What is the role of a microprocessor?

Answer 1

A microprocessor incorporates the functions of a computer's central processing unit (CPU) on a single integrated circuit (IC, or microchip). It is a multipurpose, programmable, clock-driven, register based electronic device that accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output.

To understand how a microprocessor works, it is helpful to look inside and learn about the logic used to create one. You can also learn about assembly language - the native language of a microprocessor - and many of the things that engineers can do to boost the speed of a processor.

A microprocessor executes a collection of machine instructions that tell the processor what to do. Based on the instructions, a microprocessor does three basic things:

• Using its ALU (Arithmetic/Logic Unit), a microprocessor can perform mathematical operations like addition, subtraction, multiplication and division. Modern microprocessors contain complete floating point processors that can perform extremely sophisticated operations on large floating point numbers.
• A microprocessor can move data from one memory location to another
• A microprocessor can make decisions and jump to a new set of instructions based on those decisions.

There may be very sophisticated things that a microprocessor does, but those are its three basic activities.

This is about as simple as a microprocessor gets. This microprocessor has:

• an address bus (that may be 8, 16 or 32 bits wide) that sends an address to memory
• a data bus (that may be 8, 16 or 32 bits wide) that can send data to memory or receive data from memory
• a RD (Read) and WR (Write) line to tell the memory whether it wants to set or get the addressed location
• a clock line that lets a clock pulse sequence the processor
• A reset line that resets the program counter to zero (or whatever) and restarts execution.

Let's assume that both the address and data buses are 8 bits wide in this example.

Here are the components of this simple microprocessor:

• Registers A, B and C are simply latches made out of flip-flops.
• The address latch is just like registers A, B and C.
• The program counter is a latch with the extra ability to increment by 1 when told to do so, and also to reset to zero when told to do so.
• The ALU could be as simple as an 8-bit adder (See the section on adders in How Boolean Logic Works for details), or it might be able to add, subtract, multiply and divide 8-bit values. Let's assume the latter here.
• The test register is a special latch that can hold values from comparisons performed in the ALU. An ALU can normally compare two numbers and determine if they are equal, if one is greater than the other, etc. The test register can also normally hold a carry bit from the last stage of the adder. It stores these values in flip-flops and then the instruction decoder can use the values to make decisions.
• There are 6 boxes marked "3-State" in the diagram. These are tri-state buffers. A tri-state buffer can pass a 1, a 0 or it can essentially disconnect its output (imagine a switch that totally disconnects the output line from the wire the output is heading toward). A tri-state buffer allows multiple outputs to connect to a wire, but only one of them to actually drive a 1 or a 0 onto the line.
• The instruction register and instruction decoder are responsible for controlling all of the other components.

There would also be control lines from the instruction decoder that would:

• Tell the A register to latch the value currently on the data bus.
• Tell the B register to latch the value currently on the data bus.
• Tell the C register to latch the value currently on the data bus.
• Tell the program counter register to latch the value currently on the data bus.
• Tell the address register to latch the value currently on the data bus.
• Tell the instruction register to latch the value currently on the data bus.
• Tell the program counter to increment
• Tell the program counter to reset to zero
• Activate any of the 6 tri-state buffers (6 separate lines)
• Tell the ALU what operation to perform
• Tell the test register to latch the ALUs test bits
• Activate the RD line
• Activate the WR line

Coming into the instruction decoder are the bits from the test register and the clock line, as well as the bits from the instruction register.

Answer 2

Works as arithmatic and logical unit

Give signal for time selection and control

Execute the program which store in the computer memory

Make co ordination with input and output device

Answer 3

Microprocessor is nothing but CPU built on a single IC.thus as we know that CPU is the brain of the computer thus its all the microprocessor which performs any kind of opertion in the computer be it any arithmetic operation fro instance.

Anand bhat(mca@kiit-870024)

Answer 4

Microprocessors handle just about everything in computers. I'll break this down just a bit for you. For example:

CPU: Central Processing Unit- This is the biggest "beef" of your computer, and performs almost all of the calculations, instructions, and addressing necessary in order for a computer to actually "compute" or function. This dictates what data does, where it goes, and how it is handled.

Northbridge- The NB is built into the CPU on newer processors, but it traditionally was set on the motherboard. This is a microprocessor that handles memory addressing, and acts as a liaison between expansion slots and the CPU, particularly when it comes to your RAM. This piece of hardware is also vital to a computer, and computers do not function without some form of a NB.

Microprocessor Controllers- Built into basically everything, these minor processors control the function of smaller computer parts. Individual RAM modules have a controller on them, which tells the part itself how to interpret data that comes to it. The same applies to Network Interface Cards, Hard Drives, Graphics Cards, USB Hubs, and essentially anything else that can be connected to a computer.

Guess you could say microprocessors are what make computers computers!