Patent Application
20080005423
The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present invention and together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements.
As used in the specification and claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “an array” may include a plurality of arrays unless the context clearly dictates otherwise.
In one embodiment, the invention is directed to a method for acting on removal of a peripheral from a computer, the method comprising sensing removal of the peripheral from the computer and promoting the computer to a running state in response to removal of the peripheral.
Preferably, the peripheral is a stylus and the computer is a tablet PC. The method could further include acting on replacement of the peripheral in or on the computer. Preferably, the acting on replacement of the peripheral includes causing the computer to enter one of a hibernation state or a sleep state. Preferably, the acting on removal of the peripheral includes waking the computer from one of a sleep state or a hibernation state. Preferably, the acting on removal of the peripheral further includes starting up an application software. Preferably, the computer is promoted in response to removal of the peripheral. The method could further comprise initiating a peripheral removal event in response to sensing removal of the peripheral from the computer. Preferably, the computer is promoted from one of a hibernation state or a sleep state.
In another embodiment, the invention is directed to a computer system capable of acting on removal of a peripheral. The computer system comprises a docking mechanism for removably retaining the peripheral, and a sensor connected to the docking mechanism and capable of determining when the peripheral is removed from the docking mechanism. When the sensor determines that the peripheral has been removed from the docking mechanism, it promotes the computer to a running state.
Preferably, the sensor is capable of determining when the peripheral is replaced in the docking mechanism. Preferably, when the sensor determines that the peripheral has been replaced in the docking mechanism, it causes the computer to enter one of a hibernation state or a sleep state.
Yet another embodiment relates to a method for promoting a computer containing a sensor configured to determine when the peripheral is removed from the computer, the method comprising delivering a signal from the sensor to a receiver of an embedded controller; generating an interrupt and identification of an event from the embedded controller to facilitate processing a peripheral removal event; raising notification of the peripheral removal event using an advanced configuration and power interface (ACPI) event and associated ACPI control methods; capturing the peripheral removal event with an operating system device driver that includes a device driver for the sensor; translating the peripheral removal event into a human interface device (HID) report that is read by an HID class driver; and sending an input message to application software that has registered an interest in the peripheral removal event.
Yet another embodiment relates to a method for promoting on removal of a stylus from a tablet PC comprising a sensor configured to determine when the stylus is removed from the tablet PC, the method comprising signaling an embedded controller when the stylus is removed from the tablet PC; notifying a system BIOS and device drivers when the embedded controller is signaled that the stylus has been removed; and sending an input message to application software that has registered an interest in the stylus removal.
Preferably, the sensor is located in a stylus retention mechanism. Preferably, the device drivers include an ACPI class driver. Preferably, the device drivers further include an ACPI-to-HID mapper driver. Preferably, the device drivers further include an HID device driver.
Another embodiment relates to a system configured to promote on removal of a peripheral, the system comprising a sensor configured to determine when the peripheral is removed from the computer; an embedded controller having a receiver capable of receiving a signal from the sensor that indicates when the peripheral has been removed from the computer, the embedded controller generating an interrupt and identification of an event that facilitate processing of a peripheral removal event; a system BIOS that raises notification of the peripheral removal event using an ACPI event and associated ACPI control methods; and device drivers that capture the peripheral removal event and translate the peripheral removal event into an input message sent to an application software that has registered an interest in the peripheral removal event.
In yet another embodiment, the invention is directed to a method for acting on removal of a peripheral from a computer, the method comprising sensing removal of the peripheral from the computer, initiating a peripheral removal event in response to sensing removal of the peripheral from the computer, and promoting the computer from a sleep or hibernation state to a running state in response to the peripheral removal event.
Further features of the present invention, as well as the structure of various embodiments of the present invention are described in detail below with reference to the accompanying drawings.
The present invention contemplates a computer, such as a tablet PC, with a peripheral device docking mechanism having a sensor that, when the peripheral device is removed, generates an event that triggers initiation of various programmable tasks, including automatic wake of the system from a “sleep” state. “Sleep” state refers generally to low-power states. Automatic wake is also referred to herein as promoting the computer to a running state. Promotion, as used herein, refers generally to changing a system from a lower powered state to a higher powered state. Demotion, as used herein, refers generally to changing a system from a higher powered state to a lower powered state.
The computer hardware component of a tablet PC typically includes a motherboard with a CPU. The CPU can be, for example, a 478-ball Dothan ULV processor in a micro-FCBGA package and may run nominally at, for example, 1.2 GHz in high frequency mode and at 600 MHz in low frequency mode. The CPU may be socketed or soldered to the motherboard. The system memory can be determined based on the intended application of the tablet PC through the use of commercially-available memory modules, and may include a DRAM module of 1 GB size.
The tablet PC's I/O controller hub (ICH) provides I/O capabilities with suitable known storage device interfaces. The ICH can also provide USB ports for the tablet PC, for devices such as cameras, barcode readers, wireless communication controllers, docking connectors, etc. The ICH further provides a low pin count (LPC) bus that connects to a firmware hub within the tablet PC. The firmware hub is preferably a Flash EPROM storing BIOS code and supporting the use of an embedded controller (EC, also known as a keyboard system controller). Embedded controller refers generally to a programmable microcontroller and may be, for example, a Hitachi H-8 keyboard/system controller. The programmable microcontroller is preferably compliant to the ACPI specification.
An embodiment of the invention provides, within the docking mechanism, a sensor capable of determining when the peripheral device is removed from the docking mechanism. The sensor may be, e.g., a simple mechanical switch, a capacitive sensor, a magnetic switch, or another known suitable sensor. Docking mechanism refers to a mechanism for attaching, docking, or otherwise retaining a peripheral device and can, for example, include a recessed caddy for retaining a stylus.
Upon removal of a peripheral device from the docking mechanism, a signal is created by the sensor and delivered to a receiver. The receiver includes, but is not limited to embedded controller general purpose input/output ports (GPIOs) or interrupt pins. The receiver receives the signal from the sensor for appropriate further processing as set forth below.
A typical embedded controller contains a host interface connecting it to the computer's main CPU, an interface for connection to a scan keyboard, and a number of GPIO pins. The CPU and embedded controller communicate with one another by putting data into the embedded controller's memory and causing an interrupt. The embedded controller's GPIO pins provide a set of I/O ports that can be configured for input or output. In an embodiment of the invention, the GPIO pins are attached to the sensor to sense the state of or “read” the sensor.
The embedded controller includes a memory that reflects a logical state of its GPIO pins. The embedded controller also has a data register and a status/command register that appear in the I/O space of the CPU. The CPU can write to these registers and generate (or raise) an interrupt to the embedded controller signal that something was written to the registers. Similarly, the embedded controller can write content to these registers and generate (or raise) a system control interrupt (“SCI”) to the CPU to signal that something was written to the registers.
In an embodiment of the invention, the embedded controller maps the docking mechanism sensor to a corresponding location in its memory. Data regarding the state of the sensor is then stored in the designated memory location prior to or during the interrupt, so that the CPU can be notified of changes in sensor state (i.e., removal or replacement of a peripheral).
In another embodiment of the invention, the sensor is also able to determine when the peripheral device is replaced in the docking mechanism. The sensor communicates replacement of the peripheral to the CPU as set forth above.
An exemplary embodiment of the invention is described below with reference to the peripheral device being a stylus that is docked in, for example, a recessed caddy of a tablet PC. Upon removal of the stylus from the recessed caddy, the sensor sends a signal to the embedded controller indicating the removal. The embedded controller receives the signal and creates a stylus removal event that is translated to an interface that is used by the system software. Translation involves mapping the stylus removal event as reported by the embedded controller to an HID button code in an HID input report.
The ACPI-to-HID Mapper Driver performs the translation. For example, notification of a stylus removal event can be raised using an advanced configuration and power interface (ACPI) event and associated ACPI control methods in the system BIOS. ACPI also defines an architecture-independent interpretive language called ACPI source language (ASL) that can be compiled into ACPI machine language (AML) and embedded in the system BIOS ROM. The embedded controller provides notification first to the operating system in the form of and SCI interrupt. The operating system determines that the ACPI class driver is responsible for handling the SCI interrupt and transfers control to the ACPI class driver. The ACPI class driver queries the embedded controller to determine which ACPI device type the SCI interrupt applies to, and discovers that it is the AHM device. The ACPI class driver looks to its list of registered client drivers and discovers that the ACPI-to-HID mapper driver is registered to receive AHM events, so the ACPI class driver transfers control to the ACPI-to-HID mapper driver. The ACPI-to-HID mapper driver invokes the ACPI control method(s) in the BIOS to determine that the event was a stylus event, as opposed to some other button event.
The stylus removal event is then captured by an operating system device driver, such as an ACPI-to-HID mapper driver, which generally includes a device driver for the sensor. This ACPI-to-HID mapper driver then translates the stylus removal event into human interface device (HID) keystrokes, preferably according to the USB HID standard. USB HID provides a standardized, flexible, operating system-independent and hardware-independent protocol. The operating system also includes its own hardware-independent device driver (or some other mechanism of reporting GPIO events to the operating system software) that the ACPI-to-HID mapper driver plugs into. The operating systems device driver can be an HID class driver that determines the device associated with the removal event. The HID class driver, therefore, determines that the sensor is associated with the removal event.
In an embodiment of the invention, when the tablet PC is in a sleeping state (e.g., S3 “sleep” or S4 “hibernation” states), the embedded controller designates a stylus removal event as a system “wake” event that promotes the system from its sleeping state to a running state (i.e., a wake state S0). Whether and how the embedded controller designates the stylus removal event as a wake event is determined by the engineer developing the firmware for the embedded controller, who determined which events will be “wake” events. This provides automatic promotion and ease-of-use for end users, such that a stylus removal causes the system to automatically power-up to a ready-to-use state without additional steps of effort by the user. Conversely, the present invention contemplates the system automatically returning to a sleep state upon stylus replacement. Returning the system to a sleep state is accomplished in the same manner described above upon replacing the stylus in the recessed caddy.
As used herein, BIOS refers generally to the software code run by a computer when first powered on. The primary function of the BIOS is to prepare the machine so that other software programs can load, execute, and assume control of the computer. The BIOS can also include a coded program embedded on a chip that recognizes and controls various devices that make up the computer. ACPI is an open industry standard that defines common interfaces for hardware recognition, motherboard and device configuration, and power management. A human interface device (HID) includes any computer device that interacts directly with and takes input from humans (e.g., keyboard, mouse, graphics tablet, etc.). USB (which stands for “universal serial bus”) is a serial bus standard for interfacing devices.
As illustrated in the exemplary embodiment of
In an embodiment of the invention utilizing Windows, the system includes three device drivers. They include an HID Class Driver, an ACPI-to-HID Mapper Driver, and an ACPI Class Driver. When the system boots, the ACPI-to-HID Mapper Driver loads and registers itself (using the label of “AHM”) with the ACPI Class Driver, so that the ACPI Class Driver will know that when it receives AHM events from the embedded controller, to respond by invoking the ACPI-to-HID Mapper Driver. The ACPI-to-HID Mapper Driver will service stylus (and other) events from the embedded controller. The system designer must assign button numbers to all the buttons/switches on the system. For example, the stylus sensor could be designated as button #4 (the numbers are somewhat arbitrary, but should start at 1 and count up by ones). Stylus events are delivered by the embedded controller as AHM events. In this example, when the ACPI-to-HID Mapper Driver receives notification of an AHM event, it calls BTNS(0) to determine which button/switch caused the AHM event and receives back a “4” to indicate that it was a stylus event.
After determining that a stylus event occurred, the ACPI-to-HID mapper driver reads a table (out of, for example, a Windows registry) describing which HID button codes are associated with button #4. For example, the Windows registry may indicate that button #4 should generate an HID “input report” with {HID page 12, HID usage 1, HID button usage 35} or other similar parameters. The control panel applet allows system administrators to select which HID button code will be assigned to a stylus event. The exact numeric values of the input report are standardized by the USB Implementor's Forum in a specification called the “HID Usage Tables Specification.” The ACPI-to-HID mapper driver then sends an HID report to the operating system's device driver (the HID class driver). It is to be understood that, alternatively, an application programmer can write a program to register with the HID class driver and listen for HID events occurring on a plurality of input reports, and when they occur, identify the HID button.
The interaction between the HID class driver and the application software, according to an embodiment of the invention, is as follows. Application software can “register” its interest in a particular button code, such as the stylus button code, with the HID class driver by using an application programming interface (API) provided by the operating system.
A wake sequence is initiated by the embedded controller. The firmware in the embedded controller is coded to cause the system to wake upon stylus removal. During a wake sequence, when the operating system is resumed from a sleeping state, it will send (broadcast) a “resumed” message to all running applications. When a stylus event occurs, the ACPI-to-HID mapper driver delivers the event to the HID class driver, who delivers it to the application software in the form of an input message, as well as a message buffer indicating that the input type was an HID event, and that it was the stylus button. Using these events, an application will understand that the system has reawakened, and that it was because of a stylus removal. When the stylus is reinserted, another stylus event message will be sent. When any application has been programmed to cause the system to sleep upon stylus insertion, upon receipt of the appropriate HID button code, the system initiates a suspend operation by calling the operation system's suspension API.
To cause the PC to wake or sleep, based on stylus removal or replacement, respectively, the system performs the following process. First, the embedded controller is responsible for PC power management, and is designed to be able to turn the CPU power on and off and direct it to its various wake and sleep states, the most well-known of which are:
According to an embodiment of the invention, the operating system (e.g., Windows) requests that the embedded controller put the CPU in a given mode by writing a sleep type (SLP_TYP) register in the embedded controller's memory (e.g., with a numerical wake or sleep state, such as 0, 3, 4, or 5, as described above). The operating system triggers writing a sleep type register in the embedded controller's memory when the user asks to demote the system's state. In Window's, for example, this is done by going to the Start menu, clicking the “shut down” button, and selecting shut down, restart, standby, or hibernate. Selecting shut down demotes the system to S5 (off). Selecting hibernate demotes the system to S4. Selecting standby demotes the system to S3 (sleep). Selecting restart demotes the system to S5 (off) but then causes the system to reboot.
When the embedded controller sees the request, it performs the required action. Although the embedded controller may turn the CPU and perhaps the entire PC off upon requests, the embedded controller itself may not turn off. The embedded controller continues to run off of available battery power. Firmware in the embedded controller is programmed to understand that the stylus removal should be classified as a wake event and stylus replacement should be classified as a sleep event. When the embedded controller sees a wake event, it turns the CPU on to full power. When the BIOS and operating system start up from a sleep state, they look at the registers in the embedded controller's memory and realize that they are waking from a sleep state and take the correct action. For example:
If waking from S3, memory (RAM) is still current, so the operating system doesn't have to boot anything. If waking from S4, the operating system has to re-load RAM from the hiberfile. If waking from S5, the system has to boot from a reset state. Once the operating system tells the embedded controller that it has awakened from sleep, the embedded controller raises an interrupt to process the stylus removal event as described in the above embodiment of the invention. The stylus removal event is processed by sending an AHM event notification to the ACPI class driver, which calls the ACPI-to-HID mapper driver to translate the stylus button number (e.g., 4) to an HID input report, which is forwarded to the HID class driver and is ultimately delivered to the application programs.
The present invention contemplates the user being able to enable or disable the PC's ability to wake up stylus removal or to sleep upon stylus replacement. The present invention also contemplates other actions causing the system to wake and sleep, such as plugging in or turning on a peripheral such as a keyboard, mouse, or recording device. For medical applications, the peripheral may include such devices as, for example, a wireless blood pressure gauge, a thermometer, or a wireless stethoscope. Other peripheral devices and features that might be incorporated into the platform include, but are not limited to, digital cameras, RFID readers, bar code readers, Bluetooth connectivity, audio I/O, a docking station which may include warm-swappable batteries.
This application is a continuation-in-part of U.S. patent application Ser. No. 11/447,298, filed Jun. 6, 2006, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11447298 | Jun 2006 | US |
| Child | 11529547 | US |
