The communication is termed as synchronous when a character or byte is received at constant intervals of time with a regular gap in the phases. Data that are formed are sent in a tine internal of a maximum time and this time also varies in time. In certain special cases it is known as ISO-synchronous. Again, asynchronous commission signifies those bytes that are received at various intervals of times. Voice data and telephone line are the examples of asynchronous mode.

Internal devices are available in micro controllers like SCI, SPI and SI. Separate status, registers for controlling purposes are available for each device and so that they can transmit and receive serial and data bits. Moreover, each of the devices is programmable and can be used in IO mode programs as well as in interrupted driven transmission.

The synchronous peripheral interface port has the feature of full duplex for the purpose of synchronous communication. For MOSI, MISO output and SCLK there are signals. In clock bits there is is a programmable rate with SPI feature. It also helps in the programming of positive and negative edges with a bits interval in the serial data in and out. It can also be programmed for the selection of device for slave and master.

The serial interface port is also known as a USART port and programmable rate registers are a one of its most important features. SI works in the mode of half duplex synchronous call mode0 and the full asynchronous mode is termed as mode 1 mode 3 or mode 2.

Serial connect interface port is also a UART asynchronous port mode and communication is made in the full mode of duplex for the transmission and receiver of SCI. The band arts for SCI baud are fixed and the receiver of SCI comes with a wake up character which can be programmable using RWU or Receiver Wake Up Unavailable bits.

Download ECE Technical Seminar Topic on Serial Communication of Devices with Report.