The pin diagram of 8051 microcontroller looks as follows − Hello friends I am Abhinandan your friends So toady topic is pin diagram of 8051 microcontroller hai Aur sath hi kaise jaldi yaad rahe ye bhi bataugaa ok so start a blog And requested for all friends to share my blog and like also. Pins 1 to 8 − These pins are known as Port 1. This port doesn’t serve any other functions. It is internally pulled up, bi-directional I/O port. Pin 9 − It is a RESET pin, which is used to reset the microcontroller to its initial values. Pins 10 to 17 − These pins are known as Port 3. This port serves some functions like interrupts, timer input, control signals, serial communication signals RxD and TxD, etc. Pins 18 & 19 − These pins are used for interfacing an external crystal to get the system clock. Pin 20 − This pin provides the power supply to the circuit. Pins 21 to 28 − These pins are known as Port 2. It serves as I/O port. Higher order address bus signals are also