# Cambridge International AS Level Computer Science (9618): Section 4: Processor Fundamentals

> CPU architecture, Von Neumann model, dedicated processor registers (PC, MAR, MDR, CIR, ACC, Status), system buses and bus width, the Fetch-Decode-Execute cycle and interrupt handling, assembly language instruction sets, and addressing modes.

- **Track:** [Cambridge International AS Level Computer Science (9618)](https://csmasters.dev/tracks/as-level-9618.md) (CAMBRIDGE AS LEVEL 9618)
- **Module:** Section 4: Processor Fundamentals
- **Total Lessons:** 6
- **URL:** https://csmasters.dev/tracks/as-level-9618/course_modules/4-processor-fundamentals

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## Module Lessons

### Lesson 1: [4.1 CPU Architecture & The Von Neumann Model](https://csmasters.dev/learn/as-level-9618/cpu-architecture-and-von-neumann.md)
- **Estimated Duration:** 15 mins
- **XP Reward:** 30 XP
- **Access Level:** Open Theory (All-Access Practice)
- **HTML Link:** https://csmasters.dev/learn/as-level-9618/cpu-architecture-and-von-neumann

### Lesson 2: [4.2 Processor Registers & Special Purpose Registers](https://csmasters.dev/learn/as-level-9618/processor-registers.md)
- **Estimated Duration:** 15 mins
- **XP Reward:** 30 XP
- **Access Level:** Open Theory (All-Access Practice)
- **HTML Link:** https://csmasters.dev/learn/as-level-9618/processor-registers

### Lesson 3: [4.3 System Buses & The Impact of Bus Width](https://csmasters.dev/learn/as-level-9618/system-buses-and-bus-width.md)
- **Estimated Duration:** 15 mins
- **XP Reward:** 30 XP
- **Access Level:** Open Theory (All-Access Practice)
- **HTML Link:** https://csmasters.dev/learn/as-level-9618/system-buses-and-bus-width

### Lesson 4: [4.4 The Fetch-Decode-Execute Cycle & Interrupts](https://csmasters.dev/learn/as-level-9618/fetch-decode-execute-and-interrupts.md)
- **Estimated Duration:** 15 mins
- **XP Reward:** 30 XP
- **Access Level:** Open Theory (All-Access Practice)
- **HTML Link:** https://csmasters.dev/learn/as-level-9618/fetch-decode-execute-and-interrupts

### Lesson 5: [4.5 Assembly Language & Instruction Sets](https://csmasters.dev/learn/as-level-9618/assembly-language-and-instruction-sets.md)
- **Estimated Duration:** 15 mins
- **XP Reward:** 30 XP
- **Access Level:** Open Theory (All-Access Practice)
- **HTML Link:** https://csmasters.dev/learn/as-level-9618/assembly-language-and-instruction-sets

### Lesson 6: [4.6 Addressing Modes in Assembly](https://csmasters.dev/learn/as-level-9618/addressing-modes.md)
- **Estimated Duration:** 15 mins
- **XP Reward:** 30 XP
- **Access Level:** Open Theory (All-Access Practice)
- **HTML Link:** https://csmasters.dev/learn/as-level-9618/addressing-modes