What are the conditional jump instructions related to zero and carry flag?
Conditional jump instructions – signed
| Instruction | Alternative | Action |
|---|---|---|
| JLE | JNG | Jump if sign and overflow flags are different and zero flag is set (jump if “less or equal” or “not greater”) |
| JLNE | JG | Jump if sign and overflow flags are the same and zero flag is clear (jump if “not less or equal” or “greater”) |
Which of the following instruction means jump if carry 0?
JNB
JNC (Jump if no carry, jumps if CY = 0) − The Carry flag bit in the flag (or PSW) register is used to make the decision whether to jump or not “JNC label”….Other Conditional Jumps.
| Instruction | Action |
|---|---|
| JNB | Jump if bit = 0 |
| JBC | Jump if bit = 1 and clear bit |
Which instruction is used to jump to a location if zero flag is set?
The Flags – ISOZ
| COMMANDS | EXAMPLES | |
|---|---|---|
| OP | Assembler | Explanation |
| JMP | JMP HERE | Unconditional jump. Flags are ignored. Jump forward 25h RAM locations. |
| JMP | JMP BACK | Jump Unconditional jump. Flags are ignored. Jump back -2d RAM locations. |
| JZ | JZ STOP | Jump Zero. Jump if the zero flag (Z) is set. Jump forward +42h places if the (Z) flag is set. |
Is the correct way to use Jnz instruction?
The JNZ instruction transfers control to the specified address if the value in the accumulator is not 0. If the accumulator has a value of 0, the next instruction is executed. Neither the accumulator nor any flags are modified by this instruction.
Which is not conditional jump instruction?
Conditional execution often involves a transfer of control to the address of an instruction that does not follow the currently executing instruction….Conditional Jump.
| Instruction | Description | Flags tested |
|---|---|---|
| JNC | Jump If No Carry | CF |
| JO | Jump If Overflow | OF |
| JNO | Jump If No Overflow | OF |
| JP/JPE | Jump Parity or Jump Parity Even | PF |
What is the different between signed and unsigned conditional jump instructions?
1 Answer
- Unsigned instructions, which treat values in registers/memory as unsigned values.
- Signed instructions, which treat values in registers/memory as signed values.
- Agnostic instructions, which behave in such a way that it doesn’t matter whether the values are interpreted as signed or unsigned.
What is jump if carry?
In 8085 Instruction set, we are having one mnemonic JC a16, which stands for “Jump if Carry” and “a16” stands for any 16-bit address. This instruction is used to jump to the address a16 as provided in the instruction. But as it is a conditional jump so it will happen if and only if the present carry flag value is 1.
What does the zero flag do?
Along with a carry flag, a sign flag and an overflow flag, the zero flag is used to check the result of an arithmetic operation, including bitwise logical instructions. It is set to 1, or true, if an arithmetic result is zero, and reset otherwise.
What is the importance of zero flag?
How do you set a zero flag?
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. MOV B 39 (load 39H in register B)
What is the difference between JZ and JNZ?
3 Answers. JE and JZ are just different names for exactly the same thing: a conditional jump when ZF (the “zero” flag) is equal to 1. (Similarly, JNE and JNZ are just different names for a conditional jump when ZF is equal to 0.)
What is Jnz loop?
JNZ is short for “Jump if not zero (ZF = 0)”, and NOT “Jump if the ZF is set”. If it’s any easier to remember, consider that JNZ and JNE (jump if not equal) are equivalent.
When to use the JNZ or JNE instruction?
The jnz (or jne) instruction is a conditional jump that follows a test. It jumps to the specified location if the Zero Flag (ZF) is cleared (0). jnz is commonly used to explicitly test for something not being equal to zero whereas jne is commonly found after a cmp instruction. Can be disassembled as follows:
What does JNZ stand for in 8085 instruction set?
In 8085 Instruction set, we are having one mnemonic JNZ a16, which stands for “Jump if Not Zero” and “a16” stands for any 16-bit address. This instruction is used to jump to the address a16 as provided in the instruction. But as it is a conditional jump so it will happen if and only if the present zero flag value is 0.
What happens if zero flag value is 1?
If zero flag value is 1, program flow continues sequentially. It is a 3-Byte instruction. Let us consider one example of this instruction type JNZ 4000H. It is a 3-Byte instruction. The result of execution of this instruction is shown below with an example.
https://www.youtube.com/watch?v=iEuAg81prt0