How does serial communication with UART in 8051 work?
In this case, our 8051 uC IC uses a special circuit that, by design, carries the answers to the above three questions. This special circuitry or module is known as a UART. Its full form is Universal Asynchronous Receiver or Transmitter. Let us look at the UART serial communication method to get insights on how it works.
What happens when I send UART data to a micro?
Normally when I send UART data from my computer to these micros, it is received just fine. However I have started a new project and I am getting intermittent characters missing from the beginning of a message. The code I wrote thus far reads the incoming data and prints it back to the computer. I am trying to send ” “.
Can a microcontroller support multiple UARTs at a time?
Some modern microcontrollers with 8051 IP cores support multiple UARTs in addition to other protocols like the I2C and SPI for easy interfacing with other devices. The 8051 can also use synchronous communication to transfer data but in this case, the mode of transmission is half-duplex and only one device can communicate at a time.
How is full duplex communication possible in the 8051?
Also, the 8051 supports full-duplex communication which means it can transmit and receive data at the same time. This is made possible by the special design of the SBUF register about which we will talk in the coming sections. The start bit helps in synchronization and is a low signal for a particular duration of time.
How does a UART work on a microcontroller?
Now we can go to our topic. The microcontroller MCS51 has an inbuilt UART for carrying out serial communication. The serial communication is done in the asynchronous mode. A serial port, like other PC ports, is a physical interface to establish data transfer between computer and an external hardware or device.
What does the RI bit mean on the 8051?
Thus, the 8051 lets the program know that it has “clocked out” the last byte by setting the TI bit. When the TI bit is set, the program may assume that the serial port is “free” and ready to send the next byte. Finally, the RI bit means “Receive Interrupt.”