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.