Microcontrollers - 8051 Interrupts

Microcontrollers - 8051 Interrupts Interrupts are the events that temporarily suspend the main program, pass the control to the external sources and execute their task. It then passes the control to the main program where it had left off. 8051 has 5 interrupt signals, i.e. INT0, TFO, INTR1, TF1, RI/TI. Each interrupt can be enabled or disabled by setting bits of the IE register and the whole interrupt system can be disabled by clearing the...

Read More

Microcontrollers 8051 Input Output Ports

8051 microcontrollers have 4 I/O ports each of 8-bit, which can be configured as input or output. Hence, total 32 input/output pins allow the microcontroller to be connected with the peripheral devices. Pin configuration, i.e. the pin can be configured as 1 for input and 0 for output as per the logic state. Input/Output (I/O) pin − All the circuits within the microcontroller must be connected to one of its pins except P0 port because it does not have pull-up resistors built-in. Input pin − Logic 1 is applied to a bit of the P register. ...

Read More

Microcontrollers - 8051 Pin Description

The pin diagram of 8051 microcontroller looks as follows − Pins 1 to 8 − These pins are known as Port 1. This port doesn’t serve any other functions. It is internally pulled up, bi-directional I/O port. Pin 9 − It is a RESET pin, which is used to reset the microcontroller to its initial values. Pins 10 to 17 − These pins are known as Port 3. This port serves some functions like interrupts, timer input, control signals, serial communication...

Read More

Microcontrollers - 8051 Architecture

8051 microcontroller is designed by Intel in 1981. It is an 8-bit microcontroller. It is built with 40 pins DIP (dual inline package), 4kb of ROM storage and 128 bytes of RAM storage, 2 16-bit timers. It consists of are four parallel 8-bit ports, which are programmable as well as addressable as per the requirement. An on-chip crystal oscillator is integrated in the microcontroller having crystal frequency of 12 MHz.     Let...

Read More

8085 PIN DESCRIPTION

Properties: It is a 8-bit microprocessor  Manufactured with N-MOS technology  40 pin IC package  It has 16-bit address bus and thus has 216 = 64 KB addressing capability.  Operate with 3 MHz single-phase clock  +5 V single power supply The logic pin layout and signal groups of the 8085nmicroprocessor are shown in Fig. 6. All the signals are classified into six groups: Address bus  Data bus  Control & status...

Read More

Intel 8085 Microprocessor architecture

Intel 8085 is a 8-bit microprocessor. It was the most successful 8-bit microprocessor. Here is an overview of this. In 8085 there are mainly three components: 1) Arithmetic and Logical Unit(ALU) 2) Control Unit(CU) 3) Registers 1. ALU performs the arithmetic and logical operations like Add, Sub, Increment, Decrement, OR, AND, Complement etc. ALU uses the accumulator to hold the first operand and after operation accumulator holds the result....

Read More

Difference between Analog and Digital circuit

Analog Circuits These circuits operate on continuous-valued signals(commonly referred to as analog signals).                     Analog circuits are difficult to design since each component has to be placed by hand as automation techniques for designing these circuits fail to do the job efficiently. No conversion of input signals are required before processing i.e. input signal is analog, the circuit directly performs various logical operations...

Read More

Arduino - Conditional Operator ? :

The conditional operator ? : is the only ternary operator in C. ? : conditional operator Syntax expression1 ? expression2 : expression3 Expression1 is evaluated first. If its value is true, then expression2 is evaluated and expression3 is ignored. If expression1 is evaluated as false, then expression3 evaluates and expression2 is ignored. The result will be a value of either expression2 or expression3 depending upon which of them evaluates as True. Conditional operator associates from right to left. Example /* Find max(a, b): */ max = (...

Read More

Arduino - switch case statement

Similar to the if statements, switch...case controls the flow of programs by allowing the programmers to specify different codes that should be executed in various conditions. In particular, a switch statement compares the value of a variable to the values specified in the case statements. When a case statement is found whose value matches that of the variable, the code in that case statement is run. The break keyword makes the switch statement exit, and is typically used at the end of each case. Without a break statement, the switch statement...

Read More

Arduino - If…else if …else statement

The if statement can be followed by an optional else if...else statement, which is very useful to test various conditions using single if...else if statement. When using if...else if…else statements, keep in mind − An if can have zero or one else statement and it must come after any else if's. An if can have zero to many else if statements and they must come before the else. Once an else if succeeds, none of the remaining else if or else statements...

Read More

Arduino - If …else statement

An if statement can be followed by an optional else statement, which executes when the expression is false. if … else Statement Syntax if (expression) { Block of statements; } else { Block of statements; } if…else Statement – Execution Sequence Example /* Global variable definition */ int A = 5 ; int B = 9 ; Void setup () { } Void loop () { /* check the boolean condition */ if (A > B)   /* if condition is true then...

Read More

Arduino - Control Statements

Decision making structures require that the programmer specify one or more conditions to be evaluated or tested by the program. It should be along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false. Following is the general form of a typical decision making structure found in most of the programming languages ...

Read More