It is the controling unit computer laid out on a tiny slicon chip and containing the logical elements for handling data, performing calculations and executing store instructions.
Three main task perform by the microprocessor are:
1) Data transfer between it self and an address location or I/O location.
2) Simple airthmetic and logical operations.
3) Program flow via simple decision.
BUSES OF MICROPROCESSOR
Bus is a set of physical connection or electrical path ways shared by multiple hardware for data transfer or communication.
The purpose of using bus is to reduced the number of path ways neede for communication.
1) ADDRESS BUS
It is a unidirectional bus that carries address generated by the microprocessor bus to memory and I/O elements of the computer. The width or size (number of bits) of the address bus determines the location it can execes if n is the number of bits then the number of addressable location (n=2n).
2) DATA BUS
It is a bidirectional bus that transfer actual data or instruction between microprocessor and memory or I/O location during Read/Write operation.
3) CONTROL BUS
It is a bidirectional bus that carries the timeing and control signals to coordinate the activities of the entiers system.
Memory Read/Write Signals, I/O Read/Write Signals,Clock Signals.
ROLES OF ADDRESS & CONTROL SIGNALS
A signals talls were the data should go or which location is to be execess. The width or size (number of bits) of the address bus determines the location it can execes if n is the number of bits then the number of addressable location (L=2n).
It identifies the type of transactions.for example: As a Read/Write transaction for memory or I/O.
It also synchronize the fast processor to the slow external devices it is reading from or writing to.
Memory Write (MEMW), Memory Read (MEMR), I/O Read (IOR), I/O Write (IOW).