CPU & Cache

CPU & Cache

1. Fetch Decode Execute

   • exexute
     • This happens after the decoded message has arrived. The computer reads the command and does the action you asked it to.
   • decode
     • This happens after it has transferred to the CPU. It is then decoded into binary, and is sent to be executed.
       • for example, if you typed 'Hello'. When you press the keys on a keyboard, the 'Fetchers' read your action and deliver them to the CPU to be decoded. They need to be decoded for the executers to understand the command you give them. after being successfully decoded it is sent to the Executers who put it into the RAM and then prints the H-e-l-l-o onto the output device.
   • fetch
     • This happens after you type or click on something. Your action is fetched to go to the CPU where it begins decoding it.

2. Cache

   • A piece of temporary memory. It can refer to a part of the RAM, storage disk, CPU, or an area for storing web pages.
     • L1
       • in the CPU, used for low level processing.
     • L2
       • normally in the CPU but sometimes external.
       • backup memory space for the L1