Contents
How does Xchg work?
In 8085 Instruction set, there is one mnemonic XCHG, which stands for eXCHanGe. This is an instruction to exchange contents of HL register pair with DE register pair. After execution of this instruction, the content between H and D registers and L and E registers will get swapped respectively.
What is xchg in 8086?
The XCHG instruction exchanges the content of a register with the content of another register or with the content of memory location(s). It cannot directly exchange the content of two memory locations. The source and destination must both be of the same type (bytes or words).
Which register of 8085 is 16-bit?
Stack Pointer
Stack Pointer: The stack pointer in the 8085 microprocessor is a 16-bit register that stores the address of the top of stack memory.
What is Jnz?
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.
How many flags are there in 8086 MP?
9 flags
There are total 9 flags in 8086 and the flag register is divided into two types: (a) Status Flags – There are 6 flag registers in 8086 microprocessor which become set(1) or reset(0) depending upon condition after either 8-bit or 16-bit operation.
Which flag is affected by SBB instruction?
The SBB instruction does not distinguish between signed or unsigned operands. Instead, the processor evaluates the result for both data types and sets the OF and CF flags to indicate a borrow in the signed or unsigned result, respectively. The SF flag indicates the sign of the signed result.
Which of the following register is 16-bit?
Stack Pointer: The stack pointer in the 8085 microprocessor is a 16-bit register that stores the address of the top of stack memory.
Why stack pointer is 16-bit?
In 8086, the main stack register is called stack pointer – SP. The stack segment register (SS) is usually used to store information about the memory segment that stores the call stack of currently executed program. These first instruction shall push the value stored in AX (16-bit register) to the stack.
What is Jnz example?
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….JNZ offset.
| Bytes | 2 |
|---|---|
| Operation | JNZ PC = PC + 2 IF A <> 0 PC = PC + offset |
| Example | JNZ LABEL |
What is the function of Jnz?
What does XCHG stand for in 8085 instruction set?
In 8085 Instruction set, there is one mnemonic XCHG, which stands for eXCHanGe. This is an instruction to exchange contents of HL register pair with DE register pair. This instruction uses implied addressing mode. As it is1-Byte instruction, so It occupies only 1-Byte in the memory.
Is the xchg instruction 1 byte or 1 byte?
This instruction uses implied addressing mode. As it is1-Byte instruction, so It occupies only 1-Byte in the memory. After execution of this instruction, the content between H and D registers and L and E registers will get swapped respectively.
What happens after execution of XCHG in HL and D registers?
After execution of this instruction, the content between H and D registers and L and E registers will get swapped respectively. Let us suppose, HL and DE register pairs are having ABCDH and 6789H contents respectively. After execution of instruction XCHG the contents of HL and DS register pairs will be 6789H and ABCDH respectively.
How does the central processing unit ( CPU ) work?
Now let us consider the components of the central processing unit. The control unit of the CPU contains circuitry that uses electrical signals to direct the entire computer system to carry out, or execute, stored program instructions.