03-01-2013, 04:00 PM
Introduction to Computing - Microprocessors
[attachment=46365]
Goals for Today
Today we want to learn about the microprocessor, the key component, the brain, of a computer
We’ll learn about the function of a microprocessor
And its various sub-systems
Bus interface unit]
Data & instruction cache memory
Instruction decoder
Arithmetic-Logic unit
Floating-point unit
Control unit
Microprocessor
The key element of all computers, providing the mathematical and decision making ability
Current state-of-the-art uPs (Pentium, Athlon, SPARC, PowerPC) contain complex circuits consisting of tens of millions of transistors
They operate at ultra-fast speeds – doing over a billion operations very second
Made up from a semiconductor, Silicon
Integrated Circuits
Commonly known as an IC or a chip
A tiny piece of Silicon that has several electronic parts on it
Most of the size of an IC comes form the pins and packaging; the actual Silicon occupies a very small piece of the volume
The smallest components on an IC are much smaller than the thickness of a human hair
A microprocessor system?
uPs are powerful pieces of hardware, but not much useful on their own
Just as the human brain needs hands, feet, eyes, ears, mouth to be useful; so does the uP
A uP system is uP plus all the components it requires to do a certain task
A microcomputer is 1 example of a uP system
Micro-controllers?
Micro-controllers are another type of uP systems
They are generally not that powerful, cost a few dollars a piece, and are found embedded in video games, VCRs, microwave ovens, printers, autos, etc.
They are a complete computer on a chip containing direct input and output capability and memory along with the uP on a single chip. Many times they contain other specialized application-specific components as well
The Main Memory Bottleneck
Modern super-fast uPs can process a huge amount of data in a short duration
They require quick access to data to maximize their performance
If they don’t receive the data that they require, they literally stop and wait – this results in reduced performance and wasted power
Current uPs can process an instruction in about a ns. Time required for fetching data from main memory (RAM) is of the order of 100 ns
Solution to the Bottleneck Problem
Make the main memory faster
Problem with that approach: The 1-ns memory is extremely expensive as compared the currently popular 100-ns memory
Another solution: In addition to the relatively slow main memory, put a small amount of ultra-fast RAM right next to the uP on the same chip and make sure that frequently used data and instructions resides in that ultra-fast memory
Advantage: Much better overall performance due to fast access to frequently-used data and instructions
Floating-Point Unit (FPU)
Also known as the “Numeric Unit”
It performs calculations that involve numbers represented in the scientific notation (also known as floating-point numbers).
This notation can represent extremely small and extremely large numbers in a compact form
Floating-point calculations are required for doing graphics, engineering and scientific work
The ALU can do these calculations as well, but will do them very slowly
Instruction Set
The set of machine instructions that a uP recognizes and can execute – the only language uP knows
An instruction set includes low-level, a single step-at-a-time instructions, such as add, subtract, multiply, and divide
Each uP family has its unique instruction set
Bigger instruction-sets mean more complex chips (higher costs, reduced efficiency), but shorter programs
kHz, MHz, GHz (Clock Frequency)
4004 worked at a clock frequency of 108kHz
The latest processors have clock freqs. in GHz
Out of 2 uPs having similar designs, one with higher clock frequency will be more powerful
Same is not true for 2 uPs of dissimilar designs. Example: Out of PowerPC & Pentium 4 uPs working at the same freq, the former performs better due to superior design. Same for the Athlon uP when compared with a Pentium
[attachment=46365]
Goals for Today
Today we want to learn about the microprocessor, the key component, the brain, of a computer
We’ll learn about the function of a microprocessor
And its various sub-systems
Bus interface unit]
Data & instruction cache memory
Instruction decoder
Arithmetic-Logic unit
Floating-point unit
Control unit
Microprocessor
The key element of all computers, providing the mathematical and decision making ability
Current state-of-the-art uPs (Pentium, Athlon, SPARC, PowerPC) contain complex circuits consisting of tens of millions of transistors
They operate at ultra-fast speeds – doing over a billion operations very second
Made up from a semiconductor, Silicon
Integrated Circuits
Commonly known as an IC or a chip
A tiny piece of Silicon that has several electronic parts on it
Most of the size of an IC comes form the pins and packaging; the actual Silicon occupies a very small piece of the volume
The smallest components on an IC are much smaller than the thickness of a human hair
A microprocessor system?
uPs are powerful pieces of hardware, but not much useful on their own
Just as the human brain needs hands, feet, eyes, ears, mouth to be useful; so does the uP
A uP system is uP plus all the components it requires to do a certain task
A microcomputer is 1 example of a uP system
Micro-controllers?
Micro-controllers are another type of uP systems
They are generally not that powerful, cost a few dollars a piece, and are found embedded in video games, VCRs, microwave ovens, printers, autos, etc.
They are a complete computer on a chip containing direct input and output capability and memory along with the uP on a single chip. Many times they contain other specialized application-specific components as well
The Main Memory Bottleneck
Modern super-fast uPs can process a huge amount of data in a short duration
They require quick access to data to maximize their performance
If they don’t receive the data that they require, they literally stop and wait – this results in reduced performance and wasted power
Current uPs can process an instruction in about a ns. Time required for fetching data from main memory (RAM) is of the order of 100 ns
Solution to the Bottleneck Problem
Make the main memory faster
Problem with that approach: The 1-ns memory is extremely expensive as compared the currently popular 100-ns memory
Another solution: In addition to the relatively slow main memory, put a small amount of ultra-fast RAM right next to the uP on the same chip and make sure that frequently used data and instructions resides in that ultra-fast memory
Advantage: Much better overall performance due to fast access to frequently-used data and instructions
Floating-Point Unit (FPU)
Also known as the “Numeric Unit”
It performs calculations that involve numbers represented in the scientific notation (also known as floating-point numbers).
This notation can represent extremely small and extremely large numbers in a compact form
Floating-point calculations are required for doing graphics, engineering and scientific work
The ALU can do these calculations as well, but will do them very slowly
Instruction Set
The set of machine instructions that a uP recognizes and can execute – the only language uP knows
An instruction set includes low-level, a single step-at-a-time instructions, such as add, subtract, multiply, and divide
Each uP family has its unique instruction set
Bigger instruction-sets mean more complex chips (higher costs, reduced efficiency), but shorter programs
kHz, MHz, GHz (Clock Frequency)
4004 worked at a clock frequency of 108kHz
The latest processors have clock freqs. in GHz
Out of 2 uPs having similar designs, one with higher clock frequency will be more powerful
Same is not true for 2 uPs of dissimilar designs. Example: Out of PowerPC & Pentium 4 uPs working at the same freq, the former performs better due to superior design. Same for the Athlon uP when compared with a Pentium