In earlier classes we have learned that the CPU is the central part of the computer.What does a CPU consist of?...A CPU en cooperates the function of a microprocessor to perform its basic function of computation.
A microprocessor is a multi purpose programming device that accepts digital data as input,processes the data based on the program stored inside its memory ans generate a digital output.
http://www.7chip.com/2010/08/intel-8085-microprocessor-family.html
Little History...
The first microprocessor introduced was Intel 4004 in 1971.The research for 4004 began in 1969 when a Japanese company Busicom approached the Intel to develop a chip for programmable calculator.The original design consist of a seven chip architecture and a shift register memory.Ted Hoff an Intel engineer come up with a more simplified model.Hoff came up with a four–chip architectural proposal: a ROM chip for storing the programs, a dynamic RAM chip for storing data, a simple I/O device and a 4-bit central processing unit (CPU).
Intel latter come up with more models like 8008,8085,8086 etc of which 80x86 is being used today which are based on the 8086.
More into 8085 design....
The 8085 platform remains as the base of latest x86 architecture.The instruction set of x86 platforms are derived from the 8085 and hence understanding the basic architecture is necessary for further understanding of newest designs.
http://www.8085projects.info
The 8085 architecture consist of a Arithmetic and logic unit(ALU) which performs the operations such as addition subtraction or other logic functions .
Other basic components are
Registers: The registers are fast memory location found inside the microprocessors .they are of very small size and is expensive and uses static RAM cells.
Bus Bus represents linkage between different components of the architecture say between ALU registers etc...The buses are of three types address bus which transfers address,data bus meant to transfer data and control bus which transfers control signal like read or write etc...
Interrupt signal The interrupt signal ensures that the microprocessor halts its working on its occurrences.
Program counter is a special type register which points to the next instruction to be executed that is it contains the address of the next instruction to be executed.The program execution starts when the PC points to the first location.
Instruction register is a register which the contains the present instruction which is being executed.The contents of the IR are given to the decoder circuit which decodes the value corresponding to the operation to be performed.This value is passed to the timing and control unit.The unique op code of the operation is identified in this unit and the oscillatory circuit within generates the corresponding clock this signal.This clock signal is applied to the the alu which activates the circuitry corresponding to the operation.
Basic instruction set for addition of two numbers.
Assuming that the data is available at location 5000 and 5001.The corresponding program can be written as....
LD A 5000
MOV B A
LD A 5001
ADD B
ST A 5000
HALT
The instruction set fed to the microprocessor is ..
4100 3A
4101 00
4102 50
4103 47
4104 3A
4105 01
4106 50
4107 80
4108 32
4109 00
410A 50
410B 76
The above program can be improved by the concept of jumping between steps to enble addition of n numbers.
Writing the instruction set for an instruction is a low level programming.The disadvantages of this is that the programmer should have a clear knowledge on the hardware of the system and their functioning .Also the codes are lengthy.....
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A microprocessor is a multi purpose programming device that accepts digital data as input,processes the data based on the program stored inside its memory ans generate a digital output.
http://www.7chip.com/2010/08/intel-8085-microprocessor-family.html
Little History...
The first microprocessor introduced was Intel 4004 in 1971.The research for 4004 began in 1969 when a Japanese company Busicom approached the Intel to develop a chip for programmable calculator.The original design consist of a seven chip architecture and a shift register memory.Ted Hoff an Intel engineer come up with a more simplified model.Hoff came up with a four–chip architectural proposal: a ROM chip for storing the programs, a dynamic RAM chip for storing data, a simple I/O device and a 4-bit central processing unit (CPU).
Intel latter come up with more models like 8008,8085,8086 etc of which 80x86 is being used today which are based on the 8086.
More into 8085 design....
The 8085 platform remains as the base of latest x86 architecture.The instruction set of x86 platforms are derived from the 8085 and hence understanding the basic architecture is necessary for further understanding of newest designs.
The 8085 architecture consist of a Arithmetic and logic unit(ALU) which performs the operations such as addition subtraction or other logic functions .
Other basic components are
Registers: The registers are fast memory location found inside the microprocessors .they are of very small size and is expensive and uses static RAM cells.
Bus Bus represents linkage between different components of the architecture say between ALU registers etc...The buses are of three types address bus which transfers address,data bus meant to transfer data and control bus which transfers control signal like read or write etc...
Interrupt signal The interrupt signal ensures that the microprocessor halts its working on its occurrences.
Program counter is a special type register which points to the next instruction to be executed that is it contains the address of the next instruction to be executed.The program execution starts when the PC points to the first location.
Instruction register is a register which the contains the present instruction which is being executed.The contents of the IR are given to the decoder circuit which decodes the value corresponding to the operation to be performed.This value is passed to the timing and control unit.The unique op code of the operation is identified in this unit and the oscillatory circuit within generates the corresponding clock this signal.This clock signal is applied to the the alu which activates the circuitry corresponding to the operation.
Basic instruction set for addition of two numbers.
Assuming that the data is available at location 5000 and 5001.The corresponding program can be written as....
LD A 5000
MOV B A
LD A 5001
ADD B
ST A 5000
HALT
The instruction set fed to the microprocessor is ..
4100 3A
4101 00
4102 50
4103 47
4104 3A
4105 01
4106 50
4107 80
4108 32
4109 00
410A 50
410B 76
The above program can be improved by the concept of jumping between steps to enble addition of n numbers.
Writing the instruction set for an instruction is a low level programming.The disadvantages of this is that the programmer should have a clear knowledge on the hardware of the system and their functioning .Also the codes are lengthy.....
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