In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a DTE such as a computer terminal or PC, and a DCE, such as a modem. The standard defines the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pinout of connectors. The current version of the standard is TIA-232-F Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, issued in 1997. The RS-232 standard had been commonly used in computer serial ports and is still widely used in industrial communication devices.
The 16550 UART is an integrated circuit designed for implementing the interface for serial communications. The corrected -A version was released in 1987 by National Semiconductor. It is frequently used to implement the serial port for IBM PC compatible personal computers, where it is often connected to an RS-232 interface for modems, serial mice, printers, and similar peripherals. It was the first serial chip used in the IBM PS/2 line, which were introduced in 1987.
A universal asynchronous receiver-transmitter is a peripheral device for asynchronous serial communication in which the data format and transmission speeds are configurable. It sends data bits one by one, from the least significant to the most significant, framed by start and stop bits so that precise timing is handled by the communication channel. The electric signaling levels are handled by a driver circuit external to the UART. Common signal levels are RS-232, RS-485, and raw TTL for short debugging links. Early teletypewriters used current loops.
A serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, terminals, various peripherals, and directly between computers.
COM is the original, yet still common, name of the serial port interface on PC-compatible computers. It can refer not only to physical ports, but also to emulated ports, such as ports created by Bluetooth or USB adapters.
AVR is a family of microcontrollers developed since 1996 by Atmel, acquired by Microchip Technology in 2016. These are modified Harvard architecture 8-bit RISC single-chip microcontrollers. AVR was one of the first microcontroller families to use on-chip flash memory for program storage, as opposed to one-time programmable ROM, EPROM, or EEPROM used by other microcontrollers at the time.
Asynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal. Instead of a common synchronization signal, the data stream contains synchronization information in form of start and stop signals, before and after each unit of transmission, respectively. The start signal prepares the receiver for arrival of data and the stop signal resets its state to enable triggering of a new sequence.
1-Wire is a wired half-duplex serial bus designed by Dallas Semiconductor that provides low-speed (16.3 kbit/s) data communication and supply voltage over a single conductor.
The 6551Asynchronous Communications Interface Adapter (ACIA) is an integrated circuit made by MOS Technology. It served as a companion UART chip for the widely popular 6502 microprocessor. Intended to implement RS-232, its specifications called for a maximum speed of 19,200 bits per second with its onboard baud-rate generator, or 125 kbit/s using an external 16x clock. The 6551 was used in several computers of the 1970s and 1980s, including the Commodore PET and Plus/4. It was also used by Apple Computer on the Apple II Super Serial Card, and by Radio Shack on the Deluxe RS-232 Program Pak for their TRS-80 Color Computer.
A universal synchronous and asynchronous receiver-transmitter is a type of a serial interface device that can be programmed to communicate asynchronously or synchronously. See universal asynchronous receiver-transmitter (UART) for a discussion of the asynchronous capabilities of these devices.
In computer hardware, a controller may refer to:
In computer engineering and electrical engineering, bit banging or bit bashing is a term of art for any method of data transmission that employs software as a substitute for dedicated hardware to generate transmitted signals or process received signals. Such software directly sets and samples the states of GPIOs to transmit and receive, respectively, and is responsible for meeting all timing requirements and protocol sequencing of the signals. In contrast to bit banging, dedicated hardware satisfies these requirements and, if necessary, provides a data buffer to relax software timing requirements. Bit banging can be implemented at very low cost, and is commonly used in embedded systems.
The Hyperion is an early portable computer that vied with the Compaq Portable to be the first portable IBM PC compatible. It was marketed by Infotech Cie of Ottawa, a subsidiary of Bytec Management Corp., who acquired the designer and manufacturer Dynalogic Corporation, in January 1983. In 1984, the design was licensed by Commodore International in a move that was forecast as a "radical shift of position" and a signal that Commodore would soon dominate the PC compatible market. Despite computers being "hand-assembled from kits" provided by Bytec and displayed alongside the Commodore 900 at a German trade show as their forthcoming first portable computer, it was never sold by Commodore and some analysts downplayed the pact. The Hyperion was shipped in January 1983 at C$4995, two months ahead of the Compaq Portable.
The Western Design Center (WDC) W65C134S is an 8-bit CMOS microcontroller based on a W65C02S processor core, which is a superset of the MOS Technology 6502 processor.
The CMOS W65C51 Asynchronous Communications Interface Adapter (ACIA) provides an easily implemented, program controlled interface between microprocessor based systems and serial communication data sets and modems. It is produced by Western Design Center (WDC) and is a drop-in replacement for the MOS Technology 6551.
The Western Design Center (WDC) W65C265S is a 16-bit CMOS microcontroller based on a W65C816S processor core, which is a superset of the MOS Technology 6502 processor.
A voice modem is an analog telephone data modem with a built-in capability of transmitting and receiving voice recordings over the phone line. Voice modems are used for telephony and answering machine applications. Similar to the Hayes command set used for data modems, in which the host PC commands the modem via a series of commands known as AT commands, there exists a well-defined set of common voice AT commands that are somewhat consistent throughout the industry.
Tolapai is the code name of Intel's embedded system on a chip (SoC) which combines a Pentium M (Dothan) processor core, DDR2 memory controllers and input/output (I/O) controllers, and a QuickAssist integrated accelerator unit for security functions.
The 8251 is a Universal Synchronous/Asynchronous Receiver/Transmitter (USART) packaged in a 28-pin DIP made by Intel. It is typically used for serial communication and was rated for 19.2 kilobits per second signalling rate.
Interrupt coalescing, also known as interrupt moderation, is a technique in which events which would normally trigger a hardware interrupt are held back, either until a certain amount of work is pending, or a timeout timer triggers. Used correctly, this technique can reduce interrupt load by up to an order of magnitude, while only incurring relatively small latency penalties. Interrupt coalescing is typically combined with either a hardware FIFO or direct memory access, to allow for continued data throughput while interrupts are being held back.
