Edexcel curriculum (2015)
PythonBinary/HexData representationCompressionEncryptionWhat is a computer?Working computerHardwareOperating system
Computer processes
The CPU
Memory
Input devicesOutput devicesData storageInside the CPUStored programF-D-E cycleCPU componentsNetworksLAN, WAN and PANNetwork topologiesNetwork addressingProtocolsError detectionThe internetThe world wide webHTML and CSSClient-server modelVPNsSQLImpactEthical issuesMicrocontrollers
Comp models
Emerging trends
Virtual machines
Models and sims
Algorithms
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The CPU
Inside the CPU are various areas that carry out various functions
CPU registers
Program counter (PC) - an incrementing counter that keeps track of the memory address of the instruction that is to be executed next or in other words, holds the address of the instruction to be executed next.
Memory address register (MAR) - holds the address of a memory location of which data/instruction is to be fetched/written Memory data register (MDR) - a two-way register that holds data fetched from memory (and ready for the CPU to process) or data waiting to be stored in memory. (This is also known as the memory buffer register (MBR).) Instruction register (CIR) - a temporary holding ground for the instruction that has just been fetched from memory. Control unit (CU) - decodes the program instruction in the IR, selecting machine resources such as a data source register and a particular arithmetic operation, and coordinates activation of those resources. Arithmetic logic unit (ALU) - performs mathematical and logical operations. System bus
Buses are the connective wiring found in the motherboard.
Data bus Transfers binary data from place to place Control bus Sends and receives signals that control the CPU and other components Address bus Carries the binary address of memory locations |