NSC Electrical Technology Digital Hardware of Microcontrollers: 6.1 Explain how microprocessors

Question

6.1 Explain how microprocessors provide digital processing control to appliances.

Microprocessors play a crucial role in digital processing for appliances by performing arithmetic and logic operations on data. These operations manipulate the raw data in a systematic manner to control device functionalities. The microprocessor retrieves instructions from the read-only memory (ROM), sequentially processes them, and delivers commands to the input/output (I/O) ports that influence the appliance's behavior. By executing a series of instructions, microprocessors enable automation and control of various tasks that appliances perform. Therefore, they act as the brain, facilitating the operation of appliances by controlling functions based on programmed data.

6.2 FIGURE 6.2 below shows a CPU with registers as part of microcontrollers. Answer the questions that follow.

6.2.1 Label A to D in FIGURE 6.2.

6.2.2 Explain the operating cycle of the CPU.

The operating cycle of a CPU consists of three main phases known as fetch-decode-execute. In the fetch phase, the CPU retrieves instructions along with data from memory. For decoding, the CPU interprets these instructions in binary format, which outlines operations to be performed. Finally, the execute phase entails carrying out the instruction, which may involve processing the data or affecting output based on computed results. This cycle repeats, allowing continuous operation with new incoming data.

6.3 Refer to registers within a CPU and explain the function of the following:

6.3.1 Memory address register (MAR)

The Memory Address Register (MAR) is vital in storing the memory address that the CPU needs to access. It temporarily holds the address of the instruction or data that is about to be read or written in memory, facilitating the communication between the CPU and the memory.

6.3.2 Program counter (PC)

The Program Counter (PC) contains the memory address of the next instruction that the CPU is to execute. As the CPU processes instructions sequentially, the PC updates to reflect the address of the subsequent instruction, thus directing the CPU's operational flow.

6.4 State the function of the cache memory.

The cache memory serves as a short-term storage area that keeps frequently accessed data and instructions close to the CPU. This enhances processing speed by reducing the time taken to fetch information from the main memory (RAM) because the CPU can access the cache much faster.

6.5 Refer to FIGURE 6.5 of serial communication below and answer the questions on the next page.

6.5.1 A =

6.5.2 At point A the byte of data must be converted...

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Answer

At point A, the byte of data must be converted into a string of serial bits using a parallel-in serial-out shift register, then transmitted over a single data line to point B, where it is packed into an 8-bit byte.

6.6 State TWO advantages of the serial communication interface (SCI).

The serial communication interface is beneficial in that it uses fewer wires compared to parallel communications, which reduces connections and complexity. Additionally, it provides reliable high-speed serial data transfers, thus making it suitable for long-distance communications.

6.7 Refer to FIGURE 6.7 of the inter-integrated bus (I2C) and answer the questions that follow.

6.7.1 Label line X.

6.7.2 State TWO disadvantages of the inter-integrated bus (I2C).

I2C has a slower speed compared to other communication protocols and it tends to draw more power, which can be a limiting factor in battery-operated devices.

6.7.3 State the function of pull-up resistors R p.

The pull-up resistors R p are crucial as they help maintain a high voltage level on the I2C bus lines when no device is pulling the line low. This ensures that the bus operates correctly by preventing floating states during idle periods.

6.7.4 Differentiate between the function of the master and the slave in FIGURE 6.7.

In an inter-integrated bus, the master device drives the SCL clock line and initiates data transfers, while the slave devices respond to the master's commands when instructed. One master can control multiple slaves, allowing for coordinated communication across the bus.

6.8 Refer to the software of microcontrollers and explain the difference between an algorithm and a program.

An algorithm is a detailed step-by-step procedure or set of rules followed to solve a particular problem or perform a task. Conversely, a program is a concrete set of instructions written in a programming language that a computer uses to execute the tasks defined by the algorithm. Thus, while an algorithm outlines the logical steps, a program translates those steps into code that a microcontroller or computer can understand and act upon.

6.9 Study the following algorithm and complete its flow chart in FIGURE 6.9 on the ANSWER SHEET for QUESTION 6.9.

6.1 Explain how microprocessors provide digital processing control to appliances - NSC Electrical Technology Digital - Question 6 - 2023 - Paper 1

Worked Solution & Example Answer:6.1 Explain how microprocessors provide digital processing control to appliances - NSC Electrical Technology Digital - Question 6 - 2023 - Paper 1