27-11-2012, 04:59 PM
MICROCONTROLLER-8051Features & Applications
MICROCONTROLLER-.pptx (Size: 1.26 MB / Downloads: 79)
Company profile
Advance technology
Establishment 1999
Location chandigarh
Working area
Products
Key area of training
Embedded system
VLSI designing
Wireless communication
PCB designing
Field of application
Personal information products: Cell phone, pager, watch, pocket recorder, calculator
Laptop components: mouse, keyboard, modem, fax card, sound card, battery charger
Home appliances: door lock, alarm clock, thermostat, air conditioner, TV remote, VCR, small refrigerator, exercise equipment, washer/dryer, microwave oven
Industrial equipment: Temperature/pressure controllers, Counters, timers, RPM Controllers
Toys: video games, cars, dolls, etc.
Timers /Counters
The 8051 has 2 timers/counters:
Timer/Counter 0
Timer/Counter 1
They can be used as
The Timer :Used as a time delay generator.
The clock source is the internal crystal frequency of the 8051.
An event counter.
External input from input pin to count the number of events on registers.
These clock pulses cold represent the number of people passing through an entrance, or the number of wheel rotations, or any other event that can be converted to pulses.
8051 Interrupt and it’s Sources
Original 8051 has 6 sources of interrupts
Reset
Timer 0 overflow
Timer 1 overflow
External Interrupt 0
External Interrupt 1
Serial Port events (buffer full, buffer empty, etc)
Enhanced version has 22 sources
More timers, programmable counter array, ADC, more external interrupts, another serial port (UART)
dtmf
DTMF standard was developed by Bell Laboratories.
Dual Tone Multifrequency System (DTMF), is a touch pad dialling tone.
DTMF standard is used in touch tone telephones and voice mail systems.
Allow users and devices to dial at much higher rate because of the uniformity of numbers.
Each digit corresponds to a high frequency and a low frequency
Both are transmitted simultaneously
Works by sending two sinusoids for each symbol pressed on the telephone keypad.