15 questions
8051 microcontrollers are manufactured by which of the following companies?
Atmel
Philips
Intel
All of the mentioned
8051 series has how many 16 bit registers?
2
1
0
3
When the microcontroller executes some arithmetic operations, then the flag bits of which register are affected?
PSW
SP
DPTR
PC
How are the bits of the register PSW affected if we select Bank2 of 8051?
PSW.5=0 and PSW.4=1
PSW.2=0 and PSW.3=1
PSW.3=1 and PSW.4=1
PSW.3=0 and PSW.4=1
If we push data onto the stack then the stack pointer
increases with every push
decreases with every push
increases & decreases with every push
none of the mentioned
On power up, the 8051 uses which RAM locations for register R0- R7
00-2F
00-07
00-7F
00-0F
Which of the ports act as the 16 bit address lines for transferring data through it?
PORT 0 and PORT 1
PORT 1 and PORT 2
PORT 0 and PORT 2
PORT 1 and PORT 3
Which addressing mode is used in pushing or popping any element on or from the stack?
Immediate
direct
indirect
register
Which operator is the most important while assigning any instruction as register indirect instruction?
#
@
*
&
Which of the following comes under the indexed addressing mode?
MOVX A, @DPTR
MOVC @A+DPTR,A
MOV A,R0
MOV @R0,A
A valid division instruction always makes:
CY=0,AC=1
CY=1,AC=1
CY=0,AC=0
no relation with AC and CY
When an interrupt is enabled, then where does the pointer moves immediately after this interrupt has occurred?
to the next instruction which is to be executed
to the first instruction of ISR
to a fixed location in memory called interrupt vector table
to the end of the program
Which pin of the external hardware is said to exhibit INT0 interrupt?
pin no 10
pin no 11
pin no 12
pin no 13
Which bit of the IE register is used to enable TxD/RxD interrupt?
IE.D5
IE.D2
IE.D3
IE.D4
Which of the following combination is the best to enable the external hardware interrupt 0 of the IE register (assuming initially all bits of the IE register are zero)?
EX0=1
EA=1
any of the mentioned
EX0=1 & EA=1