SPI protocol has earned a solid role in embedded systems whether it is system on chip processors, both with higher end 32-bit processors such as those using ARM, MIC or Power PC and with other microcontrollers such as the AVR, PIC etc. These chips usually include SPI controllers capable of running in either master or slave mode. In-system programmable AVR controllers can be programmed using an SPI interface.Chip or FPGA based designs sometimes use SPI to communicate.