Exchanges the contents of the destination (first) and source (second) operands. The operands can be two general-purpose registers or a register and a memory location.

2018年7月14日 · 交换指令XCHG是两个寄存器，寄存器和内存变量之间内容的交换指令，两个操作数的数据类型要相同，可以是一个字节，也可以是一个字，也可以是双字 。 其指令格式如下： 【例】 XCHG CH,AL 寄存器之间相互交换，字节操作. XCHG BX,SI 寄存器之间相互交换，字操作。 XCHG [SI],CX 存储器与寄存器之间交换，字操作。 该指令的功能和MOV指令不同，后者是一个操作数的内容被修改，而前者是两个操作数都会发生改变。 寄存器不能是段寄存器，两个操 …

2016年4月2日 · 交换指令XCHG是两个寄存器，寄存器和内存变量之间内容的交换指令，两个操作数的数据类型要相同，可以是一个字节，也可以四一个字，也可以是双字。 其指令格式如下：XCHG Reg/Mem,Men/Reg,Reg/Reg例子：XCHG CH,AL寄存器之间相互交换，字节操作XCHG BX,SI寄存器之间相互交换，字操作XCHG [SI],CX 寄存器与寄存器之间交换，字操作该 …

2017年5月7日 · ¿Is there any way to write in assembly language the function to Up and the function to Down a semaphore with the XCHG instruction? Sure, use the mutex to guard the semaphore. My recommendation would be to use the CMPXCHG instruction. This instruction basically combines a comparison and exchange in a single operation.

Exchanges the contents of the destination (first) and source (second) operands. The operands can be two general-purpose registers or a register and a memory location.

2018年4月30日 · swapping 2 registers in 8086 assembly language (16 bits) (how to efficiently swap a register with memory). xchg is only useful for this case if you need atomicity, or if you care about code-size but not speed. Or on CPUs before 386, where xchg doesn't imply lock. Can num++ be atomic for 'int num'?

In x86-64 assembly, the xchg instruction exchanges the contents of two operands. Short for ‘exchange’, xchg can be used to swap the values of two registers or a register and a memory location.

2016年10月12日 · xchg rax,rax is a collection of assembly gems and riddles I found over many years of reversing and writing assembly code. The book contains 0x40 short assembly snippets, each built to teach you one concept about assembly, math or life in general. Be warned - This book is not for beginners.

XCHG stands for eXCHanGe. It is an assembly instruction that is used to exchange the memory contents of two registers or memory locations. XCHG is a 1-byte instructions and requires 1-byte in memory for execution with 4 Clock Cycles (4 opcode fetch + 4 T-states).

2019年7月30日 · 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.