Microcontroller Based System Design Module-2

Microcontroller Based System DesignMicrocontroller Based System DesignMicrocontroller Based System DesignMicrocontroller Based System Design

Module 2Module 2Module 2Module 2

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Prepared by Emil Raj,Dept. Of ECE,MLMCE

Syllabus

� Module 2Module 2Module 2Module 2

Embedded C compiler – advantages – memory models – interrupt

functions – code optimization - 89C2051 micro-controller-

architecture-comparison with 89C51- design of a simple trainer architecture-comparison with 89C51- design of a simple trainer

circuit using 89C51/89C2051 µC – interfacing of DIP switch, LED, 7

segment display, alphanumeric LCD – relay interface – design of a

traffic light control system - interfacing programs using C and

assembly language.


89C51


FEATURES

� 8 bit CPU with registers A and B

� 16 bit PC and DPTR

� 8 bit PSW

� Four 8 bit ports:P0-P3

� Two 16 bit timers &

counters:T0&T1

� Full duplex serial data

Rxr/Txr : SBUF.

� 8 bit stack pointer

� Internal ROM 4K

� Internal RAM of 128b

� Oscillator & clock circuits

Rxr/Txr : SBUF.

� Control registers :

TCON,TMOD,

SCON,PCON,IP &IE

� 2 external & 3 internal

interrupts.


INTERNAL RAM

� Total 128 Bytes.

� Divided into 3 groups.

� 4 Register banks.

� Bit addressable memory(16

bytes).

� General purpose

registers(80 bytes).


INTERNAL RAM� Each bank has 8 registers(R0-R7).

� RS0 & RS1 bits selects the bank.� BANK 0: 00-07H

� BANK 1: 08-0FH

� BANK 2: 10-17H

� BANK 3:18-1FH

� General purpose registers.� Total 80 bytes.

� 30H to 7FH


BIT ADDRESSABLE

� 16 bytes from20H to 2FH.

� Total 128 bits.

� Specified by its bit address of

00H to 7FH.

� Set directly by SETB 2F.

� Cleared by CLR 2F.


89C2051


PIN DIAGRAM

89C51 89C2051


89C2051 FEATURES

• 2K bytes of Flash

• 128 bytes of RAM

• 15 I/O lines

• two 16-bit timer/counters

• full duplex serial port• full duplex serial port

• a precision analog comparator

• on-chip oscillator and clock circuitry

• compatible with the industry standard MCS51 instruction set.

• supports two software selectable power saving modes.

• Idle Mode

• Power down modePrepared by Emil Raj,Dept. Of ECE,MLMCE

89C2051 FEATURES

• Idle Mode

• Stops the CPU while allowing the RAM, timer/counters, serial port and interrupt

system to continue functioning.

• Power down mode• Power down mode

• Saves the RAM contents and freezes the oscillator disabling all other chip

functions until the next hardware reset.

• It has a static processor core, ie. there is no minimum clock frequency

• maximum clock frequency is 24 MHz.


89C2051 FEATURES

• Consist of Program Memory Lock Bits

� There are two on-chip lock bits which

can be left un programmed (U) or can

be programmed (P).

� They provide a kind of security for the

data.

� The Lock Bits can only be erased with

the Chip Erase operation. Prepared by Emil Raj,Dept. Of ECE,MLMCE

Comparison between 89C51 & 89C2051



� 89C2051 is having additionally an on chip precision analog comparator.

� 89C2051 has only 15 I/O lines so, port1 and port3 are only available on it.

� The architecture of 89C2051 does not support any external address/data � The architecture of 89C2051 does not support any external address/data

bus and therefore RD,WR signals are absent .

� Similar to 89C51 ,the 89C2051 also supports full-duplex serial

communication and six interrupts.



� Similar to 89C51 ,two power saving modes namely “Idle mode and power down

modes are also available in 89C2051 .

� The 89C51 has 4Kb of flash memory where as 89C2051 is having only 2Kb of flash

memory

� ALE,PSEN,EA signals are not available in 89C2051 chip.

� The analog precision comparator on the 89C2051 is used along with RC components

to build a simple comparator type ADC.










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7 SEGMENT DISPLAY


PIN CONNECTIONS


LUT for Common Anode


INTERFACING


INTERFACING


PROGRAM ORG 0000hCLR P0.1CLR P0.2MOV P2, #ffh

Loop: CLR P0.2SETB P0.1SETB P0.1

MOV P2, # B0hCALL delay

CLR P0.1SETB P0.2

MOV P2, # 0F9hCALL delay

AJMP loop


Interfacing LED & DIP Switch

� Emit light when an electric current

passes through them

LED’s are available in a wide variety of � LED’s are available in a wide variety of

sizes and shapes.

� Commonly used size are 5mm and 3mm

diameter.



� A series of tiny switches built into circuit

boards.

� DIP switches enable you to configure a

circuit board for a particular type of

computer or application.

� DIP switches are always toggle switches,

which mean they have two possible

positions -- on or off. (Instead of on and

off, you may see the numbers 1 and 0.)Prepared by Emil Raj,Dept. Of ECE,MLMCE



TRAFFIC LIGHT SYSTEM


TRAFFIC LIGHT SYSTEM


INTERFACING PRGM



RELAY

� Electromechanical switch, which perform ON and OFF operations

without any human interaction.

� The relay consists a inductor coil, a spring (not shown in the

figure), Swing terminal, and two high power contacts named as

normally closed (NC) and normally opened (NO). normally closed (NC) and normally opened (NO).

� Relay uses an Electromagnet to move swing terminal between

two contacts (NO and NC). When there is no power applied to

the inductor coil (Relay is OFF), the spring holds the swing

terminal is attached to NC contact.


� Whenever required power is applied to the inductor coil, the current

flowing through the coil generates a magnetic field which moves the swing

terminal to normally open (NO) contact.

RELAY

� When power is OFF, the spring restores the swing terminal position to NC.


TYPES OF RELAY


Relay Interfacing

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Microcontroller Based System Design Module-2

Documents

traffic light

general purpose

interfacing

swing terminal

dip switch

89c51 amp

inductor coil

emil raj