The SPI communication has been widely applied in the modern smart circuits because of its simplicity and speed. The communication is difficult to interpret with the existing instruments because of the uniqueness of its protocol, so we need a separate, own decoder device. In the Balluff’s BTL development group, a single SPI Spy device was made for this purpose, to decode their own measuring / processing ASIC’s SPI protocol.
The dissertation preparation is directed on the further develop of the mentioned SPI protocol decoder device that exists only in demo mode, without housing. The device is able to communicate with a computer through USB line, also having various triggering and message selection settings. This paper first presents the work-related theoretical basis, including the SPI communication knowledge, logic and protocol analyzers brief description, and then the analysis of the existing tool. There are illustrative figures and examples for the help of theoretical understanding. Then the steps of the detailed hardware design are coming, from the choice of components to the ready to run hardware. As the next step, the software design steps are: understanding the existing structure, improve and develop the programming code. Finally, after the last steps, which are the resulting system resuscitation and operation test, the final boxed version is complete, the work is done.