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How do I clear all flags in 8085?
Unfortunately the 8085 does not have a ‘reset carry’ instruction, but it does have ‘set carry’ and ‘complement carry’. By loading different numbers into the register and/or varying the other instructions you could set or reset flags at will.
How do I clear my flag register?
To clear the flag bits, write ‘1’s to the desired bits. The flags are not affected by the Interrupt Enable Register. I2C Port 2 Interrupt: This bit indicates the I2C port 2 bus interrupt flag. I2C Port 1 Interrupt: This bit indicates the I2C port 1 bus interrupt flag.
What are the ways to clear the accumulator?
MVI A, 00: instruction copies 00 to A. ANI 00: instruction performs bit by bit AND operation of source operand (i.e. 00) to the destination operand (i.e. the accumulator A) and store the result in accumulator A….Reset Accumulator (8085 & 8086 microprocessor)
| S.No. | MNEMONICS | COMMENT |
|---|---|---|
| 1 | MVI A, 00 | A <- 00 |
| 2 | ANI 00 | A AND 00 |
| 3 | XRA A | A XOR A |
| 4 | SUB A | A <- A – A |
How a given flag can be set or reset?
Carry Flag (CY) – Carry is generated when performing n bit operations and the result is more than n bits, then this flag becomes set i.e. 1, otherwise it becomes reset i.e. 0. During subtraction (A-B), if A>B it becomes reset and if (A
Which does not clear the accumulator?
This discussion on The instruction, that does not clear the accumulator of 8085, isa)XRA Ab)ANI 00Hc)MVI A, 00Hd)None of the aboveCorrect answer is option ‘D’.
Which instruction is not used to clear accumulator?
Which one of the following instruction may be used to clear the accumulator content irrespective of its initial value? There is no such instruction like CLRA and MOV A, 00H. There is no guarantee that ORA A will result in zero but we can be sure SUB A will reset or clear the content of accumulator.
How can I reset all flags in microprocessor 8085?
Unfortunately the 8085 does not have a ‘reset carry’ instruction, but it does have ‘set carry’ and ‘complement carry’. By loading different numbers into the register and/or varying the other instructions you could set or reset flags at will.
What are the values of flag registers in 8085?
And based upon the value of result after any type of arithmetic and logical operation the value of flag bits become either set (1) or reset (0). In 8085 microprocessor, flag register basically consists of 8 bits and from these 8 bit, only 5 of them are useful. Represented by the symbol S.
Where is the AC flag located in the 8085?
But 8085 microprocessor still stores this AC information in bit position 4 of the flags register. The result of execution of DAA instruction, is affected by the status of this flag. However, in our 8085 instruction set does not provide any instruction, which explicitly uses the AC flag.
How to reset the sign flag to 0?
These set of instructions will reset the sign flag to 0 as 40 – 30 is a positive number. Zero Flag (Z) – After any arithmetical or logical operation if the result is 0 (00)H, the zero flag becomes set i.e. 1, otherwise it becomes reset i.e. 0. 00H zero flag is 1.