Atmel AVR1922 Xplain Board Controller Firmware Application Note

About this manual

The AVR1922 application note explains the Xplain board controller, an AT90USB1287 chip that provides USB connectivity, mass‑storage via on‑board DataFlash, and reset control for the AVR XMEGA main microcontroller. It details how the board controller handles USB‑to‑serial, USB mass‑storage, and reset line control, and how it can program the main MCU through the PDI interface.

The note also provides step‑by‑step instructions for compiling the firmware, configuring the build system, and programming the AT90USB1287 using tools such as AVRONE!, JTAGICE mkII, AVR Dragon, or FLIP. It describes USB mode switching via the TDI pin on the JTAG header and references related application notes for further guidance.

What's inside

• Features
• Introduction
• Hardware Features
• USB Interface
• USB‑to‑serial Interface
• USB Mass‑storage Interface
• AVR XMEGA Reset Line Control
• AVR XMEGA Program and Debug Interface
• Firmware Overview
• USB Mode Switching

Specifications

Frequently asked questions

How do I switch between USB mass‑storage and USB‑to‑serial modes on the Xplain board?

Pull the TDI pin on the JTAG USB header to ground with a jumper for mass‑storage mode, or leave it floating for USB‑to‑serial mode.

What tools can be used to program the AT90USB1287 and ATxmega128A1 firmware?

You can program the devices with AVRONE!, JTAGICE mkII, AVR Dragon, or the FLIP software.