# Case Study: Embedded System Design

Topics: Flash memory, Embedded system, Microcontroller Pages: 168 (14869 words) Published: February 3, 2013
Embedded System Design
A Unified Hardware/Software Introduction
Solution Manual
Frank Vahid
Department of Computer Science and Engineering
University of California, Riverside
Tony Givargis
Department of Information and Computer Science
University of California, Irvine

John Wiley & Sons, Inc.

Instructors: Please do not post this or any portion of this manual in electronic format.

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Embedded System Design

CHAPTER 1: Introduction

1.1

What is an embedded system? Why is it so hard to define?
An embedded system is nearly any computing system other than a desktop computer. Embedded systems are hard to define because they cover such a board range of electronic devices.

1.2

List and define the three main characteristics of embedded systems that distinguish such systems from other computing systems.
1.
2.
3.

1.3

single functioned : executes a specific program repeatedly
tightly constrained : the specified cost, performance, and power must be met reactive and real-time: system must quickly and constantly react to outside stimuli

What is a design metric?
A design metric is a measure of an implementation’s features such as cost, size, performance, and power.

1.4

List a pair of design metrics that may compete with one another, providing an intuitive explanation of the reason behind the competition.
Size and performance compete with one another. Reducing the size of an implementation may cause performance to suffer and vice versa.

1.5

What is a “market window” and why is it so important for products to reach the market early in this window?

Embedded System Design

1

Chapter 1: Introduction

A market window is the time period in which a given product is in demand, specifically the time in which this product would yield the highest sales. Missing the window could mean significant loss in sales.

1.6

Using the revenue model of Figure 1.4(b), derive the percentage revenue loss equation for any rise angle, rather than just for 45 degrees (Hint: you should get the same equation).
tan A = opposite / adjacent
opposite = tan A * adjacent
Revenue loss = ( (on time - delayed) / on time ) * 100%
Area of on time = 1/2 * base * height
= 1/2 * 2W * tan A * W
= tan A * W2
Area of delay = 1/2 * base * height
= 1/2 * ( W-D+W ) * ( tan A * ( W-D ) )
= 1/2 * ( 2W-D ) * ( tan A * ( W-D ) )

A

A
D

W

2W

W-D

Revenue Loss = [ ( (tan A * W2) - (1/2 * (2W-D) * tan A * (W-D)) ) / (tan A * W2)] * 100%
= [ ( W2 - (1/2 * (2W-D) * (W-D)) ) / W2 ] * 100%
= [ ( W2 - 1/2*(2W2 - 2WD - WD - D2) ) / W2 ] * 100%
= [ (W2 - 1/2*(2W2 - 3WD - D2) ) / W2 ] * 100%
= [ (2W2 - 2W2 + 3WD + D2) / 2W2 ] * 100%
= [ (3WD + D2) / 2W2 ] * 100%

1.7

Using the revenue model of Figure 1.4(b), compute the percentage revenue loss if D = 5 and W = 10. If the company whose product entered the market on time earned a total revenue of \$25 million, how much revenue did the company that entered the market 5 months late lose?

percentage revenue loss = ( D * ( 3W - D ) / 2W2 ) * 100%
= ( 5 * ( 3 * 10 - 5 ) / 2 * 102 ) * 100%
= ( 5 * 25 / 200 ) * 100%
= 62.5%
revenue loss = \$25,000,000 * 0.625
= \$15,625,000

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Embedded System Design

Chapter 1: Introduction

1.8

What is NRE cost?
NRE cost is the nonrecurring engineering cost. It is the one time monetary cost of designing the system.

1.9

The design of a particular disk drive has an NRE cost of \$100,000 and a unit cost of \$20. How much will we have to add to the cost of each product to cover our NRE cost, assuming we sell: (a) 100 units, and (b) 10,000 units?

(a) added cost = NRE / # units produced
= \$100,000 / 100
= \$1,000
(b) added cost = NRE / # units produced
= \$100,000 / 10,000
= \$10

1.10 Create a graph with the x-axis the number of units and the y-axis the product cost. Plot the per-product cost function for an NRE of...