Processors

 

Basically a processor is the circuitry that executes the instructions that process data.

 

Two parts:

ALU (Arithmetic Logic Unit) and the Control Unit. In each unit there are registers that hold data.

 

ALU does the arithmetic and logical operations. Control unit directs and coordinates the processing. The control unit has an instruction pointer that keeps track of the sequence of the instruction set. Accumulators

 

Control Unit

Fetch instruction from program interpret execute in ALU move pointer fetch etc.

 

Two cycles instruction cycle and execution cycle

 

Data bus is the circuitry between components on the mother board.

Clock Speeds or Processor Clock

Cycles per second is the pace for executing

Hertz

Speed is not about the number of instructions

Word Size

Number of bits processed at a time ex. 8-bit processes 1 byte at a time

Larger the word size, more can get done per cycle

Cache

Level 1 = memory on chip

Level 2 = memory on another chip

A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.

 

Efficiency of the instruction set?

 

RISC vs. CISC?

 

How complex can the instruction set be?

8 decimal thing from Pentium.