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Input Capture
Input capture is a method of dealing with input signals in an embedded system. Embedded systems using input capture will record a timestamp in memory when an input signal is received. It will also set a flag indicating that an input has been captured. This allows the system to continue executing without interruption while an input is being received while still having the capability to trigger events based on the exact time when the input was received. The corresponding capability to trigger an output at a specified time, based on a timestamp in memory, is called output compare. There are many programmable interrupt controllers that provide dedicated input capture pins and a programmable counter along with it. These pins generate interrupts to the controller, which then executes an interrupt service routine. The interrupts can be programmed to occur at the rising or falling edge of the input signal, depending on requirements. External links - Atmel AVR135: Using timer capture to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embedded System
An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use today. , it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems. Modern embedded systems are often based on microcontrollers (i.e. microprocessors with integrated memory and peripheral interfaces), but ordinary microprocessors (using external chips for memory and peripheral interface circuits) are also common, especially in more complex systems. In either case, the processor(s) used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timestamp
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however. They can have any epoch, can be relative to any arbitrary time, such as the power-on time of a system, or to some arbitrary time in the past. The term "timestamp" derives from rubber stamps used in offices to stamp the current date, and sometimes time, in ink on paper documents, to record when the document was received. Common examples of this type of timestamp are a postmark on a letter or the "in" and "out" times on a time card. In modern times usage of the term has expanded to refer to digital date and time information attached to digital data. For example, computer files contain timestamps that tell when the file was last modified, and digital cameras add timestamps to the pictures they take, recording th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Output Compare
Output compare is the ability to trigger an output based on a timestamp in memory, without interrupting the execution of code by a processor or microcontroller. This is a functionality provided by many embedded system An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' as ...s. The corresponding ability to record a timestamp in memory when an input occurs is called input capture. Embedded systems * Microchip Documentation on Output Compare: DS39706A-page 16-1 - Section 16. Output Compare http://ww1.microchip.com/downloads/en/DeviceDoc/39706a.pdf {{compu-eng-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt Service Routine
In computer systems programming, an interrupt handler, also known as an interrupt service routine or ISR, is a special block of code associated with a specific interrupt condition. Interrupt handlers are initiated by hardware interrupts, software interrupt instructions, or software exceptions, and are used for implementing device drivers or transitions between protected modes of operation, such as system calls. The traditional form of interrupt handler is the hardware interrupt handler. Hardware interrupts arise from electrical conditions or low-level protocols implemented in digital logic, are usually dispatched via a hard-coded table of interrupt vectors, asynchronously to the normal execution stream (as interrupt masking levels permit), often using a separate stack, and automatically entering into a different execution context (privilege level) for the duration of the interrupt handler's execution. In general, hardware interrupts and their handlers are used to handle high-pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmel AVR
AVR is a family of microcontrollers developed since 1996 by Atmel, acquired by Microchip Technology in 2016. These are modified Harvard architecture 8-bit Reduced instruction set computer, RISC single-chip microcontrollers. AVR was one of the first microcontroller families to use on-chip flash memory for program storage, as opposed to Programmable read-only memory, one-time programmable ROM, EPROM, or EEPROM used by other microcontrollers at the time. AVR microcontrollers find many applications as embedded systems. They are especially common in hobbyist and educational embedded applications, popularized by their inclusion in many of the Arduino line of open hardware development boards. History The AVR architecture was conceived by two students at the Norwegian Institute of Technology (NTH), Alf-Egil Bogen and Vegard Wollan.Archived aGhostarchiveand thWayback Machine Atmel says that the name AVR is not an acronym and does not stand for anything in particular. The creators of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
