(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2007/0140199 A1
`
`Zhao et al.
`(43) Pub. Date:
`Jun. 21, 2007
`
`US 20070140199A1
`
`(54) POWER SAVING IN MULTI-PROCESSOR
`DEVICE
`
`(75)
`
`Inventors: Wen Zhao, Cupertino, CA (US); David
`Kammer, Seattle, WA (US); Mark T.
`Davis, Mill Valley, CA (US); Arun G.
`Mathias, Sunnyvale, CA (US); Isabel
`Ge Mahe, Los Altos, CA (US); Bennett
`Chana Saratogaa CA (US); Alex Yee
`Kit H0, Cupertino, CA (US)
`
`Correspondence Address:
`FOLEY & LARDNER LLP
`777 EAST WISCONSIN AVENUE
`
`Continuation-in-part of application No. 11/155,387,
`filed on Jun. 16, 2005, which is a continuation of
`application No. 10/083,044, filed on Feb. 25, 2002,
`110w Pat. No. 6,943,667.
`
`(60) Provisional application No. 60/455,178, filed on Mar.
`16, 2003.
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`(2006.01)
`H04Q 7/24
`(52) US. Cl.
`.............................................................. 370/338
`
`MILWAUKEE, WI 53202-5306 (US)
`
`(57)
`
`ABSTRACT
`
`(73) Ass1gnee: Palm, Inc.
`(2]) Appl. No.:
`11/634,366
`
`(22)
`
`Filed:
`
`Dec. 53 2006
`
`Related US. Application Data
`
`(63) Continuation-in-part of application No. 10/7 59a 5975
`filed on Jan. 15, 2004.
`
`Amobile computing device comprises a first microprocessor
`having a sleep mode and a wake mode and a second
`microprocessor configured for wireless communication. A
`communication port is configured to commumcate data irom
`the second processor to the first processor, wherein the
`second processor is configured to provide a wake signal to
`the first microprocessor and the first microprocessor is
`configured to open the communication port in response to
`the wake signal and to receive data from the second micro-
`processor through the communication port.
`
`Host Processor
`102
`
`Radio Processor
`104
`
`Memory
`124
`
`106
`
`IIO Intervene
`129
`
`Memory
`108
`
`Keypad
`110
`
`Display
`112
`
`IIO Interface
`114
`
`ANDevioes
`116
`
`Power
`Sunriy
`11B
`
`INTEL 1213
`
`INTEL 1213
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 1 of 12
`
`US 2007/0140199 A1
`
`
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 2 0f 12
`
`US 2007/0140199 A1
`
`3%
`
`100
`
`Memory 124
`
`IIOInteflaee 128
`
`Transceiver 120
`
`FIG.‘5
`
`17‘
`f
`
`Memory 108 IIII5
`HOImeflace 114
`
`Keypad 110
`
`Display 112
`
`Power
`
`5099'! 118
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 3 0f 12
`
`US 2007/0140199 A1
`
`‘3
`§
`
`PROCESSOR
`
`FIGURELi
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 4 0f 12
`
`US 2007/0140199 A1
`
`
`
`RESET_OUT
`
`
`HOST_WA KB
`HOST_WAKE
`
`
`HOST_STAT
`HOST_STAT
`
`
`
`RADIO_WAKE
`RADIO_WAKE
`
`
`
`
`
`
`
`
`ON/OFF
`[RESET
`
`IRESET_OUT
`
`
` Audio
`5'01
`CODEC _
` Analog Audio
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 5 0f 12
`
`US 2007/0140199 A1
`
`(902
`
`Q00
`
`
`
`
` Bootloader mode
`
`Low Power
`Mode
`
`Power on
`
`
`
`Fm!)
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 6 0f 12
`
`US 2007/0140199 A1
`
`
`
`
`
`
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 7 0f 12
`
`US 2007/0140199 A1
`
`
`
`MODEM-BOOT-IME Active
`
`
`Inactive
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 8 0f 12
`
`US 2007/0140199 A1
`
`APP has data
`for modern
`
`\\°O
`
`Inactive
`
`\ I0 1
`
`APP
`Active
`
`\ No more data
`to send
`
`FIG-ll
`
`APP-WAKE-MODEM
`Asserts
`
`deasserts
`
`APP-WAKE-MODEM
`asserts '
`
`
`
`
`
`750ms timer
`expiration
`
`APP-WAKE-MODEM
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 9 0f 12
`
`US 2007/0140199 A1
`
`
`POWER_0N_IODEI
`
`APP Sla‘e
`
`
`
`Acliva
`Inactive
`Active
`Inactive
`
`A
`
`B
`
`c
`
`D
`
`E
`
`F
`
`G
`
`J
`
`F l 6 .
`
`i 3
`
`Modern has data
`for APP
`
`N 0°
`
`Modem
`Inactive
`
`
`
`More modem data
`
`
`
`No more modem
`datato send
`
`750ms timer
`expiration
`
`
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 10 0f 12
`
`US 2007/0140199 A1
`
`MODEM-WAKE-APP
`asserts
`
`APP
`
`
`
`
`602'
`
`
`Inactive MODEM-WAKE-APP
`
`asserts
`
`
`
`
`
`
`lsec
`timer
`expiratio
`n
`
`MODEM—WAKE-APP
`de-asserts
`
`MODEM-BOOT-IODE
`
`
`
`
`
`active
`
`inacliw
`
`USE-UAKE—APP
`
`USB Data TX
`
`APP State
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 11 of 12
`
`US 2007/0140199 A1
`
`APP UART Ready
`
`APP USB Ready
`
`APP UART Ready
`
`APP USB PowerUp
`
`APP
`
`
`Assert APP-WAKE-MODEM
`
`APP provides USB Clock
`
`I
`
`DATA-UP Request
`
`USB Resume
`
`APP Sends Data
`
`
`
`
`MODEM
`
`
`
`
`MODEM UART Ready
`with HW/Flow Control
`
`MODEM USB UP
`
`1" L.
`
`i7»
`
`APP
`
`MODEM
`
`Assert MODEM—WAKE-APP
`
`DATA-UP Request
`APP provides USB Clock
`
`'
`
`
`
`
`. USB Resume
`
`MODEM Sends Data
`
`MODEM UART Up
`
`MODEM USB UP
`
`F\C~ 48.
`
`

`

`Patent Application Publication Jun. 21, 2007 Sheet 12 0f 12
`
`US 2007/0140199 A1
`
`APP
`
`MODEM
`
`APP USB powering
`down
`
`DATA-DOWN Request
`
`USB Clock Stops
`
`MODEM knows Host
`USB is powering
`dOWn-
`
`MODEM has to wake
`up the APP up if
`there is‘ any incoming
`data for APP
`
`resources and reduce
`
`power consumption
`based on the
`
`Pic.
`
`)7
`
`MODEM should
`release radio
`
`Protocol
`
`

`

`US 2007/0140199 A1
`
`Jun. 21, 2007
`
`POWER SAVING IN MULTI-PROCESSOR DEVICE
`
`CROSS-REFERENCE TO RELATED PATENT
`APPLICATIONS
`
`[0001] This application is a continuation-in-part of appli-
`cation Ser. No. 11/155,387 filed Jun. 16, 2005, which is a
`continuation of application Ser. No. 10/083,044 filed Feb.
`25, 2002 and issued Sep. 13, 2005 as US. Pat. No. 6,943,
`667. This application is a continuation-in-part of application
`Ser. No. 10/759,597 filed Jan. 15, 2004, which claims the
`benefit ofU.S. Provisional Application No. 60/455,178 filed
`Mar. 16, 2003.
`
`BACKGROUND
`
`[0002] Mobile computing devices are typically powered
`by batteries. Consumers who purchase mobile computing
`devices look for a device that can operate a long period of
`time without needing to recharge the battery. Therefore,
`there is a need to improve the power consumption of mobile
`computing devices.
`
`Some mobile computing devices, such as smart
`[0003]
`phones, use two microprocessors: one for radio communi-
`cation and one for running a variety of applications. Both
`microprocessors consume power, even though one micro—
`processor may be idle while the other microprocessor is
`running.
`
`[0004] Accordingly, there is a need for improved systems
`and methods for reducing power consumption in a multi-
`processor mobile computing device. Further, there is a need
`for reducing power consumption in the communication of
`data between a plurality of processors in a multi-processor
`mobile computing device. Further still, there is a need for
`reducing power consumption in a mobile computing device
`operating over a wireless communication link having a
`server time-out feature.
`
`[0005] The teachings herein extend to those embodiments
`which are within the scope of the appended claims, regard-
`less of whether they accomplish one or more of the above-
`mentioned needs.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0006] FIG. 1 is a front view of a mobile computing
`device, according to an exemplary embodiment;
`
`[0007] FIG. 2 is a back view of a mobile computing
`device, according to an exemplary embodiment;
`
`[0008] FIG. 3 is a block diagram ofthe mobile computing
`device of FIGS. 1 and 2, according to an exemplary embodi-
`ment;
`
`[0009] FIG. 4 is a block diagram illustrating a system and
`method for limiting power consumption, according to an
`exemplary embodiment;
`
`[0010] FIG. 5 is a schematic diagram illustrating commu-
`nication lines between a plurality of processors, according to
`an exemplary embodiment;
`
`FIG. 6 is a state diagram illustrating modem states
`[0011]
`and state transitions, according to an exemplary embodi-
`ment;
`
`[0012] FIG. 7 is a signaling diagram illustrating a power
`on to bootloader mode, according to an exemplary embodi-
`ment;
`
`[0013] FIG. 8 is a signaling diagram illustrating a power
`on to operating system mode, according to an exemplary
`embodiment;
`
`[0014] FIG. 9 is a signaling diagram illustrating a power
`of mode, according to an exemplary embodiment;
`
`[0015] FIG. 10 is a signaling diagram illustrating a host
`processor initiates communication mode, according to an
`exemplary embodiment;
`
`[0016] FIG. 11 is a state diagram illustrating a host pro-
`cessor wakes radio processor data flow from the host pro-
`cessor side, according to an exemplary embodiment;
`
`[0017] FIG. 12 is a state diagram illustrating a host pro-
`cessor wakes radio processor data flow from the radio
`processor side, according to an exemplary embodiment;
`
`[0018] FIG. 13 is a signaling diagram illustrating a radio
`processor initiates communication mode, according to an
`exemplary embodiment;
`
`[0019] FIG. 14 is a state diagram illustrating a radio
`processor wakes host processor data flow from the radio
`processor side, according to an exemplary embodiment;
`
`[0020] FIG. 15 is a state diagram illustrating a radio
`processor wakes host processor data flow from the host
`processor side, according to an exemplary embodiment;
`
`[0021] FIG. 16 is a signaling diagram illustrating a uni-
`versal serial bus controller wakeup mode, according to an
`exemplary embodiment;
`
`[0022] FIG. 17 is a flow diagram illustrating a universal
`serial bus controller wakeup mode, according to an exem-
`plary embodiment;
`
`[0023] FIG. 18 is a flow diagram illustrating a universal
`serial bus controller wakeup mode, according to an exem-
`plary embodiment; and
`
`[0024] FIG. 19 is a flow diagram illustrating a universal
`serial bus controller sleep mode, according to an exemplary
`embodiment.
`
`DETAILED DESCRIPTION OF THE
`EXEMPLARY EMBODIMENTS
`
`[0025] Application Ser. No. 11/155,387 filed Jun. 16,
`2005, application Ser. No. 10/083,044 filed Feb. 25, 2002
`and issued Sep. 13, 2005 as US. Pat. No. 6,943,667,
`application Ser. No. 10/759,597 filed Jan. 15, 2004, US.
`Provisional application No. 60/455,178 filed Mar. 16, 2003,
`and application Ser. No. 11/469,374 filed Aug. 31, 2006 are
`all incorporated by reference herein in their entirety.
`
`to FIG. 1, a mobile computing
`[0026] Referring first
`device 100 is shown. Device 100 is a smart phone, which is
`a combination mobile telephone and handheld computer
`having personal digital assistant functionality. The teachings
`herein can be applied to other mobile computing devices
`(e.g., a laptop computer) or other electronic devices (e.g., a
`desktop personal computer, home or car audio system, etc.).
`Personal digital assistant flmctionality can comprise one or
`more of personal information management, database func-
`
`

`

`US 2007/0140199 A1
`
`Jun. 21, 2007
`
`tions, word processing, spreadsheets, voice memo record-
`ing, etc. and is configured to synchronize personal informa-
`tion from one or more applications with a computer (e.g.,
`desktop, laptop, server, etc.). Device 100 is further config-
`ured to receive and operate additional applications provided
`to device 100 after manufacture, e.g., via wired or wireless
`download, SecureDigital card, etc.
`
`[0027] Earpiece speaker 15 may be a speaker configured
`to provide audio output with a volume suitable for a user
`placing earpiece speaker 15 against or near the ear. Loud-
`speaker 16 is an electro-acoustic transducer that converts
`electrical signals into sounds loud enough to be heard at a
`distance. Loudspeaker 16 can be a used for a speakerphone
`functionality. Device 100 comprises a housing 11 having a
`front side 13 and a back side 17 (FIG. 2). In alternative
`embodiments, display 112, user input device 110, earpiece
`speaker 15 and loudspeaker 16 may each be positioned
`anywhere on front side 13, back side 17 or the edges
`therebetween.
`
`[0028] Mobile computing device 100 may provide voice
`communications functionality in accordance with different
`types of cellular radiotelephone systems. Examples of cel-
`lular radiotelephone systems may include Code Division
`Multiple Access (CDMA) cellular radiotelephone commu-
`nication systems, Global System for Mobile Communica-
`tions (GSM) cellular radiotelephone systems, etc.
`
`In addition to voice communications functionality,
`[0029]
`the mobile computing device 100 may be arranged to
`provide data communications functionality in accordance
`with different
`types of cellular radiotelephone systems.
`Examples of cellular radiotelephone systems offering data
`communications services may include GSM with General
`Packet Radio Service (GPRS)
`systems
`(GSM/GPRS),
`CDMA/lxRTT systems, Enhanced Data Rates for Global
`Evolution (EDGE) systems, Evolution Data Only or Evo-
`lution Data Optimized (EV-DO) systems, etc.
`
`[0030] The mobile computing device 100 may be arranged
`to provide voice and/or data communications functionality
`in accordance with different
`types of wireless network
`systems. Examples of wireless network systems may include
`a wireless local area network (WLAN) system, wireless
`metropolitan area network (WMAN) system, wireless wide
`area network (WWAN) system, and so forth. Examples of
`suitable wireless network systems offering data communi-
`cation services may include the Institute of Electrical and
`Electronics Engineers (IEEE) 802.xx series of protocols,
`such as the IEEE 802.11a/b/g/n series of standard protocols
`and variants (also referred to as “WiFi”), the IEEE 802.16
`series of standard protocols and variants (also referred to as
`“WiMAX”), the IEEE 802.20 series of standard protocols
`and variants, and so forth.
`
`[0031] The mobile computing device 100 may be arranged
`to perform data communications in accordance with differ-
`ent
`types of shorter range wireless systems, such as a
`wireless personal area network (PAN) system. One example
`of a suitable wireless PAN system oifering data communi-
`cation services may include a Bluetooth system operating in
`accordance with the Bluetooth Special Interest Group (SIG)
`series of protocols, including Bluetooth Specification ver-
`sions v1.0, v1.1, v1.2, v2.0, v2.0 with Enhanced Data Rate
`(EDR), as well as one or more Bluetooth Profiles, and so
`forth.
`
`[0032] As shown in the embodiment of FIG. 3, mobile
`computing device 100 may comprise a dual processor archi-
`tecture including a host processor 102 and a radio processor
`104 (e.g., a base band processor). The host processor 102
`and the radio processor 104 may be arranged to communi-
`cate with each other using interfaces 106 such as one or
`more universal serial bus (USB)
`interfaces, micro-USB
`interfaces,
`universal
`asynchronous
`receiver-transmitter
`(UART) interfaces, general purpose input/output (GPIO)
`interfaces, control/status lines, control/data lines, shared
`memory, and so forth.
`
`[0033] The host processor 102 may be responsible for
`executing various software programs such as application
`programs and system programs to provide computing and
`processing operations for the mobile computing device 100.
`The radio processor 104 may be responsible for performing
`various voice and data communications operations for the
`mobile computing device 100 such as transmitting and
`receiving voice and data information over one or more
`wireless communications channels. Although embodiments
`of the dual processor architecture may be described as
`comprising the host processor 102 and the radio processor
`104 for purposes of illustration, it is worthy to note that the
`dual processor architecture of the mobile computing device
`100 may comprise additional processors, may be imple-
`mented as a dual- or multi-core chip with both host proces-
`sor 102 and radio processor 104 on a single chip, etc.
`
`In various embodiments, the host processor 102
`[0034]
`may be implemented as a host central processing unit (CPU)
`using any suitable processor or logic device, such as a
`general purpose processor. The host processor 102 may
`comprise, or be implemented as, a chip multiprocessor
`(CMP), dedicated processor, embedded processor, media
`processor, input/output (I/O) processor, co-processor, a field
`programmable gate array (FPGA), a programmable logic
`device (PLD), or other processing device in alternative
`embodiments. In an exemplary embodiment, host processor
`102 is an OMAP2, such as an OMAP2431 proccssor,
`manufactured by Texas Instruments, Inc.
`
`[0035] The host processor 102 may be arranged to provide
`processing or computing resources to the mobile computing
`device 100. For example, the host processor 102 may be
`responsible for executing various software programs such as
`application programs and system programs to provide com-
`puting and processing operations for the mobile computing
`device 100. Examples of application programs may include,
`for example, a telephone application, voicemail application,
`e-mail application, instant message (IM) application, short
`message service (SMS) application, multimedia message
`service (MMS) application, web browser application, per—
`sonal information manager (PIM) application, contact man-
`agement application, calendar application, scheduling appli-
`cation,
`task management application, word processing
`application, spreadsheet application, database application,
`video player application, audio player application, multime-
`dia player application, digital camera application, video
`camera application, media management application, a gam-
`ing application, and so forth. The application software may
`provide a graphical user interface (GUI) to communicate
`information between the mobile computing device 100 and
`a user.
`
`[0036] System programs assist in the running of a com-
`puter system. System programs may be directly responsible
`
`

`

`US 2007/0140199 A1
`
`Jun. 21, 2007
`
`integrating, and managing the individual
`for controlling,
`hardware components of the computer system. Examples of
`system programs may include, for example, an operating
`system (OS), device drivers, programming tools, utility
`programs, software libraries, an application programming
`interface (API), graphical user interface (GUI), and so forth.
`The mobile computing device 100 may utilize any suitable
`OS in accordance with the described embodiments such as
`a Palm OS®, Palm OS® Cobalt, Microsoft® Windows OS,
`Microsoft Windows® CE, Microsoft Pocket PC, Microsoft
`Mobile, Symbian OSTM, Embedix OS, Linux, Binary Run-
`time Environment for Wireless (BREW) OS, JavaOS, a
`Wireless Application Protocol (WAP) OS, and so forth.
`
`[0037] The mobile computing device 100 may comprise a
`memory 108 coupled to the host processor 102. In various
`embodiments, the memory 108 may be arranged to store one
`or more software programs to be executed by the host
`processor 102. The memory 108 may be implemented using
`any machine-readable or computer-readable media capable
`of storing data such as volatile memory or non-volatile
`memory, removable or non-removable memory, erasable or
`non-erasable memory, writeable or re-writeable memory,
`and so forth. Examples of machine-readable storage media
`may include, without
`limitation, random-access memory
`(RAM),
`dynamic RAM (DRAM), Double-Data-Rate
`DRAM (DDRAM), synchronous DRAM (SDRAM), static
`RAM (SRAM), read-only memory (ROM), programmable
`ROM (PROM), erasable programmable ROM (EPROM),
`electrically erasable programmable ROM (EEPROM), flash
`memory (e.g., NOR or NAND flash memory), or any other
`type of media suitable for storing information.
`
`[0038] Although the memory 108 may be shown as being
`separate from the host processor 102 for purposes of illus-
`tration, in various embodiments some portion or the entire
`memory 108 may be included on the same integrated circuit
`as the host processor 102. Alternatively, some portion or the
`entire memory 108 may be disposed on an integrated circuit
`or othcr mcdium (e.g., hard disk drivc) cxtcrnal
`to thc
`integrated circuit of host processor 102. In various embodi-
`ments, the mobile computing device 100 may comprise an
`expansion slot to support a multimedia and/or memory card,
`for example.
`
`[0039] The mobile computing device 100 may comprise a
`user input device 110 coupled to the host processor 102.
`User
`input device 110 may comprise,
`for example, a
`QWERTY key layout and an integrated number dial pad.
`The mobile computing device 100 also may comprise vari-
`ous keys, buttons, keypad, alphanumeric keypad, and
`switches such as, for example, input keys, preset and pro-
`grammable hot keys, left and right action buttons, a navi—
`gation button such as a multidirectional navigation button,
`phone/send and power/end buttons, preset and program-
`mable shortcut buttons, a volume rocker switch, a ringer
`on/olf switch having a vibrate mode, and so forth.
`
`[0040] The host processor 102 may be coupled to a display
`112. The display 112 may comprise any suitable visual
`interface for displaying content to a user of the mobile
`computing device 100. For example, the display 112 may be
`implemented by a liquid crystal display (LCD) such as a
`touch-sensitive color (e.g., 16-bit color) thin-film transistor
`(TFT) LCD screen. In some embodiments, the touch-sensi-
`tive LCD may be used with a stylus and/or a handwriting
`recognizer program.
`
`[0041] The mobile computing device 100 may comprise
`an input/output (I/O) interface 114 coupled to the host
`processor 102. The I/O interface 114 may comprise one or
`more I/O devices such as a serial connection port, an
`infrared port,
`integrated Bluetooth® wireless capability,
`and/or integrated 802.llx (WiFi) wireless capability,
`to
`enable wired (e.g., USB cable) and/or wireless connection to
`a local computer system, such as a local personal computer
`(PC). In various implementations, mobile computing device
`100 may be arranged to transfer and/or synchronize infor-
`mation with the local computer system.
`
`[0042] The host processor 102 may be coupled to various
`audio/video (A/V) devices 116 that support A/V capability
`of the mobile computing device 100. Examples of A/V
`devices 116 may include, for example, a microphone, one or
`more speakers, an audio port to connect an audio headset, an
`audio coder/decoder (codec), an audio player, a digital
`camera, a video camera, a video codec, a video player, and
`so forth.
`
`[0043] The host processor 102 may be coupled to a power
`supply 118 arranged to supply and manage power to the
`elements of the mobile computing device 100. In various
`embodiments, the power supply 118 may be implemented by
`a rechargeable battery, such as a removable and rechargeable
`lithium ion battery to provide direct current (DC) power,
`and/or an alternating current (AC) adapter to draw power
`from a standard AC main power supply.
`
`[0044] As mentioned above, the radio processor 104 may
`perform voice and/or data communication operations for the
`mobile computing device 100. For example, the radio pro-
`cessor 104 may be arranged to communicate voice infor—
`mation and/or data information over one or more assigned
`frequency bands of a wireless communication channel. In
`various embodiments,
`the radio processor 104 may be
`implemented as a communications processor using any
`suitable processor or logic device, such as a modem pro-
`cessor or baseband processor. Although some embodiments
`may be described with the radio processor 104 implemented
`as a modem processor or baseband processor by way of
`example, it may be appreciated that the embodiments are not
`limited in this context. For example, the radio processor 104
`may comprise, or be implemented as, a digital signal pro-
`cessor (DSP), media access control (MAC) processor, or any
`other type of communications processor in accordance with
`the described embodiments. Radio processor 104 may be
`any of a plurality of modems manufactured by Qualcomm,
`Inc.
`
`In various embodiments, the radio processor 104
`[0045]
`may perform analog and/or digital baseband operations for
`the mobile computing device 100. For example, the radio
`processor 104 may perform digital-to-analog conversion
`(DAC), analog-to-digital conversion (ADC), modulation,
`demodulation, encoding, decoding, encryption, decryption,
`and so forth.
`
`[0046] The mobile computing device 100 may comprise a
`transceiver module 120 coupled to the radio processor 104.
`The transceiver module 120 may comprise one or more
`transceivers arranged to communicate using different types
`of protocols, communication ranges, operating power
`requirements, RF sub-bands, information types (e.g., voice
`or data), use scenarios, applications, and so forth. In various
`embodiments, the transceiver module 120 may comprise one
`
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`or more transceivers arranged to support voice communica-
`tion for a cellular radiotelephone system such as a GSM,
`UMTS, and/or CDMA system. The transceiver module 120
`also may comprise one or more transceivers arranged to
`perform data communications in accordance with one or
`more wireless communications protocols such as WWAN
`protocols (e.g., GSM/GPRS protocols, CDMA/1xRTT pro-
`tocols, EDGE protocols, EV—DO protocols, EV—DV proto-
`cols, HSDPA protocols, etc.), WLAN protocols (e.g., IEEE
`802.11a/b/g/n, IEEE 802.16, IEEE 802.20, etc.), PAN pro-
`tocols, Infrared protocols, Bluetooth protocols, EMI proto-
`cols including passive or active RFID protocols, and so
`forth.
`
`[0047] The transceiver module 120 may be implemented
`using one or more chips as desired for a given implemen-
`tation. Although the transceiver module 120 may be shown
`as being separate from and external to the radio processor
`104 for purposes of illustration, it is worthy to note that in
`various embodiments some portion or the entire transceiver
`module 120 may be included on the same integrated circuit
`as the radio processor 104. The embodiments are not limited
`in this context.
`
`[0048] The mobile computing device 100 may comprise
`an antenna system 122 for transmitting and/or receiving
`electrical signals. As shown, the antenna system 122 may be
`coupled to the radio processor 104 through the transceiver
`module 120. The antenna system 122 may comprise or be
`implemented as one or more internal antennas and/or exter-
`nal antennas.
`
`[0049] The mobile computing device 100 may comprise a
`memory 124 coupled to the radio processor 104. The
`memory 124 may be implemented using one or more types
`of machine-readable or computer-readable media capable of
`storing data such as volatile memory or non-volatile
`memory, removable or non-removable memory, erasable or
`non-erasable memory, writeable or re-writeable memory,
`and so forth. The memory 124 may comprise, for example,
`flash memory and secure digital (SD) RAM. Although the
`memory 124 may be shown as being separate from and
`external to the radio processor 104 for purposes of illustra-
`tion, it is worthy to note that in various embodiments some
`portion or the entire memory 124 may be included on the
`same integrated circuit as the radio processor 104.
`
`[0050] The mobile computing device 100 may comprise a
`subscriber identity module (SIM) 126 coupled to the radio
`processor 104. The SIM 126 may comprise, for example, a
`removable or non-removable smart card arranged to encrypt
`voice and data transmissions and to store user-specific data
`for allowing a voice or data communications network to
`identify and authenticate the user. The SIM 126 also may
`store data such as personal settings specific to the user.
`
`[0051] The mobile computing device 100 may comprise
`an I/O interface 128 coupled to the radio processor 104. The
`I/O interface 128 may comprise one or more I/O devices to
`enable wired (e.g., serial, cable, etc.) and/or wireless (e.g.,
`WiFi, short range, etc.) communication between the mobile
`computing device 100 and one or more external computer
`systems.
`
`[0052] Referring now to FIG. 4, an exemplary system and
`method for limiting power consumption will be described.
`In some embodiments herein, the process of limiting power
`
`consumption may be referred to as a “handshaking” feature,
`in which at
`least one of host processor 102 and radio
`processor 104 is configured to control the other from a wake
`to sleep or sleep to wake state. Handshaking may refer to the
`ability of two or more processors to sleep independent of
`each other, and may be provided in any of a number of
`embodiments, some of which will be described herein. It is
`advantageous to allow each processor to move to a sleep
`state when it has no tasks, even though the other processor
`is still processing tasks. Each processor is provided with the
`ability to wake the other when communication between the
`two is needed (e.g., via UART, USB or shared memory).
`
`[0053] Host processor 102 can be placed in a sleep mode
`or a wake mode. In a sleep mode, host processor 102 is
`capable of performing certain activities such as keeping
`memory refreshed or periodically waking up; however,
`during the sleep mode host processor 102 does not perform
`to its full capability. Maintaining a microprocessor in a sleep
`mode is generally desired for energy conservation.
`
`[0054] Radio circuit 250 comprises antenna 122, radio
`processor 104, and a communication port 260 (e.g., serial
`port, universal serial bus, universal asynchronous receiver
`transmitter, etc.). In one embodiment, radio circuit 250 may
`monitor wireless traffic received over antenna 122 while
`
`host microprocessor 102 is in the sleep mode. Radio circuit
`250 continuously scans a set of defined frequencies (e.g.,
`page scan in Bluetooth standard) for an in—bound signal.
`
`[0055] A remote device (e.g., a transmitting electronic
`device, not shown) transmits a signal to mobile computing
`device 100. The transmitted signal may be an out of band
`signal requesting a connection. Radio circuit 250 scanning
`for in-bound signals detects signal 201 transmitted by the
`transmitting electronic device.
`
`[0056] The signal transmitted by the transmitting elec-
`tronic device requests a connection and may not contain user
`data. Antenna 122 coupled to radio processor 104 receives
`signal 201 (e.g., incoming connection request) and transmits
`an interaction to radio processor 104, where radio processor
`104, having a certain processing capability, determines if the
`signal is a connection attempt. Radio processor 104 coupled
`to communication port 260, determines: a) if communica-
`tion port 260 is closed; and b) if signal 201 is transmitted by
`a trustcd device.
`
`In case communication port 260 is closed and
`[0057]
`signal 201 is from a trusted device, radio processor 104
`toggles an outside line 235, which is coupled to an interrupt
`mechanism (not shown), causing the generation of an inter-
`rupt signal. Generation of the interrupt signal may be done
`in accordance with a extension of the communication pro-
`tocol
`(e.g., Bluetooth specification) which allows radio
`circuit 250 to select a line coupled to the interrupt mecha-
`nism and toggle the line if communication port 260 is
`closed. Accordingly, when communication port 260 is
`closed, the outside line is toggled and the interrupt mecha-
`nism generates an interrupt signal. The interrupt signal is
`then transmitted to host processor 102 via interrupt line 240
`causing host processor 102 to wake up to its full operational
`capability. An interrupt vector including different commu-
`nication protocols (e.g., Bluetooth, IR, etc.) resides in the
`operating system (not shown) of host processor 102. Host
`processor 102, responding to the interrupt signal, sends a
`command to its operating system to invoke an appropriate
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`communication protocol (e.g., Bluetooth, IR, etc.). Accord-
`ingly, a communication protocol
`is invoked and causes
`communication port 260 to open and receive data signal 201.
`
`If the port 260 was already open when the message
`[0058]
`was received, the interrupt signal is still generated to wake
`the host processor 102. Once wakened,
`it receives the
`message from the open port.
`
`[0059] The interrupt signal wakes the host processor 102,
`which opens the communication port 260, and data infor-
`mation is received. Advantageously, the communication port
`can be shut down when not in use thereby saving power.
`
`[0060] Referring now to FIG. 5, another exemplary system
`and method for
`limiting power consumption will be
`described. FIG. 5 is a schematic diagram illustrating com-
`munication lines between a plurality of processors, accord-
`ing to an exemplary embodiment. As can be seen, a plurality
`of digital serial ports and control signals 500 of radio
`processor 104 are coupled to host processor 102. Analog
`audio signals 502 are coupled to audio CODEC 504 for
`routing to microphones, speakers, or host processor 102. In
`one exemplary embodiment, UART1506 may be used for
`multiplexed control and data. UART2508 may be used for
`debug information during development. In an alternative
`embodiment, UART1506 may be used for command and
`diagnostics information and UART2508 may be used for
`data calls.
`
`In the system of FIG. 5, a plurality of signals are
`[0061]
`used to control power management functions between host
`processor 102 and radio processor 104.
`
`[0062] RESET/ON—OFF
`RESET_OUT~)
`
`(ON/OFF, RADIO_RESET~,
`
`[0063] ON/OFFiThis active high input signal turns
`radio processor 104 on and off. A high level on this pin
`will turn on radio processor 104 and boot host proces-
`sor 102. A low level on this pin will force radio
`processor 104 01f immediately, rather than into a grace-
`ful shutdown. The graceful shutdown will be accom-
`plished via a software command before the ON/OFF
`pin is driven low.
`
`[0064] RADIO_RESET~7The act