There are many reasons to use serial protocols in embedded systems: simplicity, low pin count and the ability to setup a kind of network of simple devices to implement a complex functionality. Focusing on the Serial Peripheral Interface (SPI), this paper explores the reasons to test and debug a SPI port.
Serial buses are everywhere in embedded design.
Among the existing protocols, SPI and I²C have established themselves as de facto standard. They are well suited for low-cost and (not always so) low-speed communication between ICs, between microprocessors and between microprocessors and peripherals. EEPROMs, real-time clocks (RTCs), ADCs, DACs, thermal management devices and LCD controllers are such peripherals. Table 1 briefly compares these two protocols.