UART

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UART

[′yü‚ärt]

UART

UART

(Universal Asynchronous Receiver Transmitter) The electronic circuit that makes up the serial port. Also known as "universal serial asynchronous receiver transmitter" (USART), it converts parallel bytes from the CPU into serial bits for transmission, and vice versa. It generates and strips the start and stop bits appended to each character. Note that in the following paragraphs, dashes have been added after the 16 for readability. Older 8250 and 16-450 UARTs are not fast enough for today's modems. A 16-550 is required for transmission up to 115,200 bps (115 Kbps).

ISDN users running both 64 Kbps channels are losing performance with a 16-550 UART, because the maximum 115 Kbps is reduced further to 92 Kbps when the start/stop bits are removed. Upgrading to a 16-650 or higher UART boosts real data speed from 92 to 128 Kbps. The 16-650 is the more sophisticated UART, providing hardware flow control that reduces the burden on the CPU. See UART overrun.

 Buffer    MaximumUART    Size      SpeedChip    (bytes)   Bits/sec
   8250     None        9,600
   16450       1        9,600
   16550      16      115,200
   16650      32      430,800
   16750      64      921,600
   16850     128          1.5 Mbps
References in periodicals archive ?
The communication USART parameters (speed, parity, even bit, serial word width, hardware protocol levels etc)
The device series also features a large number of communication interfaces such as USART, SPI and TWI as well as I2S and an audio bitstream D/A converter.
The control board has a microcontroller ATmega8, a repeater for saving the signals into buffers, several jumpers to enable the addressed receiver module (can be more receivers for taking commands from more command units, attached to the different PCs from different locations), ADC and DAC converters to take analog signals from sensors and to provide control signals for the industrial machines, USART serial for interface with wireless receiver board, a voltage regulator L7805, a power supply, and some additional circuits.
All four microcontrollers feature 32 Kbytes of self-programmable Flash memory, 2 Kbytes of SRAM and 1 Kbyte of EEPROM, 10-bit ADC, 3 Timer/Counters, USART, SPI, I2C compatible two-wire-interface, and full operation from 1.
Footnote DSP = Digital Signal Processor GPS = Global Positioning Systems I/O = Input/Output LCD = Liquid Crystal Display LNA = Low Noise Amplifier PND = Personal Navigation Device SD/MMC = Secure Digital/MultiMedia Card SiGe = Silicon Germanium SoC = System on Chip TWI = Two Wire Interface USART = Universal Synchronous/Asynchronous Receiver/Transmitter USB = Universal Serial Bus
The STM32 Connectivity Line embeds a bootloader allowing programming of a blank or programmed device using USART, CAN, or USB DFU (Device Firmware Upgrade).
0 full-speed host and device, two SPI, two-wire and two USART interfaces.
To support miniaturization and cost saving, this broad spectrum of memory densities combines with high integration of advanced peripherals, including embedded USART operating at up to 4.
They feature a 10-bit ADC, USART, SPI, Two-Wire-Interface and operate from 1.
The kit's hardware and Graphical User Interface (GUI) software allow communication between the PC and several industry-standard serial protocols on the microcontroller being tested, including I2C[TM], SPI and USART.
All devices include a hardware multiplier, one USART, one SPI, one TWI, two 8-bit and two 16-bit timers with PWM and RTC, 8-channel 10-bit ADC with differential inputs, a programmable gain amplifier and 48 programmable I/Os.
Footnote DAB = Digital Audio Broadcasting DMB = Digital Multimedia Broadcasting DVD = Digital Versatile Disk I2S = Infrared Imaging System LCD = Liquid Cristal Display ODD = Optical Disc Drive RDI = Receiver Data Interface SFCO = Simple Full Capacity Output SPDIF = Sony/Philips Digital Interface SPI = Serial Parallel Interface SSO = Serial Synchronous Output UART = Universal Asynchronous Receiver/Transmitter USB = Universal Serial Bus USART = Universal Synchronous and Asynchronous Receiver/Transmitter WXGA = Wide Extended Graphics Array