Design Metrics for Embedded Systems: The Pillars of Evaluation
Interactive Audio Lesson
Listen to a student-teacher conversation explaining the topic in a relatable way.
Unit Cost and NRE Cost
π Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Let's begin by discussing **Unit Cost**. This refers to the manufacturing cost associated with each embedded system. What factors do you think influence this cost?
I think the number of components and size of the silicon chip would affect the cost.
Exactly! The larger the chip and more components it has, the higher the costs. Now, how does **Non-Recurring Engineering (NRE) Cost** fit into this picture?
NRE cost is a one-time expense, right? Like when we invest in design and tooling tools?
Correct! It's essential when considering new designs. Remember, lowering NRE can significantly impact the overall unit cost when a product is mass-produced. Can anyone give an example of something that might increase NRE costs?
Developing a new chip design from scratch isn't cheap!
Absolutely right! If you increase the design cycle, NRE costs will also spike. Always remember the acronym **NICE**: 'NRE Impacts Cost & Efficiency.' Now, whatβs the relationship between unit cost and NRE?
Lower NRE over many units would decrease the unit cost?
Exactly! Great connection. Remember, balancing NRE and unit costs is crucial in embedded system designs.
Size and Performance Metrics
π Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Next, let's analyze **Size (Area)**. Why is minimizing chip area important?
A smaller size helps with portability and usually reduces costs.
And it might allow for more compact devices, especially in wearables!
Good points! Lastly, how do **Performance** metrics like execution time and throughput correlate with embedded systems?
Higher performance means the system can process tasks faster, which is crucial for time-sensitive applications!
Precisely! And when we optimize for performance, what are we typically looking at?
We focus on reducing execution time, increasing throughput, and often exploiting parallelism.
Exactly! Keep this sequence in mind: **EPI** - Execution, Performance, Increase. It encapsulates the essence of what we aim for in embedded designs.
Power Consumption and Flexibility
π Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Now becomes **Power Consumption**. Why is this metric critical when designing embedded systems?
Power efficiency can extend battery life, especially for portable devices.
And it can also reduce costs related to cooling methods in hardware!
Great insights! Remember, high power consumption translates to higher operational costs. Can anyone think of methods to reduce power consumption in designs?
We could use voltage scaling?
Yes, Dynamic Voltage and Frequency Scaling (DVFS) can lead to significant power savings. Finally, let's touch on **Flexibility**. What does this entail?
Flexibility is about how easily the system can be modified. SPPs have low flexibility compared to GPPs.
That's correct! Remember the principle of **Fixed Functionality** with SPPs where modifications require redesign. Keep that in mind while evaluating application needs.
Time-to-Market
π Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Lastly, let's discuss **Time-to-Market (TTM)**. Why is this an essential metric?
A shorter TTM means products can reach customers faster, which is crucial in tech!
Right! Especially with how rapidly technology evolves; being competitive is key!
Exactly! What factors contribute to TTM in designing embedded systems?
Complexity of the design and verification processes can significantly increase TTM.
Yes! Remember the acronym **FIND**: 'Factors Influencing New Development.' Keep this in mind as we move forward and consider which embedded systems will require rapid development.
Introduction & Overview
Read summaries of the section's main ideas at different levels of detail.
Quick Overview
Standard
Design metrics play a vital role in the evaluation of embedded systems, especially when making decisions about single-purpose processors (SPPs). This section reviews key metrics such as unit cost, power consumption, performance, and flexibility, emphasizing their importance in the design process and how they influence the selection of hardware solutions.
Detailed
Design Metrics for Embedded Systems: The Pillars of Evaluation
In this section, we delve into the essential design metrics that serve as the fundamental pillars for evaluating embedded systems, particularly single-purpose processors (SPPs). These metrics guide decisions in design, optimization, and evaluation processes.
Key Metrics to Consider:
- Unit Cost: This refers to the per-unit manufacturing cost of an embedded system, which encompasses factors like silicon area, packaging, testing, and materials. The optimization goal here is to minimize costs through design strategies that reduce silicon area and demand.
- Non-Recurring Engineering (NRE) Cost: A one-time cost associated with design and verification, including EDA tools and initial prototyping. To optimize NRE costs, it's essential to reduce design cycle time and possibly employ reusable intellectual property (IP).
- Size (Area): This metric pertains to the physical footprint of the silicon chip and the overall PCB area. The goal is to minimize the number of transistors and optimize interconnections, which is particularly critical for smaller devices like wearables and IoT gadgets.
- Performance: Defined by execution time, throughput, clock frequency, and critical path delay. Optimizing performance focuses on reducing execution time and increasing throughput by exploiting parallelism and minimizing the number of clock cycles required.
- Power Consumption: Electrical power dissipation measured in dynamic and static power, critical for ensuring efficiency, especially in battery-operated devices. Methods to optimize power consumption include voltage scaling and minimizing unnecessary operations that lead to power loss.
- Flexibility/Re-programmability: The ease with which system functionalities can be adjusted post-manufacturing. This poses a significant trade-off since SPPs offer low flexibility compared to their general-purpose counterparts.
- Time-to-Market (TTM): The duration from design conception to product availability, which can be optimized by utilizing existing IP and adopting design automation tools.
- Other Important Metrics: Reliability, testability, maintainability, safety, and security are additional key areas to consider during the design process.
Understanding and evaluating these metrics is crucial for making informed design choices when working with embedded systems and single-purpose processors.
Key Concepts
-
Unit Cost: The cost of manufacturing each individual system, affected by size and silicon area.
-
NRE Cost: One-time costs related to design and prototyping, impacting financial planning.
-
Size: Refers to the physical footprint of chips, crucial for design choices in portable devices.
-
Performance Metrics: Defined by execution time, throughput, and reliability in processing tasks.
-
Power Consumption: The need for energy efficiency, especially for battery-powered devices.
-
Flexibility: The ability of a system to adapt its functionalities post-production.
-
TTM: The speed with which designs can be made available on the market influences competitive positioning.
Examples & Applications
An embedded system in a smartphone requires low power consumption and high performance to ensure user satisfaction and extended usage.
A single-purpose processor designed for video encoding targets minimal size and power, optimizing area and unit costs while ensuring efficient performance for that specific task.
Memory Aids
Interactive tools to help you remember key concepts
Rhymes
For every embedded design, keep costs in mind, reduce NRE and be economically kind.
Stories
Once, there was a designer who struggled to get a product to market. They realized if they reduced their NRE costs by using existing solutions, they'd get their product out and save money in the end.
Memory Tools
Remember PFCU - Performance, Flexibility, Cost, and Unit cost; these are the foundational pillars of embedded design.
Acronyms
To remember cost metrics, think **CUP**
Cost
Unit Cost
and Performance.
Flash Cards
Glossary
- Unit Cost
The manufacturing cost for each individual embedded system.
- NonRecurring Engineering (NRE) Cost
One-time costs for design, verification, tooling, and initial prototyping of systems.
- Size (Area)
The physical footprint of the silicon chip and its PCB area.
- Performance
How quickly a system accomplishes tasks; includes metrics like execution time and throughput.
- Power Consumption
The electrical power dissipated by the system, counting both dynamic and static consumption.
- Flexibility/Reprogrammability
The ease with which a system's functionality can be adjusted post-manufacturing.
- TimetoMarket (TTM)
The duration from a productβs design conception to its commercial availability.
Reference links
Supplementary resources to enhance your learning experience.