Microcontroller consists of a lot of parts such as CPU, RAM, Flash (ROM), internal bus, oscillator parts etc.
A group of these many parts are called peripherals.
Peripherals in a Microcontroller are designed to interface with the outside world.
Lots of peripherals are embedded in a Microcontroller, some of which are shown in the picture below:
1.GPIO (General Purpose Input – Output): For reading a digital value (0 or 1) (Input) of pins or sending a digital value (Output) to the outside…
2. UART (Universal Asynchronous Receiver Transmitter): For transmitting or receiving data from one device (any device like PC, other microcontrollers or FPGA) by TXD and RXD pins.
3. SPI (Serial Peripheral Interface): For connecting the microcontroller to devices that work with SPI protocol (same as SDCards, some modules and some ICs). In SPI 3 or 4 wires are used (MISO, MOSI, SCK and SS),
4. Quad SPI is the same as SPI but it is used to speed up transmission with the help of more wires. The special mode of Quad SPI is SD Interface which is used to connect to SD Card.
5. ADC (Analog to Digital): To get a voltage from the outside. GPIOs are digital and can detect zero (0 V) or one (+VCC) but are not able to detect a voltage level between 0 to +VCC, while ADC can detect voltage levels in between.
6. Timers act as task schedulers and run instructions in a periodic manner.
7. I2C (IIC = Inter-Integrated Circuit) interface: I2c bus is used to connect 127 devices via two wires that are called SDA and SCL. Lots of ICs and modules can work with I2C.
8. Many other peripherals exist in a microcontroller, like Ethernet for connecting to network, or two-wire CAN protocol for connecting to CAN network, USB for connecting to USB bus. DMA, PWM and so on.