12 questions · 37 marks · ≈ 37 min
A computer has a Von Neumann architecture.
State three components that are part of the central processing unit (CPU) in this computer.
| Accumulator (ACC) | Hard disk drive (HDD) |
|---|---|
| Memory address register (MAR) | Program counter (PC) |
| Random access memory (RAM) | Read only memory (ROM) |
| sensor | Solid state drive (SSD) |
The computer has a single core CPU.
State one purpose of a core in a CPU.
Extract:
A student uses a laptop and a calculator for schoolwork.
The calculator has an embedded system.
Describe what is meant by an embedded system.
A computer has a Von Neumann architecture
Describe the purpose of the control unit (CU) within this computer.
A computer has a Von Neumann architecture
The computer has a single core CPU.
The computer is upgraded to a dual core CPU.
Explain how the upgrade can affect the performance of the computer
A student uses a laptop and a calculator for schoolwork.
The laptop has a central processing unit (CPU) that performs the fetch–decode–execute cycle.
The CPU has several components, including the memory data register (MDR) and the arithmetic logic unit (ALU).
Describe how the MDR and the ALU are used in the fetch–decode–execute cycle.
An office has an automated lighting system. When movement is detected in the office, the lights are switched on. If movement is not detected for a period of two minutes, the lights are switched off.
The system uses a sensor and a microprocessor
Describe what is meant by a microprocessor.
A computer is designed using the Von Neumann model for a computer system.
The computer has a central processing unit (CPU)
Data is fetched from primary storage into the CPU to be processed.
The CPU performs a cycle to process data. Fetch is the first stage in this cycle.
State the names of the second and third stages in the cycle.
Identify two components within the CPU that are used in the fetch stage of the cycle
The computer processes instructions using the fetch–decode–execute (FDE) cycle.
Draw and annotate a diagram to show the process of the fetch stage of the FDE cycle.
A computer system uses a single core CPU with a 2 GHz clock speed.
The system is upgraded to a dual core CPU with the same 2 GHz clock speed.
Explain how the clock speed affects the performance of both CPU configurations
An office has an automated lighting system. When movement is detected in the office, the lights are switched on. If movement is not detected for a period of two minutes, the lights are switched off.
The system uses a sensor and a microprocessor.
Describe how the sensor and the microprocessor are used in this automated lighting system.
Extract:
| Instruction | Mnemonic | Binary Code | Command |
|---|---|---|---|
| Add | ADD | 10100001 | Adds a value to the value currently stored in the accumulator (ACC) |
| Subtract | SUB | 00100010 | Subtracts a value from the value stored in the accumulator |
| Load | LDA | 10111111 | Loads the value stored in a memory location into the accumulator |
| Store | STA | 01100000 | Stores the value in the accumulator in a specific location in memory |
| Stop | HLT | 00000000 | Stops the program |
A program consists of the following sequence of instructions, written using the mnemonics from the table:
Explain what happens during the execution of this program, assuming it starts with an initial value of 5 in the memory location loaded by the LDA instruction and the value to add is 3.