1.1.1 Hardware: Architecture Flashcards
What is the ALU and what does it do?
The Arithmetic-Logic Unit (ALU) carries out mathematical calculations and logic operations.
What is the CIR and what does it do?
The Current Instruction Register (CIR) contains the current instruction during processing.
What is the MDR and what does it do?
The Memory Data Register (MDR)
What is the MAR and what does it do?
The Memory Address Register (MAR)
What is the CU and what does it do?
The Control Unit (CU)
What does the Accumulator do?
The Accumulator
What is the PC and what does it do? (Not referring to the term ‘Personal Computer’)
The Program Counter (PC)
Where is the CIR located within the CPU?
The Control Unit.
Where is the MDR located within the CPU?
The Arithmetic Logic Unit.
Where is the MAR located within the CPU?
The Control Unit.
Where is the Program Counter located within the CPU?
The Control Unit.
Where is the Accumulator located within the CPU?
The Arithmetic Logic Unit.
What happens in the ‘fetch’ portion of the FDE cycle?
1) Address of the next instruction is transferred from the PC to the MAR, and the PC increments by 1. The address bus carries the address of the location of the data in memory.
2) The instruction stored in memory is carried by the data bus to the MDR.
3) The instruction in the MDR is carried by the data bus to the CIR.
What happens in the ‘decode’ portion of the FDE cycle?
1) The instructions are decoded in the CIR.
2) If additional data is required, the request is passed to the MAR, and then travels along the address bus to the main memory, where data is fetched.
3) The MDR fetches the data/instruction from memory.
What happens in the ‘execute’ portion of the FDE cycle?
1) The data/instruction is passed to the Accumulator.
2) The instruction is executed, and the result is held in accumulator or sent to main memory.
What happens in the FDE Cycle?
1) Address of the next instruction is transferred from the PC to the MAR, and the PC increments by 1. The address bus carries the address of the location of the data in memory.
2) The instruction stored in memory is carried by the data bus to the MDR.
3) The instruction in the MDR is carried by the data bus to the CIR.
4) The instructions are decoded in the CIR.
5) If additional data is required, the request is passed to the MAR, and then travels along the address bus to the main memory, where data is fetched.
6) The MDR fetches the data/instruction from memory.
7) The data/instruction is passed to the Accumulator.
8) The instruction is executed, and the result is held in accumulator or sent to main memory.
What is the difference between RAM and ROM?
Random Access Memory (RAM) is very fast, Volatile (Think liable to change), holds temporary data only and capable of reading and writing.
Read-Only Memory (ROM) is relatively slow, Non-volatile, holds permanent data only and can only be read from, not written to (Use the component name to help remember this).
Recite the units of storage including capacity.
Byte (B) = 8 Bits
Kilobyte (KB) = 1024 Bytes
Megabyte (MB) = 1024 Kilobytes
Gigabyte (GB) = 1024 Megabytes
Terabyte (TB) = 1024 Gigabytes
Petabyte (PB) = 1024 Terabytes
Exabyte (EB) = 1024 Petabytes
Zettabyte (ZB) = 1024 Petabytes
Yottabyte (YB) = 1024 Zettabytes
What is the function of the Address Bus?
The Address Bus carries addresses of the memory location being written to or read from.
What is the function of the Data Bus?
The Data Bus carries data between the processor and memory and also other components.
What is the function of the Control Bus?
The Control Bus carries control signals from the control unit to communicate with other components and devices.
How does clock speed affect the performance of the CPU?
The faster the clock speed, the faster the instructions are processed, the more applications (in the FDE cycle) occur per second.
A faster clock speed increased performance, but draws more power and emits more heat.
What is Cache Memory and what does it do?
Cache is a small amount of very fast, expensive memory in the CPU.
Cache allows temporarily stored data to be accessed faster than regular main memory (RAM).
How does Cache Memory affect the performance of the CPU?
Cache memory inproves the performance of the CPU as it is able to provide instructions and data to the CPU at a much faster rate than other system memory such as RAM.
