IS220PDIAH1BE-336A5026ADP4 以太网模块

IS220PDIAH1BE-336A5026ADP4 以太网模块

ALU还执行另一种类型的运算。结果是一个地址它用于计算内存中开始加载指令的新位置。结果被放入指令指针寄存器.

指令寄存器和指针

这指令指针指定内存中包含CPU要执行的下一条指令的位置。当CPU完成当前指令的执行时，下一条指令从指令指针指向的存储单元加载到指令寄存器中。

指令加载到指令寄存器后，指令寄存器指针增加一个指令地址。递增允许它准备好将下一条指令移入指令寄存器。

隐藏物

CPU从不直接访问RAM。现代CPU有一层或多层隐藏物。CPU执行计算的能力比RAM向CPU提供数据的能力要快得多。其中的原因超出了本文的范围，但是我将在下一篇文章中进一步探讨。

高速缓冲存储器比系统RAM更快，并且更接近CPU，因为它在处理器芯片上。高速缓存提供数据存储和指令，以防止CPU等待从RAM中检索数据。当CPU需要数据时——程序指令也被认为是数据——高速缓存确定数据是否已经驻留并将其提供给CPU。

IS220PDIAH1BE-336A5026ADP4 以太网模块

The ALU also performs another type of operation. The result is an address that calculates the new location in memory to start loading instructions. The result is put into the instruction pointer register.

Instruction registers and Pointers

This instruction pointer specifies the location in memory that contains the next instruction to be executed by the CPU. When the CPU completes the execution of the current instruction, the next instruction is loaded into the instruction register from the memory unit pointed to by the instruction pointer.

After the instruction is loaded into the instruction register, the instruction register pointer is added an instruction address. Incrementing allows it to be ready to move the next instruction into the instruction register.

cache

The CPU never accesses the RAM directly. Modern cpus have one or more layers of concealment. The CPU's ability to perform calculations is much faster than the RAM's ability to provide data to the CPU. The reasons for this are beyond the scope of this article, but I will explore them further in the next article.

Cache is faster than system RAM and closer to the CPU because it is on the processor chip. The cache provides data storage and instructions to prevent the CPU from waiting to retrieve data from RAM. When the CPU needs data - program instructions are also considered data - the cache determines if the data already resides and provides it to the CPU.