Basically, USB-AtmelPrg is an USB-based "universal interface cable" connecting a host computer to the programmable device such as a microcontroller or a CPLD.
Here is a list of features:
Programming and verifying AVR microcontrollers (Atmel's 8-bit RISCs; see supported devices) flash, EEPROM and fuses via usual SPI (supports in-system programming).
JTAG support: Query IDs and execute SVF files (currently limited to one device per chain), e.g. to in-system program CPLDs.
USB-AtmelPrg can be used as JTAG cable backend for OpenOCD, e.g. to in-system program and debug ARM microcontrollers such as the AT91SAM7.
Host software for Linux featuring readline support with command completion.
Plug-n-play: USB-based, can run from USB power; no need for legacy devices.
5V logic, external level converter adds 3.3V capability.
Allows to supply the programmable device with 5V (or 3.3V with level converter).
It's free: Software, firmware and electronic circuit diagrams are available for download for private (non-commercial) use.
More features are added as I need them -- and you can add features yourself!
http://www.triplespark.net/elec/pdev/usb-atmelprg/
