Q. On power up, the 8051 uses which RAM locations for register R0- R7

View solution

Q. How many bytes of bit addressable memory is present in 8051 based micro controllers?

View solution

Q. DJNZ R0,label is how many bit instruction?

View solution

Q. JZ, JNZ, DJNZ, JC, JNC instructions monitor the bits of which register ?

View solution

Q. Calculate the jump code for again and here if code starts at 0000H

MOV R1,#0
MOV A,#0
MOV R0,#25H
AGAIN:ADD A,#0ECH
JNC HERE
HERE: INC R1
DJNZ R0,AGAIN
MOV R0,A
END

View solution

Q. When the call instruction is executed the top most element of stack comes out to be

View solution

Q. LCALL instruction takes

View solution

Q. Are PUSH and POP instructions are a type of CALL instructions?

View solution

Q. What is the time taken by one machine cycle if crystal frequency is 20MHz?

View solution

Q. Find the number of times the following loop will be executed

MOV R6,#200
BACK:MOV R5,#100
HERE:DJNZ R5, HERE
DJNZ R6,BACK
END

View solution

Q. What is the meaning of the instruction MOV A,05H ?

View solution

Q. Does the two instructions mean the same?
1) BACK: DEC R0

JZ BACK

2) BACK: DJNZ RO, BACK

View solution

Q. To initialise any port as an output port what value is to be given to it?

View solution

Q. Which out of the four ports of 8051 needs a pull-up resistor for using it is as an input or an output port?

View solution

Q. Which of the ports act as the 16 bit address lines for transferring data through it?

View solution

Q. Which of the following registers are not bit addressable?

View solution

Q. Which instruction is used to check the status of a single bit?

View solution

Q. Which addressing mode is used in pushing or popping any element on or from the stack?

View solution

Q. Which operator is the most important while assigning any instruction as register indirect instruction?

View solution

Q. What is the advantage of register indirect addressing mode?

View solution