CCAT Section C Guide — Digital Electronics, Computer Architecture & Microprocessor

Section C is meant for candidates with Electronics, Electrical, or Instrumentation backgrounds. It covers Digital Electronics (20 questions), Computer Architecture (15 questions), and Microprocessors (15 questions). If this is your branch, Section C is essentially free marks — the concepts are things you've already studied in your degree.

Digital Electronics (20 Questions)

Digital Electronics carries the highest weight in Section C. Focus on these topics:

Number Systems & Conversions (High Priority)

• Number Systems: Decimal, Binary, Octal, Hexadecimal
• Conversions: Base to Decimal, Decimal to any base, Octal ↔ Binary
• Special Codes: BCD, Excess-3, Gray Code conversions

Boolean Algebra & Logic Gates

• K-Map simplification (2-variable, 3-variable, 4-variable)
• Boolean algebra laws (De Morgan's, distributive, absorption)
• Logic Gates (AND, OR, NOT, NAND, NOR, XOR, XNOR)
• Universal Gates (NAND and NOR implementations)

Binary Arithmetic

• Binary addition, subtraction, multiplication, division
• 1's Complement and 2's Complement representation
• Signed number representation and overflow detection

Combinational Circuits

• Half Adder, Full Adder
• Half Subtractor, Full Subtractor
• Multiplexer (MUX), Demultiplexer (DEMUX)
• Encoder, Decoder

Sequential Circuits

• Flip-flops: RS, D, JK, T — know truth tables and applications
• Counters: Synchronous vs Asynchronous, Up/Down counters
• Shift Registers: SISO, SIPO, PISO, PIPO

Computer Architecture (15 Questions)

Instruction Set & Addressing Modes

• Machine Instructions types (Memory-Reference, Register-Reference, I/O)
• Addressing Modes: Immediate, Direct, Indirect, Register, Indexed

CPU & Pipelining

• ALU Data Path design
• CPU Control Unit Design (hardwired vs microprogrammed)
• Pipelining: stages, hazards, speedup calculation

Memory Hierarchy

Memory Type	Speed	Cost	Volatile?
Registers	Fastest	Highest	Yes
Cache (SRAM)	Very Fast	High	Yes
Main Memory (DRAM)	Fast	Medium	Yes
Secondary (HDD/SSD)	Slow	Low	No

RAM & ROM Types

• RAM: SRAM, DRAM, SDRAM, DDR SDRAM — know differences
• ROM: PROM, EPROM, EEPROM, Flash Memory — know characteristics

Microprocessors (15 Questions)

Architecture Comparison

Feature	RISC	CISC
Instructions	Simple, fixed-length	Complex, variable-length
Execution	Single clock cycle	Multiple clock cycles
Registers	Many	Few
Example	ARM	x86

Harvard vs Von Neumann Architecture

• Von Neumann: Single memory for data and instructions, shared bus
• Harvard: Separate memory for data and instructions, parallel access

8085 Microprocessor

• Architecture: Registers (A, B, C, D, E, H, L), flags, ALU, control unit
• Pin descriptions: Address bus (16-bit), Data bus (8-bit), Control signals
• Interrupts: TRAP, RST 7.5, RST 6.5, RST 5.5, INTR — priority order
• Instruction set: Data transfer, Arithmetic, Logical, Branching, Machine control

8086 Microprocessor

• Architecture: BIU (Bus Interface Unit) and EU (Execution Unit)
• Segment registers: CS, DS, SS, ES
• Physical address calculation: Segment × 16 + Offset

Preparation Strategy for Section C

1. Week 1-2: Digital Electronics — Number systems, Boolean algebra, K-Maps, logic gates
2. Week 3: Combinational & sequential circuits, Computer Architecture basics
3. Week 4: Microprocessors (8085, 8086), Memory hierarchy, Pipelining
4. Week 5-6: Practice MCQs and mock tests. Use Free Learning for topic-wise practice.

Frequently Asked Questions

Who should attempt CCAT Section C?

Section C is primarily for Electronics, Electrical, and Instrumentation students. CS/IT students with electronics knowledge can also attempt it for a higher total score.

How many questions are in CCAT Section C?

Section C has 50 questions: Digital Electronics (20), Computer Architecture (15), and Microprocessors (15). Duration is 1 hour.

Should I attempt both Section B and C?

If you are confident in both areas, yes. Your best score from B and C (or combined best) is considered. However, focus on one section first and only attempt the other if time permits. See our complete exam pattern guide.