摘要:
A method for facilitating fast start-up/shut-down of a computing device having a processor, volatile memory, non-volatile memory, and SRAM is described. In one embodiment, an object store for the computing device is provided in the non-volatile memory. A fast lossless shut-down of the computing device may be accomplished by periodically writing data from the object store to a non-volatile medium during operation of the computing device.
摘要:
A vehicle computer system has a housing sized to be mounted in a vehicle dashboard or other appropriate location. A computer is mounted within the housing and executes an open platform, multi-tasking operating system. The computer runs multiple applications on the operating system, including both vehicle-related applications (e.g., vehicle security application, vehicle diagnostics application, communications application, etc.) and non-vehicle-related applications (e.g., entertainment application, word processing, etc.). The computer system has an Internet wireless link to provide access to the Internet. One or more of the applications may utilize the link to access content on the Internet.
摘要:
A vehicle computer system has a housing sized to be mounted in a vehicle dashboard or other appropriate location. A computer is mounted within the housing and executes an open platform, multi-tasking operating system. The computer runs multiple applications on the operating system, including both vehicle-related applications (e.g., vehicle security application, vehicle diagnostics application, communications application, etc.) and non-vehicle-related applications (e.g., entertainment application, word processing, etc.). The applications may be supplied by the vehicle manufacturer and/or by the vehicle user.
摘要:
A multi-function, multi-mode switch for an instrument that changes the instrument between primary and secondary functions and between first and second modes of operation within the primary and secondary functions. The instrument changes from the first mode of operation to the second mode of operation when the switch is actuated for a first period of time. The instrument changes from the second mode of operation to the first mode of operation when the switch is activated for a second period of time. The instrument changes between the primary and secondary functions when the switch is operated for a third period of time. The switch controls a program that instructs the instrument to perform the appropriate operations. The program also instructs the instrument to confirm that an operation has occurred via audible and visual feedback.
摘要:
The capacitance of an unknown capacitor is measured with multimeter instrumentation employing a dual slope analog-to-digital converter. The initial voltage across the capacitor is measured and the capacitor is cyclically charged until the capacitor reaches a predetermined proportion of possible charge. The final voltage is measured. The voltage across the charging resistance is integrated over successive charging cycles to provide a value proportional to the charge delivered to the capacitor and this value is divided by the difference between the initial and final voltages.
摘要:
A vehicle computer system has an audio entertainment system implemented in a logic unit and audio digital signal processor (DSP) independent from the host CPU. The audio entertainment system employs a set of ping/pong buffers and direct memory access (DMA) circuits to transfer data between different audio devices. Audio data is exchanged using a mapping overlay technique, in which the DMA circuits for two audio devices read and write to the same memory buffer. The computer system provides an audio manager API (application program interface) to enable applications running on the computer to control the various audio sources without knowing the hardware and implementation details of the underlying sound system. Different audio devices and their drivers control different functionality of the audio system, such as equalization, volume controls and surround sound decoding. The audio manager API transfers calls made by the applications to the appropriate device driver(s). The computer system also supports a speech recognition system. Speech utterances are picked up by a microphone and sampled at an internal sampling rate. However, the speech recognition system employs a lower sampling rate. The computer system converts microphone data from the higher internal sampling rate to the desired sampling rate by piggybacking the microphone data on command/message streams to an SPI (serial peripheral interface) of the audio DSP. The DSP performs normal low-pass filtering and down sampling on the data stream and then uses the SPI to send out the microphone data at the lower sampling rate.
摘要:
Methods and systems for operating automotive computing devices are described. In one embodiment, a small amount of static RAM (SRAM) is incorporated into an automotive computing device. The SRAM is battery-backed to provide a non-volatile memory space in which critical data, e.g. the object store, can be maintained in the event of a power loss. Circuitry is provided to ensure that the SRAM receives back up power from the battery at appropriate times. Software manages the SRAM and the other storage assembly components and makes use of virtual paging or virtual addressing techniques to keep track of where various pages, including object store pages, are stored in the system. The software knows where all of the object store pages are located so that in the event of a power loss, the page locations are known and hence the pages can be used when power is restored. The SRAM is advantageously used to maintain so-called “dirty pages” or pages that have been written to so that these pages are not lost in the event of a power interruption. Additionally, the software can also provide an orderly means by which pages in the SRAM can be written out to flash memory thereby avoiding unnecessary flash write operations which, in turn, increases the lifetime of the flash memory.
摘要:
An exemplary system includes a microprocessor executing an operating system, a memory, a bus connecting the microprocessor to the memory, and a memory protection module controlling access to the memory independent of the microprocessor. Access to the memory may be based on a combination of an address, data, and memory control signals received from the microprocessor. A method includes, independent of the microprocessor executing an operating system, controlling access to a system memory based on a combination of signals received from the microprocessor.
摘要:
A vehicle computer system has an audio entertainment system implemented in a logic unit and audio digital signal processor (DSP) independent from the host CPU. The audio entertainment system employs a set of ping/pong buffers and direct memory access (DMA) circuits to transfer data between different audio devices. Audio data is exchanged using a mapping overlay technique, in which the DMA circuits for two audio devices read and write to the same memory buffer. The computer system provides an audio manager API (application program interface) to enable applications running on the computer to control the various audio sources without knowing the hardware and implementation details of the underlying sound system. Different audio devices and their drivers control different functionality of the audio system, such as equalization, volume controls and surround sound decoding. The audio manager API transfers calls made by the applications to the appropriate device driver(s). The computer system also supports a speech recognition system. Speech utterances are picked up by a microphone and sampled at an internal sampling rate. However, the speech recognition system employs a lower sampling rate. The computer system converts microphone data from the higher internal sampling rate to the desired sampling rate by piggybacking the microphone data on command/message streams to an SPI (serial peripheral interface) of the audio DSP. The DSP performs normal low-pass filtering and down sampling on the data stream and then uses the SPI to send out the microphone data at the lower sampling rate.
摘要:
A vehicle computer system has a housing sized to be mounted in a vehicle dashboard or other appropriate location. The housing includes a base unit and a faceplate. A first logic unit is mounted to the base unit to form a support module. The support module has two interfacing slots and can support connections to multiple peripheral devices. The support module facilitates high speed data exchange between the peripheral devices for streaming continuous audio or video data. The support module has a fast data memory to temporarily hold data being communicated between the peripheral devices. The support module also has a memory access circuit associated with each of the peripheral devices which designates at least one storage area within the fast data memory to hold data received from, or to be sent to, the associated peripheral device. The vehicle computer has a computer module which can be connected to or removed from one interfacing slot of the support module. A multi-bit bus (e.g., PCI bus) interfaces the computer module and the support module. The vehicle computer system also has a logic unit mounted to the faceplate to form a faceplate module. This module is detachably connected to the other interfacing slot of the support module. When the faceplate module is attached, a high speed serial interface electronically couples the support module to the faceplate module. The high speed serial interface enables the logic units on the support and faceplate modules to exchange a high speed, synchronized, serial bit stream. This data stream is organized into multiple frames, with each frame having multiple data bits and at least one valid bit to indicate whether the data bits are valid.