Low-power design patterns in Embedded C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main goal of low-power design patterns in embedded systems?

To reduce energy consumption by managing hardware and software efficiently, extending battery life and minimizing heat.

beginner

Explain the 'Sleep Mode' pattern in low-power design.

Sleep Mode turns off or reduces power to most parts of the system when idle, waking up only on interrupts or events to save energy.

intermediate

What is 'Dynamic Voltage and Frequency Scaling' (DVFS)?

DVFS adjusts the processor's voltage and clock speed based on workload to save power while maintaining performance.

intermediate

How does 'Peripheral Power Gating' help reduce power consumption?

It disables power to unused peripherals, preventing them from drawing current when not needed.

beginner

Why is event-driven programming useful in low-power embedded systems?

Because it allows the system to stay in low-power sleep states until an event occurs, avoiding constant polling and saving energy.

Which low-power design pattern puts the CPU into a minimal power state until an interrupt occurs?

A Sleep Mode

B Dynamic Voltage Scaling

C Peripheral Power Gating

D Polling Loop

Sleep Mode reduces power by stopping most CPU activity until an interrupt wakes it.

What does Dynamic Voltage and Frequency Scaling (DVFS) adjust to save power?

A Sensor sensitivity

B Peripheral power supply

C Processor voltage and clock speed

D Memory size

DVFS changes voltage and frequency to balance power and performance.

Which pattern disables unused hardware components to save energy?

A Sleep Mode

B Peripheral Power Gating

C Event-driven programming

D Polling

Peripheral Power Gating cuts power to unused peripherals.

Why is event-driven programming preferred for low-power embedded systems?

A It increases clock speed automatically

B It keeps the CPU busy all the time

C It uses constant polling to detect events

D It allows the CPU to sleep until events happen

Event-driven design lets the CPU sleep and wake only on events, saving power.

Which of these is NOT a low-power design pattern?

A Infinite busy loop

B Dynamic Voltage and Frequency Scaling

C Peripheral Power Gating

D Sleep Mode

An infinite busy loop wastes power and is not a low-power pattern.

Describe three common low-power design patterns used in embedded systems and how they save energy.

Think about how the system reduces power by stopping work, adjusting speed, or turning off parts.

Explain why event-driven programming is important for low-power embedded devices.

Consider how waiting for events helps save battery.