3.3.1.1 SPI (ISP) Header (mounted)
This 6-pin header uses the standard AVR SPI (ISP) pinout for easy connection to external targets. The signals are level-converted to allow communication with targets running at any voltage between 1.8 and 5.5V.
Note that the target voltage must be applied to pin 2 on the SPI (ISP) header for the Atmel AVR Dragons level converters.