computer system study Part1

Computersystem Study - Part1

Hardware OrganizationOverview

Buses:

Transferfixed-sized chunks of bytes known as words. For 32bit, 4 bytes, for 64bit, 8bytes.

I/O:

Input (mouse,keyboard, microphone)

Output (graphicsadapter, printer, speaker)

Memory:

DRAM. Logically,memory is organized as a linear array of bytes, each with its own uniqueaddress (array index) starting at zero.

Processor:

Engine thatinterprets (or executes) instructions stored in main memory. At its core is aword-sized

Storagedevice (or register) called the program counter.

Instructionsample:

Load: copy1 byte from memory to register, override current

Store: copyfrom register to memory, override current

Operate:copy 2 value from register into ALU, operate then got 1 value store inregister. Overrides current.

Jump: take1 instruction into PC for executing, override current.

The procedure of running aprogram.

Step 1: Read command.

Step 2: Load Exe file Diskinto memory.

Step 3: run.

Cache memory

Processorreads data from register 100+ times than from memory, so it’s meaningful to setmemory cache. (SRAM)

Memory Structure Overview.

Program context switching.

Exe runtime memorystructure Overview.

Heap:dynamically create memory, such as malloc in C language.

Stack: forrunning current program each step, executing function calls.

Kernelmemory Area: protected by system.

Sharedlibrary: this area memory for shared library.

Multiple core Memory cacheoverview

For multiple core CPU , they separated cache memory less than level 2, shared memory including level 3 and main memory (DRAM)