Computer Science Computer Architecture introduction High Level User

Computer Science Computer Architecture ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ

introduction High Level User level Application Program High Level Languages Assembly Language Machine Code Microprogram / Hardware Control Functional Language Low Level Logic Gates Transistors and Wires ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ

q. Computer Organization : which is concerned with the way the H/W components operates and the way they are connected together to form the computer system. q. Computer Design : which is concerned with the determination of what H/W should be used and how the parts should be connected. q. Computer Architecture : which is concerned with the structure and behavior of the computer as seen by the user, it include instruction format , instruction set and techniques for addressing memory ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ

Microoperations q. Is a smallest operation performed on the data stored in registers. q. Types of microoperation § Register Transfer Microoperation § Arithmetic Microoperation § Logic Microoperation § Shift Microoperation ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ

Instruction Code instruction code : is a group of bits that instruct the computer to performed a specific operation. q operation code filed: which is a group of bits that defines various operation, such as Add, subtract, Shift……. etc q. Address field: which is a group of bits that specifies a memory address or processor register. q. Mode field: which is a group of bits that specifies the way the operand or effective address of the operand is determined. ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ

Addressing Mode q Implied Mode: the operands are specified implicitly in the instruction. q Immediate Mode: the operands are specified in the instruction itself explicitly. q. Register mode : the operands are in registers that outside within the CPU. q. Register Indirect Mode : the instruction specifies a register in the CPU, whose contents give the effective address of the operand in memory. ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ

q. Direct Address Mode: the address field of the instruction contains the effective address of the operand in memory. q. Indirect Address Mode : the address of the instruction gives the address where the effective operand address is stored in main memory. q. Relative Addressing Mode : Effective address = Address part of the instruction + PC of the next instruction q. Indexed Addressing Mode: Effective address ﺍﻻﻟﻜﺘﺮﻭﻧﻲ = Address part of the instruction ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ + Contents of the index register

Control Unit Design q. Hardware Control: the control logic is implemented with gates, flip-flop , decoder and other digital circuits. It has the advantage that it can be optimized to produce a fast mode of operation. q. Microprogrammed Control : the control information is stored in a control memory. The control memory is programmed to initiate the required sequence of microoperations. ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ

Design of a Simple Computer The minimum requirement to design a simple computer are: q. Memory q. Registers q. Arithmetic, logic, shift unit (ALSU) q. Common Bus System q. Control Unit ﺍﻻﻟﻜﺘﺮﻭﻧﻲ ﻧﻈﺎﻡ ﺍﻟﻤﺤﺎﺿﺮﺍﺕ