Features of 8052 micro controller & registers of 8052
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You have knowledge about micro controller but don't know what type of questions recruiter will ask in interviews. Do not get afraid about your interviews, here are the Frequently asked Micro controller questions.
The following questions are frequently asked micro controller topic questions in various interviews.
1. What is meant by micro controller?
Microcontroller is a small chip that has in-build Micro processor, memory, ports, timers and converter. Micro controllers are designed for specific use. For instance, micro controller in TV remote is mainly designed for controlling TV.
2. List out the features of 8051 micro controller?
40 Pin IC.
128 bytes of RAM.
4K ROM.
2 Timers (Timer 0 and Timer 1).
32 Input/ Output pins.
1 serial port.
6 Interrupts (Including Reset).
3. What are the types of interrupts in 8051?
External interrupt 0 (IE0) has highest priority among interrupts.
Timer interrupt 0 (TF0)
External interrupt 1 (IE1)
Timer interrupt 1 (TF1) has lowest priority among other interrupts.
Serial port Interrupt
Reset
4. What is an interrupt?
Hardware or software can communicate to micro controller through interrupts. Interrupts are external signal that controls the micro processor. Interrupt signals are generated by sources like software programs or hardware controls.
5. What is an Interrupt service routine?
When micro controller is under sudden interrupt, it will call ISR (Interrupt service routine) that will store the address of current memory address and takes the control to new interrupt memory address. After the interrupt, the control will transfer back to its previous address.
Direct addressing
Register addressing
Register indirect addressing
Implicit addressing
Immediate addressing
Index addressing
7. Difference between JUMP and CALL instruction?
JUMP: Takes the control to newly specified address.
CALL: Takes the control to newly specified address but control will resume back to its current address once its call is finished.
8. Draw the pin diagram of 8051 micro controller?
Pin diagram of 8051 micro controller
9. What is meant by Register?
Registers are temporary storage area in micro controller. It can hold a value of 1- byte memory space.
10.What is an Accumulator?
Accumulator has another name called Register 'A'. Accumulator is an important register in 8051, because it saves all arithmetic and logical values.
11. What is 'B' register?
'B' registers are helpful in multiplication or division operation. Consider this example,
MOV A, B; value stored in A register and value stored in B register are multiplied together and the result is stored in A register.
12. What is Special Function Registers (SFR)?
The memory addresses from 80H to 0FFH are called SFR. These are 128 bytes registers specially designed for interrupts and few other operations.
13. Write a program in C to control the buzzer?
#include
void MSDelay(unsigned int);
sbit Dsensor = P1^1;
sbit Buzzer = P1^7;
void main(void)
{
Dsensor = 1;
while (Dsensor ==1)
{
buzzer=0;
MSDelay(250);
buzzer=1;
MSDelay(250);
}
void MSDelay(unsigned int itime)
{
unsigned int i,j;
for (i=0;ifor (j=0;j<1275;j++);
}
}
These questions are Interview based questions that were frequently asked in various Embedded companies and also in software companies. Take these questions as reference and try to prepare well for your interviews.