USART

Synchronous and asynchronous receiver-transmitter

Quick Explanation

  • Supports generation according to baud rate
  • Discrete device with serial communication
  • Communication can be simplex, full duplex or half duplex
  • Communication can be simplex, full duplex or half duplex
  • Attributes to be modified include: bit speed, character length, parity, and stop bits
  • a clock generator
  • input and output shift registers
  • transmit/receive control
  • read/write control logic
  • transmit/receive buffers
  • system data bus buffer
  • First-in, first-out (FIFO) buffer memory
  • Integration with third party DMA controller
  • Integrated bus mastering DMA controller (optional)

Protocol

  • Universal synchronous and asynchronous receiver-transmitter (USART)
  • Universal asynchronous receiver-transmitter (UART)

A universal asynchronous receiver-transmitter (UART) is a computer hardware device for asynchronous serial communication in which the data format and transmission speeds are configurable.A related device, the universal synchronous and asynchronous receiver-transmitter (USART) also supports synchronous operation.

The universal asynchronous receiver-transmitter (UART) takes bytes of data and transmits the individual bits in a sequential fashion. At the destination, a second UART re-assembles the bits into complete bytes. Each UART contains a shift register, which is the fundamental method of conversion between serial and parallel forms. Serial transmission of digital information (bits) through a single wire or other medium is less costly than parallel transmission through multiple wires.

The UART model requires an external traffic source and does not directly generate or receive the external signals used between different items of equipment. Communication may be simplex (in one direction only, with no provision for the receiving device to send information back to the transmitting device), full duplex (both devices send and receive at the same time) or half duplex (devices take turns transmitting and receiving).

 

UART- implements USART

USART Implementation