OLIMEX A20-SOM, User Manual

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OLIMEX© 2015 A20-SOM user's manual
Table of Contents
DISCLAIMER ............................................................................................................. 2
CHAPTER 1: OVERVIEW ........................................................................................ 5
1. Introduction to the chapter ....................................................................................................... 5
1.1 Introduction to SOM (System-On-a-Module) ....................................................................... 5
1.2 Target market of the board ..................................................................................................... 6
1.3 Features of A20-SOM .............................................................................................................. 6
1.4 Board variants .......................................................................................................................... 7
1.5 Board versions used in the manual ........................................................................................ 7
1.6 Document organization ........................................................................................................... 7
CHAPTER 2: SETTING UP THE A20-SOM BOARD ........................................... 8
2. Introduction to the chapter ....................................................................................................... 8
2.1 Electrostatic and electrical polarity warnings ....................................................................... 8
2.2 Requirements ........................................................................................................................... 8
2.3 Powering the board .................................................................................................................. 9
2.3.1 Stand-alone powering ..................................................................................................................................... 9
2.3.2 Mounted powering ....................................................................................................................................... 10
2.4 Button functions ..................................................................................................................... 10
2.5 Interacting with the board .................................................................................................... 11
2.6 Expanding the Debian file system space .............................................................................. 12
2.7 Changing the default image resolution ................................................................................ 12
2.8 Connecting and calibrating a display ................................................................................... 15
2.8.1 Android calibration ...................................................................................................................................... 16
2.8.2 Debian calibration ........................................................................................................................................ 16
2.9 Software support .................................................................................................................... 17
CHAPTER 3: BOARD DESCRIPTION ................................................................. 18
3. Introduction to the chapter ..................................................................................................... 18
3.1 Layout (top view) ................................................................................................................... 18
CHAPTER 4: THE ALLWINNER A20 MICROCONTROLLER ....................... 19
4. Introduction to the chapter ..................................................................................................... 19
4.1 The processor ......................................................................................................................... 19
4.2 Block diagram ........................................................................................................................ 20
CHAPTER 5: CONTROL CIRCUITY ................................................................... 21
5. Introduction to the chapter ..................................................................................................... 21
5.1 Reset ........................................................................................................................................ 21
5.2 Clocks ...................................................................................................................................... 21
5.3 Power supply circuit .............................................................................................................. 21
CHAPTER 6: CONNECTORS AND PINOUT ...................................................... 22
6. Introduction to the chapter ..................................................................................................... 22
6.1 Communication with A20-SOM in Linux ............................................................................ 22
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