Chapter 6: Parallel I/O ports

Jonathan Valvano and Ramesh Yerraballi

As part of the edX online class, we made some interactive web pages to illustrate fundamental concepts

Interactive web pages: Table of Contents

2. Fundamental Concepts	Number conversions
5. Introduction to C	Flowcharts, C vs assembly
6. Microcontroller Ports	Input/output, direction register
7. Design and Development	Successive refinement, if-then, loops
10. Finite State Machines	Vending machine and stepper motor
11. UART Serial Interface	Blind, busy-wait, interrupt, serial port
12. Interrupts	Mail box, context switch
13. DAC and Sound	Sampling rate, precision, how a DAC works
14. ADC and Data Acquisition	How an ADC works, Nyquist Theorem

Interactive Tool 6.1

The following tool allows you to test your understanding of what happens when you WRITE to the DATA register for PortF.
Note, writing to input pins has no effect. See what happens if you click on one of the two switches.

Enter a 5 bit number to write to GPIO_PORTF_DATA_R, bits 4 through 0:

Reprinted with approval from Embedded Systems: Introduction to ARM Cortex-M Microcontrollers, 2016, ISBN: 978-1477508992, http://users.ece.utexas.edu/~valvano/arm/outline1.htm