Embedded Systems – Homework 1

ECE471: Embedded Systems – Homework 1

For this homework short answers will suffice. There isn’t necessarily a right or wrong answer for some of
the questions, but be sure to explain your reasoning.
To submit, create a document with your answers (text, pdf, libreoffice, MS Office if you must) and e-mail
them to vincent.weaver@maine.edu by the homework deadline. Title your e-mail “ECE471 Homework 1”
and be sure your name is included in the document.
1. For each of the following three cases, classify if you would consider the device described as an embedded system or not. For each case use at least 3 of the characteristics given in class for what defines
an “embedded system” and say whether the device meets them.
(a) You buy an electric toothbrush that has an 8-bit PIC16F1516 microcontroller (16MHz, 8k flash,
512 bytes RAM), an 8 LED display, an i2c pressure sensor, and a motor driven by an H-bridge.
(b) The iPhone 11 has an Apple A13 processor in it. This processor is a six-core 64-bit CPU running
up to 2.66GHz. It includes machine learning accelerators (AMX) capable of 1 trillion 8-bit operations per second. It also has 4GB of RAM and a powerful GPU (graphics unit) with 1792x828
resolution.
(c) You open up a microwave and it has an 8-bit PIC processor in it. This processor runs at 10MHz
and the only interface is an LED display, a keypad, and some circuitry to operate the fans and
magnetron.
2. How many “bits” wide are the following systems? Why?
(a) An ARM 1176 found in the original Raspberry Pi. Its registers, integer ALU. program-counter,
and address bus are all 32-bits.
(b) A MOS 6502 processor (found in older desktop and embedded systems). Its registers, data bus,
and ALU are 8-bit while the instruction pointer and address bus are both 16-bit.
3. You are designing a small embedded system.
(a) Describe one reason why using an ASIC (application-specific integrated circuit) might be better
than using a microcontroller.
(b) Describe one reason why using a microcontroller might be better than using an ASIC.