Unit 1.1 Flashcards
(24 cards)
What does the “D” stand for, in the abbreviation, FDE?
Decode
State one purpose of the ALU
To preform mathematical (+,*,/,-) and logical (@,&,”, etc.) operations(decisions)
State one purpose of the CPU
1) Process data and instructions
2) Control the rest of the computers system.
State the components within Von Neumann Architecture.
ALU,input device, output device, CU, memory unit and CPU
State two roles of the CU
1) It fetches, decodes and executes instructions
2) Regulates and integrates the operations of the computer.
True or false? An embedded system is designed to perform many tasks
Incorrect, (false) a general purpose computer is used to preform many tasks, an embedded system is designed to only preform one task e.g a washing machine.
Define what a register is
The section of high speed memory within the CPU that stores data to be processed.
Define what a bus is (computing)
A bus is a series of wire that connect the processor to another part of the computer’s architecture, such as cache memory or main memory
Define what a Clock speed is (computing)
The amount of times the CPU can carry out an instruction
What is the role of the MDR?
A register used for holding information (program data or words) that is in the process of being transferred from memory to the central processor or vice Versa.
What is the role of the MAR?
Holds the address of the current instruction that is going to be fetched from memory to the central processor (CPU)
What is the Program counter?
A register in the CPU that records the current instruction being executed.
What is the role of the CIR (Current instruction register)?
holds the instruction that is currently being decoded and executed
What is the role of the accumulator?
temporary storage location which holds an intermediate value in mathematical and logical calculations
What is cache?
Small amount of high speed memory, built directly within the processor, which stores frequently used instructions.
What is the role of cache?
Temporarily stored data and instructions that the processor is likely to reuse
What is the clock speed measured in?
Hertz/ GigaHertz
Recall the FDE cycle. (6marks)
1) the processor checks the program counter to see which instruction to run next.
2) The program counter gives an address value in the memory location
3) The program fetches the instruction value from this memory location
4) Once the instruction has been fetched, it needs to be decoded and executed. E.g taking a value, putting it into the ALU, then taking a different value from the register and adding them together.
5) Once this is complete, the processor goes back to the program counter to find the next instruction.
6) This cycle is repeated until the program ends.
What does the abbreviation “BIOS” stand for, and where is it stored?
Basic input output system
It is stored in ROM. (Read only memory)
What is the role of the BIOS?
It checks that the hardware is functioning correctly, then runs a second program (known as the bootup or bootstrap program) that loads the computer’s operating system from the hard drive into the RAM
What is Virtual Memory and what is its role?
Secondary memory that is used to temporarily replace primary memory.
State one con of using secondary memory.
1) It is Slower than primary memory
Define ROM.
Memory that cannot be changed by a user or program, hence the name “Read Only Memory”
Name Four examples of ROM.
Music, Films, Software, cartridge used in game devices, electronic devices
