Created on: 23 October 2012
The AT91SAM7S256 microcontroller on the AT91SAM7S-EK evaluation board from Atmel can be programmed via the board's USB port without the need for any external programmer.
Any board containing an AT91SAM7S USB microcontroller that is configured for USB programming can also be programmed in the same way. The article on the hardware requirements for AT91SAM7S USB programming has more information on how the hardware must be set up.
The SAM-BA bootloader is already programmed into the AT91SAM7S256 microcontroller. All that is needed is to load it into the Flash memory of the microcontroller. This is done using a jumper on the AT91SAM7S-EK board and will be explained shortly.
A software program needs to be loaded on the PC that will transfer the firmware from the PC to the AT91SAM7S microcontroller. This is a free software program that can be downloaded from Atmel.
The SAM-BA PC software can be downloaded from the Atmel website on the Atmel SAM-BA In-system Programmer page.
To get the software, you will need to register using your name and email address. Just click register on the page as show below circled in red.
Install the software by running the downloaded file and following the installation instructions.
First load SAM-BA to the Flash memory of the AT91SAM7S microcontroller:
When the AT91SAM7S-EK board is plugged into the PC with the SAM-BA bootloader in Flash memory, the driver for SAM-BA will load in Windows. If it is the first time that the board is being used, Windows will install the driver.
You can now start the SAM-BA PC software and connect to the board. A new user firmware program can be loaded to the Flash memory using the SAM-BA software. The new firmware program will overwrite the bootloader when loaded to Flash memory, so you will need to reload the bootloader using the TST jumper the next time that you want to load newer user firmware to the microcontroller.
This video shows how to load the bootloader using the TST jumper and then load firmware to the microcontroller using SAM-BA.
Can't see the video? View on YouTube →
After installing the SAM-BA software on your Windows PC, you can find the SAM-BA User Guide under Start → All Programs → Atmel → SAM-BA v2.12