Embedded Systems/AT91SAM7S64

The AT91SAM7S64 is a noteworthy instance of the ARM processor architecture because of the availability of affordable prototyping hardware (1, 2, 3, 4) and of on-line tutorial information (1, 2). There is an open-source bootloader for it as well.

Image of Olimex board at http://www.olimex.com/dev/images/ARM/ATMEL/SAM7-Hxxx-1.jpg

There are a number of interesting projects documented for this controller (1, 2).

This page is intended to be a getting-started guide for experimenting with an affordable SAM7 board. The cheapest I can find is the Olimex header board, but it lacks debugging conveniences found on the development board. Some other SAM7 experimentation pages on the web include:

• Andreas Schwarz's ARM-based MP3/AAC Player
• http://www.triplespark.net/elec/pdev/arm/at91sam7.html
• A discussion forum with several threads about SAM7-based projects
• My own humble efforts

The chip has a lot of really interesting features. Atmel's web page describing the AT91SAM7S256 is quoted below.

The AT91SAM7S256 is a low pincount Flash microcontroller based on the 32-bit ARM7TDMI RISC processor. It features 256K bytes of embedded high-speed Flash with sector lock capabilities and a security bit, and 64K bytes of SRAM. The integrated proprietary SAM-BA Boot Assistant enables in-system programming of the embedded Flash.

Its extensive peripheral set includes a USB 2.0 Full Speed Device Port, USARTs, SPI, SSC, TWI and an 8-channel 10-bit ADC. Its Peripheral DMA Controller channels eliminate processor bottlenecks during peripheral-to-memory transfers. Its System Controller manages interrupts, clocks, power, time, debug and reset, significantly reducing the external chip count and minimizing power consumption.

In industrial temperature, worse case conditions the maximum clock frequency is 55MHz. Typical core supply is 1.8V, I/Os are supplied at 1.8V or 3.3V and are 5V tolerant. An integrated Voltage Regulator permits single supply at 3.3V. The AT91SAM7S256 is supplied in a 64-lead LQFP or QFN Green package. It is supported by an Evaluation Board and extensive application development tools.

The AT91SAM7S256 is a general-purpose microcontroller, providing an ideal migration path for 8-bit applications requiring additional performance, USB connectivity and extended memory.

And it even runs Scheme.