Abstract:
A hand-held passenger control unit for use by a passenger on an aircraft or any other type of vehicle is provided. The control unit may include a controller, a memory, and a display panel. The control unit may have a first and a second mode of operation. In the first mode of operation, the control unit controls its own display panel. In the second mode of operation, the control unit controls a remote video display unit that is disposed proximate to the passenger. The control unit may also have an integrated audio player, thereby permitting passengers to bring their own audio content aboard the aircraft without having to bring their own audio players.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/807,951, filed Jul. 21, 2006, the entire content being incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a passenger control unit for an in-flight entertainment system and a method for using the same. 
       BACKGROUND OF THE INVENTION 
       [0003]    The availability of and the type of in-flight amenities helps to differentiate airlines in the increasingly commoditized business of air travel. Airlines may offer in-flight media options such as audio and movies to their passengers. One problem with conventional in-flight audio delivery mechanisms, however, is that the same music selections are piped to all passengers on an aircraft. Passengers who do not want to listen to the canned selections of the airline are thus forced to bring their own personal audio players and audio content, hoping that their batteries last for the duration of the flight. Thus, there is a need for a device and system that addresses the foregoing problem. Also, due to space and weight limitations on an aircraft, it is also desirable that such a device and system by multifunctional, and have the ability to perform tasks beyond the playing of audio content. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    In accordance with the foregoing, a hand-held passenger control unit for use by a passenger on an aircraft or any other type of vehicle is provided. In an embodiment of the invention, the control unit includes a controller, a memory, keypad, and a display panel. In this embodiment, the control unit has at least a first and a second mode of operation. In the first mode of operation, the control unit controls its own display panel. In the second mode of operation, the control unit controls a remote video display unit that is disposed proximate to the passenger. The control can have a substantially X-shaped keypad, as well as an attendant call button and an LED light that illuminates when the call button is pressed. The cabin electronic system may provide a signal to the control unit to extinguish the LED light once the call has been answered. 
         [0005]    Various implementations of the control unit are possible. For example, the control unit may control, in response to a user&#39;s manipulation, the volume of an amplifier that is external to the control unit. In this implementation, the control unit may display a heading indicative of volume on the display panel, and may transmit a signal to limit the volume of the amplifier during a passenger announcement or public address. 
         [0006]    The control unit may also be used by a passenger to control an on-screen menu of a video display unit disposed near the passenger (such as in the seat back in front of the passenger). 
         [0007]    In another implementation, the control unit doubles as an audio player. A passenger may, for example, insert an external memory into a port on the control unit, from which the control unit downloads and decodes songs. The control unit then provides audio signals for the songs through a speaker, such as a headset. 
         [0008]    A method of delivering multimedia content to an aircraft passenger is also provided. An embodiment of the method involves receiving the connection of a video display unit, receiving the connection of a hand-held audio player, receiving the connection of a headset, receiving video content from an on-board computer network, transmitting the video content to the video display unit, receiving audio content from the hand-held audio player, and transmitting the audio content through the headset. According to this embodiment, the video display unit displays the video content to the passenger, and the audio player both receives the connection of an external memory device and downloads audio content from the external memory device. An electronics box that is disposed proximate to the passenger&#39;s seat may perform the receiving step. 
         [0009]    In some embodiments, the audio player detects the audio content on the external memory device (to which power is provided) and displays data regarding the audio content on a display screen integrated with the audio player. The audio player may also select a title to download by title. 
         [0010]    A system for providing in-flight entertainment to a passenger on an aircraft is also provided. An embodiment of the system includes a computer network, a video display unit disposed proximate to a passenger seat on the aircraft, the video display unit being communicatively linked to the computer network and receiving multimedia content from the computer network. The system of this embodiment also includes a passenger control unit communicatively linked to the video display unit. The passenger control unit executes software for downloading audio files and transmitting them to a speaker and for permitting the passenger control unit to control the functioning of the video display unit. 
         [0011]    The system may further include a temperature sensor, a device to monitor voltages provided to the passenger control unit. The passenger control unit may include a display panel, a controller, a memory, a USB interface and a user input mechanism. The system my further include an external device that can be connected to the passenger control unit by the USB interface and from which the audio files can be downloaded into the passenger control unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  illustrates an embodiment of an in-flight entertainment system, which delivers multimedia content to airline passengers; 
           [0013]      FIG. 2  is a diagram illustrating a more detailed embodiment of the in-flight entertainment system, including the seat electronics box (SEB) and the Passenger Control Unit (PCU); 
           [0014]      FIG. 3  is a perspective view of an embodiment of the PCU; and 
           [0015]      FIG. 4  is a block diagram illustrating an embodiment of the PCU. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0016]    Referring to  FIG. 1 , an in-flight entertainment system in which the passenger control unit is deployed in an embodiment of the invention will now be described. The system, generally labeled  10 , includes a head end unit  12 , one or more area distribution boxes (ADBs)  14 , one or more seat electronic boxes (SEBs)  16 , one or more floor disconnect boxes (FDBs)  18 , a local area network (LAN)  20 , and one or more RF links  22 . The head end unit  12  includes an audio-video controller (AVC)  24 , a first digital server unit (DSU)  26 , a second DSU  28  or an AVC-D  24 , and an Ethernet switching unit (ESU)  30 . The head end  12  is communicatively linked to the ADBs  14 , and the ADBs  14  are communicatively linked to one another, via the LAN  20  and the RF links  22 . As shown in  FIG. 1 , each ADB  14  is communicatively linked to one or more of the FDBs  18 . The FDBs  18  are, in turn, communicatively linked to the SEBs  16 . The LAN  20  and the RF links  22  may be implemented in a variety of ways, but are depicted in  FIG. 1  as an Ethernet-based network and RF coaxial links, respectively. It is understood that the LAN  20  may be wireless, and that the RF links may alternatively be digital. Additionally, the LAN  20  may be implemented as one or more Gigabit Copper or Fiberoptic Ethernet networks. Naturally, the embodiments described herein can be employed in any type of vehicle, such as an aircraft, bus, train, ship, and so on. 
         [0017]    Referring still to  FIG. 1 , each SEB  16  is associated with a group of passenger seats (“seat group”). There may be any number of seats in a seat group, but three are depicted in  FIG. 1 . In the embodiment in  FIG. 1  there is associated with each seat in a seat group is a passenger control unit (PCU)  32 , a video display unit (VDU)  34 , and a headset  36  that plugs into an audio jack (AJ)  38 . The SEB  16  is communicatively linked to the PCU  32 , the VDU  34 , and the AJ  38 . Each VDU  34  is associated with one of the SEBs  16 . However, in an alternative embodiment, a VDU  34  might not be associated with a seat. 
         [0018]    According to an embodiment of the invention, the VDU  34  is a terminal that a passenger can use to communicate over the LAN  20 . The VDU  34  may be mounted in a variety of locations in the cabin, such as on a seat-back, on an arm mount, or on the cabin wall. Each VDU  34  includes a display and a housing. Each VDU  34  has full access to the LAN  20 , thereby allowing the system  10  to present video graphics, video-on-demand, audio-on-demand, local games, and web content to each passenger. The passenger&#39;s access to the LAN  20  also allows the passenger to play network-based games with other passengers over the LAN  20  or over the Internet. Other types of content that may be delivered to the passengers includes satellite TV, digital radio, external internet (from an external provider), web portal access, eBook content, all types of MPEG content (including MPEG-4), picture in picture, and voice over IP (VoIP). This content may be obtained from electronic storage that is internal to the aircraft, from a land connection (when the aircraft is on the ground), or from various wireless connections, such as Swift-64 and Ku-band data communications. 
         [0019]    In various embodiments of the invention, the display of the VDU  34  is a color LCD screen, and the VDU  34  further includes a housing, internal hardware within the housing that receives power, NTSC (M) video, and Ethernet data (MPEG-1/MPEG-2/MPEG-4 streaming video/audio) from the SEB  16  associated with the VDU  34 . The internal hardware of the VDU  34  includes a power interface printed circuit board (PCB) with a backlight inverter power supply, and a processor printed circuit board (PCB). 
         [0020]    The head end unit  12  can transmit video content over the LAN  20  or the RF links  22  to the ADB  14  which in turn transmits the video content to at least one FDB which sends it to at least one SEB  16 . The SEB receives the video content and transmits it to the VDU  34  which then displays the video content to the passenger for viewing. 
         [0021]    Referring to  FIG. 2 , certain aspects of the in-flight entertainment system according to an embodiment of the invention will now be described. In this embodiment, there are multiple SEBs  16 , each of which is linked to the system  10  via power lines  100 , ethernet links  102 , and RF links  104 . There are a variety of components that may be communicatively linked to the SEBs  16 , including a VDU  34 , an electrical audio jack module (EJM)  35  (an audio jack  38  and a listening device  36  as shown in  FIG. 1 ), a PCU  32 , an external audio and/or video source  108 , and a laptop  110 . The PCU  32  may be also communicatively linked to an external device  112 . ( FIG. 2  depicts quantity of 3 PCUs with 3 EJMs, laptops, external USB devices or external audio/video sources interfaces but may include 4 or more under other configurations. Using the PCU  32  the passenger can call the flight attendant, turn the overhead reading light on or off and navigate on screen menus using an X-pad or rollerball control. The PCU  32  also permits the passenger to control the operating mode of the VDU  34 , change the audio channel up or down and increase or decrease the volume. Other functions of their PCU  32  will be described in more detail below. 
         [0022]    Referring again to  FIG. 2 , each PCU  32  is linked to an SEB  16  to receive and/or send power, data and audio output. One embodiment of the power interface between the PCU  32  and the SEB  16  is as follows. The PCU  32  receives 28 to 36 Volts DC at a current not to exceed 0.25 amps. If the Maximum Power Consumption is tested at the Organic Light Emitting Diode&#39;s (OLED&#39;s) maximum brightness, the current does not exceed 0.30 amps. The in-rush current does not exceed 1.0 amp for 100 milliseconds. In this embodiment the PCU  32  connector, power pins and printed circuit board are designed to handle current of up to 1.0 Amps, so the actual PCU  32  power consumption varies based on the functions being utilized but are no greater than 3 Watts at full load. The SEB  16  provides the PCU  32  up to 3 Watts of power for short periods of time. 
         [0023]    According to one embodiment, the PCU  32  has a USB 1.1 device port for communication with USB 1.1 host port on the SEB  16 . Alternately, the SEB  16  can use a USB 2.0 port that is able to adjust its speed down to the USB 1.1 full speed requirement (12 Mbps). 
         [0024]    In an embodiment of the invention, each PCU  32  has an external interface for communication with an external device  112 . In one embodiment the external interface is over USB 1.1 and the PCU  32  is the host for an external device  112  through a mini-A-B USB Connector. This interface enables a passenger to listen to audio content stored on an external device such as a portable memory. A passenger can for example bring a portable memory containing their personalized choice of audio content onto the aircraft and insert the memory into the external device interface of the PCU  32 . The PCU  32  then locates the audio files stored on the external memory and displays the titles of the songs stored in the audio files on the display  34 . Using the X-pad, the passenger then navigates the display  34  to select one or more of the displayed titles. In response, the PCU  32  downloads the files. The PCU  32  receives the external audio file over the USB host connection and transmits a stereo audio signal to amplifiers in the SEB  16 . The SEB transmits the audio signals to the audio jack  38  ( FIG. 1 ) and the passenger can hear their downloaded audio content by using a listening device such as headphones  36  ( FIG. 1 ). The audio output is 2.2 Volts peak to peak full scale into 600 Ohms. 
         [0025]      FIG. 3  is a perspective view illustrating the front of one possible embodiment of the PCU  32 . Referring to  FIG. 3 , PCU  32  includes a chassis  50 , a display panel  52 , a flight attendant call button  54 , a reading light button  56  for turning the passenger reading light on or off, a mode button  58 , and an X-pad keyboard (collectively referred to as  60 ) with an upper “CH” button  60   a , a lower “CH” button  60   d , a right “VOL” button  60   b  and a left “VOL” button  60   c.    
         [0026]    Using the PCU  32 , the passenger can control the volume of the audio he or she hears. The PCU  32  controls the volume by sending a signal, over the USB interface, which controls the amplifiers in the SEB  16 . In an embodiment, the PCU  32  has buttons that control the volume UP  60   c  and DOWN  60   b . The buttons  60   b ,  60   c  have an UP arrow or a DOWN arrow on them and the “VOL” heading is displayed on the PCU&#39;s display panel  52 . If the PCU  32  is used in stand-alone mode, then the audio output is calibrated to give out 75 mW rms into each 300 Ohms transducer (1 kHz sinewave) at the maximum volume setting. The audio volume control provides 32 attenuation steps and each step is a 2 dB change. At power up the audio is set to −14 dB (7 steps down from the maximum). The audio volume control may be limited for passenger announcement and/or public address (PA) operations. 
         [0027]    The PCU  32  can play a variety of audio file formats, including MPEG, MP2, MP3, DVD and DAT. When playing an audio file, the PCU  32  outputs an audio signal to the SEB  16 . The maximum volume signal produces an output level of 0 dB into 600 Ohms (2.2 Vpp) as specified in WAEA-1289-1 and WAEA-1289-2. The total harmonic distortion (THD) of the audio output into 600 Ohms is less than 1% over the audio bandwidth of 50 Hz to 15 kHz. The frequency response has an amplitude variation of less than 3 dB over the audio bandwidth of 50 Hz to 15 kHz and the signal to noise ratio at the maximum volume (0 dBM output) is 55 dB or higher. 
         [0028]    The PCU  32  has a single button for the attendant call function  54 . This button is normally not illuminated. When the attendant call button  54  is depressed, it activates an LED backlight that illuminates it and sends a message to the SEB  16 , via the USB interface, that an attendant call has occurred. If the LED light is illuminated and the passenger presses the attendant call button  54  again, a signal resetting the attendant call is sent and the button  54  is no longer illuminated. The SEB  16  is also able to reset the attendant call based on a database update. Similar to that described above, once the SEB  16  resets the attendant call, the light on the attendant call button  54  on the PCU  32  is turned off. 
         [0029]    The PCU  32  can change from controlling the PCU  32  to controlling the VDU  34  and back again. In one embodiment a single button  58  located on PCU  32  changes the mode. While in the first mode, the PCU  32  controls a menu displayed on the display panel  52  located on the PCU  32 . When the passenger presses the mode button  58 , the PCU  32  enters a second mode and controls a menu displayed on the VDU  34 . The PCU  32  can be used as a tool to navigate the display screens on either the PCU  32  itself or on the VDU  34 . In one embodiment the PCU  32  uses the X-pad keyboard  60  to navigate the screens. On the X-pad keyboard  60 , the up button  60   a  moves the cursor on a menu screen up, the down button  60   d  moves the cursor down, the a right button  60   b  moves the cursor to the right, and the left button  60   c  moves the cursor to the left of the screen. Depending on the mode selected, the user can use the X-pad keyboard  60  to navigate through either the menu on the PCU  32  or the menu on the VDU  34 . 
         [0030]    In an embodiment, the PCU  32  also has buttons to control the channel UP  60   a  and DOWN  60   d . The buttons  60   a  and  60   d  have an UP arrow and a DOWN arrow on them and a “CH” heading is displayed on the display panel  52  of the PCU  32 . Depending on whether the user has selected the mode for controlling the PCU  32  or the mode for controlling the VDU  34 , these buttons may control the menu displayed on the display panel  52  of the PCU  32  or the menu displayed on the VDU  34 . 
         [0031]    In one embodiment, the PCU  32  has, four operation modes: Normal Operation, Maintenance Mode, Decompression Mode, and Degraded Functionality. The Normal Operation is the mode the PCU  32  enters when it is powered up and has received a status indicator for typical passenger operations as described in this document, whereas the PCU  32  enters the Maintenance Mode when it is powered up and receives a status indicator for entering the Maintenance Mode. The PCU  32  is not able to place itself in Maintenance Mode; it must receive an indicator to do so. Via software, the PCU  32  can detect the system Decompression State and enter Decompression Mode. In the Decompression Mode all passenger operations are stopped except for the PSS Passenger Services System. The PCU  32  exits the Decompression Mode by the power-on reset or by detecting the system Idle State. If the PCU  32  does not obtain a status indicator within a predetermined number of seconds of powering up or, if in normal operation, has not received a status indicator within a predetermined number of seconds, the PCU  32  enters the Degraded Functionality Mode. The PCU  32  only enters this mode from normal operation. If the PCU  32  has been placed in any other mode it remains in that mode until it has been removed or until the unit is no longer powered. The PCU  32  has Built in Test Equipment (BITE) that provides functions such as a watchdog timer, temperature sensor, and monitoring of voltages provided to the OMAP Processor (1.6V) and USB (5V). 
         [0032]    The main components of the PCU  32  are a display panel (OLED or LCD display), a Main Printed Circuit Board Assembly (Main PCBA), a Keypad Printed Circuit Board Assembly (Keypad PCBA), chassis, and a cradle. Referring to  FIGS. 3 and 4 , various components of the PCU  32  in an embodiment of the invention will now be described. The display panel  52  is an OLED display  210 . One such display panel  52  is a Kodak OLED AM550L. The Kodak OLED AM550L has a display size of 2.16 in (diagonal) and an active area of 1.72 inches horizontal and 1.29 inches vertical. The other characteristics of that embodiment of an OLED display are as follows: 521×218 (Horizontal×Vertical) pixels; a contrast ratio of 100:1; a brightness of 120 cd/m 2 ; and a viewing angle of 170° top to bottom and 170° left to right. The OLED display  210  is communicatively linked to an OLED Controller  211  which is communicatively linked to the Main PCBA. One such controller is the Kodak KDP01100. The Main PCBA is communicatively linked to the Keypad PCBA  216 . 
         [0033]    The Main PCBA provides all the functions required by the PCU, the DC-DC conversion and processor functions. The Main PCBA has 16 MByte Boot Flash memory  202 , up to 128 MByte NAND Flash memory  204 , 16 MByte NOR Flash memory  206 , and 64 MByte of Synchronous Dynamic Random Access Memory (SDRAM)  208 . The Main PCBA has a dual-core processor. An example of such a processor is the Texas Instruments OMAP5910 Processor  214 , which incorporates a Data Signal Processor (DSP) core and embedded Reduced Instruction-Set Computer (RISC) microprocessor technology in the Advanced RISC Machine (ARM) core. The Keypad Printed Circuit Board Assembly (Keypad PCBA)  216  provides the button switch matrix which is continuously scanned by the processor  214  of the Main PCBA. The chassis, which holds these components, is the primary EMI and fluid shield for the unit. The chassis holds the OLED display  210 , the Main PCBA, and the Keypad PCBA  216 . The cradle has the cord reel assembly and a means to securely hold the tethered unit in place. The cord reel meets the requirements as stated in USB 1.1 specification for the data wires. The PCU  32  hardware includes BIOS for the Processor  214 . The PCU  32  has programming code to allow it to boot the processors, download the application program code, and perform peripheral initialization and monitoring of status lines. The application software is downloaded into the PCU  32  and resides in the 128 MB NAND FLASH. Integrated Circuit  204 . The application software provides the high level interface to external Line Replaceable Units (LRUs), and controls the PCU operations. The table below describes the Firmware (non-downloadable software) Partition for the PCU. 
         [0000]                                    Type   Description   Primary Functions                   BIOS   S/W Kit,   Devices initialization for OMAP5910, Audio           OMAP5910   Codec (TSC2100), Power Controller           Processor BIOS   (TPS65010), SDRAM (MT48LC32M16A2)           code   POST                    
The table below describes the downloadable software partition.
 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 Type 
                 Description 
                 Primary Functions 
               
               
                   
               
             
             
               
                 Application 
                 Linux Kernel 
                 Linux Kernel and device drivers 
               
               
                   
                   
                 BITE 
               
               
                 Application 
                 Main Application 
                 Main Application 
               
               
                   
                 Program 
                 Browser server/client 
               
               
                   
                   
                 BITE 
               
               
                   
               
             
          
         
       
     
         [0034]    The PCU  32  is able to operate at a nominal  32  VDC with max range of 28 VDC to 36 VDC of input power. The PCU  32  uses internal DC-DC switchers and Low Dropout Regulators (LDO) to create all required voltages used by the PCU  32  internal electronic circuits. The PCU  32  outputs a nominal  5  VDC per Universal Serial Bus Specification Revision 1.1. The output current of 20 mA provides power to approved external USB memory devices. The output current is limited in hardware to prevent damage and disruption of the PCU  32 . 
         [0035]    External and internal connector and interface information such as pinouts and input/output signal definitions are summarized in the table below. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Connector 
                 Function 
                 Type 
                 Pins Used 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 J1 
                 I/O Interface 
                 External 
                 8 
               
               
                   
                 J3 
                 Embedded Trace 
                 Internal 
                 24 
               
               
                   
                   
                 Macrocell 
               
               
                   
                 J5/J11 
                 Keypad Interface 
                 Internal 
                 24 
               
               
                   
                 J8 
                 OLED Interface 
                 Internal 
                 32 
               
               
                   
                 J9 
                 USB Connector 
                 External 
                 4 
               
               
                   
                 J10 
                 JTAG Interface 
                 Internal 
                 20 
               
               
                   
                   
               
             
          
         
       
     
         [0036]    The PCU  32  has two external connectors: one to interface with the SEB (J1) and one to interface with approved external USB memory devices (J9). The external Input/Output (I/O) Connector J1 has a connector specification of: SS-610808-NF-P-5, and uses an SS-310808-5 mating connector. The pin assignment on this connector is listed in the table below. 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                 1 
                 SEB_VIN 
               
               
                 2 
                 SEB_USB_FUNC_DATA+ 
               
               
                 3 
                 SEB_USB_FUNC_DATA− 
               
               
                 4 
                 SEB_VIN_RTN 
               
               
                 5 
                 SEB_DISCRETE0 
               
               
                 6 
                 SEB_AUD_IPCU_L 
               
               
                 7 
                 SEB_AUD_IPCU_R 
               
               
                 8 
                 SEB_IPCU_STOWED 
               
               
                   
               
             
          
         
       
     
         [0037]    The external USB Mini-A-B Connector Interface J9 has a connector specification of 56579-0578 and uses standard A to 5 pin Mini B Device Cable mating connectors. The pin assignment on this connector is listed in the table below. 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                 1 
                 USB_HOST_PWR 
               
               
                 2 
                 USB_HOST_DATA− 
               
               
                 3 
                 USB_USB_DATA+ 
               
               
                 4 
                 Digital Ground 
               
               
                   
               
             
          
         
       
     
         [0038]    The internal connectors/interfaces JP 1 and JP2 are jumpers used for resetting power. The pin assignments for JP1 are shown in the tables below. 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                 1 
                 Digital Ground 
               
               
                 2 
                 PWR_HOT_RESET 
               
               
                   
               
             
          
         
       
     
         [0039]    The pin assignments for JP2 are shown in the table below. 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                 1 
                 +5 V 
               
               
                 2 
                 PWR_PB_ONOFF 
               
               
                   
               
             
          
         
       
     
         [0040]    The J3 Embedded Trace Macrocell Interface provides debug and trace facilities for the ARM processor. The connector specification is 52435-2491. No mating connector is required because it uses a 24 pin flat flex cable to interface. The pin assignments on this connector are listed in the following table. 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 +3.3 V 
               
               
                 2 
                 +3.3 V 
               
               
                 3 
                 +3.3 V 
               
               
                 4 
                 Not connected 
               
               
                 5 
                 ETM Data0 
               
               
                 6 
                 ETM Data1 
               
               
                 7 
                 ETM Data2 
               
               
                 8 
                 ETM Data3 
               
               
                 9 
                 ETM Data4 
               
               
                 10 
                 ETM Data5 
               
               
                 11 
                 ETM Data6 
               
               
                 12 
                 ETM Data7 
               
               
                 13 
                 Not connected 
               
               
                 14 
                 ETM Clock 
               
               
                 15 
                 Not connected 
               
               
                 16 
                 ETM PSTAT1 
               
               
                 17 
                 ETM PSTAT2 
               
               
                 18 
                 Not connected 
               
               
                 19 
                 ETM PSTAT0 
               
               
                 20 
                 ETM SYNC 
               
               
                 21 
                 Not connected 
               
               
                 22 
                 Digital Ground 
               
               
                 23 
                 Digital Ground 
               
               
                 24 
                 Digital Ground 
               
               
                   
               
             
          
         
       
     
         [0041]    The J5/J11 keypad interface has two identical 12-pin connectors with spring-loaded contacts installed to the Keypad PCBA and that mate to pads of the Main PCBA. The Connector specification is 813-22-012-30-002-101. The pin assignment for the J5 Keypad Interface connector is listed in the table below. 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 KEYB_R0 
               
               
                 2 
                 KEYB_C0 
               
               
                 3 
                 KEYB_R1 
               
               
                 4 
                 KEYB_C1 
               
               
                 5 
                 KEYB_R2 
               
               
                 6 
                 KEYB_C2 
               
               
                 7 
                 KEYB_R3 
               
               
                 8 
                 KEYB_C3 
               
               
                 9 
                 KEYB_R4 
               
               
                 10 
                 KEYB_C4 
               
               
                 11 
                 Digital Ground 
               
               
                 12 
                 KEYB_C5 
               
               
                   
               
             
          
         
       
     
         [0042]    The pin assignment for the J11 Keypad Interface is listed in the table below. 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 +3.3 V 
               
               
                 2 
                   +5 V 
               
               
                 3 
                 +3.3 V 
               
               
                 4 
                   +5 V 
               
               
                 5 
                 KEYB_GPIO0 
               
               
                 6 
                 KEYB_GPIO2 
               
               
                 7 
                 KEYB_GPIO1 
               
               
                 8 
                 KEYB_GPIO3 
               
               
                 9 
                 Digital Ground 
               
               
                 10 
                 Digital Ground 
               
               
                 11 
                 Digital Ground 
               
               
                 12 
                 Digital Ground 
               
               
                   
               
             
          
         
       
     
         [0043]    The J8 OLED Interface Connector specification is XF2H-3215-1. The pin assignment on this connector is listed in the tables below: 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 Not Connected 
               
               
                 2 
                 DISP_CKV1 
               
               
                 3 
                 DISP_CKV2 
               
               
                 4 
                 DISP_STV 
               
               
                 5 
                 DISP_XSTV 
               
               
                 6 
                 +8.5 V 
               
               
                 7 
                 DISP_XENB 
               
               
                 8 
                 DISP_ENB 
               
               
                 9 
                 Digital Ground 
               
               
                 10 
                 DISP_CSV_PNL 
               
               
                 11 
                 DISP_VBB 
               
               
                 12 
                   −7 V 
               
               
                 13 
                   −7 V 
               
               
                 14 
                   −7 V 
               
               
                 15 
                   −7 V 
               
               
                 16 
                   +7 V 
               
               
                 17 
                   +7 V 
               
               
                 18 
                   +7 V 
               
               
                 19 
                   +7 V 
               
               
                 20 
                 Digital Ground 
               
               
                 21 
                 DISP_BLU 
               
               
                 22 
                 DISP_RED 
               
               
                 23 
                 DISP_GRN 
               
               
                 24 
                 DISP_CSH_PNL 
               
               
                 25 
                 Not Connected 
               
               
                 26 
                 Digital Ground 
               
               
                 27 
                 DISP_STH 
               
               
                 28 
                 DISP_XSTH 
               
               
                 29 
                 +8.5 V 
               
               
                 30 
                 DISP_CKH1 
               
               
                 31 
                 DISP_CKH2 
               
               
                 32 
                 Not Connected 
               
               
                   
               
             
          
         
       
     
         [0044]    The J10 JTAG and UART Interface connector specification is 51374-2093. It requires 20 pin flat flex cable to interface. The pin assignment on this connector is listed in the table below. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Pin Number 
                 Signal Description 
                 Notes 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 OMAP_TRST 
                   
               
               
                 2 
                 +3.3 V 
               
               
                 3 
                 ICE_TRST 
               
               
                 4 
                 ICE_ZDD 
               
               
                 5 
                 ICE_CONN_OMAP 
                 TDI—Test Data In 
               
               
                 6 
                 Digital Ground 
               
               
                 7 
                 ICE_TMS 
               
               
                 8 
                 Digital Ground 
               
               
                 9 
                 OMAP_TCK 
               
               
                 10 
                 Digital Ground 
               
               
                 11 
                 ICE_TCK_RET 
               
               
                 12 
                 Digital Ground 
               
               
                 13 
                 ICE_OMAP_CONN 
                 TDO—Test Data Out 
               
               
                 14 
                 UART1_TX 
               
               
                 15 
                 ICE_OMAP_RESET 
               
               
                 16 
                 UART1_RX 
               
               
                 17 
                 OMAP_EMU0 
               
               
                 18 
                 UART2_TX 
               
               
                 19 
                 OMAP_EMU1 
               
               
                 20 
                 UART2_RX 
               
               
                   
               
             
          
         
       
     
         [0045]    The PCU  32  has built-in test equipment (BITE) and performs intrusive and non-intrusive tests. An intrusive test is performed when commanded by the host. A non-intrusive test is performed periodically during normal operation. The PCU  32  periodically performs non-intrusive tests that monitor PCU  32  status in flight to verify the fault-free system operation. Should a fault be detected, the fault is recorded in a non-memory volatile memory (NVM) for later investigation on-board and in the workshop. As a guideline, the NVM capacity will record fault data for at least 256 faults covering at least 64 flight legs. Each reported fault will have a corresponding message stored in NVM. A fault detected by various BITE tests will have the same error message and record. Faults are not announced on the first occurrence until detection is confirmed. Intermittent faults are stored only one time. Non-intrusive tests include the following tests: USB port status, processor operational status, PA status, and a Decompression status. Each reported fault has a corresponding message stored in NVM. A fault detected by various BITE modes has the same error message and record. Faults are not announced on the first occurrence until detection is confirmed. Intermittent faults are stored only one time. 
         [0046]    The PCU  32  performs intrusive tests, initiated by the Maintenance Terminal on the ground to identify latent failures and to allow for a speedy system return to service testing, without additional test equipment, after completion of maintenance actions. Results from the intrusive test are reported in less than 10 seconds. The intrusive test includes the following tests: all non-intrusive tests, audio data streaming, and audio data download. 
         [0047]    The PCU  32  performs a power-on self-test (POST) on initial power-up or after a long power interrupt. When there is no confirmed failure, the unit becomes operational in less than 5 minutes following the establishment of the power supply. POST performs the following tests: all tests listed in the non-intrusive test section, the main processor memory test, and the application memory content integrity test. 
         [0048]    The PCU has a 1.0 lb maximum weight and dimensions (H×W×D) of 2.95×7.86×1.75 inches. The PCU does not require force-air-cooling. The PCU is cooled by natural convection and radiation. The PCU is designed with fault tolerance such that under failure conditions, the PCU will not halt the system operations. 
         [0049]    The Mean Time to Repair (MTTR) the PCU is less than 18 minutes. The MTTR is the time it takes to remove and replace the PCU, load the appropriate operating software, and perform a return to service test. All exterior surfaces of the PCU are designed to withstand exposure to isopropyl alcohol, household ammonia, food acids (e.g., lemon juice and soft drinks) and commercial cleaning agents. All exterior surface finishes are designed to withstand the abrasion of industrial cleaning pads soaked in commercial cleaning agents. 
         [0050]    All references, including publications, patent applications, and patents, cited herein, are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0051]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0052]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention.