Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

8051 Microcontroller
For More Contents, do subscribe to my channel
on you tube as,

”Tech_Guru Swapnil Kaware”
Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

8051 Microcontroller

Presented By,
Er
...
Kaware,
B
...
(Electronics), M
...
(Electronics)
svkaware@yahoo
...
in
Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

2

Salient Features
(1)
...

(2)
...


(3)
...

(4)
...


(5)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

3

Salient Features
(6)
...


(7)
...

(8)
...


(9)
...

(10)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

4

Salient Features
(11)
...

(12)
...


(13)
...


(14)
...

(15)
...

(16)
...


5

Salient Features
(17)
...

(18)
...

(19)
...

(20)
...


(21)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

6

8051 Block Diagram

7

Internal Architecture
Oscillator Circuit:(1)
...

(2)
...

(3)
...


(4)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

8

Internal Architecture
(5)
...


(6)
...

(7)
...

(8)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

9

Internal Memory
(1)
...

(2)
...


(3)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

10

Internal Memory
(4)
...

(5)
...


(6)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

11

Registers RAM memory space allocation in the
8051 Microcontroller

12

Register banks in the 8051 Microcontroller

13

Special Function Registers
(1)
...
B
(3)
...
SP
(5)
...
IP
(6)
...
PCON
(8)
...
TCON etc
...
8051 has 21 special function registers (SFRs) at the top of internal
RAM from address 80H to FFH
...
Most of the addresses from 80H to FFH are not defined, except for 21
of them
...
Some SFR’s are both bit-addressable and byte addressable, depending
on the instruction accessing the register
...
This area consists of a series of memory-mapped ports and registers
...
All 8051 CPU registers, I/O ports, timers and other architecture
components are accessible in 8051 C through SFRs
Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

15

B Register
(1)
...

(2)
...
and leaves
the 16 bit result in A (low byte) and B (high byte)
...
DIV AB: divided A by B, leaving the integer result in A and
remainder in B
...
B register is bit-addressable
...
Swapnil V
...
co
...
Stack pointer (SP) is an 8-bit register at address 81H
...
It contains the address of the data item currently on
top of the stack
...
Stack operations include pushing data on the stack
andpopping data off the stack
...
Pushing increments SP before writing the data
...
Popping from the stack reads the data and
decrements the SP

18

Stack Pointer
(6)
...

(7)
...

(8)
...


(9)
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

19

Data pointer (DPTR)
(1)
...

(2)
...

(3)
...


(4)
...
One of the major features of a microcontroller is the versatility
built into the I/O circuits that connect the microcontroller to the
outside world
...
To be commercially viable, the 8051 had to incorporate as many
I/O functions as were technically and economically possible
...
One of the most useful features of the 8051 is four bidirectional
I/O ports
...
Each port has an 8-bit latch in the SFR space as mentioned
earlier
...
To reduce the overall package pin count, the 8051
employs multiple functions for each port
...
Each port also has an output drive and an input buffer
...
These ports can be used to general purpose I/O, as an
address and data lines
...
The four 8-bit I/O ports P0, P1, P2 and P3 each uses 8
pins
...
Swapnil V
...
co
...
Port 0 is 8-bitbidirectional I/O port
...
Port 0 pins can be used as high-impedance inputs
...
Port 0 is also the multiplexed low-order address and data
bus during accesses to external program and data memory
...
We r using pins no
...

(5)
...


(5)
...

24

PORT 1
(1)
...


(2)
...
from 1 to 9
...
Port 1 have no dual functions
...
When used as an output the pin latches are
programmed to 0
...
When used as an input the pin latches are
programmed to 1
...
Swapnil V
...
co
...
Port 2 is an 8-bit bidirectional I/O port
...
Port 2 emits the high-order address byte during fetches from
external program memory and during accesses to external data
memory that use 16-bit addresses (MOVX @DPTR)
...
When used as an output the pin latches are programmed to 0
...
When used as an input the pin latches are programmed to 1
...
We r using pins no
...

Microcontroller Notes by Er
...
Kaware (svkaware@yahoo
...
in)

26

PORT 3
(1)
...

(2)
...
from 10 to 17
...
0): Serial input port,
TXD (P3
...
2): External interrupt,
INT1 (P3
...
4): Timer 0 external input,
T1 (P3
...
6): External data memory write strobe,
RD (P3
...
Swapnil V
...
co
...
Many microcontroller applications require the counting of
external events, such as frequency of a pulse train, or the
generation of precise internal time delays between actions
...
Both of these tasks can be accomplished using software
techniques
...
The 8051 has two 16-bit registers that can be used as either
timers or counters
...
Swapnil V
...
co
...
These two up counters are name T0 and T1 and are
provided for general use of the programmer
...
Each counter may be programmed to count internal
clock pulses, act as a timer, or programmed to count
external events as a counter
...
The counters are divided into two 8-bit registers
called the timer low (TL0, TL1) and timer high (TH0,
TH1) bytes
...
Swapnil V
...
co
...
The word "interrupt" can
often be substituted with the word "event
...

When the event occurs, the 8051 temporarily puts "on hold" the
normal execution of the program and executes a special section
of code referred to as an interrupt handler
...
Swapnil V
...
co
...

• There are total 5 interrupt sources in 8051
Microprocessor as follows
...
Timer Flag 0, (2)
...

(3)
...
INT 1, (INT 0 & INT 1 are external
interrupts)
...
Serial Port Interrupt (RI or TI)
...
Swapnil V
...
co
...
Swapnil V
...
co

---