Question

Outline any four common bus standards that are used to provide serial communication in embedded systems [3 marks each]

Embedded Systems

Answer 1

Answer 1)

Serial protocol transfers the data serially one bit a time, along the communication channel. The single bit can also be over the time for back to back protocol

The four serial protocol is mentioned below

1) Serial UART protocol :-

UART (Universal Asynchronous Receiver Transmitter). This has two wire between two connected devices as shown below and it requires some setting to be set such as baud rate well before starting any transaction. The data rate is less than 115.2 Kbps

2) SPI

SPI (Serial peripheral interface). It consists of 4 wire between the two connected devices as shown in the figure below. The SCK is the clock which removes the pre requirement of setting the baud rate in UART. The data rate is higher compared to UART and is in range of 1Mhz to 70 Mhz

3) I2C

I2C stands for Inter Integrated Circuit communication.The I2C bus can handle multiple slaves with only two wire connected between connected device as shown below. The clocks SCL is around 100 Khz to 400 Khz.

4) RS232

RS232 (Recommended Standard 232). This protocol is used for serial communication between devices like computer and its peripheral devices. The data rate is in the range of 1.492Kpbs. The RS232 protocol connection is shown below