The Amontec JTAGkey is a USB JTAG device for programming and debugging ARM microcontrollers. It can also be used to program FPGAs and CPLDs as well as do JTAG boundary-scan. The JTAGkey is made by the Amontec company in Switzerland.
Read more about the Amontec JTAGkey in the Amontec JTAGkey USB JTAG Tool article.
This Simple ARM Board Open Source Hardware project uses the AT91SAM7S256 ARM7 microcontroller from Atmel. The page at the above link contains the source files for building and modifying the board (PCB and schematic), the Gerber output files and the circuit diagram in PDF format.
AT91SAM7S ARM7 microcontrollers have a built in boot loader program called SAM-BA that allows them to be programmed in-circuit via the USB port without the need for an external programmer. This article explains what the hardware requirements are in order to use SAM-BA.
AT91SAM7S microcontrollers have a dedicated ERASE pin that can be used to erase the on-chip Flash memory and lock bits. Read the tutorial on using the AT91SAM7S erase pin.
The AT91SAM7S-EK evaluation board is designed for evaluating the AT91SAM7S range of 32-bit ARM7 microcontrollers from Atmel. It is priced at around $120 US. Read the review.
AT91SAM7S-EK – Evaluation Kit