Template:FAQ/Questions/spi used on robostix

In what way is SPI used on Robostix?
SPI is used in a way that allows a software download over SPI (NSSP on the gumstix side), to take advantage of the Power-on-reset autodownload over SPI.

On this board, there is an LDO between the V_BATT (Power Jack) and the supply to the ATmega128. So: dropping L_DD14 will drop the AT power enable, and dropping L_DD13 will drop nPROG_EN.

If the programming_enable line is low when the chip powers back up it will download boot code over the SPI.