3.1. Computer architecture
A subsection of Computer Science, 0478, through 3. Hardware
Listing 10 of 56 questions
A central processing unit (CPU) performs the fetch–decode–execute (FDE) cycle. Give the name of two registers that are used in the fetch stage of the cycle. Describe what happens at the decode stage of the cycle. Give one register in the CPU that is used in the execute stage of the cycle. Buses are used in the CPU to transmit data through the FDE cycle. Circle three buses that are used in the CPU. fetch address register execute data decode calculation central value binary control A user changes their CPU from one with a dual core and a clock speed of 2.4 GHz to one with a dual core and a clock speed of 3.5 GHz. Explain the effect this change will have on the performance of the CPU.
0478_w24_qp_11
THEORY
2024
Paper 1, Variant 1
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The table contains names and descriptions of components in a central processing unit (CPU). Complete the table by giving the missing component names and descriptions. Component name Description sends signals to manage the flow of data through the CPU program counter stores the address of the data that is about to be fetched from random access memory (RAM) into the CPU transmits data between the RAM and the CPU accumulator stores an instruction when it is being decoded
0478_w24_qp_12
THEORY
2024
Paper 1, Variant 2
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An alarm clock is controlled by a microprocessor. It uses the 24 hour clock. The hour is represented by an 8-bit register, A, and the number of minutes is represented by another 8-bit register, B. Identify what time is represented by the following two 8-bit registers. A B : Hours Minutes An alarm has been set for 07:30. Two 8-bit registers, C and D, are used to represent the hours and minutes of the alarm time. Show how 07:30 would be represented by these two registers: C D : Hours Minutes Describe how the microprocessor can determine when to sound the clock alarm. The LCD (liquid crystal display) on the clock face is back-lit using blue LEDs (light emitting diodes). The brightness of the clock face is determined by the level of light in the room. The amount of light given out by the LEDs is controlled by a control circuit. Describe how the sensor, microprocessor and LEDs are used to maintain the correct brightness of the clock face. Modern LCD monitors and televisions use LED back-lit technology. Give two advantages of using this new technology compared to the older cold cathode fluorescent lamp (CCFL) method.
0478_s15_qp_11
THEORY
2015
Paper 1, Variant 1
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An alarm clock is controlled by a microprocessor. It uses the 24 hour clock. The hour is represented by an 8-bit register, A, and the number of minutes is represented by another 8-bit register, B. Identify what time is represented by the following two 8-bit registers. A B : Hours Minutes An alarm has been set for 07:30. Two 8-bit registers, C and D, are used to represent the hours and minutes of the alarm time. Show how 07:30 would be represented by these two registers: C D : Hours Minutes Describe how the microprocessor can determine when to sound the clock alarm. The LCD (liquid crystal display) on the clock face is back-lit using blue LEDs (light emitting diodes). The brightness of the clock face is determined by the level of light in the room. The amount of light given out by the LEDs is controlled by a control circuit. Describe how the sensor, microprocessor and LEDs are used to maintain the correct brightness of the clock face. Modern LCD monitors and televisions use LED back-lit technology. Give two advantages of using this new technology compared to the older cold cathode fluorescent lamp (CCFL) method.
0478_s15_qp_13
THEORY
2015
Paper 1, Variant 3
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Questions Discovered
56