5.1 State TWO uses of a microcontroller in industrial control devices - NSC Electrical Technology Digital - Question 5 - 2019 - Paper 1

The basic function of RAM is to temporarily store data that the CPU needs to access rapidly while executing programs. It allows for both read and write operations, enabling quick data retrieval and manipulation during program execution.

ROM is used to store firmware and system software that is permanently required by the computer for startup and operation, ensuring that essential programs are always available when the device is powered on.

In the block diagram of a microcontroller, the three system buses are:

• Data Bus: Transfers data between the CPU, memory, and I/O devices.
• Address Bus: Carries the address of the data where it needs to be read or written.
• Control Bus: Carries control signals to coordinate operations among the CPU, memory, and input/output devices.

An interface is a shared boundary across which two separate components or systems communicate or interact, allowing them to exchange information and signals.

The programme counter keeps track of the address of the next instruction to be executed in the sequence, ensuring the CPU knows where to retrieve the next instruction from memory.

The memory address register stores the address of the next instruction or data that the CPU needs to access, acting as a pointer to the memory location.

One type of communication protocol is the RS-232 protocol, which is commonly used for serial communication.

A communication protocol is a set of rules and conventions that define how data is transmitted and received over a network or between devices, ensuring proper communication and data integrity.

In serial data transfer, data bits are sent one after the other along a single communication line. The block diagram includes:

• Transmitter -> sends data bits sequentially -> Receiver.

In parallel data transfer, multiple bits are sent simultaneously across multiple lines. The block diagram includes:

• Transmitter -> sends data bits simultaneously -> Receiver.

UART stands for Universal Asynchronous Receiver Transmitter.

The UART is a communication peripheral that facilitates asynchronous serial communication. It converts parallel data from the CPU into a serial data stream for transmission and vice versa for reception, allowing devices to communicate effectively.

A flowchart is a visual representation of an algorithm, illustrating the step-by-step flow of control through various processes or decision points within a program.

An algorithm is a sequence of precise steps or instructions to be followed in order to perform a specific task or solve a problem.

An instruction cycle consists of the following stages: the CPU fetches the next instruction from memory, decodes the instruction to understand what action is required, considers any inputs or conditions, and then executes the instruction accordingly.

To draw the flow chart:

1. Start.
2. Check INPUT 1.
   • If HIGH, proceed to check INPUT 2.
   • If LOW, output remains LOW.
3. If INPUT 2 is HIGH, set OUTPUT to HIGH.
4. If INPUT 1 is LOW, return OUTPUT to LOW.
5. End.