MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your 8051 Microcontroller knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
XRL,_ORL,_ANL_COMMANDS_HAVE________?$ |
| A. | accumulator as the destination address and any register, memory or any immediate data as the source address |
| B. | accumulator as the destination address and any immediate data as the source address |
| C. | any register as the destination address and accumulator, memory or any immediate data as the source address |
| D. | any register as the destination address and any immediate data as the source address |
| Answer» B. accumulator as the destination address and any immediate data as the source address | |
| 2. |
CJNE instruction makes ______? |
| A. | the pointer to jump if the values of the destination and the source address are equal |
| B. | sets CY=1, if the contents of the destination register are greater then that of the source register |
| C. | sets CY=0, if the contents of the destination register are smaller then that of the source register |
| D. | none of the mentioned |
| Answer» E. | |
| 3. |
ANL instruction is used ______? |
| A. | to AND the contents of the two registers |
| B. | to mask the status of the bits |
| C. | all of the mentioned |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 4. |
Which instructions have no effect on the flags of PSW? |
| A. | ANL |
| B. | ORL |
| C. | XRL |
| D. | All of the mentioned |
| Answer» E. | |
| 5. |
In unsigned number addition, the status of which bit is important? |
| A. | OV |
| B. | CY |
| C. | AC |
| D. | PSW |
| Answer» C. AC | |
| 6. |
In 8 bit signed number operations, OV flag is set to 1 if: |
| A. | a carry is generated from D7 bit |
| B. | a carry is generated from D3 bit |
| C. | a carry is generated from D7 or D3 bit |
| D. | a carry is generated from D7 or D6 bit |
| Answer» E. | |
| 7. |
A valid division instruction always makes: |
| A. | CY=0,AC=1 |
| B. | CY=1,AC=1 |
| C. | CY=0,AC=0 |
| D. | no relation with AC and CY |
| Answer» D. no relation with AC and CY | |
| 8. |
If SUBB A,R4 is executed, then actually what operation is being applied? |
| A. | R4+A |
| B. | R4-A |
| C. | A-R4 |
| D. | R4+A |
| Answer» D. R4+A | |
| 9. |
DAA command adds 6 to the nibble if: |
| A. | CY and AC are necessarily 1 |
| B. | either CY or AC is 1 |
| C. | no relation with CY or AC |
| D. | CY is 1 |
| Answer» C. no relation with CY or AC | |
| 10. |
When we add two numbers the destination address must always be. |
| A. | some immediate data |
| B. | any register |
| C. | accumulator |
| D. | memory |
| Answer» D. memory | |