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MICROCONTROLLERS
           8051
WHAT IS A MICROCONTROLLER?
• All of the components needed for a controller
  were built right onto one chip.
• A one chip ...
MICROPROCESSOR vs MICRO CONTROLLER
MICROPROCESSOR Vs MICRO CONTROLLER

   General-purpose                  Microcontroller
   microprocessors
               ...
Features :
• The Intel 8051 is used in embedded
  systems
  – 8-bit CPU
  – 4k bytes ROM for the program
  – 128 BYTES of ...
Block Diagram
External Interrupts


   Interrupt           4k          128 bytes           Timer 1
    Control           R...
8051 – PIN DIAGRAM
8051 – 40 PIN IC
• 8051 contains four I/O ports (P0 - P3)
                 • Each port can be used as input or output
                   (b...
PORT 3 – MULTIPLE FUNCTIONS
IMPORTANT PINS

•   PSEN (out): Program Store Enable, the read signal
    for external program memory (active low).
•   AL...
SIGNALS - OPERATION
• Vcc(pin 40):
   – Vcc provides supply voltage to the chip.
   – The voltage source is +5V.
• GND(pin...
QUARTZ CRYSTAL OSCILLATOR
• Using a quartz crystal oscillator
• We can observe the frequency on the XTAL2
  pin.      C2
 ...
XTAL Connection to an External Clock Source


• Using a TTL oscillator
• XTAL2 is unconnected.
             N             ...
RST - RESET
• RST(pin 9):reset
   – input pin and active high
       • The high pulse must be high at least 2 machine
    ...
RESET Value of Some 8051 Registers:


 Register           Reset Value

 PC                 0000

 ACC                0000
...
RESET CIRCUITARY
Vcc



                      31
                           EA/VPP
                           X1
      10 ...
EA’ & PSEN’
• EA’(pin 31):external access
   – There is no on-chip ROM in 8031 and 8032 .
   – The EA’ pin is connected to...
ALE
ALE(pin 30):address
latch enable
   It is an output pin and is
   active high.
   8051 port 0 provides
   both addre...
External code memory

       WR
       RD
     PSEN                      OE
      ALE            74LS373   CS
            ...
External data memory
       WR                      WR
       RD                      RD
     PSEN
      ALE            74...
Title

• Lorem ipsum dolor sit amet, consectetuer
  adipiscing elit. Vivamus et magna. Fusce sed
  sem sed magna suscipit ...
8051 microprocessor
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8051 microprocessor

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Transcript of "8051 microprocessor"

  1. 1. MICROCONTROLLERS 8051
  2. 2. WHAT IS A MICROCONTROLLER? • All of the components needed for a controller were built right onto one chip. • A one chip computer, or microcontroller was born. • A microcontroller is a highly integrated chip which includes, on one chip, all or most of the parts needed for a controller. • The microcontroller could be called a "one- chip solution".
  3. 3. MICROPROCESSOR vs MICRO CONTROLLER
  4. 4. MICROPROCESSOR Vs MICRO CONTROLLER General-purpose Microcontroller microprocessors  The fixed amount of on-chip  Must add RAM, ROM, I/O ROM, RAM, and number of ports, and timers externally I/O ports makes them ideal to make them functional for applications in which  Make the system bulkier cost and space are critical. and much more expensive  In many applications, the  Have the advantage of space it takes, the power it versatility on the amount of consumes, and the price per RAM, ROM, and I/O ports unit are much more critical considerations than the computing power
  5. 5. Features : • The Intel 8051 is used in embedded systems – 8-bit CPU – 4k bytes ROM for the program – 128 BYTES of RAM for variables – 32 I/O lines ( 4 PORTS WITH 8 EACH ) – 2 timers – 1 Serial port – 6 interrupt sources – Low cost (10-15 cents per chip)
  6. 6. Block Diagram External Interrupts Interrupt 4k 128 bytes Timer 1 Control ROM RAM Timer 2 CPU OSC Bus 4 I/O Ports Serial Control P0 P2 P1 P3 TXD RXD Addr/Data
  7. 7. 8051 – PIN DIAGRAM
  8. 8. 8051 – 40 PIN IC
  9. 9. • 8051 contains four I/O ports (P0 - P3) • Each port can be used as input or output (bi-direction) Port 1 Port 2 Port 3 Port 0 P1(P1.0~ P2(P2.0~ P3(P3.0~ P0(P0.0~P0.7) P1.7) P2.7) P3.7) 8-bit R/W - 8-bit R/W - General General General Purpose I/O Purpose I/O Purpose I/O Only 8-bit R/W - General Or high if not using Or acts as a Purpose byte of the any of the multiplexed I/O address internal low byte bus for peripherals address and (timers) or data bus for external external memory external memory design interrupts. design
  10. 10. PORT 3 – MULTIPLE FUNCTIONS
  11. 11. IMPORTANT PINS • PSEN (out): Program Store Enable, the read signal for external program memory (active low). • ALE (out): Address Latch Enable, to latch address outputs at Port0 and Port2 • EA (in): External Access Enable, active low to access external program memory locations 0 to 4K • RXD,TXD: UART pins for serial I/O on Port 3 • XTAL1 & XTAL2: Crystal inputs for internal oscillator.
  12. 12. SIGNALS - OPERATION • Vcc(pin 40): – Vcc provides supply voltage to the chip. – The voltage source is +5V. • GND(pin 20):ground • XTAL1 and XTAL2(pins 19,18): – These 2 pins provide external clock. – Way 1:using a quartz crystal oscillator – Way 2:using a TTL oscillator
  13. 13. QUARTZ CRYSTAL OSCILLATOR • Using a quartz crystal oscillator • We can observe the frequency on the XTAL2 pin. C2 XTAL2 30pF C1 XTAL1 30pF GND
  14. 14. XTAL Connection to an External Clock Source • Using a TTL oscillator • XTAL2 is unconnected. N XTAL2 C EXTERNAL OSCILLATOR SIGNAL XTAL1 GND
  15. 15. RST - RESET • RST(pin 9):reset – input pin and active high • The high pulse must be high at least 2 machine cycles. – power-on reset. • Upon applying a high pulse to RST, the microcontroller will reset and all values in registers will be lost. • Reset values of some 8051 registers
  16. 16. RESET Value of Some 8051 Registers: Register Reset Value PC 0000 ACC 0000 B 0000 PSW 0000 SP 0007 DPTR 0000 RAM are all zero
  17. 17. RESET CIRCUITARY Vcc 31 EA/VPP X1 10 uF 30 pF X2 RST 9 8.2 K
  18. 18. EA’ & PSEN’ • EA’(pin 31):external access – There is no on-chip ROM in 8031 and 8032 . – The EA’ pin is connected to GND to indicate the code is stored externally. – PSEN’ & ALE are used for external ROM. – For 8051, EA’ pin is connected to Vcc. – active low. • PSEN’(pin 29):program store enable – This is an output pin and is connected to the OE pin of the ROM.
  19. 19. ALE ALE(pin 30):address latch enable It is an output pin and is active high. 8051 port 0 provides both address and data. The ALE pin is used for de-multiplexing the address and data by connecting to the G pin of the 74LS373 latch.
  20. 20. External code memory WR RD PSEN OE ALE 74LS373 CS G P0.0 A0 D P0.7 A7 D0 D7 EA P2.0 A8 P2.7 A15 8051 ROM
  21. 21. External data memory WR WR RD RD PSEN ALE 74LS373 CS G P0.0 A0 D P0.7 A7 D0 D7 EA P2.0 A8 P2.7 A15 8051 RAM
  22. 22. Title • Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas. • Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas.
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