PCS Architecture

M Haneef Solangi

Processor

• A Microprocessor is the central unit of computer for performing Processing, logical, Arithmetic, and control operations.Bus: is the pathway for carrying data from one part of Computer to an other.

CPUCU MU

ALUInput devices

Output Devices

Storage Devices

What Makes a Processor Fast

• Architecture. • Clock.• Buses.• Registers, Cache.• Techniques.

Cache

One of the major tasks is to understand the underlying architecture of the available resources. Memory And Cache Utilization.Better and efficient Utilization of Memory.

Memory Hierarchy Design

• Memory hierarchy design is based on two important principles:– Locality Principle: It states a fact that memory that is

physically located closer to the CPU (Central Processing Unit) can be accessed faster. Temporal locality refers to the tendency of programs to access the same data several times in a short period of time.

– Smaller is faster: These are the levels in a typical memory hierarchy. Moving farther away from the CPU, the memory in the level becomes larger and slower.

Memory Hierarchy Design

CPUL1

CacheL2 Cache

RAM

HDD

Hub of all the

operations

Fastest and Nearest to CPU [L1 & L2 Cache] Faster and Nearer to

CPU than Hard Disk Drive

Most slow and Most Far

Alternatively referred to as L1 cache, primary cache, internal cache, or system cache.When referring to computer processors, L1 cache is cache that is built into the processor and is the fastest and most expensive cache in the computer. The L1 cache stores the most critical files that need to be executed and is the first thing the processor looks when performing an instruction.

Level 1 Caching

L2 cache was first introduced with the Intel Pentium and Pentium Pro computers and has been included with ever process since, with the exception of the early versions of Celeron processor. This cache is not as fast as the L1 cache, but is only slightly slower since it is still located on the same processor chip, and is still faster than the computers memory. The L2 cache is the second thing the computer looks at when performing instructions.

Level 2 Caching

FILES AND APPLICATIONS INSIDE THE HDD

Word Excel Compiler Task mngr Songs Cntrl pnl

RAM

L1 And L2Cache

CPU

Bus System

Lacal Bus

CPU L1 Cache

Hub of all the

operations

Fastest and Nearest to CPU [L1 Cache)

Local Bus

Back Side Bus

CPU L2 Cache

Hub of all the

operations

2nd Fastest and Nearest to CPU [L2

Cache)

Back Side Bus

Thanks