Q. 8051 series has how many 16 bit registers?

View solution

Q. When 8051 wakes up then 0x00 is loaded to which register?

View solution

Q. When the micro controller executes some arithmetic operations, then the flag bits of which register are affected?

View solution

Q. How is the status of the carry, auxiliary carry and parity flag affected if write instruction
MOV A,#9C
ADD A,#64H

View solution

Q. How are the bits of the register PSW affected if we select Bank2 of 8051?

View solution

Q. If we push data onto the stack then the stack pointer

View solution

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