Question
Download Solution PDFWhat are the XTAL 1 and XTAL 2 pins numbers for 8051?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFPin Diagram of 8051 microcontroller
1.) Pins 1 to 8: These pins are known as Port 1. This port doesn’t serve any other functions. It is an internally pulled-up, bi-directional I/O port
2.) Pin 9: It is a RESET pin, which is used to reset the microcontroller to its initial values.
3.) 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.
4.) Pins 18 & 19: The pins XTAL 1 and XTAL 2 are used for interfacing an external crystal to get the system clock.
5.) Pin 20: This pin provides the power supply to the circuit.
6.) Pins 21 to 28: These pins are known as Port 2. It serves as an I/O port. Higher-order address bus signals are also multiplexed using this port.
7.) Pin 29: This is the PSEN pin which stands for Program Store Enable. It is used to read a signal from the external program memory.
8.) Pin 30: This is the EA pin which stands for External Access input. It is used to enable/disable external memory interfacing.
9.) Pin 31: This is the ALE pin which stands for Address Latch Enable. It is used to demultiplex the address-data signal of the port.
10.) Pins 32 to 39: These pins are known as Port 0. It serves as an I/O port. Lower order address and data bus signals are multiplexed using this port.
11.) Pin 40: This pin is used to provide a power supply to the circuit.
Last updated on Jun 2, 2025
-> The RRB NTPC Admit Card 2025 has been released on 1st June 2025 on the official website.
-> Railway Recruitment Board activated the RRB ALP application form 2025 correction link, candidates can make the correction in the application form till 31st May 2025.
-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.
-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.
-> The official RRB ALP Recruitment 2025 provides an overview of the vacancy, exam date, selection process, eligibility criteria and many more.
->The candidates must have passed 10th with ITI or Diploma to be eligible for this post.
->The RRB Assistant Loco Pilot selection process comprises CBT I, CBT II, Computer Based Aptitude Test (CBAT), Document Verification, and Medical Examination.
-> This year, lakhs of aspiring candidates will take part in the recruitment process for this opportunity in Indian Railways.
-> Serious aspirants should prepare for the exam with RRB ALP Previous Year Papers.
-> Attempt RRB ALP GK & Reasoning Free Mock Tests and RRB ALP Current Affairs Free Mock Tests here