Grade 1226 periods
Fundamentals of Digital Circuits
Uses logic gates to design basic digital circuits and devices
Exam objectives
- Name and draw the symbols of NOT, AND, OR, XOR, NAND, NOR and XNOR gates
- Construct truth tables for basic and combinational gates, up to three inputs
- Explain why NAND/NOR are universal gates and build a given gate using only NAND/NOR
Important areas to cover
- Drawing gate symbols and truth tables from a given expression is asked almost every year
- "Build gate X using only NAND/NOR" is a recurring, higher-mark question
Lesson content not added yet.
Exam objectives
- State and apply Boolean postulates/laws: commutative, associative, distributive, identity, redundancy, De Morgan's
- Convert a truth table to SOP/POS form and transform between SOP and POS
- Simplify Boolean expressions using theorems and using a Karnaugh map
Important areas to cover
- Karnaugh map simplification (up to 3-4 variables) is one of the highest-value recurring essay questions in this unit — practise until it is routine
- De Morgan's law application is a frequent MCQ/short-answer trap question
Lesson content not added yet.
Exam objectives
- Derive a logic expression and truth table from a stated real-world requirement, up to three inputs
- Draw the resulting digital circuit using logic gates
Important areas to cover
- "Design a circuit for scenario X" (e.g. an alarm or voting system) is a classic essay-length question that combines 4.1-4.3
Lesson content not added yet.
Exam objectives
- Derive the truth table and logic expression for a half adder and a full adder
- Explain how a flip-flop uses a feedback loop to store one bit
Important areas to cover
- Half adder / full adder truth table and circuit diagram is a very frequently repeated essay component
- A flip-flop's role in memory is a common question linking back to Unit 2's registers
Lesson content not added yet.