Purpose

This document describes how to connect a host computer to the Atmel AT91SAM7S64-EK evaluation board in order to program the device's memory. In doing so, it serves as a technical guide to the developer and user.

Overview

One of PyMite's supported targets is the ARM7 core and the Atmel AT91SAM7 family in particular. The author supports this target because he has a AT91SAM7S64-EK evaluation board. This document describes how to load a PyMite program onto this target.

Requirements

The developer needs a host computer with a USB port and a recent copy of Subversion SCM.

The developer shall download the sam7utils open source software:

svn co https://oss.tekno.us/svn/sam7utils/trunk sam7utils

The developer shall build same7utils for his host computer:

cd sam7utils
./configure
make
sudo make install

Preparing the Device

The AT91SAM7S64-EK needs to have its bootloader restored in order to flash a new program.

To restore the bootloader (SAM-BA):

• Apply a jumper to JP5 for 15 seconds to restore SAM-BA; remove the jumper
• Disconnect, pause and reconnect the AT91SAM7S-EK's USB cable to reset the connection

Loading the PyMite Program

The sam7utils are used to load the PyMite sample program onto the AT91SAM7S64-EK. Run the following commands at a command prompt:

% sam7
found boot agent
Chip Version: 0
Embedded Processor: ARM7TDMI
NVRAM Region 1 Size: 64 K
NVRAM Region 2 Size: 0 K
SRAM Size: 16 K
Series: AT91SAM7Sxx
Page Size: 128 bytes
Lock Regions: 16

sam7> unlock_regions
unlocking region 0: done
unlocking region 1: done

sam7> flash sample.bin
sam7> boot_from_flash
sam7> <ctrl+c>

Troubleshooting

If sam7 is run and it reports, "can not find boot agent", then retry the steps in Preparing the Device with longer jumper application times.