiment of the present invention. At step  210  controller  105  monitors the connector signal VBat_host, shown in  FIG. 1 . If the VBat_host signal has a voltage level higher than logical zero (i.e., 0.5V or higher), as determined at step  220 , then controller  105  concludes that communication card  100  is connected to host  160 . Otherwise, if VBat_host is logical zero (i.e., below 0.5V), then at step  230  controller  105  concludes that communication card  100  is not connected to a host. As such, it will be appreciated by those skilled in the art that when host  160  is attached to communication card  100 , controller  105  detects this by monitoring VBat_host. 
         [0024]    In order to detect which type of host  160  is connected to communication card  100 , controller  105  monitors the HOST INT/TYPE signal, shown in  FIG. 1 . When connection to a host is detected, the HOST_INT/TYPE signal is sampled at step  240 . If HOST_INT/TYPE is a logical zero (i.e., below 0.5V), as determined at step  250 , then at step  260  the controller concludes that host  160  is a simple shell. Otherwise, if HOST_INT/TYPE is higher than logical zero (i.e., 0.5V or higher), then at step  270  the controller concludes that host  160  is to a CE device. 
         [0025]    The functionality of HOST_INT/TYPE for detecting the type of host  160 , is used when at the time host  160  is attached to communication card  100 . Afterwards, the signal HOST_INT/TYPE is used as an interrupt signal. 
         [0026]    In an alternative embodiment of the present invention, the SD_Vdd signal, shown in  FIG. 1 , may be monitored at step  210  instead of or in addition to the VBat_host signal. Whereas the VBa_host signal generally indicates whether or not communication card  100  is connected to host  160 , the SD_Vdd signal generally indicates whether or not host  160  is turned on. 
         [0027]    It will be appreciated by those skilled in the art that the threshold of 0.5V used in the above discussion is merely indicative of a general pre-designated threshold that is used to detect attached of the host to the communication card, and to detect the type of the host. 
         [0028]    When communication card controller  105  detects connection to a CE device or a shell, the internal user interface of communication card  100  is disabled at step  280 . For CE devices, communication card controller  105  receives user interface inputs, and provides feedback as bitmap graphics BMP screen shots, or as single messages, via the secure digital (SD) card bus. The CE device controls the device&#39;s display and keyboard. For shell devices, the communication card controller receives direct keyboard strokes on the shell keyboard over an SD bus, and provides the displayed image pixels/characters directly to the shell display over the SD bus. 
         [0029]    In an embodiment of the present invention, in order to be powered, shells connect their internal circuitry to the Vbat_CC signal that connects to connector  105 . If a shell  160  has a secondary battery, then the secondary battery is connected to Vbat_Host, which connects to communication card&#39;s battery subsystem  120  and is used to charge the communication card&#39;s internal battery. 
         [0030]    Similarly, the internal circuitry of a CE device  160  is powered by connecting its internal power source to Vbat_Host. CE device  160  does not use the Vbat_CC signal as a power source, but may monitor it to detect when communication card  100  is connected thereto, or to monitor the communication card&#39;s battery level. 
         [0031]    In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific exemplary embodiments without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.